Evaluación de la contractilidad del ventrículo izquierdo en pacientes con estenosis aórtica grave,flujo bajo,gradiente bajo y fracción de expulsión preservada

Introduction:

In patients with severe aortic stenosis, low-gradient, low-flow and preserved ejection fraction (≥ 50%) (LG/LFp) the decrease in stroke volume index (Svi) could be due to diminished contractility. The aim of this study was to analyze if low Svi in patients with LG/LFp is related to a decrease in contractility.

Methods:

Thirty patients with LF/LGp and 63 normal subjects were studied with Doppler echocardiography. The level of contractility (LC) was assessed by mean of midwall shortening fraction (mSF) – end-systolic stress (ESS) relationship. Relative wall thickness (RWT) and aortic valve area (AVA) were calculated.

Results:

LC was diminished in 40% of LF/LGp patients. By bivariate analysis LC correlated with RWT and mSF. Svi correlated with AVA but not with LC. In multiple linear regression RWT and mSF were predictors independents of LC. About Svi, AVA was the only predictor independent variable.

Conclusion:

Decreased contractility was present in 40% of LF/LGp patients despite preserved ejection fraction. LC had correlation with mSF and EPR. Low Svi appears to be related to aortic stenosis severity rather than low contractility.Key words: Aortic stenosis, Contractility, Echocardiography, Ventricular function