Effects of nifedipine on left ventricular diastolic function in hypertension; echo Doppler study

Hypertensive cardiac disease shows early alteration of left ventricular diastolic filling, characterized by a longer isovolumetric relaxation period and by an altered E/A ratio on the mitral spectral Doppler. We chose ten hypertensive patients who had left ventricular hypertrophy, but no left ventricular dilatation or mitral valve insufficiency and had a good left ventricular shortening fraction (greater than 26%). After the washout period we studied each of the above-mentioned parameters before and after the acute administration of nifedipine, dinitrate isosorbide, and captopril. While captopril and dinitrate isosorbide induced a prolongation of the isovolumic relaxation time and an impairment of the E/A ratio in mitral spectral Doppler (i.e., left ventricular filling), nifedipine induced an improvement in both parameters. The three drugs also induced a similar reduction in systemic blood pressure values (i.e., similar afterload). We therefore suggest that changes in diastolic function in hypertrophied cardiac fibers, induced by nifedipine, may be the result of a double action: one mediated by hemodynamic changes, the other directly affecting the cellular calcium ion exchange.