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Question 1
Correct
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A 25-year-old man is scheduled for a mitral valve repair to address mitral regurgitation. What characteristic is associated with the mitral valve?
Your Answer: Its closure is marked by the first heart sound
Explanation:To hear the mitral valve clearly, it is recommended to listen over the cardiac apex, as its closure produces the initial heart sound. The valve comprises two cusps that are connected to the ventricle wall by papillary muscles through chordae tendinae.
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 2
Incorrect
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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.
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This question is part of the following fields:
- Cardiovascular System
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Question 3
Incorrect
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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:
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 4
Incorrect
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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.
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This question is part of the following fields:
- Cardiovascular System
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Question 5
Incorrect
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An ECG is performed on a 60-year-old patient in the cardiology ward. On the ECG there are regular p waves present, and a QRS complex is associated with each p wave. The PR interval is 0.26 seconds. There are no missed p waves.
What is the most probable diagnosis?Your Answer:
Correct Answer: 1st degree heart block
Explanation:Understanding Heart Blocks: Types and Features
Heart blocks are a type of cardiac conduction disorder that can lead to serious complications such as syncope and heart failure. There are three types of heart blocks: first degree, second degree, and third degree (complete) heart block.
First degree heart block is characterized by a prolonged PR interval of more than 0.2 seconds. Second degree heart block can be further divided into two types: type 1 (Mobitz I, Wenckebach) and type 2 (Mobitz II). Type 1 is characterized by a progressive prolongation of the PR interval until a dropped beat occurs, while type 2 has a constant PR interval but the P wave is often not followed by a QRS complex.
Third degree (complete) heart block is the most severe type of heart block, where there is no association between the P waves and QRS complexes. This can lead to a regular bradycardia with a heart rate of 30-50 bpm, wide pulse pressure, and cannon waves in the neck JVP. Additionally, variable intensity of S1 can be observed.
It is important to recognize the features of heart blocks and differentiate between the types in order to provide appropriate management and prevent complications. Regular monitoring and follow-up with a healthcare provider is recommended for individuals with heart blocks.
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This question is part of the following fields:
- Cardiovascular System
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Question 6
Incorrect
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A 32-year-old arrives at the emergency department with a stab wound to the femoral artery. He has a history of intravenous drug use.
Due to poor vein quality, peripheral cannulation under ultrasound guidance is not feasible. Intraosseous access has been established, but additional access is required to administer large volume transfusions.
To obtain access to a vessel that runs anterior to the medial malleolus, the consultant has decided to perform a venous cutdown.
Which vessel will be accessed through this procedure?Your Answer:
Correct Answer: Long saphenous vein
Explanation:The correct answer is the long saphenous vein, which passes in front of the medial malleolus and is commonly used for venous cutdown procedures. This vein is the largest vessel in the superficial venous system and is formed from the dorsal venous arch of the foot. During a venous cutdown, the skin is opened up to expose the vessel, allowing for cannulation under direct vision.
The anterior tibial vein, fibular vein, and posterior tibial vein are all incorrect answers. The anterior tibial vein is part of the deep venous system and arises from the dorsal venous arch, while the fibular vein forms from the plantar veins of the foot and drains into the posterior tibial vein. The posterior tibial vein also arises from the plantar veins of the foot but ascends posterior to the medial malleolus.
The Anatomy of Saphenous Veins
The human body has two saphenous veins: the long saphenous vein and the short saphenous vein. The long saphenous vein is often used for bypass surgery or removed as a treatment for varicose veins. It originates at the first digit where the dorsal vein merges with the dorsal venous arch of the foot and runs up the medial side of the leg. At the knee, it runs over the posterior border of the medial epicondyle of the femur bone before passing laterally to lie on the anterior surface of the thigh. It then enters an opening in the fascia lata called the saphenous opening and joins with the femoral vein in the region of the femoral triangle at the saphenofemoral junction. The long saphenous vein has several tributaries, including the medial marginal, superficial epigastric, superficial iliac circumflex, and superficial external pudendal veins.
On the other hand, the short saphenous vein originates at the fifth digit where the dorsal vein merges with the dorsal venous arch of the foot, which attaches to the great saphenous vein. It passes around the lateral aspect of the foot and runs along the posterior aspect of the leg with the sural nerve. It then passes between the heads of the gastrocnemius muscle and drains into the popliteal vein, approximately at or above the level of the knee joint.
Understanding the anatomy of saphenous veins is crucial for medical professionals who perform surgeries or treatments involving these veins.
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This question is part of the following fields:
- Cardiovascular System
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Question 7
Incorrect
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A 65-year-old man presents to his GP with worsening breathlessness. He reports difficulty climbing stairs and sleeping, and finds it easier to sleep in his living room chair. He used to manage stairs fine a year ago, but now has to stop twice on the way up.
When asked about other symptoms, he reports feeling slightly wheezy and occasionally coughing up white sputum. He denies any weight loss. His medical history includes angina, non-diabetic hyperglycaemia, and hypertension. He has smoked 15 cigarettes per day since he was 25 and drinks around 5 pints of lager every Friday and Saturday night.
On examination, his oxygen saturations are 96%, respiratory rate 16/min at rest, heart rate 78/min, and blood pressure 141/88 mmHg. Bibasal crackles are heard on auscultation of his lungs.
What is the most likely diagnosis?Your Answer:
Correct Answer: Heart failure
Explanation:Orthopnoea is a distinguishing symptom that can help differentiate between heart failure and COPD in patients. While the symptoms may be non-specific, the presence of orthopnoea, or breathlessness when lying down, is a key indicator of heart failure rather than COPD.
Although the patient has a significant history of smoking, there are no other signs of lung cancer such as weight loss, persistent cough, or coughing up blood. However, it is recommended to conduct an urgent chest X-ray to rule out any serious underlying conditions.
In cases of occupational asthma, symptoms tend to worsen when exposed to triggers in the workplace and improve during time off. However, in this patient’s case, the symptoms have been gradually worsening over time.
Features of Chronic Heart Failure
Chronic heart failure is a condition that affects the heart’s ability to pump blood effectively. It is characterized by several features that can help in its diagnosis. Dyspnoea, or shortness of breath, is a common symptom of chronic heart failure. Patients may also experience coughing, which can be worse at night and accompanied by pink or frothy sputum. Orthopnoea, or difficulty breathing while lying down, and paroxysmal nocturnal dyspnoea, or sudden shortness of breath at night, are also common symptoms.
Another feature of chronic heart failure is the presence of a wheeze, known as a cardiac wheeze. Patients may also experience weight loss, known as cardiac cachexia, which occurs in up to 15% of patients. However, this may be hidden by weight gained due to oedema. On examination, bibasal crackles may be heard, and signs of right-sided heart failure, such as a raised JVP, ankle oedema, and hepatomegaly, may be present.
In summary, chronic heart failure is a condition that can be identified by several features, including dyspnoea, coughing, orthopnoea, paroxysmal nocturnal dyspnoea, wheezing, weight loss, bibasal crackles, and signs of right-sided heart failure. Early recognition and management of these symptoms can help improve outcomes for patients with chronic heart failure.
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This question is part of the following fields:
- Cardiovascular System
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Question 8
Incorrect
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A 68-year-old man arrives at the emergency department complaining of intense abdominal pain that spreads to his back. His medical history shows that he has an abdominal aortic aneurysm. During a FAST scan, it is discovered that the abdominal aorta is widely dilated, with the most significant expansion occurring at the point where it divides into the iliac arteries. What vertebral level corresponds to the location of the most prominent dilation observed in the FAST scan?
Your Answer:
Correct Answer: L4
Explanation:The abdominal aorta divides into two branches at the level of the fourth lumbar vertebrae. At the level of T12, the coeliac trunk arises, while at L1, the superior mesenteric artery branches off. The testicular artery and renal artery originate at L2, and at L3, the inferior mesenteric artery is formed.
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 9
Incorrect
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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.
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This question is part of the following fields:
- Cardiovascular System
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Question 10
Incorrect
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A 65-year-old man presents to the vascular clinic with bilateral buttock claudication that spreads down the thigh and erectile dysfunction. The vascular surgeon is unable to palpate his left femoral pulse and the right is weakly palpable. The patient is diagnosed with Leriche syndrome, which is caused by atherosclerotic occlusion of blood flow at the abdominal aortic bifurcation. He has been consented for aorto-iliac bypass surgery and is currently awaiting the procedure.
What is the vertebral level of the affected artery that requires bypassing?Your Answer:
Correct Answer: L4
Explanation: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.
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This question is part of the following fields:
- Cardiovascular System
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Question 11
Incorrect
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A 36-year-old woman is scheduled for a parathyroidectomy to treat her hyperparathyroidism. During the surgery, an enlarged inferior parathyroid gland is identified with a vessel located adjacent to it laterally. Which vessel is most likely to be in this location?
Your Answer:
Correct Answer: Common carotid artery
Explanation:The inferior parathyroid is located laterally to the common carotid artery.
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 12
Incorrect
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A 65-year-old man is admitted after experiencing an acute coronary syndrome. He is prescribed aspirin, clopidogrel, nitrates, and morphine. Due to his high 6-month risk score, percutaneous coronary intervention is planned and he is given intravenous tirofiban. What is the mechanism of action of this medication?
Your Answer:
Correct Answer: Glycoprotein IIb/IIIa receptor antagonist
Explanation:Glycoprotein IIb/IIIa Receptor Antagonists
Glycoprotein IIb/IIIa receptor antagonists are a class of drugs that inhibit the function of the glycoprotein IIb/IIIa receptor, which is found on the surface of platelets. These drugs are used to prevent blood clots from forming in patients with acute coronary syndrome, unstable angina, or during percutaneous coronary intervention (PCI).
Examples of glycoprotein IIb/IIIa receptor antagonists include abciximab, eptifibatide, and tirofiban. These drugs work by blocking the binding of fibrinogen to the glycoprotein IIb/IIIa receptor, which prevents platelet aggregation and the formation of blood clots.
Glycoprotein IIb/IIIa receptor antagonists are typically administered intravenously and are used in combination with other antiplatelet agents, such as aspirin and clopidogrel. While these drugs are effective at preventing blood clots, they can also increase the risk of bleeding. Therefore, careful monitoring of patients is necessary to ensure that the benefits of these drugs outweigh the risks.
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This question is part of the following fields:
- Cardiovascular System
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Question 13
Incorrect
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Which one of the following vessels does not directly drain into the inferior vena cava?
Your Answer:
Correct Answer: Superior mesenteric vein
Explanation:The portal vein receives drainage from the superior mesenteric vein, while the right and left hepatic veins directly drain into it. This can result in significant bleeding in cases of severe liver lacerations.
Anatomy of the Inferior Vena Cava
The inferior vena cava (IVC) originates from the fifth lumbar vertebrae and is formed by the merging of the left and right common iliac veins. It passes to the right of the midline and receives drainage from paired segmental lumbar veins throughout its length. The right gonadal vein empties directly into the cava, while the left gonadal vein usually empties into the left renal vein. The renal veins and hepatic veins are the next major veins that drain into the IVC. The IVC pierces the central tendon of the diaphragm at the level of T8 and empties into the right atrium of the heart.
The IVC is related anteriorly to the small bowel, the first and third parts of the duodenum, the head of the pancreas, the liver and bile duct, the right common iliac artery, and the right gonadal artery. Posteriorly, it is related to the right renal artery, the right psoas muscle, the right sympathetic chain, and the coeliac ganglion.
The IVC is divided into different levels based on the veins that drain into it. At the level of T8, it receives drainage from the hepatic vein and inferior phrenic vein before piercing the diaphragm. At the level of L1, it receives drainage from the suprarenal veins and renal vein. At the level of L2, it receives drainage from the gonadal vein, and at the level of L1-5, it receives drainage from the lumbar veins. Finally, at the level of L5, the common iliac vein merges to form the IVC.
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This question is part of the following fields:
- Cardiovascular System
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Question 14
Incorrect
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Isabella is an 82-year-old female who visits the cardiology clinic for a check-up. She experienced a heart attack half a year ago and has been experiencing swollen ankles and difficulty breathing when lying down. You suspect heart failure and arrange for an echocardiogram, prescribe diuretic medications, and conduct a blood test. What blood marker can indicate excessive stretching of the heart muscle?
Your Answer:
Correct Answer: Brain natriuretic peptide (BNP)
Explanation:BNP is produced by the ventricles of the heart when the cardiomyocytes are excessively stretched. Its overall effect is to reduce blood pressure by decreasing systemic vascular resistance and increasing natriuresis.
Troponin is a protein that plays a role in cardiac muscle contraction and is a specific and sensitive marker for myocardial damage in cases of myocardial infarction.
Creatine kinase and LDH can be used as acute markers for myocardial infarction.
Myoglobin is released after muscle damage, but it is not specific to acute myocardial infarction and is typically measured in cases of rhabdomyolysis.
B-type natriuretic peptide (BNP) is a hormone that is primarily produced by the left ventricular myocardium in response to strain. Although heart failure is the most common cause of elevated BNP levels, any condition that causes left ventricular dysfunction, such as myocardial ischemia or valvular disease, may also raise levels. In patients with chronic kidney disease, reduced excretion may also lead to elevated BNP levels. Conversely, treatment with ACE inhibitors, angiotensin-2 receptor blockers, and diuretics can lower BNP levels.
BNP has several effects, including vasodilation, diuresis, natriuresis, and suppression of both sympathetic tone and the renin-angiotensin-aldosterone system. Clinically, BNP is useful in diagnosing patients with acute dyspnea. A low concentration of BNP (<100 pg/mL) makes a diagnosis of heart failure unlikely, but elevated levels should prompt further investigation to confirm the diagnosis. Currently, NICE recommends BNP as a helpful test to rule out a diagnosis of heart failure. In patients with chronic heart failure, initial evidence suggests that BNP is an extremely useful marker of prognosis and can guide treatment. However, BNP is not currently recommended for population screening for cardiac dysfunction.
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This question is part of the following fields:
- Cardiovascular System
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Question 15
Incorrect
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A 68-year-old woman comes into the emergency department with her daughter after experiencing shortness of breath for 2 hours. She is in poor condition with a heart rate of 128/min, blood pressure of 90/66 mmHg, O2 saturation of 94% on air, respiratory rate of 29/min, and temperature of 36.3ยบC. Her legs are swollen up to her knees, and her JVP is visible at her ear lobe. She has a history of myocardial infarction 4 years ago, angina, and a smoking history of 20 packs per year.
What is the underlying cause of her presentation?Your Answer:
Correct Answer: Reduced cardiac output
Explanation:The cause of the patient’s acute heart failure is a decrease in cardiac output, which may be due to biventricular failure. This is evidenced by peripheral edema and respiratory distress, including shortness of breath, high respiratory rate, and low oxygen saturation. These symptoms are likely caused by inadequate heart filling, leading to peripheral congestion and pulmonary edema or pleural effusion.
The pathophysiology of myocardial infarction is not relevant to the patient’s condition, as it is not explained by her peripheral edema and elevated JVP.
While shortness of breath in heart failure may be caused by reduced ventilation/perfusion due to pulmonary edema, this is only one symptom and not the underlying mechanism of the condition.
The overactivity of the renin-angiotensin system is a physiological response to decreased blood pressure or increased renal sympathetic firing, but it is not necessarily related to the patient’s current condition.
Understanding Acute Heart Failure: Symptoms and Diagnosis
Acute heart failure (AHF) is a medical emergency that can occur suddenly or worsen over time. It can affect individuals with or without a history of pre-existing heart failure. Decompensated AHF is more common and is characterized by a background history of HF. AHF is typically caused by a reduced cardiac output resulting from a functional or structural abnormality. De-novo heart failure, on the other hand, is caused by increased cardiac filling pressures and myocardial dysfunction, usually due to ischaemia.
The most common precipitating causes of acute AHF are acute coronary syndrome, hypertensive crisis, acute arrhythmia, and valvular disease. Patients with heart failure may present with signs of fluid congestion, weight gain, orthopnoea, and breathlessness. They are broadly classified into four groups based on whether they present with or without hypoperfusion and fluid congestion. This classification is clinically useful in determining the therapeutic approach.
The symptoms of AHF include breathlessness, reduced exercise tolerance, oedema, fatigue, chest signs, and an S3-heart sound. Signs of AHF include cyanosis, tachycardia, elevated jugular venous pressure, and a displaced apex beat. Over 90% of patients with AHF have a normal or increased blood pressure.
The diagnostic workup for patients with AHF includes blood tests, chest X-ray, echocardiogram, and B-type natriuretic peptide. Blood tests are used to identify any underlying abnormalities, while chest X-ray findings include pulmonary venous congestion, interstitial oedema, and cardiomegaly. Echocardiogram is used to identify pericardial effusion and cardiac tamponade, while raised levels of B-type natriuretic peptide (>100mg/litre) indicate myocardial damage and support the diagnosis.
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This question is part of the following fields:
- Cardiovascular System
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Question 16
Incorrect
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An 80-year-old man visits his GP with complaints of worsening shortness of breath, dry cough, and fatigue over the past 6 weeks. The patient reports having to stop multiple times during his daily walk to catch his breath and sleeping with an extra pillow at night to aid his breathing. He has a medical history of hypertension and a smoking history of 30 pack-years. His current medications include ramipril, amlodipine, and atorvastatin.
During the examination, the GP observes end-inspiratory crackles at both lung bases. The patient's oxygen saturation is 94% on room air, his pulse is regular at 110 /min, and his respiratory rate is 24 /min.
What is the most probable underlying diagnosis?Your Answer:
Correct Answer: Chronic heart failure
Explanation:Orthopnoea is a useful indicator to distinguish between heart failure and COPD.
The Framingham diagnostic criteria for heart failure include major criteria such as acute pulmonary oedema and cardiomegaly, as well as minor criteria like ankle oedema and dyspnoea on exertion. Other minor criteria include hepatomegaly, nocturnal cough, pleural effusion, tachycardia (>120 /min), neck vein distension, and a third heart sound.
In this case, the patient exhibits orthopnoea (needing an extra pillow to alleviate breathlessness), rales (crackles heard during inhalation), and dyspnoea on exertion, all of which are indicative of heart failure.
While COPD can present with similar symptoms such as coughing, fatigue, shortness of breath, and desaturation, the presence of orthopnoea helps to differentiate between the two conditions.
Pulmonary fibrosis, on the other hand, does not typically present with orthopnoea.
Features of Chronic Heart Failure
Chronic heart failure is a condition that affects the heart’s ability to pump blood effectively. It is characterized by several features that can help in its diagnosis. Dyspnoea, or shortness of breath, is a common symptom of chronic heart failure. Patients may also experience coughing, which can be worse at night and accompanied by pink or frothy sputum. Orthopnoea, or difficulty breathing while lying down, and paroxysmal nocturnal dyspnoea, or sudden shortness of breath at night, are also common symptoms.
Another feature of chronic heart failure is the presence of a wheeze, known as a cardiac wheeze. Patients may also experience weight loss, known as cardiac cachexia, which occurs in up to 15% of patients. However, this may be hidden by weight gained due to oedema. On examination, bibasal crackles may be heard, and signs of right-sided heart failure, such as a raised JVP, ankle oedema, and hepatomegaly, may be present.
In summary, chronic heart failure is a condition that can be identified by several features, including dyspnoea, coughing, orthopnoea, paroxysmal nocturnal dyspnoea, wheezing, weight loss, bibasal crackles, and signs of right-sided heart failure. Early recognition and management of these symptoms can help improve outcomes for patients with chronic heart failure.
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This question is part of the following fields:
- Cardiovascular System
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Question 17
Incorrect
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A 68-year-old man is diagnosed with a transient ischaemic attack and started on modified-release dipyridamole as part of combination antiplatelet treatment. He already takes a statin. After a week of treatment, he visits his GP with concerns of the drug's mechanism of action.
What is the mechanism of action of modified-release dipyridamole?Your Answer:
Correct Answer: Phosphodiesterase inhibitor
Explanation:Dipyridamole is a medication that inhibits phosphodiesterase in a non-specific manner and reduces the uptake of adenosine by cells.
As an antiplatelet agent, dipyridamole works by inhibiting phosphodiesterase. It can be used in combination with aspirin to prevent secondary transient ischemic attacks if clopidogrel is not well-tolerated.
Tirofiban is a drug that inhibits the platelet glycoprotein IIb/IIIa receptor, which binds to collagen.
The platelet receptor glycoprotein VI interacts with subendothelial collagen.
Glycoprotein 1b is the platelet receptor for von Willebrand Factor. Although there is no specific drug that targets this interaction, autoantibodies to glycoprotein Ib are the basis of immune thrombocytopenic purpura (ITP).
Clopidogrel targets the platelet receptor P2Y12, which interacts with adenosine diphosphate.
Understanding the Mechanism of Action of Dipyridamole
Dipyridamole is a medication that is commonly used in combination with aspirin to prevent the formation of blood clots after a stroke or transient ischemic attack. The drug works by inhibiting phosphodiesterase, which leads to an increase in the levels of cyclic adenosine monophosphate (cAMP) in platelets. This, in turn, reduces the levels of intracellular calcium, which is necessary for platelet activation and aggregation.
Apart from its antiplatelet effects, dipyridamole also reduces the cellular uptake of adenosine, a molecule that plays a crucial role in regulating blood flow and oxygen delivery to tissues. By inhibiting the uptake of adenosine, dipyridamole can increase its levels in the bloodstream, leading to vasodilation and improved blood flow.
Another mechanism of action of dipyridamole is the inhibition of thromboxane synthase, an enzyme that is involved in the production of thromboxane A2, a potent platelet activator. By blocking this enzyme, dipyridamole can further reduce platelet activation and aggregation, thereby preventing the formation of blood clots.
In summary, dipyridamole exerts its antiplatelet effects through multiple mechanisms, including the inhibition of phosphodiesterase, the reduction of intracellular calcium levels, the inhibition of thromboxane synthase, and the modulation of adenosine uptake. These actions make it a valuable medication for preventing thrombotic events in patients with a history of stroke or transient ischemic attack.
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This question is part of the following fields:
- Cardiovascular System
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Question 18
Incorrect
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An individual who has been a lifelong smoker and is 68 years old arrives at the Emergency Department with a heart attack. During the explanation of his condition, a doctor mentions that the arteries supplying his heart have been narrowed and damaged. What substance is increased on endothelial cells after damage or oxidative stress, leading to the recruitment of monocytes to the vessel wall?
Your Answer:
Correct Answer: Vascular cell adhesion molecule-1
Explanation:VCAM-1 is a protein expressed on endothelial cells in response to pro-atherosclerotic conditions. It binds to lymphocytes, monocytes, and eosinophils, causing adhesion to the endothelium. Its expression is upregulated by cytokines and is critical in the development of atherosclerosis.
Understanding Acute Coronary Syndrome
Acute coronary syndrome (ACS) is a term used to describe various acute presentations of ischaemic heart disease. It includes ST elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI), and unstable angina. ACS usually develops in patients with ischaemic heart disease, which is the gradual build-up of fatty plaques in the walls of the coronary arteries. This can lead to a gradual narrowing of the arteries, resulting in less blood and oxygen reaching the myocardium, causing angina. It can also lead to sudden plaque rupture, resulting in a complete occlusion of the artery and no blood or oxygen reaching the area of myocardium, causing a myocardial infarction.
There are many factors that can increase the chance of a patient developing ischaemic heart disease, including unmodifiable risk factors such as increasing age, male gender, and family history, and modifiable risk factors such as smoking, diabetes mellitus, hypertension, hypercholesterolaemia, and obesity.
The classic and most common symptom of ACS is chest pain, which is typically central or left-sided and may radiate to the jaw or left arm. Other symptoms include dyspnoea, sweating, and nausea and vomiting. Patients presenting with ACS often have very few physical signs, and the two most important investigations when assessing a patient with chest pain are an electrocardiogram (ECG) and cardiac markers such as troponin.
Once a diagnosis of ACS has been made, treatment involves preventing worsening of the presentation, revascularising the vessel if occluded, and treating pain. For patients who’ve had a STEMI, the priority of management is to reopen the blocked vessel. For patients who’ve had an NSTEMI, a risk stratification tool is used to decide upon further management. Patients who’ve had an ACS require lifelong drug therapy to help reduce the risk of a further event, which includes aspirin, a second antiplatelet if appropriate, a beta-blocker, an ACE inhibitor, and a statin.
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This question is part of the following fields:
- Cardiovascular System
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Question 19
Incorrect
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A 67-year-old man with a stable angina history for two years visits his cardiologist for a regular check-up. During the review, the cardiologist observes that the patient's heart rate is low at 46 bpm. As a result, the cardiologist decides to replace his beta-blocker with a new anti-anginal drug called nicorandil.
What is the mode of action of the patient's new medication?Your Answer:
Correct Answer: Potassium channel activator through activation of guanylyl cyclase
Explanation:Nicorandil activates potassium channels, leading to vasodilation. This activation triggers guanylyl cyclase, which increases the production of cyclic GMP (cGMP) and activates protein kinase G (PKG). PKG phosphorylates and inhibits GTPase RhoA, reducing Rho-kinase activity and increasing myosin phosphatase activity. As a result, the smooth muscle becomes less sensitive to calcium, leading to dilation of the large coronary arteries and improved perfusion. Nicorandil does not significantly affect calcium or sodium channels. This mechanism helps alleviate anginal symptoms.
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 20
Incorrect
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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.
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This question is part of the following fields:
- Cardiovascular System
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Question 21
Incorrect
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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:
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 22
Incorrect
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A 78-year-old woman with a history of heart failure visits the clinic complaining of constipation that has lasted for 5 days. Upon further inquiry, she mentions feeling weaker than usual this week and experiencing regular muscle cramps. During the examination, you observe reduced tone and hyporeflexia in both her upper and lower limbs. You suspect that her symptoms may be caused by hypokalaemia, which could be related to the diuretics she takes to manage her heart failure. Which of the following diuretics is known to be associated with hypokalaemia?
Your Answer:
Correct Answer: Furosemide
Explanation:Hypokalaemia is a potential side effect of loop diuretics such as furosemide. In contrast, potassium-sparing diuretics like spironolactone, triamterene, eplerenone, and amiloride are more likely to cause hyperkalaemia. The patient in the scenario is experiencing symptoms suggestive of hypokalaemia, including muscle weakness, cramps, and constipation. Hypokalaemia can also cause fatigue, myalgia, hyporeflexia, and in rare cases, paralysis.
Loop Diuretics: Mechanism of Action and Clinical Applications
Loop diuretics, such as furosemide and bumetanide, are medications that inhibit the Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle. By doing so, they reduce the absorption of NaCl, resulting in increased urine output. Loop diuretics act on NKCC2, which is more prevalent in the kidneys. These medications work on the apical membrane and must first be filtered into the tubules by the glomerulus before they can have an effect. Patients with poor renal function may require higher doses to ensure sufficient concentration in the tubules.
Loop diuretics are commonly used in the treatment of heart failure, both acutely (usually intravenously) and chronically (usually orally). They are also indicated for resistant hypertension, particularly in patients with renal impairment. However, loop diuretics can cause adverse effects such as hypotension, hyponatremia, hypokalemia, hypomagnesemia, hypochloremic alkalosis, ototoxicity, hypocalcemia, renal impairment, hyperglycemia (less common than with thiazides), and gout. Therefore, careful monitoring of electrolyte levels and renal function is necessary when using loop diuretics.
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This question is part of the following fields:
- Cardiovascular System
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Question 23
Incorrect
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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 37.3ยบC
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 24
Incorrect
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An 85-year-old man presents to the hospital with complaints of breathlessness at rest. He has a medical history of type 2 diabetes and hypertension, for which he takes metformin, lisinopril, and metoprolol. He also smokes five cigarettes a day. On examination, he has a heart rate of 100 bpm, blood pressure of 128/90 mmHg, and a respiratory rate of 26 with oxygen saturation of 88% on 2l/minute. He has a regular, slow rising pulse, an ejection systolic murmur, crepitations at both lung bases, and oedema at the ankles and sacrum.
What investigation is most crucial for his immediate management?Your Answer:
Correct Answer: Electrocardiogram
Explanation:Managing Pulmonary Edema from Congestive Cardiac Failure
Pulmonary edema from congestive cardiac failure requires prompt investigation and management. The most crucial investigation is an ECG to check for a possible silent myocardial infarction. Even if the ECG is normal, a troponin test may be necessary to rule out a NSTEMI. Arterial blood gas analysis is also important to guide oxygen therapy. Additionally, stopping medications such as metformin, lisinopril, and metoprolol, and administering diuretics can help manage the condition.
It is likely that the patient has aortic stenosis, which is contributing to the cardiac failure. However, acute management of the valvular disease will be addressed separately. To learn more about heart failure and its management, refer to the ABC of heart failure articles by Millane et al. and Watson et al.
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This question is part of the following fields:
- Cardiovascular System
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Question 25
Incorrect
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A 59-year-old woman presents to a respiratory clinic with worsening breathlessness and a recent diagnosis of pulmonary hypertension. The decision is made to initiate treatment with bosentan. Can you explain the mechanism of action of this medication?
Your Answer:
Correct Answer: Endothelin antagonist
Explanation:Bosentan, a non-selective endothelin antagonist, is used to treat pulmonary hypertension by blocking the vasoconstrictive effects of endothelin. However, it may cause liver function abnormalities, requiring regular monitoring. Endothelin agonists would worsen pulmonary vasoconstriction and are not suitable for treating pulmonary hypertension. Guanylate cyclase stimulators like riociguat work with nitric oxide to dilate blood vessels and treat pulmonary hypertension. Sildenafil, a phosphodiesterase inhibitor, selectively reduces pulmonary vascular tone to treat pulmonary hypertension.
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.
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This question is part of the following fields:
- Cardiovascular System
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Question 26
Incorrect
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A 50-year-old man presents to the emergency department with acute chest pain. His ECG reveals ST depression in leads II, III, & aVF, and his troponin levels are elevated. He is diagnosed with NSTEMI and prescribed ticagrelor as part of his treatment plan.
What is the mechanism of action of ticagrelor?Your Answer:
Correct Answer: Inhibits ADP binding to platelet receptors
Explanation:Clopidogrel and ticagrelor have a similar mechanism of action in that they both inhibit the binding of ADP to platelet receptors. Heparin activates antithrombin III, which in turn inhibits factor Xa and IIa. DOACs like rivaroxaban directly inhibit factor Xa that is bound to the prothrombinase complex and associated with clots. Aspirin works by inhibiting the production of prostaglandins, while warfarin inhibits VKORC1, which is responsible for the activation of vitamin K.
ADP receptor inhibitors, such as clopidogrel, prasugrel, ticagrelor, and ticlopidine, work by inhibiting the P2Y12 receptor, which leads to sustained platelet aggregation and stabilization of the platelet plaque. Clinical trials have shown that prasugrel and ticagrelor are more effective than clopidogrel in reducing short- and long-term ischemic events in high-risk patients with acute coronary syndrome or undergoing percutaneous coronary intervention. However, ticagrelor may cause dyspnea due to impaired clearance of adenosine, and there are drug interactions and contraindications to consider for each medication. NICE guidelines recommend dual antiplatelet treatment with aspirin and ticagrelor for 12 months as a secondary prevention strategy for ACS.
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This question is part of the following fields:
- Cardiovascular System
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Question 27
Incorrect
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A 79-year-old man has just noticed that his heart is beating irregularly. Upon examination, his pulse is found to be irregularly irregular with a rate of 56 bpm. What ECG findings would you anticipate?
Your Answer:
Correct Answer: No P wave preceding each QRS complex
Explanation:Atrial Fibrillation and its Causes
Atrial fibrillation (AF) is a condition characterized by irregular heartbeats due to the constant activity of the atria. This can lead to the absence of distinct P waves, making it difficult to diagnose. AF can be caused by various factors such as hyperthyroidism, alcohol excess, mitral stenosis, and fibrous degeneration. The primary risks associated with AF are strokes and cardiac failure. Blood clots can form in the atria due to the lack of atrial movement, which can then be distributed into the systemic circulation, leading to strokes. High rates of AF can also cause syncopal episodes and cardiac failure.
The treatment of AF can be divided into controlling the rate or rhythm. If the rhythm cannot be controlled reliably, long-term anticoagulation with warfarin may be necessary to reduce the risk of stroke, depending on other risk factors. Bifid P waves are associated with hypertrophy of the left atrium, while regular P waves with no relation to QRS complexes are seen in complete heart block. Small P waves can be seen in hypokalaemia.
In cases of AF with shock, immediate medical attention is necessary, and emergency drug or electronic cardioversion may be needed. the causes and risks associated with AF is crucial in managing the condition and preventing complications.
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This question is part of the following fields:
- Cardiovascular System
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Question 28
Incorrect
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A 75-year-old woman complains of increasing shortness of breath in the past few months, especially when lying down at night. She has a history of type 2 diabetes and high blood pressure, which is managed with ramipril. She smokes 15 cigarettes per day. Her heart rate is 76 bpm, blood pressure is 160/95 mmHg, and oxygen saturation is 94% on room air. An ECG reveals sinus rhythm and left ventricular hypertrophy. On physical examination, there are no heart murmurs, but there is wheezing throughout the chest and coarse crackles at both bases. She has pitting edema in both ankles. Her troponin T level is 0.01 (normal range <0.02). What is the diagnosis for this patient?
Your Answer:
Correct Answer: Biventricular failure
Explanation:Diagnosis and Assessment of Biventricular Failure
This patient is exhibiting symptoms of both peripheral and pulmonary edema, indicating biventricular failure. The ECG shows left ventricular hypertrophy, which is likely due to her long-standing hypertension. While she is at an increased risk for a myocardial infarction as a diabetic and smoker, her low troponin T levels suggest that this is not the immediate cause of her symptoms. However, it is important to rule out acute coronary syndromes in diabetics, as they may not experience pain.
Mitral stenosis, if present, would be accompanied by a diastolic murmur and left atrial hypertrophy. In severe cases, back-pressure can lead to pulmonary edema. Overall, a thorough assessment and diagnosis of biventricular failure is crucial in determining the appropriate treatment plan for this patient.
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This question is part of the following fields:
- Cardiovascular System
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Question 29
Incorrect
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A 28-year-old, gravida 2 para 1, presents to the emergency department with pelvic pain. She delivered a healthy baby at 37 weeks gestation 13 days ago.
During the examination, it was found that she has right lower quadrant pain and her temperature is 37.8ยบ C. Further tests revealed a left gonadal (ovarian) vein thrombosis. The patient was informed about the risk of the thrombus lodging in the venous system from the left gonadal vein.
What is the first structure that the thrombus will go through if lodged from the left gonadal vein?Your Answer:
Correct Answer: Left renal vein
Explanation:The left gonadal veins empty into the left renal vein, meaning that any thrombus originating from the left gonadal veins would travel to the left renal vein. However, if the thrombus originated from the right gonadal vein, it would flow into the inferior vena cava (IVC) since the right gonadal vein directly drains into the IVC.
The portal vein is typically formed by the merging of the superior mesenteric and splenic veins, and it also receives blood from the inferior mesenteric, gastric, and cystic veins.
The superior vena cava collects venous drainage from the upper half of the body, specifically above the diaphragm.
Anatomy of the Inferior Vena Cava
The inferior vena cava (IVC) originates from the fifth lumbar vertebrae and is formed by the merging of the left and right common iliac veins. It passes to the right of the midline and receives drainage from paired segmental lumbar veins throughout its length. The right gonadal vein empties directly into the cava, while the left gonadal vein usually empties into the left renal vein. The renal veins and hepatic veins are the next major veins that drain into the IVC. The IVC pierces the central tendon of the diaphragm at the level of T8 and empties into the right atrium of the heart.
The IVC is related anteriorly to the small bowel, the first and third parts of the duodenum, the head of the pancreas, the liver and bile duct, the right common iliac artery, and the right gonadal artery. Posteriorly, it is related to the right renal artery, the right psoas muscle, the right sympathetic chain, and the coeliac ganglion.
The IVC is divided into different levels based on the veins that drain into it. At the level of T8, it receives drainage from the hepatic vein and inferior phrenic vein before piercing the diaphragm. At the level of L1, it receives drainage from the suprarenal veins and renal vein. At the level of L2, it receives drainage from the gonadal vein, and at the level of L1-5, it receives drainage from the lumbar veins. Finally, at the level of L5, the common iliac vein merges to form the IVC.
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This question is part of the following fields:
- Cardiovascular System
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Question 30
Incorrect
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A 78-year-old patient is having an upper gastrointestinal endoscopy to investigate gastro-oesophageal reflux disease. While the procedure is ongoing, the patient experiences several coughing episodes.
Which two cranial nerves are responsible for this reflex action?Your Answer:
Correct Answer: Cranial nerves IX and X
Explanation:The glossopharyngeal and vagus nerves, which are cranial nerves IX and X respectively, mediate the cough reflex. The facial nerve, or cranial nerve VII, is responsible for facial movements and taste in the anterior 2/3 of the tongue. The vestibulocochlear nerve, or cranial nerve VIII, is responsible for hearing and balance. Cranial nerve XI, also known as the spinal accessory nerve, innervates the sternocleidomastoid muscle and the trapezius muscle. The hypoglossal nerve, or cranial nerve XII, is responsible for the motor innervation of most of the tongue, and damage to this nerve can cause the tongue to deviate towards the side of the lesion when protruded.
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.
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This question is part of the following fields:
- Cardiovascular System
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