Scenario: A 64-year-old white man admitted to the transitional care unit for a “rule-in” myocardial infarction and scheduled for the catheterization laboratory in the morning. His medical history is remarkable for hypertension and diabetes; however, during this 12-lead ECG recording, he denies chest pain or any anginal equivalent and is hemodynamically stable.

Interpretation: Accelerated junctional rhythm at 83 beats per minute (bpm) with retrograde P-wave conduction.

Junctional rhythms may take the form of an escape mechanism during periods of significant bradycardia and atrioventricular (AV) block (<60 bpm); they may be accelerated (61–100 bpm) or present as a tachycardia (>100 bpm). The AV node has intrinsic automaticity that allows it to initiate and depolarize the myocardium when the sinus atrial (SA) node fails. Junctional rhythms produce a narrow QRS complex because the ventricle depolarization occurs via the normal conduction pathway. Throughout this 12-lead ECG, the narrow QRS complexes are uniform in...

You do not currently have access to this content.