Open AccessThe effect of head‐up tilt upon markers of heart rate variability in patients with atrial fibrillation
Author(s) -
Patel Hitesh C.,
Hayward Carl,
Wardle Andrew J.,
Middleton Lee,
Lyon Alexander R.,
Di Mario Carlo,
Salukhe Tushar V.,
Sutton Richard,
Rosen Stuart D.
Publication year - 2018
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12511
Subject(s) - medicine , cardiology , atrial fibrillation , heart rate variability , heart rate , sinus rhythm , hemodynamics , cohort , blood pressure , tilt table test , electrocardiography
Background Heart rate variability ( HRV ) analysis is uncommonly undertaken in patients with atrial fibrillation ( AF ) due to an assumption that ventricular response is random. We sought to determine the effects of head‐up tilt ( HUT ), a stimulus known to elicit an autonomic response, on HRV in patients with AF ; we contrasted the findings with those of patients in sinus rhythm ( SR ). Methods Consecutive, clinically indicated tilt tests were examined for 207 patients: 176 in SR , 31 in AF . Patients in AF were compared to an age‐matched SR cohort ( n = 69). Five minute windows immediately before and after tilting were analyzed using time‐domain, frequency‐domain and nonlinear HRV parameters. Continuous, noninvasive assessment of blood pressure, heart rate and stroke volume were available in the majority of patients. Results There were significant differences at baseline in all HRV parameters between AF and age matched SR . HUT produced significant hemodynamic changes, regardless of cardiac rhythm. Coincident with these hemodynamic changes, patients in AF had a significant increase in median [quartile 1, 2] DFA ‐α2 (+0.14 [−0.03, 0.32], p < .005) and a decrease in sample entropy (−0.17 [−0.50, −0.01], p < .005). Conclusion In the SR cohort, increasing age was associated with fewer HRV changes on tilting. Patients with AF had blunted HRV responses to tilting, mirroring those seen in an age matched SR group. It is feasible to measure HRV in patients with AF and the changes observed on HUT are comparable to those seen in patients in sinus rhythm.