title: Vectorcardiographic changes as predictors of cardiac complications during major vascular surgery.
abstract: OBJECTIVE
  To elucidate the relation of changes in computerized vectorcardiographic trend parameters indicating perioperative myocardial ischemia with perioperative cardiac complications.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  A single university hospital.
  
  
  METHODS
  Thirty-eight patients undergoing elective abdominal aortic surgery.
  
  
  METHODS
  Computerized vectorcardiography recorded during surgery and for 48 hours postoperatively.
  
  
  RESULTS
  Vectorcardiographic spatial alterations in the QRS complex (QRS-VD) and absolute (ST-VM) and spatial (STC-VM) ST-segment changes, previously used indicators of myocardial ischemia, were analyzed and related to the cardiac events detected clinically. In five patients with clearly ischemic (cardiac death, myocardial infarction, recurrent ischemia) and eight patients with possibly ischemic (congestive heart failure, arrhythmia) perioperative cardiac events, ST-VM and STC-VM were significantly increased intraoperatively. Postoperatively, these differences remained, but QRS-VD were also significantly increased. Intraoperative and postoperative 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 positive (69%) and negative (91%) predictive values for subsequent cardiac events. Traditional vector loop analysis showed signs of non-Q-wave infarctions in six patients, whereas only three of these were detected using standard clinical methods.
  
  
  CONCLUSIONS
  Vectorcardiographic signs of myocardial ischemia were significantly increased intraoperatively, but most pronounced postoperatively in the patients subsequently suffering cardiac events. The changes could be related to the individual cardiac morbidity with acceptable precision. Thus, continuous vectorcardiographic monitoring may be beneficial for patients at risk of developing perioperative ischemia.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Gannedahl
authors.forename: M
authors.initials: M
authors.lastname: Edner
authors.forename: O
authors.initials: O
authors.lastname: Ljungqvist
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D017202:Myocardial Ischemia / Q000175:diagnosis*; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies; D014672:Vectorcardiography