Prolongation of ventricular depolarization and repolarization in patients with cardiac surgery

Introduction: Cardiac surgery involves a series of aggressive mechanical and chemical elements that affect the cardiac muscle; which may be shown by the electrocardiogram. Objectives: To evaluate whether electrocardiographic measurements reflecting ventricular depolarization and repolarization are prolonged after cardiac surgery. Method: We studied 51 patients with cardiac surgery who underwent an electrocardiogram before and after surgery. The difference between QT, QTc, QT dispersion, T-PEAK-T-END interval (T-P-T-E), T-P-T-E dispersion and QRS duration, before and after surgery was compared using the T test. Results: Electrocardiogram after surgery showed significantly higher QTc values, QT dispersion, T-P-T-E, T-P-T-E dispersion and QRS duration (p<0.006). The uncorrected QT interval was greater in the postoperative electrocardiogram, without statistically significant difference (p=0.49). Conclusions: Myocardial aggression during cardiac surgery modifies the ventricular electrical activity and is verified by the significantly prolonged depolarization and repolarization measurements. These variables could be used in future studies as predictors of adverse events in this procedure.