Influence of thrombolysis and patency of the infarct-related coronary artery on ventricular electrical instability after acute myocardial infarction

B. Caru, R. Pedretti, R. Bonelli, D. Etro, R. Casucci, C. Anza, E. Colombo, F. Santoro

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Abstract

In the present study we evaluated the influence of intravenous thrombolysis and patency of the infarct-related coronary artery both on markers of ventricular electrical instability and late arrhythmic event incidence after AMI. Ninety one patients surviving a first AMI who consecutively performed coronary angiography because of residual myocardial ischemia, malignant ventricular tachyarrhythmias or other indications, were enrolled; 44 patients (48%) received thrombolysis, 47 patients (52%) were treated conventionally. SA ECG was available in 90/91 patients (99%), programmed ventricular stimulation in 40/91 (44%). No significant difference was observed between thrombolytic-treated and control group as concerning LP rate, SA ECG determinants and ventricular arrhythmias inducibility. In our group of patients 40/91 patients (44%) showed occlusion of the infarct-related artery: of these, 15 (37%) had LP as compared to 5/51 patients (9%) with a patent artery (p <.01). Mean left ventricular ejection fraction was not significantly different between the 2 groups (0.50 ± 0.15 vs 0.55 ± 0.12; NS). No significant difference was present between the 2 groups of patients as concerning inducibility of sustained ventricular tachyarrhythmias although a relative risk of 3.5 was observed in the group with a closed vessel. At a mean follow-up of 13 ± 9 months from AMI, 9/91 patients (10%) showed a late arrhythmic event: left ventricular ejection fraction (0.36 ± 0.16 vs 0.55 ± 0.11; p <.001), LP rate (5/8 vs 15/82; p <.05), filtered QRS duration on SA ECG (115 ± 13 vs 98 ± 15 ms; p <.01), duration of terminal low amplitude signals (48 ± 31 vs 31 ± 11 ms; p <.001), occlusion of the infarct-related coronary artery (8/9 vs 32/82; p <.05), inducible sustained monomorphic ventricular tachycardia with rate <270 bpm (4/6 vs 1/34; p <.001) showed a significant relation to late arrhythmic events. Stepwise logistic-regression analysis identified left ventricular ejection fraction (p <.001), filtered QRS duration on SA ECG (p <.05), occlusion of the infarct-related artery (p <.05) and left ventricular aneurysm (p <.05) as independent predictors of late arrhythmic events. Our data show a beneficial effect of patency of the infarct-related coronary artery both on markers of ventricular electrical instability, such as LP, and late arrhythmic events after AMI. The results of this study strongly suggest that the prevention of an arrhythmogenic substrate, by reopening of the infarct-related vessel, could play an important role in increasing survival after AMI.

Original languageEnglish
Pages (from-to)659-664
Number of pages6
JournalNew Trends in Arrhythmias
Volume7
Issue number4
Publication statusPublished - 1991

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ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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