Usefulness of a high-dose dipyridamole-echocardiography test for diagnosis of syndrome X.
This study assesses whether the high-dose dipyridamole-echocardiography test (DET, 2-D echocardiographic and 12-lead electrocardiographic monitoring during dipyridamole infusion, up to 0.84 mg/kg over 10 minutes) can help to identify patients with syndrome X. DET was performed in 10 control subjects (group A) and in 19 patients with syndrome X (group B). Patients in group B had chest pain on effort, a positive exercise stress response (more than 0.1 mV of ST-segment depression), negative ergonovine test response and normal left ventricular function and coronary angiographic findings. During DET no subject in group A showed transient asynergy or ST-segment depression and none had chest pain; in group B, no patient had transient asynergy, 13 (68%) had chest pain and 16 (84%) had more than 0.1 mV of ST-segment depression. Percent fractional shortening was not significantly different in the 2 study groups, either basally (group A, 35 +/- 7; group B, 37 +/- 8) or at peak hyperkinesia during DET (group A, 48 +/- 8; group B, 54 +/- 10). Thus, dipyridamole-induced chest pain and ST-segment depression in patients with syndrome X are not associated with impaired regional or global left ventricular function. This entity of echocardiographically silent myocardial ischemia during DET may be a clue to noninvasive detection of syndrome X.
D000328:Adult; D000787:Angina Pectoris / Q000175:diagnosis*; D002637:Chest Pain / Q000175:diagnosis; D003327:Coronary Disease / Q000175:diagnosis; D004176:Dipyridamole; D004452:Echocardiography; D004562:Electrocardiography; D004874:Ergonovine / Q000031:analogs & derivatives; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D013577:Syndrome
D004176:Dipyridamole; D004874:Ergonovine