Midwall mechanics are improved after regression of hypertensive left ventricular hypertrophy and normalization of chamber geometry

Background-It is still unclear whether substantial regression of hypertensi ve left ventricular hypertrophy (LVH) and normalization of chamber geometry are associated with improved left ventricular (LV) myocardial function. Methods and Results-Midwall mechanics were evaluated in 152 patients underg oing 1 year of effective antihypertensive treatment. Two-dimensionally dire cted M-mode echocardiography was performed as follows: (1) after a 4-week p lacebo "run-in" period, (2) after 1 year of treatment with 20 mg/d lisinopr il (alone or associated with 12.5 to 25 mg/d hydrochlorothiazide), and (3) after a final 1-month placebo period to allow blood pressure (24-hour avera ge ambulatory monitoring) to return to pretreatment levels. Treatment-induc ed reductions in blood pressure (from 149+/-16/95+/-11 to 31+/-12/83+/-10 m m Hg, P<0.05) and circumferential end-systolic wall stress (from 84+/-22 to 72+/-19 g/cm(2), P<0.05) were associated with a marked reduction in LV mas s index (from 159+/-30 to 133+/-26 g/m(2), P<0.05). LVH regression was acco mpanied by an increase in midwall fractional shortening (from 19.7+/-2.7% t o 20.9+/-2.7%, P<0.05) and by a decrease in relative wall thickness (from 4 8.2+/-7.7% to 44.1+/-6.7%, P<0.05). The improvement in midwall function ass ociated with afterload reduction and substantial LVH regression persisted a fter antihypertensive therapy withdrawal and restoration of the hypertensiv e state. Despite a significant increase in end-systolic wall stress, furthe r LV chamber remodeling did not occur. The preservation of relative wall th ickness was associated with a persistent improvement in midwall systolic fu nction. Conclusions-Regression of concentric LVH is associated with an improvement of midwall systolic function, which is more dependent on the normalization of LV geometry than on the reduction in LV systolic stress.