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Long-term haemodynamic effects of amlodipine at rest and during exercise in essential hypertension
P Lund-Johansen1, P Omvik, W White
1Medical Department, Haukeland Hospital, Bergen, Norway.
Insights
Long-term amlodipine treatment effectively lowers blood pressure in essential hypertension patients at rest and during exercise. This antihypertensive effect is achieved by reducing total peripheral resistance index without compromising cardiac function.
Area of Science:
- Cardiology
- Pharmacology
- Hypertension Management
Background:
- Essential hypertension is a common condition requiring effective long-term management.
- Amlodipine is a novel long-acting calcium antagonist with potential antihypertensive properties.
Purpose of the Study:
- To evaluate the long-term hemodynamic effects of amlodipine in patients with essential hypertension.
- To assess amlodipine's efficacy at rest and during various exercise intensities.
Main Methods:
- Intra-arterial blood pressure, dye dilution cardiac output, and electrocardiogram heart rate were measured.
- Hemodynamic parameters were assessed in 18 hypertensive patients over 11 months of amlodipine treatment (5-10 mg daily).
- Ambulatory blood pressure monitoring was used in a subset of patients.
Main Results:
- Amlodipine (mean 9 mg/day) reduced mean arterial pressure by 14% and total peripheral resistance index (TPRI) by 19% (P < 0.001).
- These reductions were consistent at rest and during 50W, 100W, and 150W bicycle exercise.
- Cardiac index was preserved, with no significant changes in heart rate or stroke index, and a trend towards increased stroke index during exercise.
Conclusions:
- Amlodipine demonstrates a significant antihypertensive effect in essential hypertension, reducing TPRI without impairing cardiac function.
- The drug provides 24-hour blood pressure control with a single daily dose.
- Amlodipine is well-tolerated, with a low incidence of side effects such as ankle edema.
Abstract:
The long-term haemodynamic responses to amlodipine, a new long-acting calcium antagonist, were studied both at rest and during exercise in 18 patients (mean age 43 years) with essential hypertension. Blood pressure was measured intra-arterially, cardiac output by dye dilution and heart rate by electrocardiogram. After 11 months of treatment with 5-10 mg amlodipine once daily (mean dose 9 mg/day), mean arterial pressure was reduced by 14% sitting at rest. The reduction in blood pressure was associated with a marked reduction in the total peripheral resistance index (TPRI) of 19% (P less than 0.001). Similar responses were seen supine at rest and during 50W, 100W and 150W bicycle exercise. No significant changes were seen in heart rate. There was a slight increase in stroke index, and cardiac index was preserved at rest and during exercise with a slight trend towards an increase. In 10 of the patients, blood pressure was monitored by a portable blood pressure recorder (Accutracker II, Suntech Medical instruments, Raleigh, North Carolina, USA). Blood pressure was well controlled throughout the full 24 h period after one daily dose. In conclusion, amlodipine exerts a clear antihypertensive effect, both at rest and during exercise, through reduction in the TPRI and without a fall in cardiac pump function. No changes in heart rate were seen and there was no tendency for a reduction in the stroke index during 8 min of exercise at 150 W; on the contrary there was a trend towards an increase. The incidence of side-effects was low (ankle oedema in two patients).