ECG Clinical Applications 2

Question 1

A patient with acute anterior MI develops a new right bundle branch block. Which ECG lead best demonstrates the RBBB pattern?

Accepted Answer

Lead V1

Answer

RBBB produces an RSR' (rabbit ears) pattern best seen in V1 with a wide S wave in lead I.

Question 2

A patient presents with syncope. ECG shows a QTc of 520 ms. Which medication is most likely responsible?

Accepted Answer

Amiodarone

Answer

Amiodarone prolongs the QT interval significantly and is a common iatrogenic cause of QTc prolongation.

Question 3

An ECG shows ST elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?

Accepted Answer

Right coronary artery

Answer

ST elevation in inferior leads (II, III, aVF) indicates inferior MI, most commonly due to RCA occlusion.

Question 4

A patient with known COPD shows peaked P waves exceeding 2.5 mm in lead II. This finding is called:

Accepted Answer

P pulmonale

Answer

Tall, peaked P waves in lead II (>2.5 mm) indicate right atrial enlargement, termed P pulmonale, commonly seen in chronic lung disease.

Question 5

Which ECG change is most characteristic of hyperkalemia?

Accepted Answer

Tall peaked T waves

Answer

Hyperkalemia causes tall, narrow, peaked (tent-shaped) T waves as an early finding due to altered ventricular repolarization.

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