Propranolol treatment of effort angina in patients with arterial hypotension

Aim. To compare antianginal efficacy and tolerability of propranolol therapy in patients with stable angina pectoris and chronic hypotension (Hpts) and normotensive patients with angina of effort (Npts). Material and methods. A randomized, single-blind, placebo-controlled study was made in 35 Hpts and 33 Npts was made using bicycle exercise tests, echocardiography, stress myocardial scintigraphy with Tl-199, Results. Acute bicycle exercise tests showed high anti-ischemic activity of propranolol in 86% Hpts and 65% Npts. Stable antianginal propranolol effect in 57% Hpts was accompanied with a decrease of myocardial perfusion defect. Secondary resistance or pseudotolerance to an antianginal effect of propranolol was observed in 43% Hpts in 4-12 weeks (vs 0 of Npts; p < 0,01) as evidenced by Tl-199 stress myocardial scintigraphy. Hpts with secondary resistance and pseudotolerance to propranolol had lower control hypotension and bradicardia (p < 0,05), more anginal attacks (p < 0,001). Conclusion. Hpts had rapidly developing secondary resistance and pseudotolerance to propranolol antianginal effect, bad tolerability of the drug.