Post-exertion changes in left ventricular systolic time intervals in patients with primary hypertension treated with hydrochlorothiazide, binazine, and propranolol.

The study involved 13 patients with primary hypertension who exercised on a bicycle ergometer with intensity increasing up to submaximum level. The exercise was carried out in four stages: before treatment (1st study), following one week treatment with 50 mg hydrochlorothiazide daily (2nd study), after one week treatment with the same dose of hydrochlorothiazide and 120 mg binazine daily (3rd study), and after one week treatment with hydrochlorothiazide and binazine, and 60 mg of propranolol daily (4th study). Using the approach of Weissler et al., left ventricular systolic time intervals were analysed at rest, after exercise and up to the 90th minute of restitution. Hydrochlorothiazide and binazine treatment decreased systolic and diastolic blood pressure, the total electromechanical systolic time index (QS2I) and the left ventricular ejection time index (LVETI), and increased the PEP/LVET index at rest and after exercise. Addition of propranolol did not augment the hypotensive effect, while the left ventricular systolic time intervals returned to the values observed before treatment.