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

ST elevation in a single territory with reciprocal ST depression

Answer

Q waves in anterior leads with deep T wave inversions

Answer

Right bundle branch block with ST elevation in V1–V2

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

It represents a normal variant in women

Answer

It indicates bundle branch block

Answer

It is diagnostic of accelerated junctional rhythm

Question 3

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

Accepted Answer

Lead II

Answer

aVR

Answer

V1

Answer

aVL

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

Progressive PR prolongation followed by a dropped QRS complex

Answer

Complete AV dissociation with independent P wave and QRS rates

Answer

Shortened PR interval with intermittently widened QRS complexes

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

ST elevation in V1–V3 with Q waves

Answer

Q waves in leads II, III, and aVF

Answer

ST elevation in leads I and aVL with lateral Q waves

Question 6

Which ECG finding best characterizes an atrial premature complex (APC)?

Accepted Answer

An early beat with an abnormally shaped P wave followed by a normal narrow QRS

Answer

An early wide QRS complex preceded by no visible P wave

Answer

An early beat with AV dissociation and fusion beats

Answer

An early narrow QRS with a retrograde P wave in the ST segment

Question 7

During an inferior MI (ST elevation in II, III, aVF), what does ST depression in V1–V3 most commonly indicate?

Accepted Answer

Reciprocal changes or posterior wall extension of the infarction

Answer

A simultaneous anterior MI

Answer

Left main coronary artery occlusion

Answer

A normal finding with no clinical significance