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  • Question 1 - A 36-year-old male comes to his GP complaining of chest pain that has...

    Correct

    • A 36-year-old male comes to his GP complaining of chest pain that has been present for a week. The pain worsens when he breathes in and is relieved when he sits forward. He also has a non-productive cough. He recently had a viral infection. An ECG was performed and showed global saddle-shaped ST elevation.

      Your Answer: Acute pericarditis

      Explanation:

      Chest pain that is relieved by sitting or leaning forward is often a symptom of acute pericarditis. This condition is commonly caused by a viral infection and may also present with flu-like symptoms, non-productive cough, and dyspnea. ECG changes may show a saddle-shaped ST elevation.

      Cardiac tamponade, on the other hand, is characterized by Beck’s triad, which includes hypotension, raised JVP, and muffled heart sounds. Dyspnea and tachycardia may also be present.

      A myocardial infarction is unlikely if the chest pain has been present for a week, as it typically presents more acutely and with constant chest pain regardless of body positioning. ECG changes would also occur in specific territories rather than globally.

      A pneumothorax presents with sudden onset dyspnea, pleuritic chest pain, tachypnea, and sweating. No ECG changes would be observed.

      A pulmonary embolism typically presents with acute onset tachypnea, fever, tachycardia, and crackles. Signs of deep vein thrombosis may also be present.

      Acute Pericarditis: Causes, Features, Investigations, and Management

      Acute pericarditis is a possible diagnosis for patients presenting with chest pain. The condition is characterized by chest pain, which may be pleuritic and relieved by sitting forwards. Other symptoms include non-productive cough, dyspnoea, and flu-like symptoms. Tachypnoea and tachycardia may also be present, along with a pericardial rub.

      The causes of acute pericarditis include viral infections, tuberculosis, uraemia, trauma, post-myocardial infarction, Dressler’s syndrome, connective tissue disease, hypothyroidism, and malignancy.

      Investigations for acute pericarditis include ECG changes, which are often global/widespread, as opposed to the ‘territories’ seen in ischaemic events. The ECG may show ‘saddle-shaped’ ST elevation and PR depression, which is the most specific ECG marker for pericarditis. All patients with suspected acute pericarditis should have transthoracic echocardiography.

      Management of acute pericarditis involves treating the underlying cause. A combination of NSAIDs and colchicine is now generally used as first-line treatment for patients with acute idiopathic or viral pericarditis.

      In summary, acute pericarditis is a possible diagnosis for patients presenting with chest pain. The condition is characterized by chest pain, which may be pleuritic and relieved by sitting forwards, along with other symptoms. The causes of acute pericarditis are varied, and investigations include ECG changes and transthoracic echocardiography. Management involves treating the underlying cause and using a combination of NSAIDs and colchicine as first-line treatment.

    • This question is part of the following fields:

      • Cardiovascular System
      6.5
      Seconds
  • Question 2 - A 22-year-old male arrives at the emergency department complaining of palpitations and feeling...

    Incorrect

    • A 22-year-old male arrives at the emergency department complaining of palpitations and feeling lightheaded. The electrocardiogram reveals supraventricular tachycardia, and the registrar administers adenosine to try and correct the abnormal rhythm.

      What is the mechanism of action of adenosine?

      Your Answer: Beta receptor antagonist

      Correct Answer: A1 receptor agonist

      Explanation:

      Adenosine is an agonist of the A1 receptor in the AV node, which inhibits adenylyl cyclase and reduces cAMP levels. This leads to hyperpolarisation by increasing potassium outflow, effectively preventing supraventricular tachycardia from continuing. It is important to note that adenosine is not an alpha receptor antagonist, beta-2 receptor agonist, or beta receptor antagonist.

      Adenosine is commonly used to stop supraventricular tachycardias. Its effects are boosted by dipyridamole, an antiplatelet agent, but blocked by theophyllines. However, asthmatics should avoid it due to the risk of bronchospasm. Adenosine works by causing a temporary heart block in the AV node. It activates the A1 receptor in the atrioventricular node, which inhibits adenylyl cyclase, reducing cAMP and causing hyperpolarization by increasing outward potassium flux. Adenosine has a very short half-life of about 8-10 seconds and should be infused through a large-caliber cannula.

      Adenosine can cause chest pain, bronchospasm, and transient flushing. It can also enhance conduction down accessory pathways, leading to an increased ventricular rate in conditions such as WPW syndrome.

    • This question is part of the following fields:

      • Cardiovascular System
      8.4
      Seconds
  • Question 3 - A young woman presents with symptoms indicative of infective endocarditis. She has no...

    Incorrect

    • A young woman presents with symptoms indicative of infective endocarditis. She has no history of injecting drug use, but her dentist notes that she has poor oral hygiene. What organism is most likely responsible for this infection?

      Your Answer: Staphylococcus epidermidis

      Correct Answer: Streptococci viridans

      Explanation:

      Infective endocarditis is most frequently caused by Streptococci viridans, which is commonly found in the oral cavity. This type of infection is often linked to patients with inadequate dental hygiene or those who have undergone dental procedures.

      Aetiology of Infective Endocarditis

      Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.

      The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are commonly found in indwelling lines and are the most common cause of endocarditis in patients following prosthetic valve surgery. Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition.

      Culture negative causes of infective endocarditis include prior antibiotic therapy, Coxiella burnetii, Bartonella, Brucella, and HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella). It is important to note that systemic lupus erythematosus and malignancy, specifically marantic endocarditis, can also cause non-infective endocarditis.

    • This question is part of the following fields:

      • Cardiovascular System
      6.7
      Seconds
  • Question 4 - 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: Ductus venosus

      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
      11.7
      Seconds
  • Question 5 - As a medical student observing a parathyroidectomy in the short-stay surgical theatre, you...

    Incorrect

    • As a medical student observing a parathyroidectomy in the short-stay surgical theatre, you witness the ligation of blood vessels supplying the parathyroid glands. The ENT consultant requests you to identify the arteries responsible for supplying oxygenated blood to the parathyroid gland. Can you correctly name these arteries?

      Your Answer: Super and inferior parathyroid arteries

      Correct Answer: Superior and inferior thyroid arteries

      Explanation:

      The superior and inferior thyroid arteries provide oxygenated blood supply to the parathyroid glands. The existence of inferior parathyroid arteries and superior parathyroid arteries is not supported by anatomical evidence. While a middle thyroid artery may exist in some individuals, it is a rare variation that is not relevant to the question at hand.

      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
      12.2
      Seconds
  • Question 6 - A 75-year-old male presents with an ejection systolic murmur that is most audible...

    Correct

    • A 75-year-old male presents with an ejection systolic murmur that is most audible over the aortic region. The patient also reports experiencing dyspnoea and angina. What is the probable diagnosis?

      Your Answer: Aortic stenosis

      Explanation:

      Differentiating Aortic Stenosis from Other Cardiac Conditions

      Aortic stenosis is a common cardiac condition that can be identified through auscultation. However, it is important to differentiate it from other conditions such as aortic sclerosis, HOCM, pulmonary stenosis, and aortic regurgitation. While aortic sclerosis may also present with an ejection systolic murmur, it is typically asymptomatic. The presence of dyspnoea, angina, or syncope would suggest a diagnosis of aortic stenosis instead. HOCM would not typically cause these symptoms, and pulmonary stenosis would not be associated with a murmur at the location of the aortic valve. Aortic regurgitation, on the other hand, would present with a wide pulse pressure and an early diastolic murmur. Therefore, careful consideration of symptoms and additional diagnostic tests may be necessary to accurately diagnose and differentiate between these cardiac conditions.

    • This question is part of the following fields:

      • Cardiovascular System
      11.2
      Seconds
  • Question 7 - You are attending a cardiology clinic one morning. A 54-year-old man presents for...

    Incorrect

    • You are attending a cardiology clinic one morning. A 54-year-old man presents for a medication review. He is currently taking a beta-blocker but is still frequently symptomatic. From his medication history, it is evident that he does not tolerate calcium channel blockers.

      The consultant considers the option of starting him on a new drug called nicorandil. The patient is hesitant to try it out as he believes it is a calcium channel blocker. You have been asked to explain the mechanism of action of nicorandil to this patient.

      What is the way in which the new drug exerts its effect?

      Your Answer: Causes vasodilation by inactivating ATP-sensitive potassium channels

      Correct Answer: Causes vasodilation by activating guanylyl cyclase which causes an increase in cGMP

      Explanation:

      Nicorandil induces vasodilation by activating guanylyl cyclase, leading to an increase in cyclic GMP. This results in the relaxation of vascular smooth muscles through the prevention of calcium ion influx and dephosphorylation of myosin light chains. Additionally, nicorandil activates ATP-sensitive potassium channels, causing hyperpolarization and preventing intracellular calcium overload, which plays a cardioprotective role.

      Nicorandil is a medication that is commonly used to treat angina. It works by activating potassium channels, which leads to vasodilation. This process is achieved through the activation of guanylyl cyclase, which results in an increase in cGMP. However, there are some adverse effects associated with the use of nicorandil, including headaches, flushing, and the development of ulcers on the skin, mucous membranes, and eyes. Additionally, gastrointestinal ulcers, including anal ulceration, may also occur. It is important to note that nicorandil should not be used in patients with left ventricular failure.

    • This question is part of the following fields:

      • Cardiovascular System
      25.4
      Seconds
  • Question 8 - A 57-year-old man presents to the emergency department with a severe headache that...

    Incorrect

    • A 57-year-old man presents to the emergency department with a severe headache that started 3 weeks ago and is localised to the back of the head. He rates it 8/10 on a pain scale and reports that it has gradually become worse. The patient has a medical history of Ehlers-Danlos syndrome.

      Unfortunately, the patient passes away after suffering a brainstem stroke.

      During the autopsy, a vertebral artery dissection is discovered at the point of entry into the cranial cavity.

      Where is this location?

      Your Answer: Foramen spinosum

      Correct Answer: Foramen magnum

      Explanation:

      The vertebral arteries pass through the foramen magnum to enter the cranial cavity.

      Other foramina and their corresponding arteries include the stylomastoid foramen for the posterior auricular artery (stylomastoid branch), the foramen ovale for the accessory meningeal artery, and the foramen spinosum for the middle meningeal 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
      20.6
      Seconds
  • Question 9 - As a curious fourth-year medical student, you observe the birth of a full-term...

    Incorrect

    • As a curious fourth-year medical student, you observe the birth of a full-term baby delivered vaginally to a mother who has given birth once before. The infant's Apgar score is 9 at 1 minute and 10 at 10 minutes, and the delivery is uncomplicated. However, a postnatal examination reveals that the ductus arteriosus has not closed properly. Can you explain the process by which this structure normally closes?

      Your Answer: It closes prior to delivery when the membrane ruptures

      Correct Answer: Decreased prostaglandin concentration

      Explanation:

      The ductus arteriosus, which is a shunt connecting the pulmonary artery with the descending aorta in utero, closes with the first breaths of life. This is due to an increase in pulmonary blood flow, which helps to clear local vasodilating prostaglandins that keep the duct open during fetal development. The opening of the lung alveoli with the first breath of life leads to an increase in oxygen tension in the blood, but this is not the primary mechanism behind the closure of the ductus arteriosus. It is important to note that oxygen tension in the blood increases after birth when the infant breathes in air and no longer receives mixed oxygenated blood via the placenta.

      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
      20.5
      Seconds
  • Question 10 - As a doctor on the cardiology ward, I am currently treating a 50-year-old...

    Incorrect

    • As a doctor on the cardiology ward, I am currently treating a 50-year-old patient who was admitted due to syncope and dyspnoea. The patient has just returned from an echocardiography which revealed a pedunculated mass. What is the most probable primary tumor that this patient is suffering from?

      Your Answer: Angioma

      Correct Answer: Myxoma

      Explanation:

      Atrial myxoma is the most frequently occurring primary cardiac tumor.

      Primary cardiac tumors are uncommon, and among them, myxomas are the most prevalent. Most of these tumors are benign and are found in the atria. Imaging typically reveals a pedunculated mass.

      The remaining options are also primary cardiac tumors.

      Atrial Myxoma: Overview and Features

      Atrial myxoma is a primary cardiac tumor that is commonly found in the left atrium, with 75% of cases occurring in this area. It is more prevalent in females and is often attached to the fossa ovalis. Symptoms of atrial myxoma include dyspnea, fatigue, weight loss, pyrexia of unknown origin, and clubbing. Emboli and atrial fibrillation may also occur. A mid-diastolic murmur, known as a tumor plop, may be present. Diagnosis is typically made through echocardiography, which shows a pedunculated heterogeneous mass attached to the fossa ovalis region of the interatrial septum.

    • This question is part of the following fields:

      • Cardiovascular System
      17.2
      Seconds
  • Question 11 - A 50-year-old male has presented with a record of blood pressure readings taken...

    Correct

    • A 50-year-old male has presented with a record of blood pressure readings taken at home over the past week. His readings have consistently been above the accepted range for his age. He is a smoker of 20 cigarettes per day.

      Your senior has prescribed a low dose of ramipril and recommended lifestyle modifications and exercise.

      You have been asked by your senior to discuss the use of this medication and provide any necessary dietary advice.

      Which of the following is the most important piece of information to communicate to this patient?

      A) Taking ramipril with paracetamol compounds its hypotensive effect
      B) Taking ramipril with alcohol compounds its hypotensive effect
      C) Taking ramipril with coffee compounds its hypotensive effect
      D) Taking ramipril with tea compounds its hypotensive effect

      Please select the correct answer and provide an explanation.

      Your Answer: Taking ramipril with alcohol compounds its hypotensive effect

      Explanation:

      ACE inhibitors’ hypotensive effects are worsened by alcohol consumption, leading to symptoms of low blood pressure such as dizziness and lightheadedness. Additionally, the effectiveness of ACE inhibitors may be reduced by hypertension-associated medications like acetaminophen and venlafaxine. Caffeine, found in both tea and coffee, can also elevate blood pressure.

      Angiotensin-converting enzyme (ACE) inhibitors are commonly used as the first-line treatment for hypertension and heart failure in younger patients. However, they may not be as effective in treating hypertensive Afro-Caribbean patients. ACE inhibitors are also used to treat diabetic nephropathy and prevent ischaemic heart disease. These drugs work by inhibiting the conversion of angiotensin I to angiotensin II and are metabolized in the liver.

      While ACE inhibitors are generally well-tolerated, they can cause side effects such as cough, angioedema, hyperkalaemia, and first-dose hypotension. Patients with certain conditions, such as renovascular disease, aortic stenosis, or hereditary or idiopathic angioedema, should use ACE inhibitors with caution or avoid them altogether. Pregnant and breastfeeding women should also avoid these drugs.

      Patients taking high-dose diuretics may be at increased risk of hypotension when using ACE inhibitors. Therefore, it is important to monitor urea and electrolyte levels before and after starting treatment, as well as any changes in creatinine and potassium levels. Acceptable changes include a 30% increase in serum creatinine from baseline and an increase in potassium up to 5.5 mmol/l. Patients with undiagnosed bilateral renal artery stenosis may experience significant renal impairment when using ACE inhibitors.

      The current NICE guidelines recommend using a flow chart to manage hypertension, with ACE inhibitors as the first-line treatment for patients under 55 years old. However, individual patient factors and comorbidities should be taken into account when deciding on the best treatment plan.

    • This question is part of the following fields:

      • Cardiovascular System
      48.3
      Seconds
  • Question 12 - A mother brings her 8-year-old son to the GP with a history of...

    Incorrect

    • A mother brings her 8-year-old son to the GP with a history of intermittent fevers, severe joint pain and feeling fatigued. Other than a recent absence from school for a sore throat, he has been well with no other past medical history of note.

      On examination, there is a pansystolic murmur heard over the left 5th intercostal space.

      Which organism is the most probable cause for the aforementioned symptoms?

      Your Answer: Streptococcus pneumoniae

      Correct Answer: Streptococcus pyogenes

      Explanation:

      An immunological reaction is responsible for the development of rheumatic fever.

      Rheumatic fever is a condition that occurs as a result of an immune response to a recent Streptococcus pyogenes infection, typically occurring 2-4 weeks after the initial infection. The pathogenesis of rheumatic fever involves the activation of the innate immune system, leading to antigen presentation to T cells. B and T cells then produce IgG and IgM antibodies, and CD4+ T cells are activated. This immune response is thought to be cross-reactive, mediated by molecular mimicry, where antibodies against M protein cross-react with myosin and the smooth muscle of arteries. This response leads to the clinical features of rheumatic fever, including Aschoff bodies, which are granulomatous nodules found in rheumatic heart fever.

      To diagnose rheumatic fever, evidence of recent streptococcal infection must be present, along with 2 major criteria or 1 major criterion and 2 minor criteria. Major criteria include erythema marginatum, Sydenham’s chorea, polyarthritis, carditis and valvulitis, and subcutaneous nodules. Minor criteria include raised ESR or CRP, pyrexia, arthralgia, and prolonged PR interval.

      Management of rheumatic fever involves antibiotics, typically oral penicillin V, as well as anti-inflammatories such as NSAIDs as first-line treatment. Any complications that develop, such as heart failure, should also be treated. It is important to diagnose and treat rheumatic fever promptly to prevent long-term complications such as rheumatic heart disease.

    • This question is part of the following fields:

      • Cardiovascular System
      42
      Seconds
  • Question 13 - An 80-year-old man arrives at the emergency department complaining of severe chest pain...

    Correct

    • An 80-year-old man arrives at the emergency department complaining of severe chest pain that spreads to his left arm. He also experiences nausea and excessive sweating. After conducting an ECG, you observe ST-segment elevation in leads II, III, and aVF, leading to a diagnosis of an inferior ST-elevation MI. Can you identify the primary coronary vessel that supplies blood to the base of the heart?

      Your Answer: Right coronary artery

      Explanation:

      The heart has several arteries that supply blood to different areas. The right coronary artery supplies the right side of the heart and can cause a heart attack in the lower part of the heart, which can lead to abnormal heart rhythms. The left anterior descending artery and left circumflex artery supply the left side of the heart and can cause heart attacks in different areas, which can be detected by changes in specific leads on an ECG. The left marginal artery branches off the left circumflex artery and supplies blood to the outer edge of the heart.

      The following table displays the relationship between ECG changes and the affected coronary artery territories. Anteroseptal changes in V1-V4 indicate involvement of the left anterior descending artery, while inferior changes in II, III, and aVF suggest the right coronary artery is affected. Anterolateral changes in V4-6, I, and aVL may indicate involvement of either the left anterior descending or left circumflex artery, while lateral changes in I, aVL, and possibly V5-6 suggest the left circumflex artery is affected. Posterior changes in V1-3 may indicate a posterior infarction, which is typically caused by the left circumflex artery but can also be caused by the right coronary artery. Reciprocal changes of STEMI are often seen as horizontal ST depression, tall R waves, upright T waves, and a dominant R wave in V2. Posterior infarction is confirmed by ST elevation and Q waves in posterior leads (V7-9), usually caused by the left circumflex artery but also possibly the right coronary artery. It is important to note that a new LBBB may indicate acute coronary syndrome.

      Diagram showing the correlation between ECG changes and coronary territories in acute coronary syndrome.

    • This question is part of the following fields:

      • Cardiovascular System
      47.1
      Seconds
  • Question 14 - A 55-year-old man with several cardiac risk factors arrives at the hospital with...

    Incorrect

    • A 55-year-old man with several cardiac risk factors arrives at the hospital with sudden onset chest pain in the center. The pain extends to his left arm and is accompanied by sweating and nausea.

      The patient's ECG reveals widespread T-wave inversion, which is a new finding compared to his previous ECGs. The level of troponin I in his serum is measured and confirmed to be elevated. The patient is initiated on treatment for acute coronary syndrome and transferred to a cardiac center.

      What is the target of this measured cardiac biomarker?

      Your Answer: Myoglobin

      Correct Answer: Actin

      Explanation:

      Troponin I is a cardiac biomarker that binds to actin, which holds the troponin-tropomyosin complex in place and regulates muscle contraction. It is the standard biomarker used in conjunction with ECGs and clinical findings to diagnose non-ST elevation myocardial infarction (NSTEMI). Troponin I is highly sensitive and specific for myocardial damage compared to other cardiac biomarkers. Troponin C, another subunit of troponin, plays a role in Ca2+-dependent regulation of muscle contraction and can also be used in the diagnosis of myocardial infarction, but it is less specific as it is found in both cardiac and skeletal muscle. Copeptin, an amino acid peptide, is released earlier than troponin during acute myocardial infarction but is not widely used in clinical practice and has no interaction with troponin. Myoglobin, an iron- and oxygen-binding protein found in both cardiac and skeletal muscle, has poor specificity for cardiac injury and is not involved in the troponin-tropomyosin complex.

      Understanding Troponin: The Proteins Involved in Muscle Contraction

      Troponin is a group of three proteins that play a crucial role in the contraction of skeletal and cardiac muscles. These proteins work together to regulate the interaction between actin and myosin, which is essential for muscle contraction. The three subunits of troponin are troponin C, troponin T, and troponin I.

      Troponin C is responsible for binding to calcium ions, which triggers the contraction of muscle fibers. Troponin T binds to tropomyosin, forming a complex that helps regulate the interaction between actin and myosin. Finally, troponin I binds to actin, holding the troponin-tropomyosin complex in place and preventing muscle contraction when it is not needed.

      Understanding the role of troponin is essential for understanding how muscles work and how they can be affected by various diseases and conditions. By regulating the interaction between actin and myosin, troponin plays a critical role in muscle contraction and is a key target for drugs used to treat conditions such as heart failure and skeletal muscle disorders.

    • This question is part of the following fields:

      • Cardiovascular System
      15.5
      Seconds
  • Question 15 - A 29-year-old man is brought to the emergency surgical theatre with multiple stab...

    Incorrect

    • A 29-year-old man is brought to the emergency surgical theatre with multiple stab wounds to his abdomen and is hypotensive despite resuscitative measures. During a laparotomy, a profusely bleeding vessel is found at a certain level of the lumbar vertebrae. The vessel is identified as the testicular artery and is ligated to stop the bleeding. At which vertebral level was the artery identified?

      Your Answer: T8

      Correct Answer: L2

      Explanation:

      The testicular arteries originate from the abdominal aorta at the level of the second lumbar vertebrae (L2).

      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
      3.9
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  • Question 16 - As the physician in charge of the health of a 70-year-old man who...

    Correct

    • As the physician in charge of the health of a 70-year-old man who came in for his yearly check-up, you discover that he smokes 15 cigarettes daily and has a medical history of hypertension and hypercholesterolemia. During the examination, you hear a left-sided carotid bruit while auscultating. A recent duplex ultrasound showed that the left internal carotid artery has a 50% stenosis. What is the final step in the pathogenesis of this man's condition?

      Your Answer: Smooth muscle proliferation and migration into the tunica 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
      24.9
      Seconds
  • Question 17 - A 57-year-old woman visits her doctor with complaints of flushing and warmth. She...

    Correct

    • A 57-year-old woman visits her doctor with complaints of flushing and warmth. She has been in good health lately, except for a stomach bug she had two weeks ago. Her medical history includes hyperlipidemia, hypertension, myocardial infarction, and type II diabetes mellitus. Although she used to smoke, she has quit and does not drink alcohol. She lives with her husband in a bungalow.

      During the consultation, she reveals that her cardiologist recently prescribed niacin to her. Her recent lab results show an increase in total cholesterol.

      Which of the following is responsible for the adverse effects observed in this patient?

      Substance P
      15%
      Bradykinin
      20%
      Prostaglandins
      48%
      Serotonin
      9%
      Kallikreins
      8%

      The adverse effects of niacin, such as flushing, warmth, and itching, are caused by prostaglandins.

      Your Answer: Prostaglandins

      Explanation:

      The adverse effects of niacin, such as flushing, warmth, and itchiness, are caused by the release of prostaglandins. Niacin activates dermal Langerhans cells, which leads to an increase in prostaglandin release and subsequent vasodilation. To prevent these side effects, aspirin is often given 30 minutes before niacin administration. Aspirin works by altering the activity of COX-2, which reduces prostaglandin release.

      Substance P acts as a neurotransmitter in the central nervous system, and its neurokinin (NK) receptor 1 is found in specific areas of the brain that affect behavior and the neurochemical response to both psychological and somatic stress.

      Bradykinin is an inflammatory mediator that causes vasodilation, but it is not responsible for the adverse effects seen with niacin use.

      Serotonin is a neurotransmitter that plays a role in regulating various processes in the brain. Low levels of serotonin are often associated with anxiety, panic attacks, obesity, and insomnia. However, serotonin does not mediate the side effects observed with niacin use.

      Nicotinic acid, also known as niacin, is a medication used to treat hyperlipidaemia. It is effective in reducing cholesterol and triglyceride levels while increasing HDL levels. However, its use is limited due to the occurrence of side-effects. One of the most common side-effects is flushing, which is caused by prostaglandins. Additionally, nicotinic acid may impair glucose tolerance and lead to myositis.

    • This question is part of the following fields:

      • Cardiovascular System
      11.3
      Seconds
  • Question 18 - An 85-year-old woman arrives at the emergency department with complaints of palpitations and...

    Correct

    • An 85-year-old woman arrives at the emergency department with complaints of palpitations and difficulty breathing. During the examination, you observe an irregularly irregular pulse. After conducting an ECG, you discover the absence of P waves and a ventricular rate of 94 beats per minute. What specific part of the heart prevents a rapid atrial rate from transmitting to the ventricles?

      Your Answer: Atrioventricular node

      Explanation:

      The correct answer is the atrioventricular (AV) node, which is located within the atrioventricular septum near the septal cusp of the tricuspid valve. It regulates the spread of excitation from the atria to the ventricles.

      The sinoatrial (SA) node is situated in the right atrium, at the top of the crista terminalis where the right atrium meets the superior vena cava. It is where cardiac impulses originate in a healthy heart.

      The bundle of His is a group of specialized cardiac myocytes that transmit the electrical impulse from the AV node to the ventricles.

      The Purkinje fibers are a collection of fibers that distribute the cardiac impulse throughout the muscular ventricular walls.

      The bundle of Kent is not present in a healthy heart. It refers to the accessory pathway between the atria and ventricles that exists in Wolff-Parkinson-White (WPW) syndrome. This additional conduction pathway allows for fast conduction of impulses between the atria and ventricles, without the additional control of the AV node. This results in a type of supraventricular tachycardia known as an atrioventricular re-entrant tachycardia.

      The patient in the above question has presented with palpitations and shortness of breath. An irregularly irregular pulse is highly indicative of atrial fibrillation (AF). ECG signs of atrial fibrillation include an irregularly irregular rhythm and absent P waves. In AF, the impulses from the fibrillating heart are typically prevented from reaching the ventricles by the AV node.

      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
      15.8
      Seconds
  • Question 19 - A 50-year-old man presents to the emergency department with excruciating chest pain that...

    Incorrect

    • A 50-year-old man presents to the emergency department with excruciating chest pain that raises suspicion of aortic dissection. Which layers are the blood expected to be flowing between?

      Your Answer: Tunica intima and tunica adventitia

      Correct Answer: Tunica intima and tunica media

      Explanation:

      In an aortic dissection, the tunica intima becomes separated from the tunica media. The tunica intima is the innermost layer of a blood vessel, while the tunica media is the second layer and the tunica adventitia is the third layer. Normally, the tunica media would be situated between the tunica intima and adventitia in the aorta. Capillaries have layers called endothelium and basal laminae, while the internal and external elastic laminae are found on either side of the tunica media.

      Artery Histology: Layers of Blood Vessel Walls

      The wall of a blood vessel is composed of three layers: the tunica intima, tunica media, and tunica adventitia. The innermost layer, the tunica intima, is made up of endothelial cells that are separated by gap junctions. The middle layer, the tunica media, contains smooth muscle cells and is separated from the intima by the internal elastic lamina and from the adventitia by the external elastic lamina. The outermost layer, the tunica adventitia, contains the vasa vasorum, fibroblast, and collagen. This layer is responsible for providing support and protection to the blood vessel. The vasa vasorum are small blood vessels that supply oxygen and nutrients to the larger blood vessels. The fibroblast and collagen provide structural support to the vessel wall. Understanding the histology of arteries is important in diagnosing and treating various cardiovascular diseases.

    • This question is part of the following fields:

      • Cardiovascular System
      7.1
      Seconds
  • Question 20 - As a medical student working in the emergency department, you come across a...

    Incorrect

    • As a medical student working in the emergency department, you come across a 75-year-old man with a medical history of hypertension, dyslipidaemia, and atrial fibrillation. He was brought in by ambulance after collapsing at home. During the examination, you notice that he is unable to raise his right arm and has reduced sensation on the right side of his body. The consultant suspects that the patient is having a stroke and orders an urgent CT head.

      Upon reviewing the results, the consultant informs you that there is a significant area of ischaemia affecting the insula, somatosensory cortex, and part of the frontal cortex. Your task is to identify the artery that is most likely to be occluded by an infarct.

      Your Answer: Right anterior cerebral artery

      Correct Answer: Left middle cerebral artery

      Explanation:

      The correct blood vessel supplying the frontal, temporal, and parietal lobes is the left middle cerebral artery. This is evident from the patient’s symptoms of right-sided loss of sensation and weakness, which are controlled by the contralateral somatosensory and motor cortex. The other options, such as the anterior spinal artery and the anterior cerebral arteries, are incorrect as they do not supply the brain or the specific areas affected in this patient.

      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
      28.1
      Seconds
  • Question 21 - A young man in his early twenties collapses during a game of basketball...

    Correct

    • A young man in his early twenties collapses during a game of basketball and is declared dead upon arrival at the hospital. The autopsy shows irregularities in his heart. What is the probable cause of the irregularities?

      Your Answer: Hypertrophic cardiomyopathy

      Explanation:

      The condition that is most commonly associated with sudden death is hypertrophic cardiomyopathy, making the other options less likely.

      Symptoms of acute myocarditis may include chest pain, fever, palpitations, tachycardia, and difficulty breathing.

      Dilated cardiomyopathy may cause right ventricular failure, leading to symptoms such as difficulty breathing, pulmonary edema, and atrial fibrillation.

      Restrictive cardiomyopathy and constrictive pericarditis have similar presentations, with right heart failure symptoms such as elevated JVP, hepatomegaly, edema, and ascites being predominant.

      Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder that affects muscle tissue and is inherited in an autosomal dominant manner. It is caused by mutations in genes that encode contractile proteins, with the most common defects involving the β-myosin heavy chain protein or myosin-binding protein C. HOCM is characterized by left ventricle hypertrophy, which leads to decreased compliance and cardiac output, resulting in predominantly diastolic dysfunction. Biopsy findings show myofibrillar hypertrophy with disorganized myocytes and fibrosis. HOCM is often asymptomatic, but exertional dyspnea, angina, syncope, and sudden death can occur. Jerky pulse, systolic murmurs, and double apex beat are also common features. HOCM is associated with Friedreich’s ataxia and Wolff-Parkinson White. ECG findings include left ventricular hypertrophy, non-specific ST segment and T-wave abnormalities, and deep Q waves. Atrial fibrillation may occasionally be seen.

    • This question is part of the following fields:

      • Cardiovascular System
      19.5
      Seconds
  • Question 22 - A 2-year-old child presents with cyanosis shortly after birth. The child has no...

    Incorrect

    • A 2-year-old child presents with cyanosis shortly after birth. The child has no family history of paediatric problems and the pregnancy was uneventful. Upon examination, the child is cyanotic, has a respiratory rate of 60 breaths per minute, and nasal flaring. An urgent echocardiogram reveals Ebstein's anomaly. Which valvular defect is commonly associated with this condition?

      Your Answer: Aortic stenosis

      Correct Answer: Tricuspid regurgitation

      Explanation:

      Ebstein’s anomaly is a congenital heart defect that results in the right ventricle being smaller than normal and the right atrium being larger than normal, a condition known as ‘atrialisation’. Tricuspid regurgitation is often present as well.

      While aortic regurgitation is commonly associated with infective endocarditis, ascending aortic dissection, or connective tissue disorders like Marfan’s or Ehlers-Danlos, it is not typically seen in Ebstein’s anomaly. Similarly, aortic stenosis is usually caused by senile calcification rather than congenital heart disease.

      The mitral valve is located on the left side of the heart and is not affected by Ebstein’s anomaly. Mitral regurgitation, on the other hand, can be caused by conditions such as rheumatic heart disease or left ventricular dilatation.

      Pulmonary stenosis is typically associated with other congenital heart defects like Turner’s syndrome or Noonan’s syndrome, rather than Ebstein’s anomaly.

      Understanding Ebstein’s Anomaly

      Ebstein’s anomaly is a type of congenital heart defect that is characterized by the tricuspid valve being inserted too low, resulting in a large atrium and a small ventricle. This condition is also known as the atrialization of the right ventricle. It is believed that exposure to lithium during pregnancy may cause this condition.

      Ebstein’s anomaly is often associated with other heart defects such as patent foramen ovale (PFO) or atrial septal defect (ASD), which can cause a shunt between the right and left atria. Additionally, patients with this condition may also have Wolff-Parkinson White syndrome.

      Clinical features of Ebstein’s anomaly include cyanosis, a prominent a wave in the distended jugular venous pulse, hepatomegaly, tricuspid regurgitation, and a pansystolic murmur that worsens during inspiration. Patients may also exhibit right bundle branch block, which can lead to widely split S1 and S2 heart sounds.

      In summary, Ebstein’s anomaly is a congenital heart defect that affects the tricuspid valve and can cause a range of symptoms and complications. Early diagnosis and treatment are essential for managing this condition and improving patient outcomes.

    • This question is part of the following fields:

      • Cardiovascular System
      20.2
      Seconds
  • Question 23 - A 42-year-old man presents to the emergency department with gradual-onset central chest pain....

    Correct

    • A 42-year-old man presents to the emergency department with gradual-onset central chest pain. The pain is 7/10 in severity and started six hours ago. He reports no shortness of breath or haemoptysis. The pain worsens when taking a deep breath in and improves when leaning forward.

      The patient has no significant medical history and is not taking any regular medications, but he recently completed a course of amoxicillin for an upper respiratory tract infection. His grandfather died of a heart attack at the age of 84. He has a smoking history of 3 pack-years but currently does not smoke or drink alcohol. He has not traveled recently. During a recent well man check at his GP, his 10-year QRISK score was determined to be 3%.

      On examination, the patient appears comfortable at rest. His heart rate is 88/min, blood pressure is 136/78 mmHg, oxygen saturation is 98% on air, respiratory rate is 16 breaths per minute, and temperature is 36.8ºC. No additional heart sounds are heard, and lung fields are clear on auscultation. The abdomen is soft and non-tender, with bowel sounds present.

      An ECG taken on admission shows concave ST-segment elevation and PR depression present in all leads.

      What is the most likely diagnosis?

      Your Answer: Pericarditis

      Explanation:

      The most likely diagnosis for a patient with global ST and PR segment changes is pericarditis. This condition is characterized by inflammation of the pericardium, which often occurs after a respiratory illness. Patients with pericarditis typically experience sharp chest pain that worsens with inspiration or lying down and improves when leaning forward.

      While benign early repolarization (BER) can also cause ST elevation, it is less likely in this case as the patient’s symptoms are more consistent with pericarditis. Additionally, BER often presents with a fish hook pattern on the ECG.

      Infective endocarditis, pulmonary embolism (PE), and myocardial infarction (MI) are less likely diagnoses. Infective endocarditis typically presents with fever and a murmur, while PE is associated with tachycardia, haemoptysis, and signs of deep vein thrombosis. MI is usually confined to a specific territory on the ECG and is unlikely in a patient with low cardiac risk factors.

      Acute Pericarditis: Causes, Features, Investigations, and Management

      Acute pericarditis is a possible diagnosis for patients presenting with chest pain. The condition is characterized by chest pain, which may be pleuritic and relieved by sitting forwards. Other symptoms include non-productive cough, dyspnoea, and flu-like symptoms. Tachypnoea and tachycardia may also be present, along with a pericardial rub.

      The causes of acute pericarditis include viral infections, tuberculosis, uraemia, trauma, post-myocardial infarction, Dressler’s syndrome, connective tissue disease, hypothyroidism, and malignancy.

      Investigations for acute pericarditis include ECG changes, which are often global/widespread, as opposed to the ‘territories’ seen in ischaemic events. The ECG may show ‘saddle-shaped’ ST elevation and PR depression, which is the most specific ECG marker for pericarditis. All patients with suspected acute pericarditis should have transthoracic echocardiography.

      Management of acute pericarditis involves treating the underlying cause. A combination of NSAIDs and colchicine is now generally used as first-line treatment for patients with acute idiopathic or viral pericarditis.

      In summary, acute pericarditis is a possible diagnosis for patients presenting with chest pain. The condition is characterized by chest pain, which may be pleuritic and relieved by sitting forwards, along with other symptoms. The causes of acute pericarditis are varied, and investigations include ECG changes and transthoracic echocardiography. Management involves treating the underlying cause and using a combination of NSAIDs and colchicine as first-line treatment.

    • This question is part of the following fields:

      • Cardiovascular System
      13.3
      Seconds
  • Question 24 - A 48-year-old man comes to the clinic for a hypertension follow-up. He was...

    Incorrect

    • A 48-year-old man comes to the clinic for a hypertension follow-up. He was diagnosed with high blood pressure two months ago and started on ramipril. However, his blood pressure remained uncontrolled, so amlodipine was added to his treatment four weeks ago. Today, his blood pressure reading is 161/91mmHg. You decide to prescribe indapamide, a thiazide diuretic. Can you identify the primary site of action of thiazides in the nephron?

      Your Answer: Ascending limb of the loop of Henle

      Correct Answer: Distal convoluted tubule

      Explanation:

      Thiazide diuretics, such as indapamide, work by blocking the Na+-Cl− symporter at the beginning of the distal convoluted tubule, which inhibits sodium reabsorption. Loop diuretics, on the other hand, inhibit Na+/K+ 2Cl- channels in the thick ascending loop of Henle. There are currently no diuretic agents that specifically target the descending limb of the loop of Henle. Carbonic anhydrase inhibitors prevent the exchange of luminal Na+ for cellular H+ in both the proximal and distal tubules. Potassium-sparing diuretics, such as amiloride, inhibit the Na+/K+ ATPase in the cortical collecting ducts either directly or by blocking aldosterone receptors, as seen in spironolactone.

      Thiazide diuretics are medications that work by blocking the thiazide-sensitive Na+-Cl− symporter, which inhibits sodium reabsorption at the beginning of the distal convoluted tubule (DCT). This results in the loss of potassium as more sodium reaches the collecting ducts. While thiazide diuretics are useful in treating mild heart failure, loop diuretics are more effective in reducing overload. Bendroflumethiazide was previously used to manage hypertension, but recent NICE guidelines recommend other thiazide-like diuretics such as indapamide and chlorthalidone.

      Common side effects of thiazide diuretics include dehydration, postural hypotension, and electrolyte imbalances such as hyponatremia, hypokalemia, and hypercalcemia. Other potential adverse effects include gout, impaired glucose tolerance, and impotence. Rare side effects may include thrombocytopenia, agranulocytosis, photosensitivity rash, and pancreatitis.

      It is worth noting that while thiazide diuretics may cause hypercalcemia, they can also reduce the incidence of renal stones by decreasing urinary calcium excretion. According to current NICE guidelines, the management of hypertension involves the use of thiazide-like diuretics, along with other medications and lifestyle changes, to achieve optimal blood pressure control and reduce the risk of cardiovascular disease.

    • This question is part of the following fields:

      • Cardiovascular System
      28
      Seconds
  • Question 25 - A 14-year-old girl presents to the general practitioner with fever, malaise, involuntary movements...

    Incorrect

    • A 14-year-old girl presents to the general practitioner with fever, malaise, involuntary movements of the neck and arms and erythema marginatum. She was previously unwell with tonsillitis six weeks ago. She is taken to the hospital and after a series of investigations is diagnosed with rheumatic fever.

      What is the underlying pathology of this condition?

      Your Answer: Autoimmune destruction of postsynaptic acetylcholine receptors

      Correct Answer: Molecular mimicry of the bacterial M protein

      Explanation:

      The development of rheumatic fever is caused by molecular mimicry of the bacterial M protein. This results in the patient experiencing constitutional symptoms such as fever and malaise, involuntary movements of the neck and arms known as Sydenham chorea, and a distinctive rash called erythema marginatum. The antibodies produced against the M protein cross-react with myosin and smooth muscle in arteries, leading to the characteristic features of rheumatic fever. Autoimmune demyelination of peripheral nerves, autoimmune demyelination of the central nervous system, and autoimmune destruction of postsynaptic acetylcholine receptors are all incorrect as they are the pathophysiology of other conditions such as Guillain Barre syndrome, multiple sclerosis, and myasthenia gravis, respectively.

      Rheumatic fever is a condition that occurs as a result of an immune response to a recent Streptococcus pyogenes infection, typically occurring 2-4 weeks after the initial infection. The pathogenesis of rheumatic fever involves the activation of the innate immune system, leading to antigen presentation to T cells. B and T cells then produce IgG and IgM antibodies, and CD4+ T cells are activated. This immune response is thought to be cross-reactive, mediated by molecular mimicry, where antibodies against M protein cross-react with myosin and the smooth muscle of arteries. This response leads to the clinical features of rheumatic fever, including Aschoff bodies, which are granulomatous nodules found in rheumatic heart fever.

      To diagnose rheumatic fever, evidence of recent streptococcal infection must be present, along with 2 major criteria or 1 major criterion and 2 minor criteria. Major criteria include erythema marginatum, Sydenham’s chorea, polyarthritis, carditis and valvulitis, and subcutaneous nodules. Minor criteria include raised ESR or CRP, pyrexia, arthralgia, and prolonged PR interval.

      Management of rheumatic fever involves antibiotics, typically oral penicillin V, as well as anti-inflammatories such as NSAIDs as first-line treatment. Any complications that develop, such as heart failure, should also be treated. It is important to diagnose and treat rheumatic fever promptly to prevent long-term complications such as rheumatic heart disease.

    • This question is part of the following fields:

      • Cardiovascular System
      15.9
      Seconds
  • Question 26 - A 4-year-old boy is observed by his mother to turn blue around the...

    Incorrect

    • A 4-year-old boy is observed by his mother to turn blue around the lips abruptly after crying. This has occurred several times before and the child promptly assumes the squatting position to alleviate his symptoms. During previous check-ups, the child was found to have various heart issues, including a boot-shaped heart on his chest x-ray.

      What is the probable diagnosis for his condition and what is the underlying cause?

      Your Answer: Defect in the ostium primum

      Correct Answer: Failed migration of the neural crest cells

      Explanation:

      The division of the truncus arteriosus into the aorta and pulmonary trunk is dependent on the migration of neural crest cells from the pharyngeal arches. If this process is disrupted, it can lead to Tetralogy of Fallot, which is likely the condition that the patient in question is experiencing. The patient’s frequent ‘tet’ spells and adoption of a squatting position are indicative of this condition, as is the boot-shaped heart seen on chest x-ray due to right ventricular hypertrophy. Other conditions that can result from failed neural crest cell migration include transposition of the great vessels and persistent truncus arteriosus.

      On the other hand, a VSD is associated with a failure of the endocardial cushion, but this would not explain all of the patient’s malformations. Similarly, defects in the ostium primum or secundum would result in an ASD, which is often asymptomatic.

      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
      20.7
      Seconds
  • Question 27 - Which of the following is true about endothelin? ...

    Incorrect

    • Which of the following is true about endothelin?

      Your Answer: It is a potent vasodilator

      Correct Answer: Endothelin antagonists are useful in primary pulmonary hypertension

      Explanation:

      Antagonists are used in primary pulmonary hypertension because endothelin induced constriction of the pulmonary blood vessels.

      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
      7.3
      Seconds
  • Question 28 - Which one of the following is not a branch of the subclavian artery?...

    Incorrect

    • Which one of the following is not a branch of the subclavian artery?

      Your Answer: Vertebral artery

      Correct Answer: Superior thyroid artery

      Explanation:

      The branches of the subclavian artery can be remembered using the mnemonic VIT C & D, which stands for Vertebral artery, Internal thoracic, Thyrocervical trunk, Costalcervical trunk, and Dorsal scapular. It is important to note that the Superior thyroid artery is actually a branch of the external carotid artery.

      The Subclavian Artery: Origin, Path, and Branches

      The subclavian artery is a major blood vessel that supplies blood to the upper extremities, neck, and head. It has two branches, the left and right subclavian arteries, which arise from different sources. The left subclavian artery originates directly from the arch of the aorta, while the right subclavian artery arises from the brachiocephalic artery (trunk) when it bifurcates into the subclavian and the right common carotid artery.

      From its origin, the subclavian artery travels laterally, passing between the anterior and middle scalene muscles, deep to scalenus anterior and anterior to scalenus medius. As it crosses the lateral border of the first rib, it becomes the axillary artery and is superficial within the subclavian triangle.

      The subclavian artery has several branches that supply blood to different parts of the body. These branches include the vertebral artery, which supplies blood to the brain and spinal cord, the internal thoracic artery, which supplies blood to the chest wall and breast tissue, the thyrocervical trunk, which supplies blood to the thyroid gland and neck muscles, the costocervical trunk, which supplies blood to the neck and upper back muscles, and the dorsal scapular artery, which supplies blood to the muscles of the shoulder blade.

      In summary, the subclavian artery is an important blood vessel that plays a crucial role in supplying blood to the upper extremities, neck, and head. Its branches provide blood to various parts of the body, ensuring proper functioning and health.

    • This question is part of the following fields:

      • Cardiovascular System
      2.1
      Seconds
  • Question 29 - An 80-year-old patient who recently had a TIA is admitted to the vascular...

    Incorrect

    • An 80-year-old patient who recently had a TIA is admitted to the vascular ward in preparation for a carotid endarterectomy tomorrow. During her pre-operative consultation, the surgeon explained that the artery will be tied during the procedure. The patient asks about the different arteries and their functions. You inform her that the internal carotid artery supplies the brain, while the external carotid artery divides into two arteries after ascending the neck. One of these arteries is the superficial temporal artery, but what is the other?

      Your Answer: Deep temporal artery

      Correct Answer: Maxillary artery

      Explanation:

      The correct answer is the maxillary artery, which is one of the two terminal branches of the external carotid artery. It supplies deep structures of the face and usually bifurcates within the parotid gland to form the superficial temporal artery and maxillary artery. The facial artery supplies superficial structures in the face, while the lingual artery supplies the tongue. The middle meningeal artery is a branch of the maxillary artery and supplies the dura mater and calvaria. There are also two deep temporal arteries that arise from the maxillary artery and supply the temporalis muscle. The patient is scheduled to undergo carotid endarterectomy, a surgical procedure that involves removing atherosclerotic plaque from the common carotid artery to reduce the risk of subsequent ischaemic strokes or transient ischaemic attacks.

      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
      15.9
      Seconds
  • Question 30 - A 25-year-old is suffering from tonsillitis and experiencing significant pain. Which nerve is...

    Correct

    • A 25-year-old is suffering from tonsillitis and experiencing significant pain. Which nerve is responsible for providing sensory innervation to the tonsillar fossa?

      Your Answer: Glossopharyngeal nerve

      Explanation:

      The tonsillar fossa is primarily innervated by the glossopharyngeal nerve, with a smaller contribution from the lesser palatine nerve. As a result, patients may experience ear pain (otalgia) after undergoing a tonsillectomy.

      Tonsil Anatomy and Tonsillitis

      The tonsils are located in the pharynx and have two surfaces, a medial and lateral surface. They vary in size and are usually supplied by the tonsillar artery and drained by the jugulodigastric and deep cervical nodes. Tonsillitis is a common condition that is usually caused by bacteria, with group A Streptococcus being the most common culprit. It can also be caused by viruses. In some cases, tonsillitis can lead to the development of an abscess, which can distort the uvula. Tonsillectomy is recommended for patients with recurrent acute tonsillitis, suspected malignancy, or enlargement causing sleep apnea. The preferred technique for tonsillectomy is dissection, but it can be complicated by hemorrhage, which is the most common complication. Delayed otalgia may also occur due to irritation of the glossopharyngeal nerve.

    • This question is part of the following fields:

      • Cardiovascular System
      19.3
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular System (10/30) 33%
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