Left ventricular geometric adaptation to chronic pressure overload: Differences between systemic hypertension and valvular aortic stenosis - An echocardiographic study

In patients with systemic hypertension, the adaptation of left ventricle to pressure overload may manifest with four geometric patterns on the echocardiographic tracing, and each of them seems to reflect a different hemodynamic profile and to have a different prognostic value. The aim of this study was to analyze how the left ventricle adapts to pressure overload in a group of adult patients with valvular aortic stenosis, compared to a group of hypertensive subjects. Left ventricular (LV) mass indexed for body surface area and relative wall thickness (2 x posterior wall thickness/LV end-diastolic diameter) were measured on M-mode echo in 100 patients with essential hypertension of different severities and 80 patients with isolated valvular aortic stenosis (mean valve area by Doppler: 0.67 +/- 0.2 cm(2)). LV mass index was significantly higher in aortic stenosis compared to hypertensive patients (187 +/- 50 vs. 128 +/- 42 g/m(2); p < 0.001); mean wall thickness was also higher in the aortic stenosis group (13.6 +/- 2 vs. 11.3 +/- 2.2 mm; p < 0.01) while LV end-diastolic diameter and LV fractional shortening were similar in the two groups. Among hypertensive patients, LV mass and relative wall thickness were normal in 33%, whereas 22% had increased relative wall thickness with normal LV mass (concentric remodeling), 32% had increased mass and increased relative wall thickness ('typical' concentric hypertrophy) and 13% had increased LV mass with normal relative wall thickness (eccentric hypertrophy). Among aortic stenosis patients, none had a normal LV anatomy, 11% showed a concentric remodeling pattern, 69% a concentric hypertrophy and 20% an eccentric hypertrophy. It is of interest that most aortic patients with eccentric hypertrophy (14 out of 16) had a clinical picture of severe congestive heart failure associated with a significant LV dilation with a marked reduction of LV fractional shortening and more severe valve stenosis. In conclusion, compared to hypertensive patients, aortic stenosis patients show a larger LV hypertrophy probably indicating a higher hemodynamic overload. Furthermore, other than with hypertension, the presence of eccentric hypertrophy in patients with aortic stenosis usually indicates a more severe disease. The evaluation of the geometric pattern of the left ventricle may add useful information to the clinical evaluation of patients with chronic pressure overload.