Perioperative correlates of malignant ventricular tachyarrhythmias complicating coronary surgery

Sustained ventricular tachyarrhythmias (VT), such as monomorphic or polymor phic ventricular tachycardia, and ventricular fibrillation, represent the m ost serious arrhythmic events that can complicate the postoperative course of coronary artery bypass grafting (CABG). The perioperative factors potent ially associated with post-CABG sustained VT onset have not been thoroughly investigated. As a consequence, the aim of our study was to identify which perioperative variables might predict post-CABG VT occurrence. One hundred and fifty-two consecutive patients who underwent CABG surgery a t our Institute were included in the study. Post-CABG VT occurred in 13 out of 152 patients (8.5%, sis cases of monomorphic ventricular tachycardia an d seven cases of ventricular fibrillation). Univariate analysis revealed th at VT patients were significantly younger (54.8 +/- 6.6 vs 60.1 +/- 8.8, P = 0.038), exhibited mon severe coronary artery disease (CAD) (no. of diseas ed vessels, 2.92 +/- 0.3 vs 2.45 +/- 0.7, P = 0.023. and percentage of pati ents with three-vessel CAD, 91.7 vs 57.3%, P = 0.043), and received a great er number of CABGs than those remaining in sinus rhythm (SR) (percentage of patients receiving three or more CABGs, 76.9 vs 38.8%, P = 0.018) Moreover , VT patients more frequently developed intra- or postoperative myocardial infarction (total CK > 1000, 76.9 vs 38%, P = 0.016; and MB-CK > normal ran ge, 72.7 vs 30.7%, P = 0.014), electrolyte derangement (84.6 vs 45.6%, P = 0.017) and a severe hemodynamic impairment (need for intra-aortic balloon p ump (IABP), 23 vs 2.9%, P = 0.009). On multivariate analysis, total CK > 10 00, postoperative electrolyte imbalance, the need for three or more CABCs, and for IABP all were independent correlates for VT. In conclusion, post-CABG VT seem to be related to the preexistence of a sev ere underlying coronary artery disease along with perioperative triggering factors, such as acute ischemia, electrolytic disorders, and sudden hemodyn amic impairment.