Decreased Cardiovagal Regulation in Exfoliation Syndrome

Abstract

To investigate the parasympathetic cardiovascular regulation, baroreflex sensitivity (BRS), and pulse wave velocity (PWV) in exfoliation syndrome (XFS). Heart rate variability indices [standard deviation of all RR intervals (SDNN); the mean of absolute successive differences (RMSSD); the percentage of intervals differing by >50 ms from the preceding interval (pNN50); low frequency power, and high frequency power], as well as BRS and PWV, were determined on 27 consecutive white XFS patients and 20 white control subjects under standard circumstances, with controlled breath rate of 0.25 Hz. The paired t test, the Mann-Whitney U test, and the Fisher exact test were used for comparisons. There was no significant difference between the XFS and control groups in sex distribution, age, heart rate, blood pressure, body mass index, systemic diseases, or medication. But in XFS patients, SDNN (mean+/-SD, 24+/-7.3 vs. 49+/-16.5 ms), RMSSD (17+/-7.3 vs. 45+/-29.1 ms), pNN50 (1.6%+/-2.5% vs. 17.7%+/-25.9%), high frequency (112+/-109 vs. 479+/-554 ms), and BRS (4.64+/-2.12 vs. 9.49+/-4.76 ms/mm Hg for BRS+ and 5.28+/-2.16 vs. 10.29+/-4.62 ms/mm Hg for BRS-) were all significantly lower than in the control group (P<0.01 for each parameter). Low frequency was also reduced in XFS (72+/-55 vs. 253+/-241 ms) (P=0.027). In XFS, PWV was significantly increased compared with the control group (11.6+/-4.1 vs. 9.3+/-2.2 m/s) (P=0.023). Our results suggest a clinically and statistically significant impairment of cardiovagal regulation and impairment of conduit artery function in XFS patients.