Sustained Monomorphic Ventricular Tachycardia: A Single Electrocardiographic Expression of Different Patterns of Reentry

Sustained monomorphic ventricular tachycardia (SMVT) can be the electrocardiographic expression of a reentrant impulse in the ventricles. In this study we analyzed the different types of reentry that might lead to SMVT, Methods: The pattern of activation of 73 episodes of SMVT induced in thin sheets of epicardium in 50 Langendorff perfused rabbit hearts were visualized with high resolution epicardial mapping (248 points). Results: Five different patterns of reentry resulting in SMVT were identified: (1) Single-loop reentry around a fixed obstacle (n = 40); (2) Single-loop reentry around a functional arc of conduction block (n = 17); (3) Double-wave reentry around a fixed obstacle (n = 9); (4) Figure-of-eight reentry around two areas of functional block (n = 5); and (5) Multiple synchronized circuits around multiple areas of functional block (n = 2), Conclusion: SMVT is a single electrocardiographic expression of different patterns of reentry. Accurate mopping is mandatory to identify the reentrant pathway and the pathophysiological substrate of the arrhythmia.