[Comparative sensitivities of exercise, isoproterenol infusion and cold pressor tests for detecting myocardial ischemia].

Abstract

The comparative sensitivities of exercise (supine ergometer), isoproterenol (ISP) infusion and cold pressor test (CPT) for detecting myocardial ischemia in patients with effort angina (45 cases) and vasospastic angina (16 cases) were investigated. Twenty-three patients with atypical chest pain served as normal controls. Left ventricular function was evaluated by computerized quantitative analysis using the following three graphic methods: 1) radionuclide angiography during exercise (EX-RI) and ISP infusion (ISP-RI), 2) two-dimensional echocardiography during ISP infusion (ISP-2DE) and CPT (CP-2DE) and 3) digital subtraction angiography during CPT (CP-DSA). The incidence of regional wall motion abnormalities (WMA) induced by these three stress tests in patients with effort angina were as follows: 83% in EX-RI, 80% in ISP-2DE, 80% in ISP-RI, 75% in CP-2DE and 86% in CP-DSA. In patients with vasospatic angina, the WMA were as follows: 40% in EX-RI, 0% in ISP-RI and 71% in CP-DSA. In patients with atypical chest pain, the WMA were 0% in EX-RI, 0% in ISP-RI, 8% in ISP-2DE, 13% in CP-2DE and 13% in CP-DSA. The left ventricular ejection fraction (EF) was unchanged during ISP (from 65 +/- 11% to 68 +/- 12%) and it decreased both during exercise (from 64 +/- 10% to 58 +/- 9%, p less than 0.05) and during CPT (from 69 +/- 10% to 65 +/- 9%, p less than 0.05) in patients with effort angina. In patients with vasospastic angina, the EF was unchanged both during exercise (from 70 +/- 7% to 68 +/- 13%) and during the CPT (from 76 +/- 5% to 75 +/- 4%), while it increased during ISP infusion (from 63 +/- 8% to 79 +/- 7%, p less than 0.01). In patients with atypical chest pain, the EF was increased both during exercise (from 72 +/- 7% to 79 +/- 5%, p less than 0.01) and during ISP infusion (from 67 +/- 5% to 78 +/- 7%, p less than 0.01), while it was unchanged during CPT (from 77 +/- 7% to 76 +/- 8%). In exercise and in ISP infusion tests, WMA were provoked concomitantly with ST segment deviations in nearly all patients. However, during CPT, WMA were produced without the occurrence of ST segment deviations. Myocardial ischemia due to organic coronary artery stenosis was difficult to distinguish from coronary artery spasm by exercise test. However, the susceptibility to ISP infusion and CPT differed in producing WMA in patients with vasospastic angina.(ABSTRACT TRUNCATED AT 400 WORDS)