CVT ECG Interpretation & Analysis 2 — Questions and Answers
Question 1: Which ECG finding is most characteristic of Wolff-Parkinson-White (WPW) syndrome?
- Prolonged QT interval
- Delta wave with short PR interval (Correct answer)
- Tall peaked P waves
- Widened QRS with left axis deviation
Correct answer: Delta wave with short PR interval
WPW is characterized by a delta wave (slurred QRS upstroke) and a short PR interval (<120 ms) due to an accessory pathway bypassing the AV node.
Question 2: A patient's ECG shows an RSR' pattern in V1 and a wide S wave in lead I. This pattern is consistent with:
- Left bundle branch block
- Right bundle branch block (Correct answer)
- Left anterior fascicular block
- Posterior fascicular block
Correct answer: Right bundle branch block
Right bundle branch block (RBBB) produces an RSR' (rabbit ears) pattern in V1 and a wide S wave in leads I and V6.
Question 3: On a 12-lead ECG, ST elevation in leads II, III, and aVF with reciprocal depression in I and aVL suggests:
- Anterior STEMI
- Lateral STEMI
- Inferior STEMI (Correct answer)
- Posterior STEMI
Correct answer: Inferior STEMI
Leads II, III, and aVF are inferior leads; ST elevation there with reciprocal changes in high lateral leads (I, aVL) localizes the infarct to the inferior wall.
Question 4: Torsades de pointes is most closely associated with which underlying ECG abnormality?
- Short PR interval
- Prolonged QT interval (Correct answer)
- Delta waves
- ST depression in V4-V6
Correct answer: Prolonged QT interval
Torsades de pointes is a polymorphic ventricular tachycardia that arises in the setting of a prolonged QT interval, creating dispersion of repolarization.
Question 5: Which lead provides the best view for identifying P waves in a patient with a rapid heart rate?
- Lead I
- Lead aVR
- Lead V1 (Correct answer)
- Lead V5
Correct answer: Lead V1
Lead V1 is positioned over the right atrium and clearly shows P wave morphology, making it ideal for identifying atrial activity at fast heart rates.
Question 6: A QRS axis of -60° is best described as:
- Normal axis
- Right axis deviation
- Left axis deviation (Correct answer)
- Extreme axis deviation
Correct answer: Left axis deviation
Left axis deviation is defined as a QRS axis more negative than -30°; an axis of -60° falls within this range.
Question 7: Which of the following ECG changes is consistent with hyperkalemia?
- Prominent U waves
- Short QT interval
- Peaked (tall, narrow) T waves (Correct answer)
- Prolonged PR with delta wave
Correct answer: Peaked (tall, narrow) T waves
Hyperkalemia causes tall, narrow, peaked (tented) T waves as an early sign due to increased resting membrane potential.
CVT ECG Interpretation & Analysis 2
Which ECG finding is most characteristic of Wolff-Parkinson-White (WPW) syndrome?