[Characteristics of the clinical aspects and symptomatology of ischemic heart disease with various degrees of stenosis of the left coronary artery].

The case histories, painful syndromes, clinical pictures, ECG at rest, and the exercise ECG test data were examined in 169 patients with degrees I-IV of left coronary artery stenosis. The gravity of the clinical picture was found to be augmented with the stenosis degree. The number of daily angina pectoris attacks and their gravity increased, while the pains at rest, night time, after meal, and during transition from the vertical to the horizontal position occurred more frequently. As the stenosis degree progressed, the coronary insufficiency area on the ECG at rest became larger. The exercise tolerance threshold appeared particularly low in patients with degrees II-IV of stenosis, being slightly higher in those with degree I of stenosis. The number of patients who survived myocardial infarction declined with stenosis progression. Patients with degree I of stenosis manifested a grave clinical picture. Stenosis of the left coronary artery up to 50% of the initial trunk was a clinically significant lesion.