Rapid assessment of ventricular fibrillation thresholds during experimental infarction in the canine heart

Sophisticated instrumentation is described which allows the rapid estimation of vulnerability of the ventricle to multiple responses and fibrillation with the classical technique described by Wiggers and Wegria. It seems particularly pertinent to the assessment of the significance of "R on T" type of ventricular extrasystoles in myocardial infarction. The thresholds to tachyarrhythmia were decreased by about 64% within 10 min of coronary occlusion and persisted at that level for 60-90 min, suggesting the usefulness of this model in assessing anti-fibrillatory drug regimes during the early evolutionary stage of myocardial infarction.