Background and Goal of Study:Ventricular Fibrillation (VF) after release of the aortic cross-clamping (ACC) in patients undergoing cardiac surgery is reported to occur in 74% to 96% of cases, and defibrillation by direct current countershocks results in myocardial injury [1]. However, few studies have focused on the risk of VF after release of ACC in cardiac surgery patients. We conducted a retrospective study to clarify the prediction of VF after release of ACC in cardiovascular surgery patients.

Materials and Methods:The ethics committee from our hospital approved this retrospective study. Two hundreds forty consecutive patients undergoing cardiovascular surgery from Jury 2011 to November 2017 were included in this study. Patients who were <18 years of age, emergency surgery, surgery without ACC and patients with cardiac pacemaker were excluded. We divided them into two groups; VF group and NonVF group. We compared ages, sex, heart rate (HR) and duration of QTc in preoperative electrocardiogram (ECG), interventricular septum thickness (IVST), left ventricular posterior wall thickness (LVPWth) and ejection fraction (EF) by preoperative ultrasound examination, preoperative electrolytes (potassium, calcium, magnesium), preoperative beta-blocker usage, CPB duration, catecholamine index (CAI) after release of ACC. For statistical analysis, we used the chi-squared test and unpaired t-test, the receiver operating characteristic curve (ROC) analysis, and p <0.05 was considered statistically significant. 

Results and Discussion:VF after release of ACC occurred in 47 patients (19.6%). Duration of QTc in VF group is significantly longer than that in NonVF group (436±32 vs 450±36 msec, p=0.02), and CAI after release of ACC in VF group is significantly higher than that in NonVF group (5.1±3.0 vs 6.3±4.2, p=0.02)(Table1). In multivariate analysis, QTc and CAI are independent factors of VF after release of ACC. In the receiver operating characteristic curve (ROC) analysis, the cut-off value of QTc is 477 msec (Specificity 0.684, Sensitivity 0.574, Area under ROC 0.60).

Conclusion(s):The preoperative QTc and CAI after release of ACC was associated with VF after release of ACC in cardiovascular surgery patients.

References (optional):[1] J Cardiothorac Vasc Anesth. 2000 Oct;14(5):531-3.


11 / The prediction of ventricular fibrillation after release of aortic cross-clamping in cardiovascular surgery patients