1. Which of the following ECG changes is most indicative of an acute inferior myocardial infarction?
- A) ST elevation in leads V1, V2, and V3
- B) ST elevation in leads II, III, and aVF
- C) ST elevation in leads I, aVL, V5, and V6
- D) Peaked T waves in leads V2 to V4
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.
2. What is the most common cause of right-sided heart failure?
- A) Cor pulmonale
- B) Tricuspid valve regurgitation
- C) Left-sided heart failure
- D) Pulmonary embolism
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.
3. Which of the following ECG findings is pathognomonic for Wolff-Parkinson-White (WPW) syndrome?
- A) Prolonged PR interval with dropped beats
- B) Delta wave (slurred upstroke of the QRS complex)
- C) U waves
- D) Diffuse PR segment depression
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.
4. What is the standard first-line reversal agent for patients experiencing severe bleeding while on Warfarin?
- A) Protamine sulfate
- B) Idarucizumab
- C) Prothrombin Complex Concentrate (PCC) and Vitamin K
- D) Desmopressin (DDAVP)
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.
5. In a normal adult resting ECG, what is the standard duration of a normal PR interval?
- A) 0.04 to 0.10 seconds
- B) 0.12 to 0.20 seconds
- C) 0.20 to 0.24 seconds
- D) 0.35 to 0.44 seconds
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.