Detection of Myocardial Ischemia With a Computer-Assisted 12-lead 24-hour ECG Monitoring System (EAGLE) in Patients With Suspected Unstable Angina

Abstract

This study was undertaken to evaluate the diagnostic value of a new device, the `EAGLE' computer-assisted multiple-lead long-term electrocardiography (ECG) monitoring and analyzing system, in patients with suspected unstable angina, and to compare the results with the Holter monitor. A total of 101 patients with a history of suspected unstable angina underwent a simultaneous 24-h examination with the EAGLE and 2-channel Holter monitors. The diagnosis of unstable angina was established in 70 patients: 41 had significant organic stenosis, and 29 had coronary spasm. Ischemic ST deviations were detected 229 times in 44 patients (62.9%) with the EAGLE system and 101 times in 20 patients (28.6%) with the Holter monitor. The sensitivity of myocardial ischemia in unstable angina with the EAGLE system was significantly higher than that with Holter monitor (62.9 vs 28.6%, p<0.05). The difference of sensitivity was due mainly to the low detection rate of the Holter monitor for asymptomatic myocardial ischemia (EAGLE vs Holter ; 187 times vs 72 times) and myocardial ischemia in the infero-posterior area in patients with organic stenosis (30 times vs none). It is concluded that the EAGLE system is a sensitive tool for the diagnosis of unstable angina in patients without significant ECG changes, and an excellent tool for evaluating silent myocardial ischemia or myocardial ischemia of the infero-posterior area. (Jpn Circ J 1998; 62: 586 - 591)