CCS Cardiac Rhythm Interpretation & ECG Analysis 3

Question 1

Which ECG finding pattern is most suggestive of acute pericarditis?

Accepted Answer

Diffuse ST elevation in multiple leads with PR segment depression

Answer

Acute pericarditis classically shows diffuse ST elevation in multiple leads (except aVR and V1) accompanied by PR depression, without the reciprocal changes or Q waves seen in STEMI.

Question 2

What is the clinical significance of a corrected QT interval (QTc) greater than 500 ms?

Accepted Answer

It significantly increases the risk of torsades de pointes and sudden cardiac death

Answer

A QTc >500 ms represents severe QT prolongation, which greatly increases the risk of triggered torsades de pointes and potentially fatal ventricular arrhythmias.

Question 3

In normal sinus rhythm, in which standard lead is the P wave consistently upright (positive)?

Accepted Answer

Lead II

Answer

In sinus rhythm, the P wave is upright in lead II because atrial depolarization travels inferiorly and to the left from the SA node, aligned with the positive pole of lead II.

Question 4

What is the characteristic ECG pattern of Mobitz Type II (second-degree AV block)?

Accepted Answer

Constant PR interval with sudden non-conducted P waves (dropped QRS beats)

Answer

Mobitz Type II features a constant PR interval with sudden, unpredictable failure of AV conduction, producing dropped QRS complexes without prior PR lengthening.

Question 5

Which ECG finding in leads V1–V2 is pathognomonic of a posterior myocardial infarction?

Accepted Answer

Tall broad R waves, ST depression, and upright T waves in V1–V2

Answer

Posterior MI produces reciprocal changes in V1–V2 including tall, broad R waves, horizontal ST depression, and upright T waves—mirror images of the posterior injury current.

(CCS) Certified Cardiovascular Specialist Practice Test

(CCS) Certified Cardiovascular Specialist Practice Test

CCS Cardiac Rhythm Interpretation & ECG Analysis 3