VECTORCARDIOGRAPHIC CHANGES AS PREDICTORS OF CARDIAC COMPLICATIONS DURING MAJOR VASCULAR-SURGERY

Objective: To elucidate the relation of changes in computerized vector cardiographic trend parameters indicating perioperative myocardial isc hemia with perioperative cardiac complications. Design: Prospective cl inical study. Setting: A single university hospital. Participants: Thi rty-eight patients undergoing elective abdominal aortic surgery. Inter ventions: Computerized vectorcardiography recorded during surgery and for 48 hours postoperatively. Measurements and Main Results: Vectorcar diographic spatial alterations in the ORS complex (ORS-VD) and absolut e (ST-VM) and spatial (STC-VM) ST-segment changes, previously used ind icators of myocardial ischemia, were analyzed and related to the cardi ac events detected clinically. In five patients with clearly ischemic (cardiac death, myocardial infarction, recurrent ischemia) and eight p atients with possibly ischemic (congestive heart failure, arrhythmia) perioperative cardiac events, ST-VM and STC-VM were significantly incr eased intraoperatively. Postoperatively, these differences remained, b ut ORS-VD were also significantly increased. Intraoperative and postop erative changes indicating ischemia were strongly related (r = 0.83). The signs of ischemia were most pronounced during the postoperative 12 to 36 hours. The presence of 60 minutes of signs of ischemia during 2 hours revealed high sensitivity (85%), specificity (80%), and positiv e (69%) and negative (91%) predictive values for subsequent cardiac ev ents. Traditional vector loop analysis showed signs of non-Q-wave infa rctions in six patients, whereas only three of these were detected usi ng standard clinical methods. Conclusions: Vectorcardiographic signs o f myocardial ischemia were significantly increased intraoperatively, b ut most pronounced postoperatively in the patients subsequently suffer ing cardiac events. The changes could be related to the individual car diac morbidity with acceptable precision. Thus, continuous vectorcardi ographic monitoring may be beneficial for patients at risk of developi ng perioperative ischemia. Copyright (C) 1998 by W.B. Saunders Company .