Association of hemolysis with the incidence of heart rhythm disturbances following coronary artery bypass graft surgery

Introduction: Coronary artery bypass grafting (CABG) might be associated with the development of heart rhythm disturbances. We aimed at evaluating an association of intraoperative hemolysis (IOH) with the development of cardiac rhythm disturbances in patients with coronary artery disease after on-pump CABG.

Methods. The assessment of the degree of IOH was performed according to the level of plasma free hemoglobin [Hb] at baseline, immediately after the patient was connected to the cardiopulmonary bypass (CPB) device and 15 minutes before cessation of CPB. We included 123 patients, and they were divided into 3 groups (gr.) according to free [Hb] level: gr.1 - ≤0.1 g/l; gr.2 - > 0.1 g/l and <0,5 g/l; gr.3 - ≥0.5 g/l. A variety of ECG screening methods were applied for the detection of cardiac arrhythmia in the postoperative period. The follow-up period was 1 months.

Results. Arrhythmias were observed in 2.3% of patients in the 1st group, in 11.9% in the 2nd group, and in 52.6% in the 3rd group. The level of plasma free [Hb] in samples taken at the end of CPB was strongly associated with the arrhythmia detection (rs=0,70, p <0.001). Life-threatening and hemodynamically unstable arrhythmias were more frequently detected in the group with a higher degree of IOH (p <0.001), and accounted for about half of all arrhythmias.

Conclusions. On-pump CABG is associated with the development of cardiac arrhythmias in the postoperative period in 22% of patients. A significant proportion of these arrhythmias are potentially life-threatening. The highest proportion of patients with cardiac rhythm disturbances after CABG was observed when the level of plasma free hemoglobin was >0.5 g.