Clinical and echocardiographic determinants of diastolic dysfunction among Nigerian hypertensive subjects

Background: Diastolic dysfunction can occur either as an early marker or in late stages of hypertensive heart disease. Knowledge about its determinants is crucial to its management. Reports about clinical and echocardiographic determinants of diastolic dysfunction among Nigerian hypertensive subjects are few. This study aimed at describing the main clinical and echocardiographic determinants of diastolic dysfunction among Nigerian hypertensive subjects. Methods: Two hundred and forty-five hypertensive subjects and 68 age and sex-matched normotensives that had echocardiography were used for this study. Diastolic function was assessed by a combination using the ratio of early and late mitral flow velocity E/A ratio, isovolumic relaxation time (IVRT) and deceleration time (DT). Statistical analysis was carried out with the SPSS 16.0. Correlation and stepwise regression analysis were used for univariate and multivariate analysis respectively. Results: Mean age of the hypertensive subjects was similar with that of the controls (56.8±12.2 vs. 55.0±7.9 respectively, P>0.05). Diastolic dysfunction was commoner among hypertensive subjects than controls. Age, systolic and diastolic blood pressure (BP), and left ventricular chamber dimensions generally showed the greatest correlation with indices of diastolic function among the study population. Using the multivariate analysis, age was the strongest determinant of DT and IVRT followed by left ventricular chamber dimension for DT and systolic BP for IVRT. Left ventricular internal chamber dimension was the strongest determinant of mitral E/A ratio followed by diastolic BP. Conclusion: Age, systolic BP, and left ventricular volume and dimension are the major determinants of the diastolic dysfunction among hypertensive Nigerians. They affect different aspect of the diastolic parameters.