The "compensatory pause" of atrial fibrillation

Area of Science:

• Cardiology
• Electrophysiology

Background:

• The diagnostic value of compensatory pauses in identifying premature ventricular complexes (PVCs) during atrial fibrillation is debated.
• Previous studies have not systematically validated compensatory pauses using programmed stimulation and intracardiac recordings.

Purpose of the Study:

• To systematically investigate and confirm the presence of compensatory pauses following induced PVCs during atrial fibrillation.
• To assess the reliability of compensatory pauses as a diagnostic marker.

Main Methods:

• Five patients with normal sinus rhythm ECGs underwent induced atrial fibrillation via rapid atrial pacing.
• Premature ventricular complexes (PVCs) were induced using ventricular extrastimuli during atrial fibrillation.
• Intracardiac recordings and programmed stimulation were employed to analyze cardiac cycles post-PVC.

Main Results:

• Induced PVCs during atrial fibrillation were consistently followed by a compensatory pause.
• The mean cycle length after PVCs was significantly longer (107-136 msec) than control cycles (p < 0.001).
• This effect was observed across all patients studied.

Conclusions:

• The study confirms the consistent presence of a compensatory pause after stimulated PVCs during atrial fibrillation.
• Compensatory pauses are a reliable phenomenon following PVCs in this arrhythmia.
• This validates their potential diagnostic utility in clinical electrophysiology.