[Silent myocardial ischemia. Experience with ambulatory electrocardiographic monitoring]

A 24-hour recording of ambulatory EKG (Holter) was obtained in 159 patients with coronary disease: previous myocardial infarction (n = 76), myocardial revascularization (n = 66), severe obstruction during cine-coronarography (n = 13) or during coronary angioplasty (n = 4). Prophylactic anti-anginal drugs were maintained during the Holter and, despite the medication, transitory episodes of myocardial ischemia (MI) were recorded in 51 patients (32%), either with angina (AMI) or silent (SMI), isolated SMI was recorded in 44 patients (86%), 6 subjects had both SMI (16 episodes) and AMI (12 episodes) and one patient had only one episode of AMI. There was a total of 119 episodes of MI, 106 of SMI (89.1%) and 13 AMI (10.9%). The total duration of the episodes of SMI per patient varied from 1 min to 235 min and the IMS maximal duration was 221 min. In the six cases with both SMI and AMI, the total duration of SMI was 461 min and AMI was 306 min. The circadian distribution of the episodes of SMI was: from 12:00 to 18:00-31.4%, 18:00 to 24:00-27.6%, 0:00 to 6:00-7.7% and 6:00 to 12:00-33.3%. The SMI activity was recorded in 89 episodes-23.6% during sleep, 22.4% at rest, 46% during physical activity and 8% during other activities. The mean ST segment depression during SMI (n = 106) was of -2.25 mm and during AMI (n = 13) was of -3.25 mm.(ABSTRACT TRUNCATED AT 250 WORDS)