Day-to-day variations in inducibility of ventricular tachyarrhythmias during the late postmyocardial infarction phase in conscious dogs.
The inducibility of ventricular tachyarrhythmias was studied daily on days 3 through 8 after experimental myocardial infarction in 15 conscious dogs. Although a sustained ventricular tachyarrhythmia was produced on one or more occasions in 11 of 15 dogs (73%), there was marked daily variation in the results of programmed stimulation. Ventricular fibrillation or sustained ventricular tachycardia was elicited in six dogs on day 3 after infarction. In two of these dogs, no sustained tachycardia could be induced by day 7. In nine dogs sustained ventricular arrhythmias were not inducible on day 3. By day 6 to 7, sustained ventricular tachycardia was inducible in five of these dogs. In clinical practice similar variation in the inducibility of sustained ventricular arrhythmias may conceivably complicate the use of results of programmed ventricular stimulation as determinants of risk of sudden death after myocardial infarction.
D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D006329:Heart Conduction System / Q000503:physiopathology; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D011379:Prognosis; D013610:Tachycardia / Q000209:etiology*; D014693:Ventricular Fibrillation / Q000209:etiology