00
Correct
00
Incorrect
00 : 00 : 00
Session Time
00 : 00
Average Question Time ( Secs)
  • Question 1 - 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: Supraorbital foramen

      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
      44.7
      Seconds
  • Question 2 - A 55-year-old man is scheduled for CABG surgery and your consultant has tasked...

    Incorrect

    • A 55-year-old man is scheduled for CABG surgery and your consultant has tasked you, a foundation doctor on the surgical ward, with explaining the procedure to him. You are aware that the bypass will involve using the left internal thoracic artery to supply the affected coronary vessel. Can you identify the artery from which the left internal thoracic artery arises?

      Your Answer: Left axillary artery

      Correct Answer: Left subclavian artery

      Explanation:

      The left internal thoracic artery originates from the left subclavian artery near its source and runs down the chest wall beneath the ribs to supply blood to the front of the chest and breasts. During coronary artery bypass grafting (CABG), the proximal portion of the ITA is preserved while the distal end is grafted beyond the atherosclerotic segment of the affected coronary vessel to restore blood flow to the heart.

      The left axillary artery is a continuation of the left subclavian artery and is referred to as the axillary artery beyond the lateral border of the first rib. It becomes the brachial artery after passing the lower border of the teres major muscle.

      The left common carotid artery emerges from the aortic arch and divides into the internal and external carotid arteries at the fourth cervical vertebrae.

      The aortic arch is a continuation of the ascending aorta and branches off into the right brachiocephalic trunk, the left common carotid artery, and the left subclavian artery before continuing as the descending aorta.

      The thyrocervical trunk, which arises from the subclavian artery, is a brief vessel that gives rise to four branches: the inferior thyroid artery, suprascapular artery, ascending cervical artery, and transverse cervical artery.

      Coronary Artery Bypass Grafting (CABG)

      Coronary artery bypass grafting (CABG) is a surgical procedure commonly used to treat coronary artery disease. The procedure involves using multiple grafts, with the internal mammary artery being increasingly used instead of the saphenous vein due to its lower likelihood of narrowing. The surgery requires the use of a heart-lung bypass machine and systemic anticoagulation. Suitability for the procedure is determined by cardiac catheterisation or angiography. The surgery is carried out under general anaesthesia, and patients typically stay in the hospital for 7-10 days, with a return to work within 3 months.

      Complications of CABG include atrial fibrillation (30-40% of cases, usually self-limiting) and stroke (2%). However, the prognosis for the procedure is generally positive, with 90% of operations being successful. Further revascularisation may be needed in 5-10% of cases after 5 years, but the mortality rate is low, at 1-2% at 30 days.

    • This question is part of the following fields:

      • Cardiovascular System
      37.6
      Seconds
  • Question 3 - A 2-year-old toddler is brought to the cardiology clinic by her mother due...

    Correct

    • A 2-year-old toddler is brought to the cardiology clinic by her mother due to concerns of episodes of turning blue, especially when laughing or crying. During the examination, the toddler is observed to have clubbing of the fingernails and confirmed to be cyanotic. Further investigation with an echocardiogram reveals a large ventricular septal defect, leading to a diagnosis of Eisenmenger's syndrome. What is the ultimate treatment for this condition?

      Your Answer: Heart- lung transplant

      Explanation:

      The most effective way to manage Eisenmenger’s syndrome is through a heart-lung transplant. Calcium-channel blockers can be used to decrease the strain on the right side of the circulation by increasing the right to left shunt. Antibiotics are also useful in preventing endocarditis. However, the use of oxygen as a long-term treatment is still a topic of debate and is not considered a definitive solution. Patients with Eisenmenger’s syndrome may also experience significant polycythemia, which may require venesection as a treatment option.

      Understanding Eisenmenger’s Syndrome

      Eisenmenger’s syndrome is a medical condition that occurs when a congenital heart defect leads to pulmonary hypertension, causing a reversal of a left-to-right shunt. This happens when the left-to-right shunt is not corrected, leading to the remodeling of the pulmonary microvasculature, which eventually obstructs pulmonary blood and causes pulmonary hypertension. The condition is commonly associated with ventricular septal defect, atrial septal defect, and patent ductus arteriosus.

      The original murmur may disappear, and patients may experience cyanosis, clubbing, right ventricular failure, haemoptysis, and embolism. Management of Eisenmenger’s syndrome requires heart-lung transplantation. It is essential to diagnose and treat the condition early to prevent complications and improve the patient’s quality of life. Understanding the causes, symptoms, and management of Eisenmenger’s syndrome is crucial for healthcare professionals to provide appropriate care and support to patients with this condition.

    • This question is part of the following fields:

      • Cardiovascular System
      44.8
      Seconds
  • Question 4 - A 34-year-old woman visits her doctor after discovering she is pregnant. She is...

    Correct

    • A 34-year-old woman visits her doctor after discovering she is pregnant. She is currently taking the following medications:

      - Loratadine 10mg once daily
      - Omeprazole 10mg once daily
      - Metformin 500mg three times daily
      - Warfarin 5 mg once daily
      - Senna 15mg at night

      Which medication(s) should she discontinue during her pregnancy?

      Your Answer: Warfarin

      Explanation:

      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
      27.4
      Seconds
  • Question 5 - A man in his 50s arrives at the emergency department exhibiting signs of...

    Correct

    • A man in his 50s arrives at the emergency department exhibiting signs of a stroke. After undergoing a CT angiogram, it is revealed that there is a constriction in the artery that provides blood to the right common carotid.

      What is the name of the affected artery?

      Your Answer: Brachiocephalic artery

      Explanation:

      The largest branch from the aortic arch is the brachiocephalic artery, which originates from it. This artery gives rise to both the right subclavian artery and the right common carotid arteries. The brachiocephalic artery is supplied by the aortic arch, while the coronary arteries are supplied by the ascending aorta. Additionally, the coeliac trunk is a branch that stems from the abdominal aorta.

      The Brachiocephalic Artery: Anatomy and Relations

      The brachiocephalic artery is the largest branch of the aortic arch, originating at the apex of the midline. It ascends superiorly and posteriorly to the right, lying initially anterior to the trachea and then on its right-hand side. At the level of the sternoclavicular joint, it divides into the right subclavian and right common carotid arteries.

      In terms of its relations, the brachiocephalic artery is anterior to the sternohyoid, sterno-thyroid, thymic remnants, left brachiocephalic vein, and right inferior thyroid veins. Posteriorly, it is related to the trachea, right pleura, right lateral, right brachiocephalic vein, superior part of the SVC, left lateral, thymic remnants, origin of left common carotid, inferior thyroid veins, and trachea at a higher level.

      The brachiocephalic artery typically has no branches, but it may have the thyroidea ima artery. Understanding the anatomy and relations of the brachiocephalic artery is important for medical professionals, as it is a crucial vessel in the human body.

    • This question is part of the following fields:

      • Cardiovascular System
      14.9
      Seconds
  • Question 6 - 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
      89.9
      Seconds
  • Question 7 - A 52-year-old man comes to the emergency department complaining of severe crushing chest...

    Incorrect

    • A 52-year-old man comes to the emergency department complaining of severe crushing chest pain that spreads to his left arm and jaw. He also feels nauseous. Upon conducting an ECG, you observe ST-segment elevation in several chest leads and diagnose him with ST-elevation MI. From which vessel do the coronary vessels arise?

      Your Answer: Descending aorta

      Correct Answer: Ascending aorta

      Explanation:

      The left and right coronary arteries originate from the left and right aortic sinuses, respectively. The left aortic sinus is located on the left side of the ascending aorta, while the right aortic sinus is situated at the back.

      The coronary sinus is a venous vessel formed by the confluence of four coronary veins. It receives venous blood from the great, middle, small, and posterior cardiac veins and empties into the right atrium.

      The descending aorta is a continuation of the aortic arch and runs through the chest and abdomen before dividing into the left and right common iliac arteries. It has several branches along its path.

      The pulmonary veins transport oxygenated blood from the lungs to the left atrium and do not have any branches.

      The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. It splits into the left and right pulmonary arteries, which travel to the left and right lungs, respectively.

      The patient in the previous question has exhibited symptoms indicative of acute coronary syndrome, and the ECG results confirm an ST-elevation myocardial infarction.

      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
      43.9
      Seconds
  • Question 8 - Which of the following is true about endothelin? ...

    Incorrect

    • Which of the following is true about endothelin?

      Your Answer: Release is stimulated by nitric oxide

      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
      42.7
      Seconds
  • Question 9 - A 65-year-old man presents to the GP for a routine hypertension check-up. He...

    Correct

    • A 65-year-old man presents to the GP for a routine hypertension check-up. He has a medical history of hypertension, ischaemic heart disease, osteoarthritis, rheumatic fever and COPD.

      During the physical examination, the GP hears a mid-late diastolic murmur that intensifies during expiration. The GP suspects that the patient may have mitral stenosis.

      What is the primary cause of this abnormality?

      Your Answer: Rheumatic fever

      Explanation:

      Understanding Mitral Stenosis

      Mitral stenosis is a condition where the mitral valve, which controls blood flow from the left atrium to the left ventricle, becomes obstructed. This leads to an increase in pressure within the left atrium, pulmonary vasculature, and right side of the heart. The most common cause of mitral stenosis is rheumatic fever, but it can also be caused by other rare conditions such as mucopolysaccharidoses, carcinoid, and endocardial fibroelastosis.

      Symptoms of mitral stenosis include dyspnea, hemoptysis, a mid-late diastolic murmur, a loud S1, and a low volume pulse. Severe cases may also present with an increased length of murmur and a closer opening snap to S2. Chest x-rays may show left atrial enlargement, while echocardiography can confirm a cross-sectional area of less than 1 sq cm for a tight mitral stenosis.

      Management of mitral stenosis depends on the severity of the condition. Asymptomatic patients are monitored with regular echocardiograms, while symptomatic patients may undergo percutaneous mitral balloon valvotomy or mitral valve surgery. Patients with associated atrial fibrillation require anticoagulation, with warfarin currently recommended for moderate/severe cases. However, there is an emerging consensus that direct-acting anticoagulants may be suitable for mild cases with atrial fibrillation.

      Overall, understanding mitral stenosis is important for proper diagnosis and management of this condition.

    • This question is part of the following fields:

      • Cardiovascular System
      24.6
      Seconds
  • Question 10 - A 50-year-old man visits the diabetic foot clinic and has his foot pulses...

    Correct

    • A 50-year-old man visits the diabetic foot clinic and has his foot pulses checked. During the examination, the healthcare provider palpates the posterior tibial pulse and the dorsalis pedis pulse. What artery does the dorsalis pedis artery continue from?

      Your Answer: Anterior tibial artery

      Explanation:

      The dorsalis pedis artery in the foot is a continuation of the anterior tibial artery.

      At the level of the pelvis, the common iliac artery gives rise to the external iliac artery.

      The lateral compartment of the leg is supplied by the peroneal artery, also known as the fibular artery.

      A branch of the popliteal artery is the tibioperoneal trunk.

      The anterior tibial artery is formed by the popliteal artery.

      The anterior tibial artery starts opposite the lower border of the popliteus muscle and ends in front of the ankle, where it continues as the dorsalis pedis artery. As it descends, it runs along the interosseous membrane, the distal part of the tibia, and the front of the ankle joint. The artery passes between the tendons of the extensor digitorum and extensor hallucis longus muscles as it approaches the ankle. The deep peroneal nerve is closely related to the artery, lying anterior to the middle third of the vessel and lateral to it in the lower third.

    • This question is part of the following fields:

      • Cardiovascular System
      25.5
      Seconds
  • Question 11 - A 72-year-old male with urinary incontinence visits the urogynaecology clinic and is diagnosed...

    Incorrect

    • A 72-year-old male with urinary incontinence visits the urogynaecology clinic and is diagnosed with overactive bladder incontinence. He is prescribed a medication that works by blocking the parasympathetic pathway. What other drugs have a similar mechanism of action to the one he was prescribed?

      Your Answer:

      Correct Answer: Atropine

      Explanation:

      Atropine is classified as an antimuscarinic drug that works by inhibiting the M1 to M5 muscarinic receptors. While oxybutynin is commonly prescribed for urinary incontinence due to its ability to block the M3 muscarinic receptors, atropine is more frequently used in anesthesia to reduce salivation before intubation.

      Alfuzosin, on the other hand, is an alpha blocker that is primarily used to treat benign prostate hyperplasia.

      Meropenem is an antibiotic that is reserved for infections caused by bacteria that are resistant to most beta-lactams. However, it is typically used as a last resort due to its potential adverse effects.

      Mirabegron is another medication used to treat urinary incontinence, but it works by activating the ÎČ3 adrenergic receptors.

      Understanding Atropine and Its Uses

      Atropine is a medication that works against the muscarinic acetylcholine receptor. It is commonly used to treat symptomatic bradycardia and organophosphate poisoning. In cases of bradycardia with adverse signs, IV atropine is the first-line treatment. However, it is no longer recommended for routine use in asystole or pulseless electrical activity (PEA) during advanced life support.

      Atropine has several physiological effects, including tachycardia and mydriasis. However, it is important to note that it may trigger acute angle-closure glaucoma in susceptible patients. Therefore, it is crucial to use atropine with caution and under the guidance of a healthcare professional. Understanding the uses and effects of atropine can help individuals make informed decisions about their healthcare.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 12 - A woman with longstanding angina visits her doctor and reports persistent symptoms. The...

    Incorrect

    • A woman with longstanding angina visits her doctor and reports persistent symptoms. The patient was previously prescribed a calcium channel blocker, but due to her asthma, a beta blocker cannot be prescribed. The doctor decides to prescribe ivabradine. What is the site of action of ivabradine in the heart?

      Your Answer:

      Correct Answer: Sinoatrial node

      Explanation:

      The mechanism of action of Ivabradine in heart failure involves targeting the If ion current present in the sinoatrial node to lower the heart rate.

      Ivabradine: An Anti-Anginal Drug

      Ivabradine is a type of medication used to treat angina by reducing the heart rate. It works by targeting the If (‘funny’) ion current, which is found in high levels in the sinoatrial node. By doing so, it decreases the activity of the cardiac pacemaker.

      However, Ivabradine is not without its side effects. Many patients report experiencing visual disturbances, such as luminous phenomena, as well as headaches, bradycardia, and heart block.

      Despite its potential benefits, there is currently no evidence to suggest that Ivabradine is superior to existing treatments for stable angina. As with any medication, it is important to weigh the potential benefits against the risks and side effects before deciding whether or not to use it.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 13 - A 55-year-old man is undergoing investigation for a secondary cause of early-onset heart...

    Incorrect

    • A 55-year-old man is undergoing investigation for a secondary cause of early-onset heart failure and a systolic murmur. He is referred for an echocardiogram, which reveals an ejection fraction of 62% and impaired diastolic function of the myocardial tissue. Additionally, the report notes a septal wall thickness of 17mm. What is the most probable condition responsible for these findings?

      Your Answer:

      Correct Answer: Hypertrophic obstructive cardiomyopathy

      Explanation:

      Hypertrophic obstructive cardiomyopathy (HOCM) is a likely cause of diastolic dysfunction, which can lead to heart failure with preserved ejection fraction (HF-pEF). This genetic cardiomyopathy is associated with sudden cardiac death, syncope, and heart failure. Unlike other conditions, such as degenerative calcification of the aortic valve or dilated cardiomyopathy, HOCM typically presents with diastolic dysfunction rather than systolic dysfunction. Ischaemic heart disease is also unlikely to be the cause of diastolic dysfunction and would typically present with heart failure and systolic dysfunction.

      Types of Heart Failure

      Heart failure is a clinical syndrome where the heart cannot pump enough blood to meet the body’s metabolic needs. It can be classified in multiple ways, including by ejection fraction, time, and left/right side. Patients with heart failure may have a normal or abnormal left ventricular ejection fraction (LVEF), which is measured using echocardiography. Reduced LVEF is typically defined as < 35 to 40% and is termed heart failure with reduced ejection fraction (HF-rEF), while preserved LVEF is termed heart failure with preserved ejection fraction (HF-pEF). Heart failure can also be described as acute or chronic, with acute heart failure referring to an acute exacerbation of chronic heart failure. Left-sided heart failure is more common and may be due to increased left ventricular afterload or preload, while right-sided heart failure is caused by increased right ventricular afterload or preload. High-output heart failure is another type of heart failure that occurs when a normal heart is unable to pump enough blood to meet the body's metabolic needs. By classifying heart failure in these ways, healthcare professionals can better understand the underlying causes and tailor treatment plans accordingly. It is important to note that many guidelines for the management of heart failure only cover HF-rEF patients and do not address the management of HF-pEF patients. Understanding the different types of heart failure can help healthcare professionals provide more effective care for their patients.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 14 - A 72-year-old woman is prescribed digoxin for the treatment of atrial fibrillation that...

    Incorrect

    • A 72-year-old woman is prescribed digoxin for the treatment of atrial fibrillation that was not effectively managed with atenolol alone. Digoxin works by inhibiting a crucial element in the cardiac action potential that restores resting potential. This inhibition leads to changes in the levels of specific ions on either side of the membrane, resulting in an enhanced contractile force of the heart and an improvement in left ventricular ejection fraction.

      Which element does digoxin inhibit to achieve this effect?

      Your Answer:

      Correct Answer: Na+/K+ ATPase

      Explanation:

      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
      0
      Seconds
  • Question 15 - A 75-year-old man arrives at the emergency department complaining of lightheadedness and difficulty...

    Incorrect

    • A 75-year-old man arrives at the emergency department complaining of lightheadedness and difficulty breathing. Upon examination, his ECG reveals supraventricular tachycardia, which may be caused by an irregularity in the cardiac electrical activation sequence. He is successfully cardioverted to sinus rhythm.

      What is the anticipated sequence of his cardiac electrical activation following the procedure?

      Your Answer:

      Correct Answer: SA node- atria- AV node- Bundle of His- right and left bundle branches- Purkinje fibres

      Explanation:

      The correct order of cardiac electrical activation is as follows: SA node, atria, AV node, Bundle of His, right and left bundle branches, and Purkinje fibers. Understanding this sequence is crucial as it is directly related to interpreting ECGs.

      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
      0
      Seconds
  • Question 16 - What changes occur in the newborn after delivery? ...

    Incorrect

    • What changes occur in the newborn after delivery?

      Your Answer:

      Correct Answer: The ductus arteriosus closes

      Explanation:

      Within a few hours of birth, the foramen ovale, ductus arteriosus, and umbilical vessels all close. The foramen ovale, which allows blood to bypass the lungs by shunting from the right atrium to the left atrium, closes as the lungs become functional and the left atrial pressure exceeds the right atrial pressure. The ductus arteriosus, which connects the pulmonary artery to the aorta, also closes to form the ligamentum arteriosum, allowing blood to circulate into the pulmonary artery and become oxygenated. After a few days, Haemoglobin F is replaced by Haemoglobin A, which has a lower affinity for oxygen and may cause physiological jaundice in the newborn due to the breakdown of fetal blood cells. The first few breaths help to expel lung fluid from the fetal alveoli. If the ductus arteriosus fails to close, it can result in a patent ductus arteriosus (PDA), which can lead to serious health complications such as pulmonary hypertension, heart failure, and arrhythmias.

      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
      0
      Seconds
  • Question 17 - 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:

      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
      0
      Seconds
  • Question 18 - A 24-year-old male patient arrives at the emergency department complaining of dizziness and...

    Incorrect

    • A 24-year-old male patient arrives at the emergency department complaining of dizziness and palpitations. Upon triage, cardiac monitoring reveals supraventricular tachycardia with a heart rate of 200 beats per minute. This rapid heart rate is facilitated by the specialized cells and nerve fibers in the heart that conduct action potentials during systole.

      What type of cells and nerve fibers in the heart have the highest conduction velocities?

      Your Answer:

      Correct Answer: Purkinje fibres

      Explanation:

      The Purkinje fibres have the fastest conduction velocities in the heart, reaching about 4m/sec. During cardiac electrical activation, the SA node generates action potentials that spread throughout the atria muscle during atrial systole, conducting at a velocity of approximately 0.5m/sec. The atrioventricular node acts as a pathway for action potentials to enter from the atria to the ventricles, also conducting at a similar velocity of about 0.5m/sec. The Bundle of His, located at the base of the ventricle, divides into the left and right bundle branches, which conduct at a faster velocity of around 2m/sec. These bundles then divide into an extensive system of Purkinje fibres that conduct the impulse throughout the ventricles at an even faster velocity of about 4m/sec.

      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
      0
      Seconds
  • Question 19 - A 78-year-old man with an ST-elevation myocardial infarction receives bivalirudin, aspirin, and clopidogrel...

    Incorrect

    • A 78-year-old man with an ST-elevation myocardial infarction receives bivalirudin, aspirin, and clopidogrel before undergoing percutaneous coronary intervention. What is the mode of action of bivalirudin?

      Your Answer:

      Correct Answer: Reversible direct thrombin inhibitor

      Explanation:

      Bivalirudin inhibits thrombin directly in a reversible manner.

      Warfarin prevents the conversion of vitamin K to its active hydroquinone form by acting as an antagonist.

      Heparins activate antithrombin II and also form inactive complexes with other clotting factors.

      Aspirin inhibits COX.

      Clopidogrel functions as a/an.

      Bivalirudin: An Anticoagulant for Acute Coronary Syndrome

      Bivalirudin is a medication that acts as a direct thrombin inhibitor, meaning it prevents the formation of blood clots. It is commonly used as an anticoagulant in the treatment of acute coronary syndrome, a condition where blood flow to the heart is blocked or reduced. Bivalirudin is a reversible inhibitor, meaning its effects can be reversed if necessary.

      Acute coronary syndrome is a serious condition that can lead to heart attack or other complications if left untreated. Bivalirudin is an effective treatment option for preventing blood clots and reducing the risk of further complications. Its reversible nature also makes it a safer option for patients who may need to undergo surgery or other procedures while on anticoagulant therapy. Overall, bivalirudin is an important medication in the management of acute coronary syndrome and plays a crucial role in improving patient outcomes.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 20 - A 50-year-old man undergoes carotid endarterectomy surgery after experiencing a transient ischaemic attack....

    Incorrect

    • A 50-year-old man undergoes carotid endarterectomy surgery after experiencing a transient ischaemic attack. The procedure is successful with no complications. However, the patient develops new hoarseness of voice and loss of effective cough mechanism post-surgery. There are no notable findings upon examination of the oral cavity.

      Which structure has been affected by the surgery?

      Your Answer:

      Correct Answer: Cranial nerve X

      Explanation:

      Speech is innervated by the vagus (X) nerve, so any damage to this nerve can cause speech problems. Injuries to one side of the vagus nerve can result in hoarseness and vocal cord paralysis on the same side, while bilateral injuries can lead to aphonia and stridor. Other symptoms of vagal disease may include dysphagia, loss of cough reflex, gastroparesis, and cardiovascular effects. The facial nerve (VII) may also be affected during carotid surgery, causing muscle weakness in facial expression. However, the vestibulocochlear nerve (VIII) is not involved in speech and would not be damaged during carotid surgery. The accessory nerve (XI) does not innervate speech muscles and is rarely affected during carotid surgery, causing weakness in shoulder elevation instead. Hypoglossal (XII) palsy is a rare complication of carotid surgery that causes tongue deviation towards the side of the lesion, but not voice hoarseness.

      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
      0
      Seconds
  • Question 21 - A 75-year-old man presents to the clinic with a chief complaint of dyspnea...

    Incorrect

    • A 75-year-old man presents to the clinic with a chief complaint of dyspnea while in a supine position. Despite having a normal ejection fraction, what could be a potential cause for his symptoms?

      Your Answer:

      Correct Answer: He has diastolic dysfunction

      Explanation:

      When there is systolic dysfunction, the ejection fraction decreases as the stroke volume decreases. However, in cases of diastolic dysfunction, ejection fraction is not a reliable indicator as both stroke volume and end-diastolic volume may be reduced. Diastolic dysfunction occurs when the heart’s compliance is reduced.

      Cardiovascular physiology involves the study of the functions and processes of the heart and blood vessels. One important measure of heart function is the left ventricular ejection fraction, which is calculated by dividing the stroke volume (the amount of blood pumped out of the left ventricle with each heartbeat) by the end diastolic LV volume (the amount of blood in the left ventricle at the end of diastole) and multiplying by 100%. Another key measure is cardiac output, which is the amount of blood pumped by the heart per minute and is calculated by multiplying stroke volume by heart rate.

      Pulse pressure is another important measure of cardiovascular function, which is the difference between systolic pressure (the highest pressure in the arteries during a heartbeat) and diastolic pressure (the lowest pressure in the arteries between heartbeats). Factors that can increase pulse pressure include a less compliant aorta (which can occur with age) and increased stroke volume.

      Finally, systemic vascular resistance is a measure of the resistance to blood flow in the systemic circulation and is calculated by dividing mean arterial pressure (the average pressure in the arteries during a heartbeat) by cardiac output. Understanding these measures of cardiovascular function is important for diagnosing and treating cardiovascular diseases.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 22 - A 78-year-old woman visits her doctor complaining of increasing breathlessness at night and...

    Incorrect

    • A 78-year-old woman visits her doctor complaining of increasing breathlessness at night and swollen ankles over the past 10 months. She has a medical history of ischaemic heart disease, but an echocardiogram reveals normal valve function. During the examination, the doctor detects a low-pitched sound at the start of diastole, following S2. What is the probable reason for this sound?

      Your Answer:

      Correct Answer: Rapid movement of blood entering ventricles from atria

      Explanation:

      S3 is an unusual sound that can be detected in certain heart failure patients. It is caused by the rapid movement and oscillation of blood into the ventricles.

      Another abnormal heart sound, S4, is caused by forceful atrial contraction and occurs later in diastole.

      While aortic regurgitation causes an early diastolic decrescendo murmur and mitral stenosis can cause a mid-diastolic rumble with an opening snap, these conditions are less likely as the echocardiogram reported normal valve function.

      A patent ductus arteriosus typically causes a continuous murmur and would present earlier in life.

      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
      0
      Seconds
  • Question 23 - A 50-year-old man is having a lymph node biopsy taken from the posterior...

    Incorrect

    • A 50-year-old man is having a lymph node biopsy taken from the posterior triangle of his neck. What structure creates the posterior boundary of this area?

      Your Answer:

      Correct Answer: Trapezius muscle

      Explanation:

      The posterior triangle of the neck is an area that is bound by the sternocleidomastoid and trapezius muscles, the occipital bone, and the middle third of the clavicle. Within this triangle, there are various nerves, vessels, muscles, and lymph nodes. The nerves present include the accessory nerve, phrenic nerve, and three trunks of the brachial plexus, as well as branches of the cervical plexus such as the supraclavicular nerve, transverse cervical nerve, great auricular nerve, and lesser occipital nerve. The vessels found in this area are the external jugular vein and subclavian artery. Additionally, there are muscles such as the inferior belly of omohyoid and scalene, as well as lymph nodes including the supraclavicular and occipital nodes.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 24 - A 54-year-old man comes to the Emergency Department complaining of central chest pain....

    Incorrect

    • A 54-year-old man comes to the Emergency Department complaining of central chest pain. After a brief history and physical examination, the emergency medicine physician suspects a myocardial infarction. During the examination, the physician detects a 4th heart sound. What is the underlying reason for a 4th heart sound?

      Your Answer:

      Correct Answer: Forceful atrial contraction

      Explanation:

      S4 occurs late in diastole and is caused by the atria contracting forcefully to compensate for a stiff ventricle. It is commonly observed in patients with heart failure. In contrast, S3 occurs earlier in diastole and is caused by rapid blood flow into the ventricle.

      A pericardial effusion can produce a rubbing sound when the pericardium is examined. A systolic murmur may be caused by a ventricular septal defect, while a diastolic murmur may be caused by mitral regurgitation.

      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
      0
      Seconds
  • Question 25 - Which of the following is not a hepatic artery branch? ...

    Incorrect

    • Which of the following is not a hepatic artery branch?

      Your Answer:

      Correct Answer: Pancreatic artery

      Explanation:

      The Coeliac Axis and its Branches

      The coeliac axis is a major artery that supplies blood to the upper abdominal organs. It has three main branches: the left gastric, hepatic, and splenic arteries. The hepatic artery further branches into the right gastric, gastroduodenal, right gastroepiploic, superior pancreaticoduodenal, and cystic arteries. Meanwhile, the splenic artery gives off the pancreatic, short gastric, and left gastroepiploic arteries. Occasionally, the coeliac axis also gives off one of the inferior phrenic arteries.

      The coeliac axis is located anteriorly to the lesser omentum and is related to the right and left coeliac ganglia, as well as the caudate process of the liver and the gastric cardia. Inferiorly, it is in close proximity to the upper border of the pancreas and the renal vein.

      Understanding the anatomy and branches of the coeliac axis is important in diagnosing and treating conditions that affect the upper abdominal organs, such as pancreatic cancer or gastric ulcers.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 26 - A 16-year-old competitive swimmer visits the paediatric clinic after experiencing palpitations during races...

    Incorrect

    • A 16-year-old competitive swimmer visits the paediatric clinic after experiencing palpitations during races or intense training. She has never had shortness of breath or chest pain, but one persistent episode led her to the emergency department where an ECG was taken. Based on the shortening of one of the ECG intervals, a provisional diagnosis of Wolff-Parkinson-White syndrome was made. What does this abnormal section of the ECG represent in terms of electrical activity?

      Your Answer:

      Correct Answer: The time between atrial depolarisation and ventricular depolarisation

      Explanation:

      The PR interval on an ECG represents the duration between atrial depolarisation and ventricular depolarisation. In Wolff-Parkinson-White syndrome, an accessory pathway called the Bundle of Kent exists between the atrium and ventricle, allowing electrical signals to bypass the atrioventricular node and potentially leading to tachyarrhythmias. This results in a shorter PR interval on the ECG. Atrial repolarisation is not visible on the ECG, while the depolarisation of the sinoatrial node is represented by the p wave. The QT interval on the ECG represents the time between ventricular depolarisation and repolarisation, while the QRS complex represents ventricular depolarisation, not the PR interval.

      Understanding the Normal ECG

      The electrocardiogram (ECG) is a diagnostic tool used to assess the electrical activity of the heart. The normal ECG consists of several waves and intervals that represent different phases of the cardiac cycle. The P wave represents atrial depolarization, while the QRS complex represents ventricular depolarization. The ST segment represents the plateau phase of the ventricular action potential, and the T wave represents ventricular repolarization. The Q-T interval represents the time for both ventricular depolarization and repolarization to occur.

      The P-R interval represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. The duration of the QRS complex is normally 0.06 to 0.1 seconds, while the duration of the P wave is 0.08 to 0.1 seconds. The Q-T interval ranges from 0.2 to 0.4 seconds depending upon heart rate. At high heart rates, the Q-T interval is expressed as a ‘corrected Q-T (QTc)’ by taking the Q-T interval and dividing it by the square root of the R-R interval.

      Understanding the normal ECG is important for healthcare professionals to accurately interpret ECG results and diagnose cardiac conditions. By analyzing the different waves and intervals, healthcare professionals can identify abnormalities in the electrical activity of the heart and provide appropriate treatment.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 27 - Which one of the following is typically not provided by the right coronary...

    Incorrect

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

      Your Answer:

      Correct 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
      0
      Seconds
  • Question 28 - A 70-year-old male presents to the Emergency Department with a 3-hour history of...

    Incorrect

    • A 70-year-old male presents to the Emergency Department with a 3-hour history of tearing chest pain. He has a past medical history of poorly controlled hypertension. His observations show:

      Respiratory rate of 20 breaths/min
      Pulse of 95 beats/min
      Temperature of 37.3ÂșC
      Blood pressure of 176/148 mmHg
      Oxygen saturations of 97% on room air

      Auscultation of the heart identifies a diastolic murmur, heard loudest over the 2nd intercostal space, right sternal border.

      What CT angiography findings would be expected in this patient's likely diagnosis?

      Your Answer:

      Correct Answer: False lumen of the ascending aorta

      Explanation:

      A false lumen in the descending aorta is a significant indication of aortic dissection on CT angiography. This condition is characterized by tearing chest pain, hypertension, and aortic regurgitation, which can be detected through a diastolic murmur over the 2nd intercostal space, right sternal border. The false lumen is formed due to a tear in the tunica intima of the aortic wall, which fills with a large volume of blood and is easily visible on angiographic CT.

      Ballooning of the aortic arch is an incorrect answer as it refers to an aneurysm, which is a condition where the artery walls weaken and abnormally bulge out or widen. Aneurysms are prone to rupture and can have varying effects depending on their location.

      Blurring of the posterior wall of the descending aorta is also an incorrect answer as it is a sign of a retroperitoneal, contained rupture of an aortic aneurysm. This condition may present with hypovolemic shock, hypotension, tachycardia, and tachypnea, leading to collapse.

      Total occlusion of the left anterior descending artery is another incorrect answer as it would likely result in ST-elevation myocardial infarction (STEMI). Although chest pain is a symptom of both conditions, the nature of the pain and investigation findings make aortic dissection more likely. It is important to note that coronary arteries can only be viewed through coronary angiography, which involves injecting contrast directly into the coronary arteries using a catheter, and not through CT angiography.

      Aortic dissection is classified according to the location of the tear in the aorta. The Stanford classification divides it into type A, which affects the ascending aorta in two-thirds of cases, and type B, which affects the descending aorta distal to the left subclavian origin in one-third of cases. The DeBakey classification divides it into type I, which originates in the ascending aorta and propagates to at least the aortic arch and possibly beyond it distally, type II, which originates in and is confined to the ascending aorta, and type III, which originates in the descending aorta and rarely extends proximally but will extend distally.

      To diagnose aortic dissection, a chest x-ray may show a widened mediastinum, but CT angiography of the chest, abdomen, and pelvis is the investigation of choice. However, the choice of investigations should take into account the patient’s clinical stability, as they may present acutely and be unstable. Transoesophageal echocardiography (TOE) is more suitable for unstable patients who are too risky to take to the CT scanner.

      The management of type A aortic dissection is surgical, but blood pressure should be controlled to a target systolic of 100-120 mmHg while awaiting intervention. On the other hand, type B aortic dissection is managed conservatively with bed rest and IV labetalol to reduce blood pressure and prevent progression. Complications of a backward tear include aortic incompetence/regurgitation and MI, while complications of a forward tear include unequal arm pulses and BP, stroke, and renal failure. Endovascular repair of type B aortic dissection may have a role in the future.

    • This question is part of the following fields:

      • Cardiovascular System
      0
      Seconds
  • Question 29 - A 67-year-old woman visits her GP for a check-up after suffering from a...

    Incorrect

    • A 67-year-old woman visits her GP for a check-up after suffering from a significant anterior ST-elevation myocardial infarction (STEMI) 3 months ago. She has been feeling constantly fatigued and unwell and is worried that her heart may be causing these symptoms. Additionally, she has been experiencing sharp chest pain that worsens when she lies down and feels slightly breathless.

      During the examination, the GP observes that her blood pressure drops by approximately 10mmHg when she inhales.

      What is the probable reason for her symptoms and examination results?

      Your Answer:

      Correct Answer: Dressler syndrome (DS)

      Explanation:

      The most likely pathology in this case is Dressler syndrome (DS), which is a complication that can occur after a myocardial infarction (MI) from 2 weeks to several months post-MI. The patient’s symptoms of fatigue, malaise, pleuritic chest pain, and mild dyspnoea are consistent with DS. Additionally, the physical examination finding of decreased blood pressure (>10mmHg) on inspiration, known as ‘pulsus paradoxes’, is associated with DS.

      Heart failure with reduced ejection fraction (HFrEF) is an incorrect option as it does not typically cause pleuritic chest pain or pulsus paradoxes. Medication-related causes are also unlikely as the combination of symptoms described in this stem would not be caused by post-MI medications alone. Post-MI depression is another incorrect option as it would not account for all the symptoms present.

      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
      0
      Seconds
  • Question 30 - Where are the arterial baroreceptors situated? ...

    Incorrect

    • Where are the arterial baroreceptors situated?

      Your Answer:

      Correct Answer: Carotid sinus and aortic arch

      Explanation:

      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
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Cardiovascular System (5/10) 50%
Passmed