• A reentrant, often triggered by an automaticity focus, is a circuit loop that conducts electrical impulses continuously and rapidly, resulting in fast heart rate or tachyarrhythmia.
• A reentrant loop can be either “macro” or “micro”:
Macro-reentrant loop: one large continously conducting circuit loop, e.g. AVRT, AVNRT, atrial flutter, and certain types of ventricular tachycardia
Micro-reentrant loop: often multiple rapid-firing small circuit loops, e.g. atrial fibrillation, ventricular fibrillation
• Examples of reentrant circuits are listed below.
