Hyperventilation and cold-pressor stress echocardiography for noninvasive diagnosis of coronary artery spasm

We report the usefulness of 2-dimensional echocardiography during the cold-pressor test immediately after hyperventilation for noninvasive diagnosis of coronary vasospasm in 43 patients with suspected vasospastic angina. The stress test consisted of hyperventilation for 6 minutes, followed by cold water pressor stress for 2 minutes under continuous electrocardiographic and echocardiographic monitoring. Coronary angiography with an intracoronary injection of acetylcholine was performed within 2 weeks after the stress test. Coronary spasm was observed in 33 patients by angiography. Multivessel spasm was diagnosed in 26 patients by stress echocardiography and in 23 patients by angiography. The stress-induced wall motion abnormalities occurred earlier than the ST-segment changes and chest pain. The wall motion abnormalities shown on the echocardiogram correlated well with the vascular territories of the coronary artery that had the spasm. The sensitivity, specificity, and diagnostic accuracy of hyperventilation and cold-pressor stress echocardiography for detecting vasospastic angina against coronary angiography with an intracoronary injection of acetylcholine were 91%, 90%, and 91%, respectively. However, the sensitivity, specificity, and diagnostic accuracy of hyperventilation and cold-pressor stress electrocardiography for detecting vasospastic angina were 48%, 100%, and 60%, respectively. No major side effects were observed during or after the stress test. Echocardiographic monitoring during the stress test detected spasm unaccompanied by either ST- segment changes or chest pain and revealed the location of multivessel coronary spasm. Hyperventilation and cold-pressor stress echocardiography is thus a noninvasive and useful tool for the diagnosis of vasospastic angina.