CCRN Cardiac Rhythm Interpretation and Management 3

Question 1

A patient with a permanent pacemaker shows pacer spikes on the monitor that are not followed by QRS complexes. What pacemaker malfunction does this represent?

Accepted Answer

Failure to capture

Answer

Failure to capture occurs when the pacemaker spike is delivered but fails to depolarize the myocardium, meaning the spike appears without a following P wave or QRS complex.

Question 2

Which ECG change is most consistent with an acute anterior ST-elevation myocardial infarction (STEMI)?

Accepted Answer

ST elevation in leads V1 through V4

Answer

The left anterior descending artery supplies the anterior wall; its occlusion causes ST elevation in the precordial leads V1–V4, the territory those leads overlie.

Question 3

Long QT syndrome predisposes a patient to which potentially fatal dysrhythmia?

Accepted Answer

Torsades de pointes

Answer

A prolonged QT interval represents delayed ventricular repolarization, creating a vulnerable window during which a premature beat can trigger torsades de pointes.

Question 4

A 12-lead ECG demonstrates a short PR interval, a slurring at the beginning of the QRS (delta wave), and a wide QRS complex. This pattern is characteristic of:

Accepted Answer

Wolff-Parkinson-White (WPW) syndrome

Answer

WPW is identified by the triad of a short PR interval, delta wave (pre-excitation slurring), and widened QRS caused by an accessory pathway bypassing the AV node.

Question 5

A junctional escape rhythm in a post-cardiac surgery patient is best identified by which ECG finding?

Accepted Answer

Absent or retrograde P waves with narrow QRS complexes at 40–60 bpm

Answer

Junctional escape rhythms originate in the AV node/junction, producing narrow QRS complexes at 40–60 bpm; P waves are absent, inverted, or retrograde depending on where conduction spreads.

CCRN Review Practice Test

CCRN Review Practice Test

CCRN Cardiac Rhythm Interpretation and Management 3