Detection of silent myocardial ischemia by Holter monitoring and its relation to severity of coronary artery disease.

ABSTRACT

Thirty-five patients of chronic stable angina, unstable angina and post MI angina, who were on medical treatment, underwent 24 hours Holter monitoring and coronary angiography to find out the incidence of Silent Myocardial Ischemia (SMI) and its relation to anatomic severity of coronary artery disease. Total duration of Holter monitoring was 835.32 hours (average 23.40 hours per patient) with 48 ischemic episodes out of which 16 were painful and 32 painless. Total duration of painful episodes was 189 minutes and that of painless episodes was 428 minutes (70% was constituted by SMI). Out of 35 patients, 6 (17.14%) had SMI; 2 of 17 (11.7%) of chronic stable angina, 2 of 8 (25%) of unstable angina, and 2 of 10 (20%) of post-infarction angina patients. On analysis of coronary angiogram, all 6 (100%) patients with SMI, and only 22 out of 29 (76%) without SMI, had severe multiple coronary artery disease. Thus, although the overall incidence of SMI in this series is low, its presence invariably indicates a severe degree of coronary artery disease.