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.