title: Postinfarction sudden death: significance of inducible ventricular tachycardia and infarct size in a conscious canine model.
abstract: The relationship between inducible ventricular tachycardia in the convalescent phase of myocardial infarction and subsequent spontaneous ventricular fibrillation is uncertain. Thirty conscious instrumented dogs underwent programmed ventricular stimulation 5 days after anterior infarction; 15 had inducible ventricular tachycardia and 15 were noninducible. Following programmed ventricular stimulation, the application of a 150 uA current to the intima of the proximal circumflex artery initiated intimal damage, thrombosis, and acute ischemia of the posterolateral wall. After 20 minutes of ischemia, 73% inducible and 15% noninducible animals developed ventricular fibrillation (p less than 0.005) without previous hypotension. At 24 hours, 7% inducible and 85% noninducible animals survived (p less than 0.001). Anterior infarct size (percentage of left ventricular mass) was much larger in inducible (24.7 +/- 1.7%) than in noninducible (5.3 +/- 1.1%) (p less than 0.001) animals. Inducible ventricular tachycardia following infarction was highly predictive of spontaneous ventricular fibrillation during a later ischemic episode in this model. The mass of previously injured myocardium was a critical determinant of both.
mesh_terms: D000818:Animals; D002304:Cardiac Pacing, Artificial; D003326:Coronary Circulation; D003645:Death, Sudden / Q000209:etiology* / Q000473:pathology; D004285:Dogs; D004562:Electrocardiography; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D013610:Tachycardia / Q000209:etiology / Q000503:physiopathology*; D014693:Ventricular Fibrillation / Q000209:etiology / Q000503:physiopathology