Cardiology Practice Questions

Q: In a 60-year-old man with chronic heart failure, what is the most likely cause of decreased exercise tolerance?

Decreased cardiac output. ***Decreased cardiac output*** - **Chronic heart failure** is characterized by the heart's inability to pump sufficient blood to meet the body's metabolic demands, directly leading to **decreased cardiac output**. [1] - Reduced cardiac output limits oxygen delivery to muscles during exertion, causing **fatigue** and decreased **exercise tolerance**. [1] *Increased systemic vascular resistance* - While **increased systemic vascular resistance (SVR)** can occur in heart failure as a compensatory mechanism (due to activation of the **renin-angiotensin-aldosterone system** and sympathetic nervous system), it primarily raises afterload and further impedes cardiac output, rather than being the direct cause of exercise intolerance. - The direct cause of reduced exercise capacity is the resultant **lowered cardiac output**, which this increased resistance contributes to. *Decreased total peripheral resistance* - **Decreased total peripheral resistance** would typically improve cardiac output by reducing afterload, and thus would not be a cause of decreased exercise tolerance in chronic heart failure. - In fact, in chronic heart failure, compensatory mechanisms often lead to **increased**, not decreased, peripheral resistance. *Increased stroke volume due to compensatory mechanisms* - In heart failure, the **stroke volume** is typically **reduced** due to impaired contractility or filling. [1] - While compensatory mechanisms like **Frank-Starling law** (increased preload) can transiently increase stroke volume, chronic heart failure is fundamentally marked by a **failing heart** and an overall inability to maintain adequate stroke volume and cardiac output, especially during exertion. [1]

Q: A 60-year-old patient presents with chest pain and a crescendo-decrescendo systolic murmur that radiates to the neck. What is the most likely diagnosis?

Aortic stenosis. ***Aortic stenosis*** - A **crescendo-decrescendo systolic murmur** radiating to the **neck** is a classic finding in aortic stenosis, indicative of turbulent flow through a narrowed aortic valve during systole [1]. - Chest pain in this context is often due to increased myocardial oxygen demand from the pressure overload [2]. *Mitral valve prolapse* - Characterized by a **mid-systolic click** followed by a **late systolic murmur**, and typically does not radiate to the neck [1]. - Symptoms can include atypical chest pain and palpitations, but the murmur presentation is distinct. *Mitral regurgitation* - Produces a **holosystolic murmur** that radiates to the **axilla**, not the neck, due to blood flowing back into the left atrium [3]. - The murmur in mitral regurgitation is usually plateau-shaped, unlike the crescendo-decrescendo pattern. *Aortic regurgitation* - Causes a **diastolic decrescendo murmur** best heard at the left sternal border, resulting from blood leaking back into the left ventricle during diastole [4]. - This condition does not present with a systolic murmur radiating to the neck.

Q: A 35-year-old male experiences sudden chest pain and shortness of breath. An ECG reveals ST-segment elevation. What is the most likely underlying physiological process?

Myocardial infarction. ***Myocardial infarction*** - **ST-segment elevation** on an ECG is a classic sign of an **ST-elevation myocardial infarction (STEMI)**, indicating transmural ischemia [2]. - This is caused by a complete and sustained occlusion of a **coronary artery**, leading to myocardial cell death [1] [3]. *Aortic dissection* - While it causes sudden severe chest pain, an aortic dissection typically presents with a **tearing or ripping pain** and often involves pulse deficits or blood pressure differentials. - ECG findings are usually non-specific or show signs of left ventricular hypertrophy, but **ST-segment elevation** is not characteristic. *Pulmonary embolism* - Pulmonary embolism presents with sudden chest pain and shortness of breath, but its hallmark ECG finding is often **tachycardia** and signs of right heart strain (e.g., S1Q3T3 pattern). - It does not typically cause **ST-segment elevation** unless it's a massive PE leading to severe myocardial ischemia secondary to profound hypotension. *Pericarditis* - Pericarditis causes chest pain that is often **sharp, pleuritic**, and relieved by leaning forward, and it can cause diffuse **ST-segment elevation** on ECG. - However, in pericarditis, the ST elevation is typically **concave up** and widespread, rather than localized to specific coronary territories as seen in myocardial infarction [3].

Q: Which anticoagulant is recommended for preventing thromboembolism in patients with mechanical heart valves?

Warfarin. ***Warfarin*** - **Warfarin** is a vitamin K antagonist that effectively prevents thrombosis on the high-thrombogenic surface of mechanical heart valves. - Its efficacy in this specific patient population is well-established, with **dosing adjusted** to achieve a target international normalized ratio (INR) of 2.5-3.5. *Aspirin* - While aspirin has antiplatelet effects, it is generally **insufficient as monotherapy** for thrombosis prevention in patients with mechanical heart valves. - It is sometimes used as an **adjunctive therapy** with warfarin but does not replace it as the primary anticoagulant. *Rivaroxaban* - **Direct oral anticoagulants (DOACs)** like rivaroxaban are generally **contraindicated** in patients with mechanical heart valves due to increased risk of thromboembolism and bleeding complications. - Studies have shown **inferiority** of DOACs compared to warfarin in this population. *Dabigatran* - Similar to rivaroxaban, **dabigatran** is a direct thrombin inhibitor and is **not recommended** for patients with mechanical heart valves. - Clinical trials have demonstrated an **increased risk of stroke and bleeding** with dabigatran compared to warfarin in this setting.

Q: A 72-year-old patient presents with the acute onset of chest pain and electrocardiographic changes indicative of an anterior wall myocardial infarction. What is the most effective initial treatment?

Primary percutaneous coronary intervention (PCI). ### Primary percutaneous coronary intervention (PCI) - For **ST-segment elevation myocardial infarction (STEMI)**, primary PCI is the most effective initial treatment as it directly restores blood flow to the ischemic myocardium by opening the occluded coronary artery [2]. - Guidelines recommend PCI within **90 minutes door-to-balloon time** or 120 minutes if transfer to a PCI-capable facility is required. *High-dose aspirin therapy* - While **aspirin** is crucial for its antiplatelet effects and is part of the initial management of MI, it is not the definitive treatment for reperfusion. - It helps prevent further thrombus formation but does not actively dissolve or remove the existing occlusive clot. *Intravenous nitroglycerin* - **Nitroglycerin** helps relieve angina by causing vasodilation, reducing preload and afterload, and improving coronary blood flow, but it does not directly open a completely occluded artery. - It is contraindicated in cases of **inferior wall MI with right ventricular involvement** due to the risk of severe hypotension. *Oral beta-blocker therapy* - **Beta-blockers** reduce myocardial oxygen demand, limit infarct size, and prevent arrhythmias, but they do not provide immediate reperfusion [1]. - They are typically initiated after the acute phase, once the patient is hemodynamically stable, or in specific clinical scenarios [1].

Q: Which of the following best describes the initial management of a patient with Klippel-Trenaunay syndrome?

Conservative management with compression stockings. ***Conservative management with compression stockings*** * **Klippel-Trenaunay syndrome (KTS)** is a congenital disorder characterized by a triad of capillary malformations (port-wine stains), venous malformations (varicose veins), and limb overgrowth. * Initial management focuses on alleviating symptoms and preventing complications through non-invasive methods, with **compression garments** being crucial for managing lymphedema, venous insufficiency, and pain. *Immediate surgical intervention* * **Surgical intervention** in KTS is typically reserved for severe complications or functional impairment, like limb length discrepancy or arterial-venous fistulas, which are not the primary initial approach. * Non-conservative measures are usually explored only after conservative treatment fails or if there are life-threatening complications. *Sclerotherapy for varicose veins* * While sclerotherapy can be used for **varicose veins** in KTS, it is usually considered after or in conjunction with conservative management. * It specifically targets the venous malformations but does not address the other components like **limb overgrowth** or comprehensive symptom management in the initial phase. *Lymphatic drainage* * **Manual lymphatic drainage (MLD)** is a component of complete decongestive therapy for managing lymphedema. * While lymphedema can be a feature of KTS, **lymphatic drainage** alone is usually part of a broader conservative strategy that often includes compression therapy.

Q: A 55-year-old woman with a history of rheumatic fever presents with exertional dyspnea and palpitations. On examination, there is a mid-diastolic murmur at the apex. Which valvular abnormality is most likely present?

Mitral stenosis. ***Mitral stenosis*** - A history of **rheumatic fever** is a common cause of mitral stenosis [1], leading to thickening and calcification of the mitral valve. - The classic auscultatory finding in mitral stenosis is a **mid-diastolic murmur heard best at the apex** [1]. Exertional dyspnea and palpitations are symptoms of left atrial enlargement and pulmonary congestion [1]. *Aortic stenosis* - While aortic stenosis can cause exertional dyspnea and palpitations, its characteristic murmur is a **systolic ejection murmur** heard best at the right upper sternal border, often radiating to the carotid arteries. - Aortic stenosis is more commonly associated with **degenerative calcification** in older adults [2] or a bicuspid aortic valve, rather than rheumatic fever as the primary cause in this age group, though rheumatic fever can affect this valve too. *Tricuspid regurgitation* - This condition presents with a **holosystolic murmur** best heard at the left lower sternal border, which typically **intensifies with inspiration**. - While rheumatic fever can affect the tricuspid valve, isolated tricuspid regurgitation is less common as the primary finding with these symptoms and a mid-diastolic murmur is not characteristic. *Pulmonic stenosis* - Pulmonic stenosis is characterized by a **systolic ejection murmur** heard best at the left upper sternal border, often associated with a thrill. - Symptoms like exertional dyspnea and palpitations can occur, but it is less commonly caused by rheumatic fever and does not produce a mid-diastolic murmur at the apex.

Q: A 70-year-old man with chronic heart failure is currently on optimal medical therapy with an ACE inhibitor, beta-blocker, and loop diuretic, but is experiencing worsening symptoms. Which diuretic should be added to his regimen to provide additional benefit?

Spironolactone. ***Spironolactone*** - As an **aldosterone antagonist**, spironolactone is particularly indicated for **HFrEF (Heart Failure with reduced Ejection Fraction)** based on landmark trials like **RALES** and **EMPHASIS-HF**, providing additional diuretic effects and mortality benefit. - It's typically used as **add-on therapy** in patients already on **ACE inhibitors/ARBs** and **beta-blockers**, offering **cardioprotective benefits** by reducing myocardial fibrosis and improving ventricular remodeling. *Furosemide* - Furosemide is a **loop diuretic** often used as **first-line therapy** in heart failure for rapid symptom relief, but the question implies a patient already on a regimen needing *additional* relief. - While it can be **titrated upward**, adding another class of diuretic like an aldosterone antagonist provides **synergistic effects** and addresses different pathophysiological mechanisms. *Hydrochlorothiazide* - Hydrochlorothiazide is a **thiazide diuretic** typically used for **hypertension** or mild edema, which has **limited efficacy** in advanced heart failure due to reduced renal perfusion. - Its diuretic effect is generally **weaker than loop diuretics** and not usually the preferred add-on for worsening symptoms in chronic heart failure. *Mannitol* - Mannitol is an **osmotic diuretic** primarily used to reduce **intracranial** or **intraocular pressure**, not for chronic heart failure management. - It can **acutely increase intravascular volume**, which might worsen heart failure symptoms in patients with compromised cardiac function.

Q: A 50-year-old male with a history of hypertension presents with sudden, severe chest pain radiating to the back. CT angiography reveals an aortic dissection. What is the best immediate management?

Blood pressure control with IV beta-blockers. ***Blood pressure control with IV beta-blockers*** - Immediate management of **aortic dissection** involves rapidly reducing **blood pressure** and **heart rate** to decrease shear stress on the aortic wall [2]. - **Intravenous beta-blockers** are the first-line agents for this purpose, as they achieve both **heart rate** and **blood pressure reduction** [3]. *Surgical repair* - While ultimately necessary for **Type A dissections** (involving the ascending aorta), it is not the *immediate* first step [2]. - **Hemodynamic stabilization** with medication is critical prior to surgery to reduce the risk of further dissection or rupture during transport and preparation. *Observation* - **Aortic dissection** is a medical emergency with high mortality if untreated [2]. - **Observation** alone is inappropriate and would lead to rapid deterioration and potentially death. *Administration of thrombolytics* - **Thrombolytics** are used to dissolve clots in conditions like **myocardial infarction** or **stroke** [1]. - In aortic dissection, thrombolytics are **contraindicated** as they can worsen bleeding and lead to catastrophic rupture.

Q: A patient with suspected myocardial infarction has a troponin I level of 0.5 ng/mL (normal <0.4 ng/mL). What is the next best step in managing this patient?

Obtain 12-lead ECG. ***Obtain 12-lead ECG*** - An elevated **troponin I level** (even if mildly elevated above the normal threshold) in the context of suspected **myocardial infarction** necessitates further investigation to assess for acute cardiac injury [3]. - A **12-lead ECG** is crucial for identifying acute ischemic changes (e.g., **ST-segment elevation or depression**, **T-wave inversions**) which can guide immediate management decisions [1], [2]. *Discharge with lifestyle modification* - Discharging the patient with an elevated **troponin I** without further evaluation would be premature and potentially harmful, as it indicates ongoing myocardial injury. - **Lifestyle modifications** are important for long-term cardiovascular health but are not an immediate management step for acute cardiac symptoms and elevated biomarkers. *Repeat troponin in 3 hours* - While serial troponin measurements are essential for evaluating the **kinetics of cardiac injury**, an initial elevated value requires immediate assessment of the electrical activity of the heart. - Waiting to repeat troponin before getting an **ECG** could delay critical interventions if acute myocardial ischemia is present. *Immediate thrombolysis* - **Thrombolysis** is a treatment reserved for specific scenarios of **ST-elevation myocardial infarction (STEMI)** where percutaneous coronary intervention (PCI) is not immediately available. - Administering thrombolysis based solely on an elevated troponin without an **ECG** confirming STEMI or without consideration of contraindications would be inappropriate and potentially dangerous [2].

Question 1

In a 60-year-old man with chronic heart failure, what is the most likely cause of decreased exercise tolerance?

Accepted Answer

Decreased cardiac output

Answer

Decreased total peripheral resistance

Answer

Increased systemic vascular resistance

Answer

Increased stroke volume due to compensatory mechanisms

Question 2

A 60-year-old patient presents with chest pain and a crescendo-decrescendo systolic murmur that radiates to the neck. What is the most likely diagnosis?

Accepted Answer

Aortic stenosis

Answer

Mitral valve prolapse

Answer

Mitral regurgitation

Answer

Aortic regurgitation

Question 3

A 35-year-old male experiences sudden chest pain and shortness of breath. An ECG reveals ST-segment elevation. What is the most likely underlying physiological process?

Accepted Answer

Myocardial infarction

Answer

Aortic dissection

Answer

Pulmonary embolism

Answer

Pericarditis

Question 4

Which anticoagulant is recommended for preventing thromboembolism in patients with mechanical heart valves?

Accepted Answer

Warfarin

Answer

Aspirin

Answer

Rivaroxaban

Answer

Dabigatran

Question 5

A 72-year-old patient presents with the acute onset of chest pain and electrocardiographic changes indicative of an anterior wall myocardial infarction. What is the most effective initial treatment?

Accepted Answer

Primary percutaneous coronary intervention (PCI)

Answer

High-dose aspirin therapy

Answer

Intravenous nitroglycerin

Answer

Oral beta-blocker therapy

Question 6

Which of the following best describes the initial management of a patient with Klippel-Trenaunay syndrome?

Accepted Answer

Conservative management with compression stockings

Answer

Immediate surgical intervention

Answer

Sclerotherapy for varicose veins

Answer

Lymphatic drainage

Question 7

A 55-year-old woman with a history of rheumatic fever presents with exertional dyspnea and palpitations. On examination, there is a mid-diastolic murmur at the apex. Which valvular abnormality is most likely present?

Accepted Answer

Mitral stenosis

Answer

Aortic stenosis

Answer

Tricuspid regurgitation

Answer

Pulmonic stenosis

Question 8

A 70-year-old man with chronic heart failure is currently on optimal medical therapy with an ACE inhibitor, beta-blocker, and loop diuretic, but is experiencing worsening symptoms. Which diuretic should be added to his regimen to provide additional benefit?

Accepted Answer

Spironolactone

Answer

Furosemide

Answer

Hydrochlorothiazide

Answer

Mannitol

Question 9

A 50-year-old male with a history of hypertension presents with sudden, severe chest pain radiating to the back. CT angiography reveals an aortic dissection. What is the best immediate management?

Accepted Answer

Blood pressure control with IV beta-blockers

Answer

Surgical repair

Answer

Observation

Answer

Administration of thrombolytics

Question 10

A patient with suspected myocardial infarction has a troponin I level of 0.5 ng/mL (normal <0.4 ng/mL). What is the next best step in managing this patient?

Accepted Answer

Obtain 12-lead ECG

Answer

Discharge with lifestyle modification

Answer

Repeat troponin in 3 hours

Answer

Immediate thrombolysis

Cardiology — MCQs

Cardiology — MCQs

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