Frequency and significance of conduction defects early after orthotopic heart transplantation

To define the clinical significance of conduction defects after orthotopic heart transplantation sequential electrocardiograms (ECG) of 124 patients were analyzed during their postoperative hospital stay. The first ECG was abnormal in 90 patients (73%), with a predominance of right bundle branch block, and normal in 34 (27%). Sex, age, mean donor ischemic time, duration of aortic cross clamping and use of previous antiarrhythmic therapy were not significantly different in the 2 groups. During hospital follow-up, patients were grouped according to evolution of the initial electrocardiographic abnormalities. In group 1, 25 patients continued to have an initially normal ECG. In groups 2 and 3, 30 and 48 patients, respectively, had evidence of transient and permanent conduction defects. The 21 patients in group 4 showed progressive deterioration of conduction with either a new (9 patients) or worsening preexisting conduction defect (12 patients). The evolution of the initial ECG was strongly dependent on the duration of the donor heart ischemic time and the severity of the in-hospital cardiac rejection. Patients with persistent conduction abnormalities had a statistically longer ischemic time than either patients with normal or transient conduction defects (182 ± 84 vs 144 ± 68 and 130 ± 66 minutes, p = 0.04). Although the overall percentage of patients with histologic evidence of moderate to severe rejection was similar across the groups, 66.6 and 46.1% of patients in groups 3 and 4, respectively, had multiple episodes of rejection compared with 16.6 and 0% in the remaining 2 groups (p = 0.044). The in-hospital mortality was greater in patients with an abnormal ECG than in patients with a transient conduction defect or a normal ECG (21.7 vs 5.4%, p = 0.01).