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Effect of intravenous calcium antagonists on left ventricular diastolic function in hypertension: assessed by
1Second Department of Internal Medicine, Nagoya City University Hospital, Japan.
Insights
Calcium antagonists like nicardipine and diltiazem lower blood pressure by reducing total peripheral resistance. These drugs also improve left ventricular diastolic filling in hypertensive patients.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Hypertension management often requires medications that affect hemodynamics.
- Left ventricular diastolic function is crucial for cardiac health.
Purpose of the Study:
- To evaluate the acute effects of nicardipine and diltiazem on blood pressure.
- To assess the impact of these calcium antagonists on left ventricular diastolic filling.
Main Methods:
- Pulsed-Doppler echocardiography measured transmitral flow velocities.
- Direct arterial pressure and hemodynamic indices were monitored.
- Seven essential hypertension patients received escalating doses of nicardipine or diltiazem.
Main Results:
- Both drugs significantly reduced blood pressure and total peripheral resistance.
- Nicardipine increased heart rate; diltiazem decreased it.
- Both agents enhanced early diastolic filling velocities and the E:F ratio, independent of heart rate changes.
Conclusions:
- Intravenous nicardipine and diltiazem effectively lower blood pressure via reduced peripheral resistance.
- These calcium antagonists offer beneficial effects on left ventricular diastolic filling in hypertensive patients.
Objective:
To investigate the acute effects of the calcium antagonists nicardipine and diltiazem on blood pressure and left ventricular diastolic filling in hypertensive patients.
Design:
Transmitral flow velocities were measured by pulsed-Doppler echocardiography before and during infusion of nicardipine (1, 2 and 3 micrograms/kg per min) and diltiazem (5, 10 and 15 micrograms/kg per min) in seven patients with essential hypertension. Arterial pressure was measured directly, and other haemodynamic indices were obtained using a right-sided heart catheter.
Results:
The calcium antagonists significantly decreased blood pressure and total peripheral resistance. Changes in mean blood pressure correlated with those in total peripheral resistance. Heart rate was significantly increased by nicardipine but decreased by diltiazem. Nicardipine and diltiazem both increased significantly the peak early filling velocity and the peak velocities of early: late filling ratio. The changes in the ratio correlated inversely with those in total peripheral resistance.
Conclusion:
Intravenous infusion of nicardipine or diltiazem causes a fall in blood pressure by decreasing total peripheral resistance, with beneficial effects on left ventricular diastolic filling that are independent of changes in heart rate in patients with hypertension.