A-Flutter or A-Fib with Junctional Rhythm

Atrial flutter or atrial fibrillation with junctional rhythm is the combination of rapid regular (atrial flutter) or rapid irregularly irregular (atrial fibrillation) atrial rhythm with an atrioventricular-originating rhythm (narrow QRS complex, rate between 40-60 beats per minute).

This indicates a third-degree AV block, as none of the atrial impulses are being conducted to the ventricles. The impulses are originating at the AV node as a junctional escape rhythm.

CHARACTERISTICS

• Narrow QRS complex, and
• Rate between 40-60 beats per minute.

A-Flutter or A-Fib with Pre-Excitation Syndromes

Pre-excitation syndromes are cardiac arrhythmias with at least one extra abnormal conductive pathway, allowing for early depolarization of the ventricles.

Atrial flutter or atrial fibrillation with pre-excitation syndromes can be the combination of a rapid regular (atrial flutter) or rapid irregular (atrial fibrillation) atrial rhythm with a ventricular-originating rhythm:

CHARACTERISTICS

• Wide QRS complex, and
• Rate between 20-40 beats per minute.

This indicates a third-degree AV block, as none of the atrial impulses are being conducted to the ventricles. None of the atrial impulses are being conducted to the ventricles, The impulses are originating in the ventricles--a ventricular rhythm.