Are electrocardiographic Q-wave criteria reliable for diagnosis of perioperative myocardial infarction after coronary surgery?
1998 (English)In: European Journal of Cardio-Thoracic Surgery, ISSN 1010-7940, E-ISSN 1873-734X, Vol. 13, no 6, 655-661 p.Article in journal (Refereed) Published
Objective: A major assumption in cardiovascular medicine is that Q-waves on the electrocardiogram indicate major myocardial tissue damage. The appearance of a new Q-wave has therefore been considered the most reliable criterion for diagnosis of perioperative myocardial infarction (PMI) in cardiac surgery. In a study, originally intended to evaluate troponin-T as a marker of PMI, analysis of our data aroused the need to address the reliability of Q-wave criteria for diagnosis of PMI.
Methods: In 302 consecutive patients undergoing coronary surgery, Q-wave and other electrocardiogram (ECG) criteria were compared with biochemical markers of myocardial injury and the postoperative course. All ECGs were analysed by a cardiologist blinded to the biochemical analyses and the clinical course.
Results: The incidence of positive Q-wave criteria was 8.1%. Combined biochemical (CK-MB≥70 μg/l) and Q-wave criteria were found in 1.0%. Patients with new Q-waves did not have CK-MB or troponin-T levels significantly different from those without Q-waves. More than 25% of the Q-waves were associated with plasma troponin-T below the reference level (<0.2 μg/l) on the fourth postoperative day. Q-wave criteria alone did not influence the postoperative course. In contrast, biochemical markers correlated with clinical outcome.
Conclusions: The majority of Q-waves appearing after coronary surgery were not associated with major myocardial tissue damage, and according to troponin-T one-fourth of the Q-waves were not associated with myocardial necrosis. Furthermore, the appearance of Q-waves had little influence on short term clinical outcome. Therefore, the use of Q-wave criteria as the gold standard for diagnosis of PMI may have to be questioned.
Place, publisher, year, edition, pages
1998. Vol. 13, no 6, 655-661 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-81054DOI: 10.1016/S1010-7940(98)00091-8OAI: oai:DiVA.org:liu-81054DiVA: diva2:550046