RESUMO
BACKGROUND AND OBJECTIVES: Heart failure (HF) may occur in atrial fibrillation (AF) patients with a normal left ventricular (LV) systolic function if the diastolic function is impaired. The association of new parameters from the relationship between the preceding RR interval (RR-1) and LV outflow peak ejection velocity (Vpe) with systolic function has been reported. The aim of this study was to observe whether these parameters were associated with HF in AF patients with a normal systolic function. SUBJECTS AND METHODS: AF patients with a normal systolic function were divided into two groups according to the presence (n=16) or absence (n=30) of a history of HF. From the logarithmic equation between RR-1 and Vpe, the slope, Vpe at RR-1 second (Vpe-1), and Slope/Vpe-1 were calculated. RESULTS: Patients with a history of HF were older (p=0.037) and tended to more frequently have hypertension (p=0.063) than those with no history of HF. The ejection fractions were similar between the two groups. In the coordinates with RR-1 from 0.6 to 1 second, the slope tended to be steeper (p=0.074) and slope/Vpe-1 was higher in patients with a history of HF (p=0.011). The Vpe-1 was similar between the two groups (p=0.66). A multiple forward logistic regression analysis showed that slope/Vpe-1 was the only independent variable associated with the occurrence of HF. Slope/Vpe-1 was related with aortic regurgitation, HF history, and the interventricular septal thickness in a multiple stepwise regression analysis. CONCLUSION: New parameters from the relationship between the RR intervals and LV performances were associated with the occurrence of HF in AF patients with a normal systolic function. This finding suggests that these parameters may be related with the LV diastolic function.