ABSTRACT
BACKGROUND: Several lines of evidence suggest that atrial fibrillation (AF) may be a consequence of vascular disease. We investigated the relationship between cardio-ankle vascular index (CAVI), a new index of arterial stiffness, and the presence of paroxysmal AF (PAF). METHODS AND RESULTS: 181 outpatients (91 patients with PAF and 90 age- and gender-matched subjects without PAF) were analysed for their sinus rhythm. The CAVI was significantly higher in patients with PAF than in subjects without PAF (9.0±1.0 vs 8.7±0.8, p<0.01). In all subjects, the CAVI was significantly correlated with the left ventricular mass index (r=0.30, p<0.01), left atrial diameter (r=0.22, p<0.01), and augmentation index, a parameter of wave reflection (r=0.32, p<0.01), in addition to age, systolic blood pressure and pulse pressure. Logistic analysis demonstrated that the CAVI was independently associated with PAF even after adjustment for confounding factors. The adjusted OR of PAF was 1.8 for each unit increase in the CAVI (p=0.01). CONCLUSIONS: Our finding suggests that increased arterial stiffness may be involved in the maintenance of AF.
ABSTRACT
BACKGROUND: The plasma B-type natriuretic peptide (BNP) level has been shown to be increased in patients with chronic atrial fibrillation (AF) independent of left ventricular ejection fraction (LVEF). The purpose of this study is to evaluate the relationship between the plasma BNP level and heart rate variation in patients with AF. HYPOTHESIS: The plasma BNP level is associated with heart rate variation in patients with AF. METHODS: A total of 102 patients with AF and preserved LVEF were included from 2 hospitals. The ambulatory electrocardiographic recording and measurement of plasma BNP levels were performed simultaneously. Echo-Doppler parameters were measured as the average of 10 consecutive cardiac cycles. RESULTS: A difference in the mean heart rate between night and day (DIFF) and the standard deviation of the 5-miniute mean R-R interval (SDARR) were significantly associated with log-transformed BNP levels (r = -0.411, P < 0.001 and r = -0.243, P = 0.049, respectively). In echocardiography, the ratio of E velocity to early diastolic velocity, which reflects left ventricular (LV) filling pressure, was significantly correlated with the DIFF and SDARR, along with the log-transformed BNP level. Stepwise multiple linear regression analysis revealed that the DIFF and age were independent factors related with the BNP level (P < 0.01). CONCLUSIONS: The reduced diurnal variation of heart rate was significantly associated with increased BNP, which is linked to LV diastolic dysfunction in patients with AF.
