Redução da função sistolica e diastolica do ventriculo esquerdo, estimada pela velocidade do anel mitral, em pacientes hipertensos com e sem hipertrofia ventricular / Longitudinal mitral annulus velocities are reduced in hypertensive subjects with left ventricule hypertrophy

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Epidemiological studies have established a continuous relationship between the left ventricular (LV) mass and cardiovascular risk in the general and hypertensive population. The poorer prognosis of hypertensive subjects with major increases in LV mass has been, in part, attributed to myocardial dysfunction, but it remains unknown whether hypertensive subjects without clinically defined LV hypertrophy have subtle abnormalities of myocardial function. Echocardiographic indices derived from LV chamber dimensions and Doppler measurements of flow velocities have been proved to be generally nonspecific and insensitive for the detection of minor abnormalities of cardiac relaxation and contraction. Tissue Doppler imaging (TDI) has been advocated as a reliable, rapid, and efficient method to assess myocardial function. In hypertensive patients with LV hypertrophy, TDI mitral annulus systolic and diastolic velocities have been shown to be reduced. However, a comprehensive TDI approach has not been reported in hypertensive subjects without or with minor increases in LV mass. The present study examines whether, by using TDI early systolic and diastolic velocities, one might identify changes in LV myocardial contraction and relaxation in subsets of hypertensive with and without clear-cut, clinically defined LV hypertrophy and normal LV ejection fraction. Normotensive and hypertensive subjects with and without left ventricular (LV) hypertrophy (LV mass index [LVMI] ?51 g/m2.7) were examined by conventional echocardiography and tissue Doppler imaging of mitral annulus motion. The subgroups included non obese normotensive subjects (n=16; age 51±9 years; 11 female; systolic blood pressure [SBP] 109±11 mm Hg, body mass index [BMI] 24±2.7 kg/m2; LVMI 32±5.5 g/m2.7), non obese hypertensive subjects without LV hypertrophy (n=16; age 54±12 years; 12 female; SBP 166±15 mm Hg; BMI 25±2.7 kg/m2; LVMI 42_5.5 g/m2.7), and hypertensive subjects with LV hypertrophy (n=22; age 56±10 years; 10 female; SBP 181±19 mm Hg; BMI 26±2.3 kg/m2; LVMI 69±16 g/m2.7). Ejection fraction was comparable among the subgroups, but midwall fractional shortening was reduced in hypertensive subjects with LV hypertrophy (?26%). Isovolumic relaxation time was increased in subjects with LV hypertrophy, whereas mitral wave A velocity was increased in hypertensive subjects with and without LV hypertrophy. Tissue Doppler imaging mitral annulus systolic (SM) and diastolic (EM) velocities were reduced in subjects with and without LV hypertrophy compared with normotensive subjects. There was a positive correlation between SM and EM (r=0.68; P<0.0001) and negative correlations between these 2 variables and LVMI (SM, r= -0.41; P=0.002; EM, r=-0.56; P<0.0001). Thus, reductions in mitral annulus systolic and diastolic velocities parallel increases in LV mass in hypertensive subjects, beginning at LV mass within the clinically defined normal values

ASSUNTO(S)

tissue doppler função ventricular ecocardiografia hipertensão ventricular function hypertension doppler tecidual miocardio myocardium echocardiography

ACESSO AO ARTIGO

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