SUSTAINED SUPRAVENTRICULAR TACHYARRHYTHMIAS FOLLOWING CORONARY-ARTERY BYPASS-SURGERY COMPARING MAMMARY VERSUS SAPHENOUS-VEIN GRAFTS

This retrospective study was designed to determine the incidence of sustained supraventricular tachyarrhythmias (SVTs) in patients undergoing coronary artery bypass grafting (CABG) with internal mammary artery (IMA) grafts, Group A, compared with those with saphenous vein grafts (SVG), Group B. Among 569 consecutive patients who underwent CABG surgery in the same institution, a total of 80 cases from Group A and 80 cases from Group B were selected for this study after application of exclusion criteria. Excluded from this study were the following: patients wth preexisting or prior history of SVTs, significant left ventricular dysfunction (ejection fraction less than 40%), postoperative myocardial infarction, drug toxicity or electrolyte imbalance, and advanced chronic obstructive lung disease. Group A consisted of 63 men and 17 women and Group B consisted of 52 men and 28 women. All patients were monitored either in ICU or by telemetry for a period of three to six days after surgery and all had a predischarge 12-lead electrocardiogram. Both groups were fairly comparable in most of their clinical profile and number of grafts. The incidence of SVTs in Group A was 31% (25 of 80 patients) and in Group B was 24% (19 of 80 patients). Furthermore, the incidence of postoperative pericarditis was noted in 35% (28 of 80 patients) of Group A and in 19% (15 of 80 patients) in Group B. The authors conclude that male tobacco smokers of Group A tended to have a significantly higher incidence of postoperative pericarditis with a higher trend for postoperative SVTs than patients from Group B.