平井 寛則, 原田 昌彦, 鈴木 真事, 西沢 茂樹, 杉山 祐公, 李 哲雄, 酒井 英行, 大蔵 勝弥, 山口 徹

Hironori HIRAI, Masahiko HARADA, Makoto SUZUKI, Shigeki NISHIZAWA, Yuko SUGIYAMA, Tetsuo LEE, Hideyuki SAKAI, Katsuya OKURA, Tetsuo YAMAGUCHI

東邦大学　内科学第三講座　東邦大学大橋病院

Third Department of Internal Medicine, Toho University School of Medicine Ohashi Hospital

キーワード : ATP (adenosine triphosphate disodium), Myocardial ischemia, Stress echocardiography, T1-201 (thallium-201) scintigraphy

Background: In recent years the pharmacologic stress test with adenosine, the half-life of which is extremely short, has been used clinically to detect myocardial ischemia. Adenosine triphosphate disodium (ATP) is used instead of adenosine, which is hard to obtain in Japan, in stress echocardiography. The usefulness of detection of myocardial ischemia with ATP has not been sufficiently evaluated.
Purpose: To evaluate the usefulness of ATP stress echocardiography (ATP echo) for diagnosis of myocardial ischemia, we compare the results of ATP echo with those of ATP thallium-201 (T1-201) myocardial scintigraphy (T1 scintigraphy).
Method: ATP echo was performed in 33 patients with 53 lesions (average age, 65±15years) with significant coronary stenosis. ATP (0.16 mg/kg/m) was injected continuously for 5 minutes, and T1-201 was injected 4 minutes after ATP injection. Two-dimensional echocardiograms (long axis view, short axis view, and four chamber view of the left ventricle)were recorded continuously from before the ATP injection until 2 minutes after the end of the injection. The denning criterion of myocardial ischemia in echocardiography is appearance of new abnormality of wall motion. T1-201 scintigrams (SPECT) were obtained 5 minutes after and 4 hours after the end of the ATP injection.
Results: Rate of detection of myocardial ischemia in 33 patients was 76% (25/33) using ATP echo and 100% using SPECT. Rate of detection of myocardial ischemia by number of diseased coronary arteries with ATP echo was 69% in one-vessel disease , 73% in two-vessel disease, and 100% in three-vessel disease. Rate of detection of myocardial ischemia with ATP echo among the 53 lesions was 55% in the right coronary artery, 58% in the left anterior descending artery, and 44% in the left circumflex artery. Meanwhile, the rate of detection of myocardial ischemia with SPECT was 55% in the right coronary artery, 96% in the left anterior descending artery, and 61% in the left circumflex artery. The rate of detection of myocardial ischemia was 24% with ATP echo and 53% with SPECT in stenosis less than 90% but more than 75%, and 64% with ATP echo and 83% with SPECT in stenosis more than 90%.
Conclusion: ATP stress echocardiography is useful for detecting myocardial ischemia in severe coronary stenosis or multi-vessel coronary artery disease.