Abstract

HITA, Alejandro et al. Relationship of Ventricular Function and Morphometry in Patients with Symptomatic Aortic StenosisRelationship of Ventricular Function and Morphometry in Patients with Symptomatic Severe Aortic Stenosis. Rev. argent. cardiol. [online]. 2011, vol.79, n.4, pp.329-336. ISSN 1850-3748.

Background Ventricular hypertrophy is an adaptive mechanism of the myocardium to pressure overload in aortic stenosis. Different studies have postulated a correlation between structure and function in pressure overload due to aortic stenosis and the possible association with the development of pathological ventricular growth. However, there are a few studies evaluat-ing these variables in hearts with compensated ventricular hypertrophy (without a significant increase in wall stress) and preserved ejection fraction. Objectives To evaluate systolic and diastolic ventricular function in patients with symptomatic severe aortic stenosis with preserved ejection fraction and its correlation with collagen volume fraction and myocyte cross-sectional area. Material and Methods A total of 12 patients with symptomatic severe aortic stenosis were evaluated and compared with 6 patients without valvular heart disease; mean age was 65±13 years and 58% were men. All patients underwent tissue Doppler imaging and cardiac catheterization. Endomyocardial biopsies were obtained to determine collagen volume fraction and myocyte cross-sectional area (µm²). Results Mean collagen volume was 6.1±0.7%; mean myocyte cross-sectional area was 388.4±15.8 µm² and median strain in the basal septum was 14% (IIC 6.9-19). There was a significant correlation between septal strain measured by tissue Doppler imaging and collagen volume fraction (correlation coefficient -0.79; p = 0.03). We found no correlation between septal strain and myocyte cross-sectional area (R² = 0.15; p = 0.8). The max positive dP/dt normalized for left ventricular end-diastolic pressure obtained during cardiac catheterization had a negative correlation with the myocyte cross-sectional area (R -0.94; p = 0.005).The time constant of pressure decay (tau) increased by 55%±3,5% (p <0,05) and had a positive correlation with the myocyte cross-sectional area (R = 0.81; p = 0.04). Conclusion This study demonstrates the presence of anomalies in diastolic and systolic function in patients with symptomatic severe aortic stenosis and preserved ejection fraction that correlate with structural changes in the left ventricle, represented by increased interstitial collagen volume fraction and myocyte cross-sectional area.

Keywords : Aortic stenosis; Ventricular Function; Myocyte morphometry; Interstitial collagen.

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