Maximum longitudinal relaxation velocity of the left ventricle: its clinical value and relationship with NT-proBNP plasma levels in heart failure.

BACKGROUND: M-mode recordings of the mitral annulus to measure the maximum ascending velocity during early diastole as an expression of maximum longitudinal relaxation velocity of the left ventricle (RVm) can be used as an index of left ventricular (LV) diastolic function. The purpose of this study was to determine the relationship of RVm with LV functional parameters in patients with heart failure, with N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels, and with their functional classification. METHODS AND RESULTS: RVm was recorded in 97 patients by M-mode echocardiography. Patients were classified according to the New York Heart Association (NYHA) and the concentration of NT-proBNP was determined. Patients with ejection fraction (EF)>40 showed a significant correlation between RVm and mitral annulus motion (MAM), mitral flow propagation velocity, E/A, age, deceleration time (DT), and NT-proBNP. In patients with EF40, though its relationship with NT-proBNP both in patients with EF>or40 it is influenced only by age. RVm values showed a significant decrease in NYHA class II and III.

Left ventricular cavity area reflects N-terminal pro-brain natriuretic peptide plasma levels in heart failure.

AIMS: N-terminal pro-brain natriuretic peptide (NT-proBNP) is useful in the diagnosis of heart failure (HF). LV two-dimensional cavity area from end-diastole (LVEDA) and end-systole (LVESA), and LV fractional area change (LVFAC) reflect changes in LV morphology and function without using geometric assumptions. In a multicenter study, we correlated LVEDA, LVESA and LVFAC with NT-proBNP, comparing patients with dilated and ischemic cardiomyopathy. METHODS AND RESULTS: We studied 106 HF patients. In the dilated group, NT-proBNP correlated with LVEDAI (r=0.6), LVESAI (r=0.7) and LVFAC (r=-0.6), all significant at p<0.001. In patients with ischemic cardiomyopathy we found LVESAI (r=0.3, p<0.05) and LVFAC (r=-0.4, p<0.01). After adjustment for age and BMI, LVFAC and LVESAI were associated in a multiple linear regression analysis with peptide levels (adjusted r(2)=0.5, p<0.001). CONCLUSIONS: In this study we found a good correlation of NT-proBNP with LV cavity areas and LVFAC. Multiple regression analysis showed that when adjusted for age and BMI, LVFAC and LVESAI are independent predictors of NT-proBNP levels in both dilated and ischemic etiologies. Patients with dilated cardiomyopathy showed better results than those with ischemic cardiomyopathy. We think LV areas are a useful and reproducible parameter, do not need geometric assumptions and reflect NT-proBNP plasma levels.