New Series of Interactive Cardiology MCQs 1

Correct Answer: B) ST elevation in leads II, III, and aVF

Explanation: Leads II, III, and aVF look at the inferior wall of the left ventricle, which is typically supplied by the right coronary artery (RCA). ST segment elevation in these specific leads is the hallmark sign of an acute inferior myocardial infarction.

Correct Answer: C) Left-sided heart failure

Explanation: While primary pulmonary conditions (cor pulmonale) can cause right heart failure, the most common overall cause of right-sided heart failure is secondary to left-sided heart failure. The failing left ventricle increases pressure in the pulmonary circulation, which eventually overloads and damages the right ventricle.

Correct Answer: B) Delta wave

Explanation: A delta wave—a slurred upstroke on the QRS complex—along with a shortened PR interval, is characteristic of WPW syndrome. It occurs because an accessory electrical pathway (Bundle of Kent) bypasses the AV node, causing early activation (pre-excitation) of the ventricles.

Correct Answer: C) Prothrombin Complex Concentrate (PCC) and Vitamin K

Explanation: In cases of severe, life-threatening bleeding associated with Warfarin (a Vitamin K antagonist), immediate reversal is achieved using Prothrombin Complex Concentrate (PCC), which provides rapid replacement of clotting factors II, VII, IX, and X. IV Vitamin K is administered concurrently for sustained reversal. Protamine is the reversal agent for heparin.

Correct Answer: B) 0.12 to 0.20 seconds

Explanation: The normal PR interval, which represents the time it takes for an electrical impulse to travel from the SA node, through the AV node, and into the ventricles, is between 0.12 and 0.20 seconds (3 to 5 small squares on standard ECG paper). A prolonged PR interval (>0.20s) indicates first-degree AV block.