Exploring Postinfarction Reentrant Ventricular Tachycardia With Entrainment Mapping

TLDR

Ventricular tachycardia after myocardial infarction is usually caused by reentry within the infarct zone, and these circuits can be large, complex, and difficult to delineate, hindering both study and catheter ablation. The study proposes using pacing through the electrodes of a mapping catheter as a novel method for mapping postinfarction reentrant ventricular tachycardia. The technique applies pacing stimuli from the mapping catheter to evaluate tachycardia responses that depend on the pacing site’s position relative to the reentry circuit. This approach identifies portions of the reentry circuit without mapping the entire loop, locates isthmuses suitable for small radiofrequency lesions, and classifies circuits into functional components to predict ablation success, thereby advancing the definition of human reentry circuits. J Am Coll Cardiol 1997;29:1180–9.

Abstract

Ventricular tachycardia late after myocardial infarction is usually due to reentry in the infarct region. These reentry circuits can be large, complex and difficult to define, impeding study in the electrophysiology laboratory and making catheter ablation difficult. Pacing through the electrodes of the mapping catheter provides a new approach to mapping. When pacing stimuli capture the effects on the tachycardia depend on the location of the pacing site relative to the reentry circuit. The effects observed allow identification of various portions of the reentry circuit, without the need for locating the entire circuit. Isthmuses where relatively small lesions produced by radiofrequency catheter ablation can interrupt reentry can often be identified. A classification that divides reentry circuits into one or more functional components helps to conceptualize the reentry circuit and predicts the likelihood that heating with radiofrequency current will terminate tachycardia. These methods are helping to define human reentry circuits. (J Am Coll Cardiol 1997;29:1180–9)