Routine electrocardiograms after cardiac catheterization. Are they useful?
In order to assess the value of routine electrocardiograms after cardiac catheterization (ECGs), 150 consecutive patients undergoing diagnostic cardiac catheterization were studied prospectively. The physician performing each catheterization was asked to rate his or her clinical index of suspicion that the electrocardiogram would be changed as a result of events during the procedure. Clinical index of suspicion and electrocardiograms were then compared for their ability to predict outcomes. Urgent clinical events within 24 hours of cardiac catheterization were defined as (1) new intensive care unit admission; (2) myocardial infarction; (3) coronary artery bypass graft surgery; (4) percutaneous transluminal coronary angioplasty; or (5) death. Chi square analysis demonstrated that neither ECGs (x2 = 2.12, p greater than 0.1) nor clinical index of suspicion (x2 = 2.43, p greater than 0.1) was better than chance alone in predicting urgent clinical events. The addition of ECGs to positive clinical index of suspicion did not increase the ability to predict urgent clinical events (x2 = 2.38, p greater than 0.1). Both ECGs and clinical index of suspicion were found to be relatively insensitive tests (sensitivity = 29% for ECGs, 43% for clinical index of suspicion). While both tests demonstrated high specificity, (89% for ECGs, 79% for clinical index of suspicion), their predictive value was equally poor (21% for ECGs, 17% for clinical index of suspicion). The addition of ECGs to clinical index of suspicion marginally increased the sensitivity of both tests to 50%. We conclude that routine postcatheterization electrocardiograms are no better at predicting urgent clinical events than clinical observation during catheterization alone, and should be performed only when index of suspicion dictates.
Silverman
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Cardiology Division, West Roxbury Veterans Administration Medical Center, Massachusetts.
Folland
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D015906:Angioplasty, Balloon, Coronary; D006328:Cardiac Catheterization / Q000009:adverse effects; D001026:Coronary Artery Bypass; D004562:Electrocardiography / Q000706:statistics & numerical data*; D004630:Emergencies; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity