Effects of different beta-receptor antagonists on handgrip in essential hypertension.

To assess the influence of selective and nonselective beta blockers with or without ISA we evaluated the extent of pressor responses to isometric exercise in 15 hypertensive patients who had first been treated with atenolol (100 mg/day) and subsequently with mepindolol (15 mg/day) for 2 months each following placebo administration for 2 weeks. Isometric handgrip was always performed in a supine position. Blood pressure and heart rate were measured at 30% of the maximal voluntary contraction. The percentages of blood pressure increases associated with the isometric test were similar during treatment with the two beta blockers; only heart rate was significantly lower. Systolic and diastolic blood pressures showed a lower increase with mepindolol than with atenolol, but the differences were not statistically significant. In conclusion, cardioselective beta blockers without ISA and nonselective beta blockers with ISA influence systolic and diastolic blood pressure responses to a handgrip of 30% in the same way. Only heart rate shows a lower but rather small increase during the cardioselective drug treatment.