Preoperative Cardiovascular Monitoring

Abstract

Summary Clinicians have available to them a variety of preoperative screening and monitoring techniques allowing detection of CAD, infarction, and evaluation of ventricular function, factors that have been shown to correlate with postoperative cardiac morbidity. Electrocardiography has been the traditional mainstay for detecting CAD. The increasing use of ambulatory ST-segment monitoring should ensure its importance for the foreseeable future. The use of techniques that unmask CAD by increasing myocardial oxygen demand, or by use of pharmacologic vasodilation to induce regional differences in coronary blood flow, have greater sensitivity than tests performed in the resting state. Dipyridamole-thallium imaging, attractive due to its application to patients unable to exercise, has grown in popularity. Although it may be a sensitive predictor of adverse outcome or intraoperative ischemia, evidence suggests that it has little value as a routine screening tool. Evaluation of left ventricular function is possible using many different techniques, although radionuclide angiography is the most sensitive. Low ejection fraction, especially below 0.40, identifies a subgroup of patients at high risk. Aggressive therapy of myocardial ischemia or congestive heart failure, identified by these techniques, may enhance perioperative survival in these patients. Preoperative assessment remains the cornerstone of perioperative care.