Related Experiment Videos
Comparative effects of propranolol and diltiazem on systolic and diastolic left ventricular function in essential
K B Ramanathan1, T E Ratts, B Griffin
1Department of Medicine, University of Tennessee, Memphis.
Insights
Propranolol and diltiazem effectively lower blood pressure in hypertensive patients. These drugs did not significantly impair left ventricular systolic or diastolic function after four months of treatment.
Area of Science:
- Cardiology
- Pharmacology
- Hypertension Research
Background:
- Hypertension poses risks to cardiovascular function.
- Understanding the impact of antihypertensive medications on cardiac function is crucial.
Purpose of the Study:
- To evaluate the effects of propranolol and diltiazem on left ventricular systolic and diastolic function.
- To assess cardiac function in hypertensive patients treated with these drugs.
Main Methods:
- 21 hypertensive patients (DBP 90-114 mmHg) participated in a double-blind study.
- M-mode and 2D echocardiograms assessed systolic and diastolic function parameters.
- Measurements included fractional shortening, velocity of fiber shortening, and diastolic dimensions (MAXD, EDD, LDD).
Main Results:
- Both propranolol and diltiazem similarly reduced systolic and diastolic blood pressure.
- No significant changes in systolic function parameters were observed with either drug.
- Neither drug significantly altered MAXD or EDD; diltiazem showed a trend towards improving maximal rate of posterior wall thinning (MAX PWT).
Conclusions:
- Propranolol and diltiazem effectively lower blood pressure in hypertensive individuals.
- These medications do not appear to have significant deleterious effects on left ventricular systolic or diastolic function.
- Baseline diastolic function remained stable, with no consistent drug-induced changes observed.
Abstract:
The effects of propranolol and diltiazem on left ventricular systolic and diastolic function in hypertensive subjects (DBP 90-114 mmHg) were examined with M-mode and 2D echocardiograms in 21 patients in a double-blind fashion prior to and after 4 months of treatment. Systolic function was assessed by measurement of fractional shortening, mean velocity of fibre shortening, peak systolic pressure/end systolic dimension ratio, and end systolic stress/end systolic dimension ratio. To assess diastolic function, maximal rate of change in left ventricular dimension (MAXD), maximal rate of change in posterior wall thinning (MAX PWT) and early diastolic (EDD) and late diastolic dimension changes (LDD) were calculated using digitised M-mode images of mid-wall diameter. Both propranolol and diltiazem reduced systolic and diastolic pressures similarly. No significant changes were observed in any of the parameters of systolic function with either drug. Similarly neither propranolol nor diltiazem altered MAXD or EDD significantly. Although changes in maximal rate of posterior wall thinning (MAX PWT) were not significant with either drug, diltiazem improved MAX PWT in 7 of 8 patients. The results of the study demonstrate that both propranolol and diltiazem reduce blood pressure without significant deleterious effects on systolic or diastolic function. Diastolic functional parameters, which were not abnormal at baseline, showed no consistent change with either propranolol or diltiazem.