부산대학교 도서관

Coronary artery bypass surgery is used to treat patients with severe atherosclerosis - the hardening build-up of fatty plaques - in multiple coronary arteries. It is important to assess the extent of residual ischemia (poor blood flow) after surgery, and most techniques rely on analysis of exercise-induced blood flow changes, which is not appropriate for patients immediately after surgery. Dipyridamole is a drug that increases coronary blood flow and dilation of blood vessels, but has little effect in ischemic areas. It has been used in combination with echocardiography (ultrasound imaging of the heart) to detect myocardial (heart muscle) ischemia. The effectiveness of dipyridamole plus transesophageal echocardiography (in which the ultrasound probe is placed in the esophagus) in assessing residual ischemia two hours after bypass surgery was studied in 11 male patients. Results were compared with those obtained after one week from a dipyridamole-transthoracic echocardiography (where the probe is placed on the chest exterior) stress test. The postsurgical stress test showed that six patients obtained normalization of blood flow and function, three patients had abnormal heart contraction reversed following surgery, while in two, abnormalities persisted. The study provides preliminary evidence that the dipyridamole echocardiographic stress test can evaluate patients' conditions and validate the function of grafted arteries after coronary bypass surgery. (Consumer Summary produced by Reliance Medical Information, Inc.)