Left ventricular function in the successive phases of systemic hypertension evaluated with pulsed Doppler echocardiography

ABSTRACT

Systolic and diastolic function is impaired in patients with hypertensive heart disease. Systolic hypertension induces a succession of LV hemodynamic changes and can be regarded as a spectrum from maladaptive hypertophy to heart failure. The left ventricular hemdynamic changes that occur can be measured non-invasively by Doppler echocardiography. The aim of the study was to hemodynamically characterize the different phases of left ventricular [LV] function in patients affected by systemic hypertension [SH]. 95 normotensive healthy controls [group I] and 94 hypertensives [group II] were enrolled. Hypertensive patients were divided in two sub-groups according to echocardiographic signs of left ventricular hypertrophy [LVH]. Other echocardiographic parameters measured using tissue Doppler were Isovolumic Relaxation Time [IRT], isovolumic contraction time [ICT], and systolic motion [Sm]. Myocardial Performance Index [MPI] using Tissue Doppler Echocardiography [TDE] was defined in both the control group and the two hypertensive subgroups. Ejection fraction [EF] was also calculated in all participants. An increased MPI derived from the rise of isovolumetric relaxation time [IRT] was found in hypertensives without LVH [sub-group II-a], whereas isovolumetric contraction time [ICT] and Systolic motion [Sm] were unchanged. Hypertensive patients with LVH demonstrated more prominent increase of MPI, increase in IRT-prolongation, ICT-increase and Sm-decrease. The results obtained indicate impaired relaxation in sub-group II-a. On the contrary, a systolo-diastolic LV dysfunction was found in sub-group II-b. E.F decreased in this same sub-group of hypertensives in comparison with controls and sub-group II-a, as a sign of maladaptive LVH evolving towards heart failure. Doppler echocardiography appears able to distinguish the different forms and degrees of LV dysfunction in SH in relation to the different phases of the hypertensive disease process