Cardiology MCQs: Part 5
Answered: 0 / 25
Current Score
1. What is the specific mechanism of action of the heart failure medication Ivabradine?
Explanation: Ivabradine specifically binds to and inhibits the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in the SA node, blocking the If current to lower heart rate without affecting contractility.
2. Which of the following is the most common cause of restrictive cardiomyopathy in the developed world?
Explanation: In the developed world, cardiac amyloidosis (both AL and ATTR types) is the leading cause of restrictive cardiomyopathy. Endomyocardial fibrosis is more common in tropical regions.
3. A classic ECG finding associated with severe hypokalemia is:
Explanation: Hypokalemia typically presents on an ECG with ST segment depression, flattening or inversion of T waves, and prominent U waves (creating an apparent prolonged QT, though it is actually the QU interval).
4. Which anomalous coronary artery origin carries the highest risk of sudden cardiac death, particularly in young athletes?
Explanation: Anomalous origin of the Left Main (or LAD) from the right coronary cusp with an interarterial course (between the aorta and pulmonary artery) carries the highest risk of compression and sudden death during exertion.
5. The physical sign “Pulsus parvus et tardus” is most characteristically associated with which valvular lesion?
Explanation: Pulsus parvus (weak, small amplitude) et tardus (delayed peak) is the classic arterial pulse finding in severe, fixed aortic valve stenosis due to delayed and reduced LV emptying.
6. The Austin Flint murmur is a mid-to-late diastolic rumble heard at the apex. It is functionally created by which underlying pathology?
Explanation: Severe AR jets can impinge on the anterior leaflet of the mitral valve, prematurely closing it and creating a functional mitral stenosis rumble known as the Austin Flint murmur.
7. What echocardiographic parameter is the most sensitive and early predictor for anthracycline-induced cardiotoxicity?
Explanation: A relative reduction in GLS of >15% from baseline is an early, highly sensitive marker of subclinical left ventricular dysfunction in patients receiving cardiotoxic chemotherapy, occurring before a drop in LVEF.
8. Which class of oral anti-diabetic medications has become a foundational “4th pillar” of Guideline-Directed Medical Therapy (GDMT) for HFrEF regardless of diabetes status?
Explanation: SGLT2 inhibitors (like Dapagliflozin and Empagliflozin) have shown dramatic reductions in cardiovascular mortality and heart failure hospitalizations in HFrEF patients, even in those without diabetes.
9. The “scooped” ST-segment depression on an ECG (often resembling Salvador Dali’s mustache) is indicative of:
Explanation: This specific morphology is known as “digoxin effect.” It indicates that the patient is taking digoxin, but does not necessarily imply digoxin toxicity (which presents with arrhythmias or AV block).
10. Congenital complete heart block in a neonate is most strongly associated with maternal antibodies against:
Explanation: Maternal anti-Ro (SSA) and anti-La (SSB) antibodies (associated with SLE or Sjögren’s syndrome) can cross the placenta and destroy the fetal AV node, causing irreversible congenital heart block.
11. In a normal Jugular Venous Pressure (JVP) tracing, the “y descent” corresponds to:
Explanation: The ‘y’ descent marks the fall in right atrial pressure as the tricuspid valve opens and blood rapidly empties into the right ventricle during early diastole.
12. In cardiac tamponade, which component of the JVP tracing is typically blunted or absent?
Explanation: In cardiac tamponade, early diastolic filling is severely restricted due to external pericardial pressure. This prevents the normal rapid drop in atrial pressure, leading to a blunted or absent ‘y’ descent.
13. What is the most common cardiac source of systemic emboli (e.g., causing ischemic stroke)?
Explanation: In patients with atrial fibrillation (the most common cause of cardioembolic stroke), over 90% of thrombi form in the poorly contractile left atrial appendage.
14. Lutembacher syndrome is classically defined by the presence of an Atrial Septal Defect (ASD) in combination with:
Explanation: Lutembacher syndrome is a rare combination of a congenital ostium secundum ASD and acquired rheumatic mitral stenosis.
15. According to guidelines, what calculated aortic valve area defines “severe” aortic stenosis?
Explanation: Severe aortic stenosis is hemodynamically defined as an aortic valve area ≤ 1.0 cm², a mean transvalvular gradient ≥ 40 mmHg, or a peak velocity ≥ 4.0 m/s.
16. How is Mean Arterial Pressure (MAP) most accurately estimated at rest?
Explanation: Because diastole lasts approximately twice as long as systole at rest, MAP is calculated as the Diastolic Pressure plus one-third of the Pulse Pressure (SBP – DBP).
17. Which MRI finding is a hallmark characteristic of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)?
Explanation: ARVC is characterized pathologically and on MRI by progressive fibrofatty infiltration of the right ventricular free wall, predisposing the patient to fatal ventricular arrhythmias.
18. Orthostatic hypotension is clinically defined as a sustained reduction in systolic BP or diastolic BP within 3 minutes of standing by at least:
Explanation: The standard definition of orthostatic hypotension is a drop in systolic BP of ≥20 mm Hg or diastolic BP of ≥10 mm Hg within 3 minutes of assuming an upright posture.
19. The potent P2Y12 inhibitor Prasugrel is absolutely contraindicated in patients with a history of:
Explanation: Due to a significantly increased risk of fatal intracranial hemorrhage, prasugrel is strictly contraindicated in patients with any prior history of TIA or stroke.
20. What is the standard pattern of genetic inheritance for Hypertrophic Cardiomyopathy (HCM)?
Explanation: HCM is most commonly caused by mutations in sarcomere protein genes (like MYH7 and MYBPC3) and is inherited in an autosomal dominant pattern.
21. In a patient presenting with an inferior STEMI, ST-segment elevation in which specific right-sided ECG lead is highly diagnostic of concomitant Right Ventricular (RV) infarction?
Explanation: ST elevation > 1mm in right-sided lead V4R is the most sensitive and specific ECG sign for right ventricular infarction, guiding therapy (volume loading, avoiding nitrates).
22. What is the specific monoclonal antibody fragment used as a rapid reversal agent for the direct thrombin inhibitor Dabigatran?
Explanation: Idarucizumab (Praxbind) binds specifically and irreversibly to dabigatran, rapidly neutralizing its anticoagulant effect in emergency bleeding situations. Andexanet alfa is for factor Xa inhibitors (apixaban, rivaroxaban).
23. Which drug is considered first-line medical therapy for symptomatic relief in patients with Hypertrophic Cardiomyopathy (HCM)?
Explanation: Beta-blockers decrease heart rate (prolonging diastole and filling) and reduce myocardial contractility, which decreases the left ventricular outflow tract gradient and relieves angina and dyspnea.
24. The presence of a prominent, systolic, harsh murmur that radiates to the carotids, coupled with an absent or diminished second heart sound (S2), suggests:
Explanation: Radiation to the carotids and an absent or paradoxically split S2 (due to rigid, immobile aortic leaflets) are hallmark physical findings of severe aortic stenosis.
25. Carvallo’s sign is an auscultatory finding characterized by:
Explanation: Carvallo’s sign (or Rivero-Carvallo sign) is the amplification of a right-sided heart murmur, notably tricuspid regurgitation, during inspiration due to increased venous return to the right heart.