title: Clinical significance of a new Q wave after cardiac surgery.
abstract: OBJECTIVE
  The appearance of new Q waves on the electrocardiogram (ECG) after cardiac surgery has been traditionally considered a sign of major myocardial tissue damage. The aim of this study was to investigate the clinical significance of new Q waves appearing following cardiac surgery and to correlate them with the release of myocardial cell damage biomarkers.
  
  
  METHODS
  206 consecutive patients undergoing cardiac surgery were prospectively evaluated. A 12 lead ECG was recorded and cardiac troponin I and creatinekinase subfraction MB assayed the day before surgery, on arrival at the intensive care Unit. 4 and 18 h postoperatively and every morning until the fifth postoperative day.
  
  
  RESULTS
  The incidence of new Q waves was 7.3%. Patients with isolated ECG findings had an uneventful postoperative course; on the contrary, when ECG changes were coupled with the release of myocardial necrosis biomarkers, patients had a complicated postoperative course.
  
  
  CONCLUSIONS
  The association of a new Q wave and high levels of myocardial necrosis biomarkers is strongly associated with postoperative cardiac events. On the contrary, the isolated appearance of a new Q wave has no impact on the postoperative cardiac outcome.
authors.affiliation: Department of Cardiovascular Anesthesia, IRCCS San Raffaele Hospital of Milan, Via Olgettina, 60, 20132 Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Crescenzi
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bove
authors.forename: Federico
authors.initials: F
authors.lastname: Pappalardo
authors.forename: Anna M
authors.initials: AM
authors.lastname: Scandroglio
authors.forename: Giovanni
authors.initials: G
authors.lastname: Landoni
authors.forename: Giacomo
authors.initials: G
authors.lastname: Aletti
authors.forename: Alberto
authors.initials: A
authors.lastname: Zangrillo
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis; D011183:Postoperative Complications / Q000175:diagnosis*; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form