CCT Rhythm Analysis: Atrial/Junctional 2

Question 1

What ECG characteristics are used to identify atrial flutter with 2:1 conduction?

Accepted Answer

Sawtooth flutter waves at approximately 300 bpm with a regular ventricular rate of approximately 150 bpm

Answer

Irregularly irregular ventricular rhythm with absent P waves

Answer

Regular P waves at 75 bpm with normal PR intervals

Answer

Chaotic atrial activity at 400-700 bpm with irregular QRS complexes

Question 2

Which ECG finding is pathognomonic for Wolff-Parkinson-White (WPW) syndrome during sinus rhythm?

Accepted Answer

Short PR interval (< 0.12 sec) plus a delta wave (slurred QRS onset) plus wide QRS

Answer

Long PR interval with normal QRS morphology

Answer

Right bundle branch block pattern with RSR' in V1

Answer

Sawtooth flutter waves with regular ventricular response

Question 3

Multifocal atrial tachycardia (MAT) is most commonly associated with which underlying condition?

Accepted Answer

Chronic obstructive pulmonary disease (COPD) and other severe pulmonary conditions

Answer

Hypothyroidism

Answer

Hypertensive heart disease with left atrial enlargement

Answer

Hypokalemia without pulmonary disease

Question 4

On the ECG, a junctional escape rhythm typically presents with which rate and P wave pattern?

Accepted Answer

Rate 40-60 bpm; P waves absent, inverted (retrograde) before or after QRS, or hidden within the QRS, with narrow QRS morphology

Answer

Rate 60-100 bpm with normal upright P waves and normal PR interval

Answer

Rate 100-150 bpm with absent P waves

Answer

Rate 20-40 bpm with wide QRS and inverted T waves

Question 5

What is the key ECG difference between a premature atrial contraction (PAC) with aberrant conduction and a premature ventricular contraction (PVC)?

Accepted Answer

A PAC with aberrancy has a preceding (often abnormal) P wave and typically shows RBBB morphology; a PVC has no preceding P wave and has a different QRS morphology with a full compensatory pause

Answer

Both have identical QRS morphology and can only be distinguished by clinical history

Answer

A PAC always shows LBBB morphology; a PVC shows RBBB morphology

Answer

A PVC has a shorter coupling interval than a PAC with aberrancy

Question 6

Atrial fibrillation (AFib) with a rapid ventricular response typically presents with a ventricular rate in which range?

Accepted Answer

100-170 bpm (can be higher), irregular rhythm with absent discrete P waves, replaced by fibrillatory f waves

Answer

60-80 bpm with regular rhythm

Answer

40-60 bpm with regular P waves and long PR intervals

Answer

200-300 bpm with regular sawtooth waves