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Effects of diltiazem on cardiovascular responses during exercise in systemic hypertension and comparison with
Insights
Diltiazem effectively lowers blood pressure (BP) during exercise in hypertensive patients, unlike placebo or propranolol. This calcium channel blocker may benefit patients with coronary artery disease due to its vasodilatory and heart rate-lowering effects.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Systemic hypertension requires effective management, especially during physical activity.
- Understanding the effects of antihypertensive medications on exercise hemodynamics is crucial for patient care.
Purpose of the Study:
- To compare the effects of diltiazem and propranolol on blood pressure and heart rate during exercise in patients with uncomplicated hypertension.
- To assess the potential benefits of diltiazem in hypertensive patients, particularly those with coexisting coronary artery disease.
Main Methods:
- A randomized, crossover study involving 16 patients with uncomplicated systemic hypertension.
- Patients received placebo, diltiazem (180 mg/day), and propranolol (60 mg/day) for one month each.
- Multistage symptom-limited treadmill exercise tests were performed during each treatment period.
Main Results:
- No significant difference in maximal exercise duration was observed between treatments.
- Both diltiazem and propranolol significantly reduced resting, submaximal, and maximal exercise blood pressure and heart rate.
- Diltiazem showed smaller reductions in systolic blood pressure, heart rate, and pressure-rate product during exercise compared to propranolol, indicating minimal beta-blocking activity.
Conclusions:
- Diltiazem effectively reduces systemic blood pressure during exercise in hypertensive patients.
- Diltiazem may be a beneficial treatment for hypertension, especially when associated with coronary artery disease, due to its coronary vasodilatory and heart rate-reducing properties.
Abstract:
Sixteen patients with uncomplicated systemic hypertension were treated with placebo, diltiazem (180 mg/day) and propranolol (60 mg/day) for 1 month each. Each patient performed multistage symptom-limited treadmill exercise tests during each period of administration. There was no significant difference in maximal exercise duration between placebo, diltiazem and propranolol. Diltiazem significantly decreased both systolic and diastolic blood pressure (BP) and heart rate at rest, during submaximal exercise at the same work load and maximal exercise. Propranolol produced similar changes in systemic BP and heart rate at rest and during exercise. However, the reductions in systolic BP, heart rate and pressure-rate product with diltiazem during exercise were smaller than those with propranolol at small doses, suggesting that diltiazem in its usual therapeutic dose was almost devoid of beta-blocking activity. Thus, diltiazem may be of benefit to hypertensive patients because it reduces systemic BP even during exercise. It is particularly useful when systemic hypertension occurs in association with coronary artery disease because of its effects of coronary artery dilatation and heart rate reduction.