Clinical Significance of Left ventricular Relative Wall Thickness by M-mode Echocardiography in Hypertensive Subjects

Park, Ock Kyu; Park, Jong Cheol; Jeong, Jin Won

Abstract

BACKGROUND
Recent studies have shown that ultrasound assessment of left ventricular(LV) and arterial geomatry and identify "preclinical" cardiovascular disease in asymptomatic hypertensive patients. Left ventricular geometry may be classified into four groups on the basis of LV mass and realtive wall thickness(RWT). Increased LV mass including concentric hypertrophy or eccentric hypertrophy and increased RWT including concentric hypertrophy or concentric remodeling predicts greater risk of cardiovascular events, independent of arterial pressure, other risk factors of the presence of coronary artery disease. Thus we evaluated the relative wall thickness(RWT) in the normotensive and hypertensive subjects and studied its ralation to LV structure and systolic function. METHOD: RWT, LV systolic function indices(ejection fraction, %fractional shortening, meanvelocity of circumferential fiber shortening)and load independent indices, such as, peak systolic pressure(PSP)/end-systolic diameter(ESD), PSP/end-systolic volume index(ESVI), and end-systolic wall stress(EWS)/end-systolic volume index(ESVI) were investigated by 2-D guided M-mode echocardiography in 133 normal subjects who were free of clinically apparent cardiovascular disease and in 118 patients with essential hypertension with no preexisting cardiac disease or anti-hypertensive medication.
RESULTS
1) RWT was significantly increased in hypertensive subjects(0.5±0.117) compared to normotensive subjects(0.34±0.054)(p < 0.0001). 2) RWT in all subjects, correlated well with systolic and diastolic blood pressure, calculated mean blood pressure, LV mass, LV mass index by height and body surface area, and PSP/ESD ratio at coefficient of 0.6787, 0.5893, 0.6630, 0.7594, 0.7653, and 0.6673, respectively. 3) RWT in hypertensive subjects was positively correlated well with LV mass, LV mass index at coefficient at 0.7129 and 0.7005 and negatively with peak systolic wall stress at a coefficient at âˆ’0.7730.
CONCLUSION
We concluded that increased RWT in hypertensives is well associated with increased LV mass and decreased LV peak systolic wall stress, so that RWT can be used as rather an index of compensatory LV hypertrophy than of systolic fuction, and as one of the risk predictors for cardiovascular events as well as LV mass itself.