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  • Question 1 - A 25-year-old woman is having a trendelenberg procedure to treat her varicose veins....

    Incorrect

    • A 25-year-old woman is having a trendelenberg procedure to treat her varicose veins. While dissecting the saphenofemoral junction, which structure is most susceptible to injury?

      Your Answer: Femoral artery

      Correct Answer: Deep external pudendal artery

      Explanation:

      The deep external pudendal artery is situated near the origin of the long saphenous vein and can be damaged. The highest risk of injury occurs during the flush ligation of the saphenofemoral junction. However, if an injury is detected and the vessel is tied off, it is rare for any significant negative consequences to occur.

      The Anatomy of Saphenous Veins

      The human body has two saphenous veins: the long saphenous vein and the short saphenous vein. The long saphenous vein is often used for bypass surgery or removed as a treatment for varicose veins. It originates at the first digit where the dorsal vein merges with the dorsal venous arch of the foot and runs up the medial side of the leg. At the knee, it runs over the posterior border of the medial epicondyle of the femur bone before passing laterally to lie on the anterior surface of the thigh. It then enters an opening in the fascia lata called the saphenous opening and joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction. The long saphenous vein has several tributaries, including the medial marginal, superficial epigastric, superficial iliac circumflex, and superficial external pudendal veins.

      On the other hand, the short saphenous vein originates at the fifth digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot and runs along the posterior aspect of the leg with the sural nerve. It then passes between the heads of the gastrocnemius muscle and drains into the popliteal vein, approximately at or above the level of the knee joint.

      Understanding the anatomy of saphenous veins is crucial for medical professionals who perform surgeries or treatments involving these veins.

    • This question is part of the following fields:

      • Cardiovascular System
      13.9
      Seconds
  • Question 2 - Sophie, a 6-week-old baby, presents to the emergency department for evaluation. Her mother...

    Incorrect

    • Sophie, a 6-week-old baby, presents to the emergency department for evaluation. Her mother has observed that Sophie has been experiencing shortness of breath for the past 3 weeks, particularly during feeding. Sophie was born at 36 weeks and her mother reports no other issues since birth.

      During the examination, a continuous machinery murmur with a left-sided sub-clavicular thrill is detected, and a diagnosis of patent ductus arteriosus is made. Surgery is not deemed necessary, but a medication that inhibits prostaglandin synthesis is recommended.

      What is the most probable pharmacological treatment that will be offered?

      Your Answer: Bisoprolol

      Correct Answer: Indomethacin

      Explanation:

      The inhibition of prostaglandin synthesis in infants with patent ductus arteriosus is achieved through the use of indomethacin. This medication (or ibuprofen) is effective in promoting closure of the ductus arteriosus by inhibiting prostaglandin synthesis.

      Beta-blockers such as bisoprolol are not used in the management of PDA, making this answer incorrect.

      Steroids like dexamethasone and prednisolone are not typically used in the treatment of PDA, although they may be given to the mother if premature delivery is expected. Therefore, these answers are also incorrect.

      Understanding Patent Ductus Arteriosus

      Patent ductus arteriosus is a type of congenital heart defect that is generally classified as ‘acyanotic’. However, if left uncorrected, it can eventually result in late cyanosis in the lower extremities, which is termed differential cyanosis. This condition is caused by a connection between the pulmonary trunk and descending aorta. Normally, the ductus arteriosus closes with the first breaths due to increased pulmonary flow, which enhances prostaglandins clearance. However, in some cases, this connection remains open, leading to patent ductus arteriosus.

      This condition is more common in premature babies, those born at high altitude, or those whose mothers had rubella infection in the first trimester. The features of patent ductus arteriosus include a left subclavicular thrill, continuous ‘machinery’ murmur, large volume, bounding, collapsing pulse, wide pulse pressure, and heaving apex beat.

      The management of patent ductus arteriosus involves the use of indomethacin or ibuprofen, which are given to the neonate. These medications inhibit prostaglandin synthesis and close the connection in the majority of cases. If patent ductus arteriosus is associated with another congenital heart defect amenable to surgery, then prostaglandin E1 is useful to keep the duct open until after surgical repair. Understanding patent ductus arteriosus is important for early diagnosis and management of this condition.

    • This question is part of the following fields:

      • Cardiovascular System
      20
      Seconds
  • Question 3 - A 57-year-old patient is being evaluated on the ward 3 days after experiencing...

    Incorrect

    • A 57-year-old patient is being evaluated on the ward 3 days after experiencing a transmural myocardial infarction (MI). The patient reports experiencing sharp, severe retrosternal chest pain that worsens with inspiration.

      During the assessment, the patient's vital signs are heart rate 82 beats/min, BP 132/90 mmHg, temperature 37.8ºC, and oxygen saturation 97% on room air. Upon auscultation, a pericardial friction rub is audible.

      What is the histological change in the myocardial tissue that is consistent with this presentation?

      Your Answer: Coagulative necrosis with basophil infiltration

      Correct Answer: Coagulative necrosis with neutrophil infiltration

      Explanation:

      Myocardial infarction (MI) can lead to various complications, which can occur immediately, early, or late after the event. Cardiac arrest is the most common cause of death following MI, usually due to ventricular fibrillation. Cardiogenic shock may occur if a large part of the ventricular myocardium is damaged, and it is difficult to treat. Chronic heart failure may result from ventricular myocardium dysfunction, which can be managed with loop diuretics, ACE-inhibitors, and beta-blockers. Tachyarrhythmias, such as ventricular fibrillation and ventricular tachycardia, are common complications. Bradyarrhythmias, such as atrioventricular block, are more common following inferior MI. Pericarditis is common in the first 48 hours after a transmural MI, while Dressler’s syndrome may occur 2-6 weeks later. Left ventricular aneurysm and free wall rupture, ventricular septal defect, and acute mitral regurgitation are other complications that may require urgent medical attention.

    • This question is part of the following fields:

      • Cardiovascular System
      16.5
      Seconds
  • Question 4 - An 80-year-old patient comes in for a routine follow-up appointment and reports a...

    Correct

    • An 80-year-old patient comes in for a routine follow-up appointment and reports a decline in exercise tolerance. They mention having difficulty with stairs and experiencing occasional central chest pain that radiates to their back, which is relieved by rest. The pain is not present at rest.

      During the examination, you observe a regular, slow-rising pulse and record a blood pressure of 110/95mmHg. Upon auscultation of the precordium, you detect an ejection systolic murmur.

      To further assess cardiac function and valves, an echocardiogram is scheduled. Based on the likely diagnosis, what additional exam findings are you most likely to discover?

      Your Answer: Fourth heart sound (S4)

      Explanation:

      The patient’s symptoms and physical exam suggest the presence of aortic stenosis. This is indicated by the ejection systolic murmur, slow-rising pulse, and progressive heart failure symptoms. The fourth heart sound (S4) is also present, which occurs when the left atrium contracts forcefully to compensate for a stiff ventricle. In aortic stenosis, the left ventricle is hypertrophied due to the narrowed valve, leading to the S4 sound.

      While hepatomegaly is more commonly associated with right heart valvular disease, it is not entirely ruled out in this case. However, the patient’s history is more consistent with aortic stenosis.

      Malar flush, a pink flushed appearance across the cheeks, is typically seen in mitral stenosis due to hypercarbia causing arteriole vasodilation.

      Pistol shot femoral pulses, a sound heard during systole when auscultating the femoral artery, is a finding associated with aortic regurgitation and not present in this case.

      Heart sounds are the sounds produced by the heart during its normal functioning. The first heart sound (S1) is caused by the closure of the mitral and tricuspid valves, while the second heart sound (S2) is due to the closure of the aortic and pulmonary valves. The intensity of these sounds can vary depending on the condition of the valves and the heart. The third heart sound (S3) is caused by the diastolic filling of the ventricle and is considered normal in young individuals. However, it may indicate left ventricular failure, constrictive pericarditis, or mitral regurgitation in older individuals. The fourth heart sound (S4) may be heard in conditions such as aortic stenosis, HOCM, and hypertension, and is caused by atrial contraction against a stiff ventricle. The different valves can be best heard at specific sites on the chest wall, such as the left second intercostal space for the pulmonary valve and the right second intercostal space for the aortic valve.

    • This question is part of the following fields:

      • Cardiovascular System
      17.6
      Seconds
  • Question 5 - A 3-week old girl is presented to the GP by her mother who...

    Incorrect

    • A 3-week old girl is presented to the GP by her mother who has noticed yellowish discharge from her umbilicus on a daily basis. The baby was born without any complications and is healthy otherwise.

      Which embryological structure is most likely responsible for this issue?

      Your Answer: Umbilical vein

      Correct Answer: Allantois

      Explanation:

      If the allantois persists, it can result in a patent urachus, which may manifest as urine leakage from the belly button.

      A patent urachus is a remnant of the allantois from embryonic development that links the bladder to the umbilicus, enabling urine to flow through and exit from the abdominal area.

      When the vitelline duct fails to close, it can lead to the formation of a Meckel’s diverticulum.

      The ductus venosus acts as a bypass for umbilical blood to avoid the liver in the fetus.

      The umbilical vessels serve as a conduit for blood to and from the fetus during gestation. They are not connected to the bladder and would not cause daily leakage.

      During cardiovascular embryology, the heart undergoes significant development and differentiation. At around 14 days gestation, the heart consists of primitive structures such as the truncus arteriosus, bulbus cordis, primitive atria, and primitive ventricle. These structures give rise to various parts of the heart, including the ascending aorta and pulmonary trunk, right ventricle, left and right atria, and majority of the left ventricle. The division of the truncus arteriosus is triggered by neural crest cell migration from the pharyngeal arches, and any issues with this migration can lead to congenital heart defects such as transposition of the great arteries or tetralogy of Fallot. Other structures derived from the primitive heart include the coronary sinus, superior vena cava, fossa ovalis, and various ligaments such as the ligamentum arteriosum and ligamentum venosum. The allantois gives rise to the urachus, while the umbilical artery becomes the medial umbilical ligaments and the umbilical vein becomes the ligamentum teres hepatis inside the falciform ligament. Overall, cardiovascular embryology is a complex process that involves the differentiation and development of various structures that ultimately form the mature heart.

    • This question is part of the following fields:

      • Cardiovascular System
      9.5
      Seconds
  • Question 6 - Oliver is an 80-year-old man with known left-sided heart failure. He has a...

    Incorrect

    • Oliver is an 80-year-old man with known left-sided heart failure. He has a left ventricular ejection fraction of 31%. He has recently been admitted to the cardiology ward as the doctors are concerned his condition is worsening. He is short of breath on exertion and has peripheral oedema.

      Upon reviewing his ECG, you note a right bundle branch block (RBBB) indicative of right ventricular hypertrophy. You also observe that this was present on an ECG of his on an emergency department admission last month.

      What is the most likely cause of the RBBB in Oliver?

      Your Answer: Rheumatic heart disease

      Correct Answer: Cor pulmonale

      Explanation:

      A frequent underlying cause of RBBB that persists over time is right ventricular hypertrophy, which may result from the spread of left-sided heart failure to the right side of the heart. Oliver’s shortness of breath is likely due to an accumulation of fluid in the lungs, which can increase pulmonary perfusion pressure and lead to right ventricular strain and hypertrophy. This type of right heart failure that arises from left heart failure is known as cor-pulmonale. While a pulmonary embolism or rheumatic heart disease can also cause right ventricular strain, they are less probable in this case. Myocardial infarction typically presents with chest pain, which is not mentioned in the question stem regarding Oliver’s symptoms.

      Right bundle branch block is a frequently observed abnormality on ECGs. It can be differentiated from left bundle branch block by remembering the phrase WiLLiaM MaRRoW. In RBBB, there is a ‘M’ in V1 and a ‘W’ in V6, while in LBBB, there is a ‘W’ in V1 and a ‘M’ in V6.

      There are several potential causes of RBBB, including normal variation which becomes more common with age, right ventricular hypertrophy, chronically increased right ventricular pressure (such as in cor pulmonale), pulmonary embolism, myocardial infarction, atrial septal defect (ostium secundum), and cardiomyopathy or myocarditis.

    • This question is part of the following fields:

      • Cardiovascular System
      223.6
      Seconds
  • Question 7 - An 80-year-old man arrives at the emergency department with complaints of lightheadedness, fatigue,...

    Incorrect

    • An 80-year-old man arrives at the emergency department with complaints of lightheadedness, fatigue, and shortness of breath during exertion. Upon examination, you observe a pulse rate of 42 beats per minute, mild bibasal crepitations, and bilateral peripheral pitting edema. The patient's ECG reveals a dissociation between the P waves and QRS complexes. Which aspect of the JVP waveform is most likely to be impacted in this individual?

      Your Answer: v wave

      Correct Answer: a wave

      Explanation:

      A complete heart block is indicated by a pulse rate of approximately 40 beats per minute and ECG results. This means that the atria and ventricles are contracting in an unsynchronized manner. When the tricuspid valve is closed and the right atrium contracts, the JVP will experience a significant increase, which is referred to as cannon a waves.

      Understanding the Jugular Venous Pulse

      The jugular venous pulse is a useful tool in assessing right atrial pressure and identifying underlying valvular disease. The waveform of the jugular vein can provide valuable information, such as a non-pulsatile JVP indicating superior vena caval obstruction and Kussmaul’s sign indicating constrictive pericarditis.

      The ‘a’ wave of the jugular venous pulse represents atrial contraction and can be large in conditions such as tricuspid stenosis, pulmonary stenosis, and pulmonary hypertension. However, it may be absent in atrial fibrillation. Cannon ‘a’ waves occur when atrial contractions push against a closed tricuspid valve and are seen in complete heart block, ventricular tachycardia/ectopics, nodal rhythm, and single chamber ventricular pacing.

      The ‘c’ wave represents the closure of the tricuspid valve and is not normally visible. The ‘v’ wave is due to passive filling of blood into the atrium against a closed tricuspid valve and can be giant in tricuspid regurgitation. The ‘x’ descent represents the fall in atrial pressure during ventricular systole, while the ‘y’ descent represents the opening of the tricuspid valve.

      Understanding the jugular venous pulse and its various components can aid in the diagnosis and management of cardiovascular conditions.

    • This question is part of the following fields:

      • Cardiovascular System
      15.5
      Seconds
  • Question 8 - Which of these statements relating to the external carotid is false? ...

    Correct

    • Which of these statements relating to the external carotid is false?

      Your Answer: It ends by bifurcating into the superficial temporal and ascending pharyngeal artery

      Explanation:

      The external carotid artery ends by splitting into two branches – the superficial temporal and maxillary branches. It has a total of eight branches, with three located on its anterior surface – the thyroid, lingual, and facial arteries. The pharyngeal artery is a medial branch, while the posterior auricular and occipital arteries are located on the posterior surface.

      Anatomy of the External Carotid Artery

      The external carotid artery begins on the side of the pharynx and runs in front of the internal carotid artery, behind the posterior belly of digastric and stylohyoid muscles. It is covered by sternocleidomastoid muscle and passed by hypoglossal nerves, lingual and facial veins. The artery then enters the parotid gland and divides into its terminal branches within the gland.

      To locate the external carotid artery, an imaginary line can be drawn from the bifurcation of the common carotid artery behind the angle of the jaw to a point in front of the tragus of the ear.

      The external carotid artery has six branches, with three in front, two behind, and one deep. The three branches in front are the superior thyroid, lingual, and facial arteries. The two branches behind are the occipital and posterior auricular arteries. The deep branch is the ascending pharyngeal artery. The external carotid artery terminates by dividing into the superficial temporal and maxillary arteries within the parotid gland.

    • This question is part of the following fields:

      • Cardiovascular System
      7
      Seconds
  • Question 9 - A 75-year-old man with confirmed heart failure visits the GP clinic for wound...

    Incorrect

    • A 75-year-old man with confirmed heart failure visits the GP clinic for wound dressing on his left leg. During the visit, the nurse informs the GP that she suspects the patient's legs are swollen. Upon examination, the GP observes bilateral pitting edema that extends up to the knee and decides to prescribe a diuretic. Which diuretic inhibits the sodium-potassium-chloride cotransporter?

      Your Answer: Bendroflumethiazide (thiazide diuretic)

      Correct Answer: Furosemide (loop diuretic)

      Explanation:

      Loop Diuretics: Mechanism of Action and Clinical Applications

      Loop diuretics, such as furosemide and bumetanide, are medications that inhibit the Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle. By doing so, they reduce the absorption of NaCl, resulting in increased urine output. Loop diuretics act on NKCC2, which is more prevalent in the kidneys. These medications work on the apical membrane and must first be filtered into the tubules by the glomerulus before they can have an effect. Patients with poor renal function may require higher doses to ensure sufficient concentration in the tubules.

      Loop diuretics are commonly used in the treatment of heart failure, both acutely (usually intravenously) and chronically (usually orally). They are also indicated for resistant hypertension, particularly in patients with renal impairment. However, loop diuretics can cause adverse effects such as hypotension, hyponatremia, hypokalemia, hypomagnesemia, hypochloremic alkalosis, ototoxicity, hypocalcemia, renal impairment, hyperglycemia (less common than with thiazides), and gout. Therefore, careful monitoring of electrolyte levels and renal function is necessary when using loop diuretics.

    • This question is part of the following fields:

      • Cardiovascular System
      17.5
      Seconds
  • Question 10 - An elderly man in his late 60s is admitted to the cardiology ward...

    Correct

    • An elderly man in his late 60s is admitted to the cardiology ward due to worsening shortness of breath. He has a medical history of hypertension and ischaemic heart disease. During examination, bibasal crackles and pitting oedema to the knees bilaterally are observed. Blood tests are conducted, and the results show a brain natriuretic peptide level of 4990 pg/mL (< 400). What is the most probable physiological change that occurs in response to this finding?

      Your Answer: Decreased afterload

      Explanation:

      BNP has several actions, including vasodilation which can decrease cardiac afterload, diuretic and natriuretic effects, and suppression of both sympathetic tone and the renin-angiotensin-aldosterone system. In the case of heart failure, BNP is primarily secreted by the ventricular myocardium to compensate for symptoms by promoting diuresis, natriuresis, vasodilation, and suppression of sympathetic tone and renin-angiotensin-aldosterone activity. Vasodilation of the peripheral vascular system leads to a decrease in afterload, reducing the force that the left ventricle has to contract against and lowering the risk of left ventricular failure progression. BNP also suppresses sympathetic tone and the RAAS, which would exacerbate heart failure symptoms, and contributes to natriuresis, aiding diuresis and improving dyspnea.

      B-type natriuretic peptide (BNP) is a hormone that is primarily produced by the left ventricular myocardium in response to strain. Although heart failure is the most common cause of elevated BNP levels, any condition that causes left ventricular dysfunction, such as myocardial ischemia or valvular disease, may also raise levels. In patients with chronic kidney disease, reduced excretion may also lead to elevated BNP levels. Conversely, treatment with ACE inhibitors, angiotensin-2 receptor blockers, and diuretics can lower BNP levels.

      BNP has several effects, including vasodilation, diuresis, natriuresis, and suppression of both sympathetic tone and the renin-angiotensin-aldosterone system. Clinically, BNP is useful in diagnosing patients with acute dyspnea. A low concentration of BNP (<100 pg/mL) makes a diagnosis of heart failure unlikely, but elevated levels should prompt further investigation to confirm the diagnosis. Currently, NICE recommends BNP as a helpful test to rule out a diagnosis of heart failure. In patients with chronic heart failure, initial evidence suggests that BNP is an extremely useful marker of prognosis and can guide treatment. However, BNP is not currently recommended for population screening for cardiac dysfunction.

    • This question is part of the following fields:

      • Cardiovascular System
      23.2
      Seconds
  • Question 11 - A teenage boy suddenly collapses outside his home. He is found to be...

    Correct

    • A teenage boy suddenly collapses outside his home. He is found to be in cardiac arrest and unfortunately passed away in the hospital. Posthumously, he is diagnosed with arrhythmogenic right ventricular cardiomyopathy. What alterations would this condition bring about in the heart?

      Your Answer: Myocardium replaced by fatty and fibrofatty tissue

      Explanation:

      Arrhythmogenic right ventricular cardiomyopathy is characterized by the replacement of the right ventricular myocardium with fatty and fibrofatty tissue. Hypertrophic obstructive cardiomyopathy, which is the leading cause of sudden cardiac death, is associated with asymmetrical thickening of the septum. Left ventricular hypertrophy can be caused by hypertension, aortic valve stenosis, hypertrophic cardiomyopathy, and athletic training. While arrhythmogenic right ventricular cardiomyopathy can cause ventricular dilation in later stages, it is not transient. Transient ballooning would suggest a diagnosis of Takotsubo cardiomyopathy, which is triggered by acute stress.

      Arrhythmogenic right ventricular cardiomyopathy (ARVC), also known as arrhythmogenic right ventricular dysplasia or ARVD, is a type of inherited cardiovascular disease that can lead to sudden cardiac death or syncope. It is considered the second most common cause of sudden cardiac death in young individuals, following hypertrophic cardiomyopathy. The disease is inherited in an autosomal dominant pattern with variable expression, and it is characterized by the replacement of the right ventricular myocardium with fatty and fibrofatty tissue. Approximately 50% of patients with ARVC have a mutation in one of the several genes that encode components of desmosome.

      The presentation of ARVC may include palpitations, syncope, or sudden cardiac death. ECG abnormalities in V1-3, such as T wave inversion, are typically observed. An epsilon wave, which is best described as a terminal notch in the QRS complex, is found in about 50% of those with ARVC. Echo changes may show an enlarged, hypokinetic right ventricle with a thin free wall, although these changes may be subtle in the early stages. Magnetic resonance imaging is useful in showing fibrofatty tissue.

      Management of ARVC may involve the use of drugs such as sotalol, which is the most widely used antiarrhythmic. Catheter ablation may also be used to prevent ventricular tachycardia, and an implantable cardioverter-defibrillator may be recommended. Naxos disease is an autosomal recessive variant of ARVC that is characterized by a triad of ARVC, palmoplantar keratosis, and woolly hair.

    • This question is part of the following fields:

      • Cardiovascular System
      21.1
      Seconds
  • Question 12 - A 67-year-old woman visits the anticoagulation clinic for her regular INR test. She...

    Incorrect

    • A 67-year-old woman visits the anticoagulation clinic for her regular INR test. She has a medical history of deep vein thrombosis and pulmonary embolism and is currently taking warfarin for life. During this visit, her INR level is found to be 4.4, which is higher than her target of 3.0. Upon further inquiry, she reveals that she had been prescribed antibiotics by her GP recently. Can you identify the clotting factors that warfarin affects?

      Your Answer: Factors II, V, X

      Correct Answer: Factors II, VII, IX, X

      Explanation:

      Warfarin is an oral anticoagulant that is widely used to prevent blood clotting in various medical conditions, including stroke prevention in atrial fibrillation and venous thromboembolism. Warfarin primarily targets the Vitamin K dependent clotting factors, which include factors II, VII, IX, and X.

      To monitor the effectiveness of warfarin therapy, the International Normalized Ratio (INR) is used. However, the INR can be affected by drug interactions, such as those with antibiotics. Therefore, it is important to be aware of the common drug interactions associated with warfarin.

      Understanding Warfarin: Mechanism of Action, Indications, Monitoring, Factors, and Side-Effects

      Warfarin is an oral anticoagulant that has been widely used for many years to manage venous thromboembolism and reduce stroke risk in patients with atrial fibrillation. However, it has been largely replaced by direct oral anticoagulants (DOACs) due to their ease of use and lack of need for monitoring. Warfarin works by inhibiting epoxide reductase, which prevents the reduction of vitamin K to its active hydroquinone form. This, in turn, affects the carboxylation of clotting factor II, VII, IX, and X, as well as protein C.

      Warfarin is indicated for patients with mechanical heart valves, with the target INR depending on the valve type and location. Mitral valves generally require a higher INR than aortic valves. It is also used as a second-line treatment after DOACs for venous thromboembolism and atrial fibrillation, with target INRs of 2.5 and 3.5 for recurrent cases. Patients taking warfarin are monitored using the INR, which may take several days to achieve a stable level. Loading regimes and computer software are often used to adjust the dose.

      Factors that may potentiate warfarin include liver disease, P450 enzyme inhibitors, cranberry juice, drugs that displace warfarin from plasma albumin, and NSAIDs that inhibit platelet function. Warfarin may cause side-effects such as haemorrhage, teratogenic effects, skin necrosis, temporary procoagulant state, thrombosis, and purple toes.

      In summary, understanding the mechanism of action, indications, monitoring, factors, and side-effects of warfarin is crucial for its safe and effective use in patients. While it has been largely replaced by DOACs, warfarin remains an important treatment option for certain patients.

    • This question is part of the following fields:

      • Cardiovascular System
      7.1
      Seconds
  • Question 13 - An occlusion of the anterior cerebral artery may affect the blood supply to...

    Incorrect

    • An occlusion of the anterior cerebral artery may affect the blood supply to which of the following structures, except for:

      Your Answer: Corpus callosum

      Correct Answer: Brocas area

      Explanation:

      The Circle of Willis is an anastomosis formed by the internal carotid arteries and vertebral arteries on the bottom surface of the brain. It is divided into two halves and is made up of various arteries, including the anterior communicating artery, anterior cerebral artery, internal carotid artery, posterior communicating artery, and posterior cerebral arteries. The circle and its branches supply blood to important areas of the brain, such as the corpus striatum, internal capsule, diencephalon, and midbrain.

      The vertebral arteries enter the cranial cavity through the foramen magnum and lie in the subarachnoid space. They then ascend on the anterior surface of the medulla oblongata and unite to form the basilar artery at the base of the pons. The basilar artery has several branches, including the anterior inferior cerebellar artery, labyrinthine artery, pontine arteries, superior cerebellar artery, and posterior cerebral artery.

      The internal carotid arteries also have several branches, such as the posterior communicating artery, anterior cerebral artery, middle cerebral artery, and anterior choroid artery. These arteries supply blood to different parts of the brain, including the frontal, temporal, and parietal lobes. Overall, the Circle of Willis and its branches play a crucial role in providing oxygen and nutrients to the brain.

    • This question is part of the following fields:

      • Cardiovascular System
      7.5
      Seconds
  • Question 14 - A 68-year-old woman arrives at the emergency department with complaints of shortness of...

    Correct

    • A 68-year-old woman arrives at the emergency department with complaints of shortness of breath and palpitations. During the examination, you observe an irregularly irregular pulse. To check for signs of atrial fibrillation, you opt to conduct an ECG. In a healthy individual, where is the SA node located in the heart?

      Your Answer: Right atrium

      Explanation:

      The SA node is situated at the junction of the superior vena cava and the right atrium, and is responsible for initiating cardiac impulses in a healthy heart. The AV node, located in the atrioventricular septum, regulates the spread of excitation from the atria to the ventricles. The patient’s symptoms of palpitations and shortness of breath, along with an irregularly irregular pulse, strongly indicate atrial fibrillation. ECG findings consistent with atrial fibrillation include an irregularly irregular rhythm and the absence of P waves.

      The heart has four chambers and generates pressures of 0-25 mmHg on the right side and 0-120 mmHg on the left. The cardiac output is the product of heart rate and stroke volume, typically 5-6L per minute. The cardiac impulse is generated in the sino atrial node and conveyed to the ventricles via the atrioventricular node. Parasympathetic and sympathetic fibers project to the heart via the vagus and release acetylcholine and noradrenaline, respectively. The cardiac cycle includes mid diastole, late diastole, early systole, late systole, and early diastole. Preload is the end diastolic volume and afterload is the aortic pressure. Laplace’s law explains the rise in ventricular pressure during the ejection phase and why a dilated diseased heart will have impaired systolic function. Starling’s law states that an increase in end-diastolic volume will produce a larger stroke volume up to a point beyond which stroke volume will fall. Baroreceptor reflexes and atrial stretch receptors are involved in regulating cardiac output.

    • This question is part of the following fields:

      • Cardiovascular System
      50.3
      Seconds
  • Question 15 - A newborn male delivered at 38 weeks gestation presents with severe cyanosis within...

    Incorrect

    • A newborn male delivered at 38 weeks gestation presents with severe cyanosis within the first hour of life. He experiences worsening respiratory distress and is unable to feed properly. The infant is immediately transferred to the neonatal intensive care unit for supportive care. The mother did not receive any prenatal care and the baby was delivered via an uncomplicated spontaneous vaginal delivery.

      During physical examination, the neonate appears lethargic and cyanotic. His vital signs are as follows: respiratory rate 60/min, oxygen saturation 82% (on 65% oxygen), heart rate 155/min, blood pressure 98/68 mmHg. Cardiac auscultation reveals a loud S2 heart sound.

      A chest x-ray shows an 'eggs on a string' appearance of the cardiac silhouette. An electrocardiogram (ECG) indicates right ventricular dominance. Further diagnostic testing with echocardiography confirms a congenital heart defect.

      What is the most likely embryological pathology underlying this neonate's congenital heart defect?

      Your Answer: Defect in interatrial septum

      Correct Answer: Failure of the aorticopulmonary septum to spiral

      Explanation:

      Transposition of great vessels is caused by the failure of the aorticopulmonary septum to spiral during early life, resulting in a cyanotic heart disease. The classic X-ray description and clinical findings support this diagnosis. Other cyanotic heart defects, such as tricuspid atresia and Tetralogy of Fallot, have different clinical features and X-ray findings. Non-cyanotic heart defects, such as atrial septal defect, have a defect in the interatrial septum. Aortic coarctation is characterized by a narrowing near the insertion of ductus arteriosus.

      Understanding Transposition of the Great Arteries

      Transposition of the great arteries (TGA) is a type of congenital heart disease that results in cyanosis. This condition occurs when the aorticopulmonary septum fails to spiral during septation, causing the aorta to leave the right ventricle and the pulmonary trunk to leave the left ventricle. Infants born to diabetic mothers are at a higher risk of developing TGA.

      The clinical features of TGA include cyanosis, tachypnea, a loud single S2, and a prominent right ventricular impulse. Chest x-rays may show an egg-on-side appearance. To manage TGA, prostaglandins can be used to maintain the ductus arteriosus. However, surgical correction is the definitive treatment for this condition.

    • This question is part of the following fields:

      • Cardiovascular System
      78.6
      Seconds
  • Question 16 - Which one of the following is typically not provided by the right coronary...

    Correct

    • Which one of the following is typically not provided by the right coronary artery?

      Your Answer: The circumflex artery

      Explanation:

      The left coronary artery typically gives rise to the circumflex artery.

      The walls of each cardiac chamber are made up of the epicardium, myocardium, and endocardium. The heart and roots of the great vessels are related anteriorly to the sternum and the left ribs. The coronary sinus receives blood from the cardiac veins, and the aortic sinus gives rise to the right and left coronary arteries. The left ventricle has a thicker wall and more numerous trabeculae carnae than the right ventricle. The heart is innervated by autonomic nerve fibers from the cardiac plexus, and the parasympathetic supply comes from the vagus nerves. The heart has four valves: the mitral, aortic, pulmonary, and tricuspid valves.

    • This question is part of the following fields:

      • Cardiovascular System
      3.7
      Seconds
  • Question 17 - Sophie is a 22-year-old woman who was diagnosed with hypertrophic cardiomyopathy 4 years...

    Incorrect

    • Sophie is a 22-year-old woman who was diagnosed with hypertrophic cardiomyopathy 4 years ago. Since then she has developed pulmonary hypertension which has added to her symptom load. To alleviate this, Sophie's doctor considers prescribing ambrisentan, an endothelin receptor antagonist. By inhibiting the mediator, endothelin, the doctor hopes to improve Sophie's symptoms until she receives a heart transplant.

      What are the main physiological impacts of this mediator?

      Your Answer: Decreased systemic vascular resistance and increased excretion of sodium

      Correct Answer: Vasoconstriction and bronchoconstriction

      Explanation:

      Endothelin is a potent vasoconstrictor and bronchoconstrictor that is secreted by endothelial cells and plays a crucial role in vascular homeostasis. However, excessive production of endothelin has been linked to various pathologies, including primary pulmonary hypertension. Inhibiting endothelin receptors can help lower pulmonary blood pressure.

      It’s important to note that endothelin does not affect systemic vascular resistance or sodium excretion, which are regulated by atrial and ventricular natriuretic peptides. Aldosterone, on the other hand, is responsible for increasing sodium reabsorption in the kidneys, and it’s believed that endothelin and aldosterone may work together to regulate sodium homeostasis.

      While endothelin causes vasoconstriction, it does not cause bronchodilation. Adrenaline, on the other hand, causes both vasoconstriction and bronchodilation, allowing for improved oxygen absorption from the lungs while delivering blood to areas of the body that require it for action.

      Finally, endothelin does not increase endovascular permeability, which is a function of histamine released by mast cells in response to noxious stimuli. Histamine enhances the recruitment of leukocytes to an area of inflammation by causing vascular changes.

      Understanding Endothelin and Its Role in Various Diseases

      Endothelin is a potent vasoconstrictor and bronchoconstrictor that is secreted by the vascular endothelium. Initially, it is produced as a prohormone and later converted to ET-1 by the action of endothelin converting enzyme. Endothelin interacts with a G-protein linked to phospholipase C, leading to calcium release. This interaction is thought to be important in the pathogenesis of many diseases, including primary pulmonary hypertension, cardiac failure, hepatorenal syndrome, and Raynaud’s.

      Endothelin is known to promote the release of angiotensin II, ADH, hypoxia, and mechanical shearing forces. On the other hand, it inhibits the release of nitric oxide and prostacyclin. Raised levels of endothelin are observed in primary pulmonary hypertension, myocardial infarction, heart failure, acute kidney injury, and asthma.

      In recent years, endothelin antagonists have been used to treat primary pulmonary hypertension. Understanding the role of endothelin in various diseases can help in the development of new treatments and therapies.

    • This question is part of the following fields:

      • Cardiovascular System
      13.6
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  • Question 18 - A 40-year-old woman visits her GP complaining of muscle cramps, fatigue, and tingling...

    Incorrect

    • A 40-year-old woman visits her GP complaining of muscle cramps, fatigue, and tingling in her fingers and toes for the past two weeks. Upon conducting a blood test, the doctor discovers low levels of serum calcium and parathyroid hormone. The patient is new to the clinic and seems a bit confused, possibly due to hypocalcemia, and is unable to provide a complete medical history. However, she mentions that she was recently hospitalized. What is the most probable cause of her hypoparathyroidism?

      Your Answer: Chronic kidney disease

      Correct Answer: Thyroidectomy

      Explanation:

      Due to their location behind the thyroid gland, the parathyroid glands are at risk of damage during a thyroidectomy, leading to iatrogenic hypoparathyroidism. This condition is characterized by low levels of both parathyroid hormone and calcium, indicating that the parathyroid glands are not responding to the hypocalcemia. The patient’s confusion and prolonged hospital stay are likely related to the surgery.

      Hypocalcemia can also be caused by chronic kidney disease, which triggers an increase in parathyroid hormone production in an attempt to raise calcium levels, resulting in hyperparathyroidism. Additionally, a deficiency in vitamin D, which is activated by the kidneys and aids in calcium absorption in the terminal ileum, can also lead to hyperparathyroidism.

      While a parathyroid adenoma is a common occurrence, it is more likely to cause hyperparathyroidism than hypoparathyroidism, which is a relatively rare side effect of thyroidectomy.

      Anatomy and Development of the Parathyroid Glands

      The parathyroid glands are four small glands located posterior to the thyroid gland within the pretracheal fascia. They develop from the third and fourth pharyngeal pouches, with those derived from the fourth pouch located more superiorly and associated with the thyroid gland, while those from the third pouch lie more inferiorly and may become associated with the thymus.

      The blood supply to the parathyroid glands is derived from the inferior and superior thyroid arteries, with a rich anastomosis between the two vessels. Venous drainage is into the thyroid veins. The parathyroid glands are surrounded by various structures, with the common carotid laterally, the recurrent laryngeal nerve and trachea medially, and the thyroid anteriorly. Understanding the anatomy and development of the parathyroid glands is important for their proper identification and preservation during surgical procedures.

    • This question is part of the following fields:

      • Cardiovascular System
      18.7
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  • Question 19 - A 72-year-old man is admitted to the renal ward with acute kidney injury...

    Incorrect

    • A 72-year-old man is admitted to the renal ward with acute kidney injury following 3 days of diarrhoea and vomiting. Laboratory results reveal that his potassium levels are below normal limits, likely due to his gastrointestinal symptoms. You review his medications to ensure that none are exacerbating the situation and discover that he is taking diuretics for heart failure management. Which of the following diuretics is linked to hypokalaemia?

      Your Answer: Amiloride

      Correct Answer: Bumetanide

      Explanation:

      Hypokalaemia may be caused by loop diuretics such as bumetanide. It is important to note that spironolactone, triamterene, eplerenone, and amiloride are potassium-sparing diuretics and are more likely to cause hyperkalaemia. In this case, the patient has been admitted to the hospital with acute kidney injury (AKI) due to diarrhoea and vomiting, which are also possible causes of hypokalaemia. It is important to manage all of these factors. Symptoms of hypokalaemia include fatigue, muscle weakness, myalgia, muscle cramps, constipation, hyporeflexia, and in rare cases, paralysis.

      Loop Diuretics: Mechanism of Action and Clinical Applications

      Loop diuretics, such as furosemide and bumetanide, are medications that inhibit the Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle. By doing so, they reduce the absorption of NaCl, resulting in increased urine output. Loop diuretics act on NKCC2, which is more prevalent in the kidneys. These medications work on the apical membrane and must first be filtered into the tubules by the glomerulus before they can have an effect. Patients with poor renal function may require higher doses to ensure sufficient concentration in the tubules.

      Loop diuretics are commonly used in the treatment of heart failure, both acutely (usually intravenously) and chronically (usually orally). They are also indicated for resistant hypertension, particularly in patients with renal impairment. However, loop diuretics can cause adverse effects such as hypotension, hyponatremia, hypokalemia, hypomagnesemia, hypochloremic alkalosis, ototoxicity, hypocalcemia, renal impairment, hyperglycemia (less common than with thiazides), and gout. Therefore, careful monitoring of electrolyte levels and renal function is necessary when using loop diuretics.

    • This question is part of the following fields:

      • Cardiovascular System
      16.8
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  • Question 20 - During surgery on her neck, a woman in her 50s suffers a vagus...

    Correct

    • During surgery on her neck, a woman in her 50s suffers a vagus nerve injury where the nerve is cut near the exit from the skull. She wakes up with a high heart rate and high blood pressure due to loss of parasympathetic tone.

      What other features would be expected with a vagus nerve injury?

      Your Answer: Hoarse voice

      Explanation:

      The vagus (X) nerve is responsible for all innervation related to speech, meaning that any injuries to this nerve can lead to speech problems. It’s important to note that the vagus nerve has both autonomic and somatic effects, with the latter being the most crucial for speech. This involves the motor supply to the larynx through the recurrent laryngeal nerves, which are branches of the vagus. If one vagus nerve is damaged, it would have the same impact as damage to a single recurrent laryngeal nerve, resulting in a hoarse voice.

      However, it’s worth noting that anal tone, erections, and urination are controlled by the sacral parasympathetics and would not be affected by the loss of the vagus nerve. Similarly, pupillary constriction is controlled by parasympathetics on the oculomotor nerve and would not be impacted by the loss of the vagus nerve.

      The vagus nerve is responsible for a variety of functions and supplies structures from the fourth and sixth pharyngeal arches, as well as the fore and midgut sections of the embryonic gut tube. It carries afferent fibers from areas such as the pharynx, larynx, esophagus, stomach, lungs, heart, and great vessels. The efferent fibers of the vagus are of two main types: preganglionic parasympathetic fibers distributed to the parasympathetic ganglia that innervate smooth muscle of the innervated organs, and efferent fibers with direct skeletal muscle innervation, largely to the muscles of the larynx and pharynx.

      The vagus nerve arises from the lateral surface of the medulla oblongata and exits through the jugular foramen, closely related to the glossopharyngeal nerve cranially and the accessory nerve caudally. It descends vertically in the carotid sheath in the neck, closely related to the internal and common carotid arteries. In the mediastinum, both nerves pass posteroinferiorly and reach the posterior surface of the corresponding lung root, branching into both lungs. At the inferior end of the mediastinum, these plexuses reunite to form the formal vagal trunks that pass through the esophageal hiatus and into the abdomen. The anterior and posterior vagal trunks are formal nerve fibers that splay out once again, sending fibers over the stomach and posteriorly to the coeliac plexus. Branches pass to the liver, spleen, and kidney.

      The vagus nerve has various branches in the neck, including superior and inferior cervical cardiac branches, and the right recurrent laryngeal nerve, which arises from the vagus anterior to the first part of the subclavian artery and hooks under it to insert into the larynx. In the thorax, the left recurrent laryngeal nerve arises from the vagus on the aortic arch and hooks around the inferior surface of the arch, passing upwards through the superior mediastinum and lower part of the neck. In the abdomen, the nerves branch extensively, passing to the coeliac axis and alongside the vessels to supply the spleen, liver, and kidney.

    • This question is part of the following fields:

      • Cardiovascular System
      7.4
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  • Question 21 - A young woman presents with sudden palpitations and difficulty breathing, and her ECG...

    Correct

    • A young woman presents with sudden palpitations and difficulty breathing, and her ECG reveals tachycardia. Which cardiac component typically experiences the most rapid depolarization?

      Your Answer: Sino-atrial node

      Explanation:

      The heart’s conducting system is made up of specialized cardiac muscle cells and fibers that generate and rapidly transmit action potentials. This system is crucial for coordinating the contractions of the heart’s chambers during the cardiac cycle. When this system malfunctions due to conduction blockages or abnormal action potential sources, it can lead to arrhythmias.

      The conducting system has five main components:

      1. The sino-atrial (SAN) node, located in the right atrium, generates electrical signals.
      2. These signals stimulate the atria to contract and travel to the atrio-ventricular (AVN) node in the interatrial septum.
      3. After a delay, the stimulus diverges and is conducted through the left and right bundle of His.
      4. The conduction then passes to the respective Purkinje fibers for each side of the heart.
      5. Finally, the electrical signals reach the endocardium at the apex of the heart and the ventricular epicardium.

      Understanding the Cardiac Action Potential and Conduction Velocity

      The cardiac action potential is a series of electrical events that occur in the heart during each heartbeat. It is responsible for the contraction of the heart muscle and the pumping of blood throughout the body. The action potential is divided into five phases, each with a specific mechanism. The first phase is rapid depolarization, which is caused by the influx of sodium ions. The second phase is early repolarization, which is caused by the efflux of potassium ions. The third phase is the plateau phase, which is caused by the slow influx of calcium ions. The fourth phase is final repolarization, which is caused by the efflux of potassium ions. The final phase is the restoration of ionic concentrations, which is achieved by the Na+/K+ ATPase pump.

      Conduction velocity is the speed at which the electrical signal travels through the heart. The speed varies depending on the location of the signal. Atrial conduction spreads along ordinary atrial myocardial fibers at a speed of 1 m/sec. AV node conduction is much slower, at 0.05 m/sec. Ventricular conduction is the fastest in the heart, achieved by the large diameter of the Purkinje fibers, which can achieve velocities of 2-4 m/sec. This allows for a rapid and coordinated contraction of the ventricles, which is essential for the proper functioning of the heart. Understanding the cardiac action potential and conduction velocity is crucial for diagnosing and treating heart conditions.

    • This question is part of the following fields:

      • Cardiovascular System
      8.7
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  • Question 22 - A 67-year-old patient with well-controlled Parkinson's disease presents following several syncopal episodes. Each...

    Incorrect

    • A 67-year-old patient with well-controlled Parkinson's disease presents following several syncopal episodes. Each episode is preceded by a change in posture, typically when the patient gets out of bed in the morning. The patient feels dizzy and nauseous and falls. He recovers within seconds after the event. The neurologist states these symptoms are likely a side-effect of the patient's levodopa, and prescribes a medication to treat the condition.

      What medication would be the most appropriate for managing the symptoms of this patient?

      Your Answer: Theophylline

      Correct Answer: Fludrocortisone

      Explanation:

      Orthostatic hypotension can be treated with midodrine or fludrocortisone. Fludrocortisone is a synthetic mineralocorticoid that can replace low levels of aldosterone and is often used as an alternative to midodrine, which can cause side-effects such as hypertension and BPH in some patients. Atenolol is a beta-blocker used to treat angina and hypertension, while losartan is an angiotensin-II-receptor antagonist used to manage hypertension. Adenosine is a medication used to treat supraventricular tachycardias.

      Understanding Orthostatic Hypotension

      Orthostatic hypotension is a condition that is more commonly observed in older individuals and those who have neurodegenerative diseases such as Parkinson’s, diabetes, or hypertension. Additionally, certain medications such as alpha-blockers used for benign prostatic hyperplasia can also cause this condition. The primary feature of orthostatic hypotension is a sudden drop in blood pressure, usually more than 20/10 mm Hg, within three minutes of standing. This can lead to presyncope or syncope, which is a feeling of lightheadedness or fainting.

      Fortunately, there are treatment options available for orthostatic hypotension. Midodrine and fludrocortisone are two medications that can be used to manage this condition. It is important to consult with a healthcare professional to determine the best course of treatment for each individual case. By understanding the causes, symptoms, and treatment options for orthostatic hypotension, individuals can take steps to manage this condition and improve their quality of life.

    • This question is part of the following fields:

      • Cardiovascular System
      14.6
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  • Question 23 - A 55-year-old chronic smoker presents to the cardiology clinic with worsening chest pain...

    Incorrect

    • A 55-year-old chronic smoker presents to the cardiology clinic with worsening chest pain during physical activity. After initial investigations, an outpatient coronary angiography is performed which reveals severe stenosis/atheroma in multiple vessels. The patient is informed that this condition is a result of various factors, including the detrimental effects of smoking on the blood vessels.

      What is the ultimate stage in the development of this patient's condition?

      Your Answer: Collagen disruption and break down of the tunica externa

      Correct Answer: Smooth muscle proliferation and migration from the tunica media into the intima

      Explanation:

      Understanding Atherosclerosis and its Complications

      Atherosclerosis is a complex process that occurs over several years. It begins with endothelial dysfunction triggered by factors such as smoking, hypertension, and hyperglycemia. This leads to changes in the endothelium, including inflammation, oxidation, proliferation, and reduced nitric oxide bioavailability. As a result, low-density lipoprotein (LDL) particles infiltrate the subendothelial space, and monocytes migrate from the blood and differentiate into macrophages. These macrophages then phagocytose oxidized LDL, slowly turning into large ‘foam cells’. Smooth muscle proliferation and migration from the tunica media into the intima result in the formation of a fibrous capsule covering the fatty plaque.

      Once a plaque has formed, it can cause several complications. For example, it can form a physical blockage in the lumen of the coronary artery, leading to reduced blood flow and oxygen to the myocardium, resulting in angina. Alternatively, the plaque may rupture, potentially causing a complete occlusion of the coronary artery and resulting in a myocardial infarction. It is essential to understand the process of atherosclerosis and its complications to prevent and manage cardiovascular diseases effectively.

    • This question is part of the following fields:

      • Cardiovascular System
      15.7
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  • Question 24 - An 85-year-old man presents to the hospital with complaints of breathlessness at rest....

    Correct

    • An 85-year-old man presents to the hospital with complaints of breathlessness at rest. He has a medical history of type 2 diabetes and hypertension, for which he takes metformin, lisinopril, and metoprolol. He also smokes five cigarettes a day. On examination, he has a heart rate of 100 bpm, blood pressure of 128/90 mmHg, and a respiratory rate of 26 with oxygen saturation of 88% on 2l/minute. He has a regular, slow rising pulse, an ejection systolic murmur, crepitations at both lung bases, and oedema at the ankles and sacrum.

      What investigation is most crucial for his immediate management?

      Your Answer: Electrocardiogram

      Explanation:

      Managing Pulmonary Edema from Congestive Cardiac Failure

      Pulmonary edema from congestive cardiac failure requires prompt investigation and management. The most crucial investigation is an ECG to check for a possible silent myocardial infarction. Even if the ECG is normal, a troponin test may be necessary to rule out a NSTEMI. Arterial blood gas analysis is also important to guide oxygen therapy. Additionally, stopping medications such as metformin, lisinopril, and metoprolol, and administering diuretics can help manage the condition.

      It is likely that the patient has aortic stenosis, which is contributing to the cardiac failure. However, acute management of the valvular disease will be addressed separately. To learn more about heart failure and its management, refer to the ABC of heart failure articles by Millane et al. and Watson et al.

    • This question is part of the following fields:

      • Cardiovascular System
      53.5
      Seconds
  • Question 25 - A 53-year-old woman presents with stroke symptoms after experiencing difficulty speaking and changes...

    Incorrect

    • A 53-year-old woman presents with stroke symptoms after experiencing difficulty speaking and changes in vision while at a hair salon. She developed a headache after having her hair washed, and further examination reveals a vertebral arterial dissection believed to be caused by hyperextension of her neck.

      What is the pathway of this blood vessel as it enters the cranial cavity?

      Your Answer: Foramen ovale

      Correct Answer: Foramen magnum

      Explanation:

      The vertebral arteries pass through the foramen magnum to enter the cranial cavity. If the neck is hyperextended, it can compress and potentially cause dissection of these arteries. A well-known example of this happening is when a person leans back to have their hair washed at a salon. The vertebral artery runs alongside the medulla in the foramen magnum. The carotid canal is not involved in this process, as it contains the carotid artery. Similarly, the foramen ovale contains the accessory meningeal artery, not the vertebral artery, and the foramen spinosum contains the middle meningeal artery, not the vertebral artery.

      The Circle of Willis is an anastomosis formed by the internal carotid arteries and vertebral arteries on the bottom surface of the brain. It is divided into two halves and is made up of various arteries, including the anterior communicating artery, anterior cerebral artery, internal carotid artery, posterior communicating artery, and posterior cerebral arteries. The circle and its branches supply blood to important areas of the brain, such as the corpus striatum, internal capsule, diencephalon, and midbrain.

      The vertebral arteries enter the cranial cavity through the foramen magnum and lie in the subarachnoid space. They then ascend on the anterior surface of the medulla oblongata and unite to form the basilar artery at the base of the pons. The basilar artery has several branches, including the anterior inferior cerebellar artery, labyrinthine artery, pontine arteries, superior cerebellar artery, and posterior cerebral artery.

      The internal carotid arteries also have several branches, such as the posterior communicating artery, anterior cerebral artery, middle cerebral artery, and anterior choroid artery. These arteries supply blood to different parts of the brain, including the frontal, temporal, and parietal lobes. Overall, the Circle of Willis and its branches play a crucial role in providing oxygen and nutrients to the brain.

    • This question is part of the following fields:

      • Cardiovascular System
      20.3
      Seconds
  • Question 26 - An 80-year-old woman comes to the hospital complaining of chest pain, vomiting, and...

    Correct

    • An 80-year-old woman comes to the hospital complaining of chest pain, vomiting, and sweating for the past two hours. She has a medical history of hypertension and peripheral arterial disease. Despite using sublingual nitrate spray at home, the pain has not subsided. Upon admission, she is found to be tachycardic and tachypneic, but no other respiratory or cardiac abnormalities are detected. An ECG reveals ST segment elevation in leads II, III, and aVF, as well as ST segment depression in leads I and aVL. Which coronary artery is most likely affected?

      Your Answer: Right coronary artery

      Explanation:

      The observed ECG alterations are indicative of an ischemic injury in the lower region of the heart. The ST depressions in leads I and aVL, which are located in the lateral wall, are common reciprocal changes that occur during an inferior myocardial infarction. Typically, the right coronary artery is the most probable site of damage in cases involving lesions in the lower wall.

      Understanding Acute Coronary Syndrome

      Acute coronary syndrome (ACS) is a term used to describe various acute presentations of ischaemic heart disease. It includes ST elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI), and unstable angina. ACS usually develops in patients with ischaemic heart disease, which is the gradual build-up of fatty plaques in the walls of the coronary arteries. This can lead to a gradual narrowing of the arteries, resulting in less blood and oxygen reaching the myocardium, causing angina. It can also lead to sudden plaque rupture, resulting in a complete occlusion of the artery and no blood or oxygen reaching the area of myocardium, causing a myocardial infarction.

      There are many factors that can increase the chance of a patient developing ischaemic heart disease, including unmodifiable risk factors such as increasing age, male gender, and family history, and modifiable risk factors such as smoking, diabetes mellitus, hypertension, hypercholesterolaemia, and obesity.

      The classic and most common symptom of ACS is chest pain, which is typically central or left-sided and may radiate to the jaw or left arm. Other symptoms include dyspnoea, sweating, and nausea and vomiting. Patients presenting with ACS often have very few physical signs, and the two most important investigations when assessing a patient with chest pain are an electrocardiogram (ECG) and cardiac markers such as troponin.

      Once a diagnosis of ACS has been made, treatment involves preventing worsening of the presentation, revascularising the vessel if occluded, and treating pain. For patients who’ve had a STEMI, the priority of management is to reopen the blocked vessel. For patients who’ve had an NSTEMI, a risk stratification tool is used to decide upon further management. Patients who’ve had an ACS require lifelong drug therapy to help reduce the risk of a further event, which includes aspirin, a second antiplatelet if appropriate, a beta-blocker, an ACE inhibitor, and a statin.

    • This question is part of the following fields:

      • Cardiovascular System
      35
      Seconds
  • Question 27 - A 65-year-old man with heart failure visits his GP complaining of peripheral edema....

    Correct

    • A 65-year-old man with heart failure visits his GP complaining of peripheral edema. Upon examination, he is diagnosed with fluid overload, leading to the release of atrial natriuretic peptide by the atrial myocytes. What is the mechanism of action of atrial natriuretic peptide?

      Your Answer: Antagonist of angiotensin II

      Explanation:

      Angiotensin II is opposed by atrial natriuretic peptide, while B-type natriuretic peptides inhibit the renin-angiotensin-aldosterone system and sympathetic activity. Additionally, aldosterone is antagonized by atrial natriuretic peptide. Renin catalyzes the conversion of angiotensinogen into angiotensin I.

      Atrial natriuretic peptide is a hormone that is primarily secreted by the myocytes of the right atrium and ventricle in response to an increase in blood volume. It is also secreted by the left atrium, although to a lesser extent. This peptide hormone is composed of 28 amino acids and acts through the cGMP pathway. It is broken down by endopeptidases.

      The main actions of atrial natriuretic peptide include promoting the excretion of sodium and lowering blood pressure. It achieves this by antagonizing the actions of angiotensin II and aldosterone. Overall, atrial natriuretic peptide plays an important role in regulating fluid and electrolyte balance in the body.

    • This question is part of the following fields:

      • Cardiovascular System
      17.3
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  • Question 28 - A 67-year-old man is scheduled for surgery to treat transitional cell carcinoma of...

    Incorrect

    • A 67-year-old man is scheduled for surgery to treat transitional cell carcinoma of the left kidney. During the procedure, the surgeon needs to locate and dissect the left renal artery. Can you identify the vertebral level where the origin of this artery can be found?

      Your Answer: L4

      Correct Answer: L1

      Explanation:

      The L1 level is where the left renal artery is located.

      Located just below the superior mesenteric artery at L1, the left renal artery arises from the abdominal aorta. It is positioned slightly lower than the right renal artery.

      At the T10 vertebral level, the vagal trunk accompanies the oesophagus as it passes through the diaphragm.

      The T12 vertebral level marks the point where the aorta passes through the diaphragm, along with the thoracic duct and azygous veins. Additionally, this is where the coeliac trunk branches out.

      The aorta is a major blood vessel that carries oxygenated blood from the heart to the rest of the body. At different levels along the aorta, there are branches that supply blood to specific organs and regions. These branches include the coeliac trunk at the level of T12, which supplies blood to the stomach, liver, and spleen. The left renal artery, at the level of L1, supplies blood to the left kidney. The testicular or ovarian arteries, at the level of L2, supply blood to the reproductive organs. The inferior mesenteric artery, at the level of L3, supplies blood to the lower part of the large intestine. Finally, at the level of L4, the abdominal aorta bifurcates, or splits into two branches, which supply blood to the legs and pelvis.

    • This question is part of the following fields:

      • Cardiovascular System
      10.3
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  • Question 29 - Mrs. Smith is a 75-year-old woman who presents to the emergency department with...

    Incorrect

    • Mrs. Smith is a 75-year-old woman who presents to the emergency department with progressive shortness of breath over the past 5 days. Last night she woke up suddenly because she couldn't catch her breath and developed a dry cough. Her breathing improved when she sat upright on the edge of her bed. She denies any chest pain, leg pain or fainting spells.

      Her past medical history includes a myocardial infarction 5 years ago for which she underwent a coronary artery bypass graft, hypertension and type 2 diabetes. She has been smoking for 30 years and doesn't drink any alcohol.

      What is the most likely diagnosis?

      Your Answer: Pulmonary embolism

      Correct Answer: Left-sided heart failure

      Explanation:

      The likely diagnosis for a patient experiencing paroxysmal nocturnal dyspnoea is left-sided heart failure. This symptom, which involves sudden waking at night due to shortness of breath, is a common feature of heart failure, particularly on the left side. Aortic dissection, myocardial infarction, and pulmonary embolism are unlikely diagnoses as they present with different symptoms. Right-sided heart failure is also an unlikely diagnosis as it presents with different features such as raised JVP, ankle oedema, and hepatomegaly.

      Features of Chronic Heart Failure

      Chronic heart failure is a condition that affects the heart’s ability to pump blood effectively. It is characterized by several features that can help in its diagnosis. Dyspnoea, or shortness of breath, is a common symptom of chronic heart failure. Patients may also experience coughing, which can be worse at night and accompanied by pink or frothy sputum. Orthopnoea, or difficulty breathing while lying down, and paroxysmal nocturnal dyspnoea, or sudden shortness of breath at night, are also common symptoms.

      Another feature of chronic heart failure is the presence of a wheeze, known as a cardiac wheeze. Patients may also experience weight loss, known as cardiac cachexia, which occurs in up to 15% of patients. However, this may be hidden by weight gained due to oedema. On examination, bibasal crackles may be heard, and signs of right-sided heart failure, such as a raised JVP, ankle oedema, and hepatomegaly, may be present.

      In summary, chronic heart failure is a condition that can be identified by several features, including dyspnoea, coughing, orthopnoea, paroxysmal nocturnal dyspnoea, wheezing, weight loss, bibasal crackles, and signs of right-sided heart failure. Early recognition and management of these symptoms can help improve outcomes for patients with chronic heart failure.

    • This question is part of the following fields:

      • Cardiovascular System
      34.8
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  • Question 30 - A 63-year-old man arrives at the emergency department with sudden and severe chest...

    Correct

    • A 63-year-old man arrives at the emergency department with sudden and severe chest pain that began an hour ago. He experiences nausea and sweating, and the pain spreads to his left jaw and arm. The patient has a medical history of essential hypertension and type 2 diabetes mellitus. He is a current smoker with a 30 pack years history and drinks about 30 units of alcohol per week. He used to work as a lorry driver but is now retired. An electrocardiogram in the emergency department reveals ST segment elevations in leads II, III, and aVF, and a blood test shows elevated cardiac enzymes. The man undergoes a percutaneous coronary intervention and is admitted to the coronary care unit. After two weeks, he is discharged. What is the complication that this man is most likely to develop on day 7 after his arrival at the emergency department?

      Your Answer: Cardiac tamponade

      Explanation:

      The patient’s symptoms suggest that he may have experienced an ST elevation myocardial infarction in the inferior wall of his heart. There are various complications that can arise after a heart attack, and the timing of these complications can vary.

      1. Ventricular arrhythmia is a common cause of death after a heart attack, but it typically occurs within the first 24 hours.
      2. Ventricular septal defect, which is caused by a rupture in the interventricular septum, is most likely to occur 3-5 days after a heart attack.
      3. This complication is autoimmune-mediated and usually occurs several weeks after a heart attack.
      4. Cardiac tamponade can occur when bleeding into the pericardial sac impairs the heart’s contractile function. This complication is most likely to occur 5-14 days after a heart attack.
      5. Mural thrombus, which can result from the formation of a true ventricular aneurysm, is most likely to occur at least two weeks after a heart attack. Ventricular pseudoaneurysm, on the other hand, can occur 3-14 days after a heart attack.

      Understanding Cardiac Tamponade

      Cardiac tamponade is a medical condition where there is an accumulation of pericardial fluid under pressure. This condition is characterized by several classical features, including hypotension, raised JVP, and muffled heart sounds, which are collectively known as Beck’s triad. Other symptoms of cardiac tamponade include dyspnea, tachycardia, an absent Y descent on the JVP, pulsus paradoxus, and Kussmaul’s sign. An ECG can also show electrical alternans.

      It is important to differentiate cardiac tamponade from constrictive pericarditis, which has different characteristic features such as an absent Y descent, X + Y present JVP, and the absence of pulsus paradoxus. Constrictive pericarditis is also characterized by pericardial calcification on CXR.

      The management of cardiac tamponade involves urgent pericardiocentesis. It is crucial to recognize the symptoms of cardiac tamponade and seek medical attention immediately to prevent further complications.

    • This question is part of the following fields:

      • Cardiovascular System
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