Anterior left ventricular aneurysm: Factors associated with the development of sustained ventricular tachycardia

Abstract

Fifty patients with anteroapical left ventricular aneurysm secondary to prior myocardial infarction underwent aneurysmectomy, at which time endocardial sinus rhythm mapping was performed. Forty patients had a history of recurrent sustained monomorphic ventricular tachycardia, and 10 had an aneurysm hot no history of spontaneous sustained tachycardia. A comparison of the clinical, angiographic and sinus rhythm endocardial clectrographic characteristics of these two groups revealed that the patients without spontaneous ventricular tachycardia had more severe coronary artery disease (2.6 ± 0.5 versus 1.9 ± 0.8 coronary arteries having >70% stenosis; p < 0.03), underwent surgery earlier after infarction (3 ± 2 versus 46 ± 53 months; p < 0.003) and had less extensive wall motion abnormalities on contrast ventriculography (0 of 8 versus 13 of 35 patients assessed had an abnormally contracting ventriculographic segment length >60%; p < 0.04).During intraoperative programmed electrical stimulation, all 40 patients with and 4 of 10 without a history of spontaneous ventricular tachycardia had induciblc tachycardia. The patients with inducible tachycardia had a larger area of endocardium from which abnormal electrograms (duration >70 ms or amplitude <0.7 mV) were recorded (62 ± 17 versus 45 ± 20% of electrograms; p < 0.03) as well as fractionated (duration >90 ms, amplitude <0.3 mV) electrograms (20 ± 14 versus 9 ± 7% of electrograms; p < 0.04) than did patients without inducible tachycardia, but there were no angiographic diffirenres between groups.These data suggest that 1) differences between groups of patients with versus without either inducible or spontaneous ventricular tachycardia are more quantitative than qualitative; and 2) the pathophysiologic substrate for ventricular tachycardia may develop relatively early after infarc tion, but other factors determine the development of spontaneous episodes of tachycardia. In the absence of features that clearly identify those patients with an aneurysm who are at high risk for future episodes of spontaneous ventricular tachycardia, it may be reasonable to consider performing pre- or intraoperative stimulation or blind subendocardial resection in such patients at the time of elective aneurysmcctomy.