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Angina in hypertensive patients. With particular reference to the negative chronotropic effects of sympatholytic
Insights
Beta-blockers improved exercise tolerance in hypertensive patients with angina, unlike other antihypertensives. Combining sympatholytic and beta-blocker drugs offered the best blood pressure and angina control.
Area of Science:
- Cardiology
- Pharmacology
- Hypertension Research
Background:
- Hypertension and angina are significant cardiovascular concerns.
- Understanding the impact of antihypertensive treatments on exercise tolerance is crucial.
Purpose of the Study:
- To evaluate the effects of different antihypertensive drugs on blood pressure, heart rate, and exercise tolerance in hypertensive patients with and without angina.
- To compare the efficacy of sympatholytic drugs versus beta-receptor blocking drugs in managing angina and hypertension.
Main Methods:
- Standardized treadmill exercise tests were performed on hypertensive patients before and after treatment.
- Patients received treatments including bethanidine, debrisoquine, guanethidine, oxprenolol, or propranolol, alone or in combination.
Main Results:
- No significant difference in blood pressure or heart rate response to exercise was observed between hypertensive patients with and without angina.
- Sympatholytic drugs (bethanidine, debrisoquine, guanethidine) reduced heart rate but did not improve exercise tolerance.
- Beta-receptor blocking drugs (oxprenolol, propranolol) improved exercise tolerance in patients with angina.
- Combination therapy of sympatholytic and beta-blocker drugs provided the best control of blood pressure and angina.
Conclusions:
- Beta-blockers are effective in improving exercise tolerance in hypertensive patients experiencing angina.
- Combination therapy offers superior management of both hypertension and angina.
- Late-onset angina in hypertensive patients may be linked to coronary occlusion rather than hypertension control.
Abstract:
There was no significant difference in the blood pressure and heart rate response of hypertensive patients with and without angina to standardised exercise on a treadmill before and after anti-hypertensive treatment. There was no improvement in exercise tolerance in the hypertensive patients with angina treated with bethanidine, debrisoquine or guanethidine despite a reduction of resting and exercise heart rates after treatment. The negative chronotropic effect of these sympatholytic drugs was less than that of oxprenolol or propranolol, but the hypotensive response was greater. Both of these beta-receptor blocking drug produced an an improvement in exercise tolerance in patients with angina either alone or in combination with other hypotensive therapy. The best control of blood pressure and angina was often achieved by a combination of a sympatholytic drug and beta-receptor blocking drug. In hypertensive patients treated for several years, angina at presentation was occassionally reduced by reduction of blood pressure. Later onset of angina appeared to be unrelated to control of hypertension but to be due to coincidental coronary occlusion. There was no evidence that myocardial infarction was precipitated by postural or exercise hypotension although these effects occasionally precipitated angina.