New-onset sustained ventricular tachycardia after cardiac surgery

Background-The de novo occurrence of sustained ventricular tachycardia (VT) after CABG has been described, but the incidence, mortality rate, long-ter m follow-up, and mechanism are not well defined. Methods and Results-This prospective study enrolled consecutive patients un dergoing CABG at a single institution. Patients were followed up fur the de velopment of sustained VT, and a detailed analysis of clinical, angiographi c, and surgical variables associated with the occurrence of VT was performe d. A total of 382 patients participated, and 12 patients (3.1%) experienced greater than or equal to 1 episode of sustained VT 4.1+/-4.8 days after CA BG. In Ii of 12 patients, no postoperative complication explained the VT; 1 patient had a perioperative myocardial infarction. The in-hospital mortali ty rate was 25%. Patients with VT were more likely to have prior myocardial infarction (92% versus 50%, P<0.01), severe congestive heart failure (56% versus 21%, P<0.01), and ejection fraction <0.40 (70% versus 29%, P<0.01). When all 3 factors were present, the risk of VT was 30%, a 14-fold increase . Patients with VT had more noncollateralized totally occluded vessels on a ngiogram (1.4+/-0.97 versus 0.54+/-0.7, P<0.01), a bypass graft across a no ncollateralized occluded vessel (1.50+/-1.0 versus 0.42+/-0.62, P<0.01), an d a bypass graft across a noncollateralized occluded vessel to an infarct z one (1.50+/-1.0 versus 0.17+/-0.38, P<0.01). By multivariate analysis, the number of bypass grafts across a noncollateralized occluded vessel to an in farct zone was the only independent factor predicting VT. Conclusions-The first presentation of sustained monomorphic VT in the recov ery period after CABG is uncommon, but the incidence is high in specific cl inical subsets. Placement of a bypass graft across a noncollateralized tota l occlusion in a vessel supplying an infarct zone was strongly and independ ently associated with the development of VT.