Issue 135 Item 5 Exercise Tolerance Test Helpful For Detecting Myocardial Ischem

Stress cardiac exercise tolerance tests proved the most useful for detecting myocardial ischemia in asymptomatic type 2 diabetic patients. Investigators from the Diabetology Unit, the Department of Nuclear Medicine and the Cardiology Unit at Al-Amiri Hospital at the Kuwaiti Ministry of Health, evaluated non-invasive procedures for detecting silent myocardial ischemia in 42 patients with type 2 diabetes. Patients were 41 to 72 years old and had no clinical history of coronary heart disease.

Stress cardiac exercise tolerance tests, 12-lead electrocardiography, transthoracic echocardiography and stress myocardial perfusion scans were all compared for their ability to detect myocardial ischemia.

Results showed that myocardial ischemia could be detected in 11 patients (26.2 percent) using the stress cardiac exercise tolerance test.

Resting electrocardiography suggested ischemia in only two patients (4.8 percent), stress myocardial perfusion scans showed ischemia in three patients (7.3 percent) and echocardiography revealed diastolic dysfunction in nine patients (21.4 percent).

In patients over 57 years old, age, ischemic exercise tolerance tests and diastolic dysfunction were related.

Positive results for ischemia in exercise tolerance tests were more likely in patients with diastolic dysfunction and in patients with microalbuminuria.

Other major cardiac risk factors, including hypertension, dyslipidemia, smoking, sex, duration of diabetes, body mass index and glycated haemoglobin levels, were not related to results of myocardial ischemia on exercise tolerance tests.

Cardiac exercise tolerance tests are useful in detecting silent myocardial ischemia in type 2 diabetic patients, the investigators conclude. In cases were these tests are equivocal, echocardiography may by helpful. Med Princ Pract 2002; 11: 171-175