We aimed at investigating the relation between left ventricle (LV) systolic parameters and beat-to-beat distances and also whether this relation is different in heart failure with reduced ejection fraction (HFrEF) patients with atrial fibrillation (AF). The relation between peak velocity in left ventricular outflow (VLVOT), left atrioventricular plane displacement (LAVPD) or peak systolic tissue Doppler velocity of lateral mitral annulus (Lateral S') and preceding beat-to-beat distance (RR1) or prepreceding beat-to-beat distance (RR2) were analyzed by linear regression analysis. From this analysis, three parameters were obtained: slope of regression line, constant of regression line, and square of regression coefficient (r2) of linear relation. In the group with HFrEF, the slope and r2 values of the regression line showing the relationship between the RR1 interval and VLVOT, LAVPD, and Lateral S' values were higher and the constants were lower. In the Kendall rank correlation analysis, the slope, constant, and r2 values of the regression analysis between RR1 interval and VLVOT or Lateral S' were in significant correlation with LVEF. The r2 of VLVOT-RR1 analysis, slope of this analysis, and slope of Lateral S'-RR1 regression line values were mostly predictive for detecting HFrEF. It was concluded that the novel parameters obtained by linear regression analysis between LV systolic function parameters and RR1 interval, but not RR2, might be beneficial for evaluating systolic heart failure in patients with AF. They might have potential for future research about the physiopathology of heart and prognosis in patient with AF.
Keywords: Atrial fibrillation; Beat-to-beat distance; Heart failure; Left ventricle; Systolic function.
© 2021. The Author(s), under exclusive licence to Springer Nature B.V.