Cardiac autonomic dysfunction in patients with gastroesophageal reflux disease

Table 8 Holter ECG heart rate and long-term HRV analysis (mean ± SD)

Parameter	Reflux	Controls	P value1
Mean RR (ms)	822.59 ± 82.76	811.08 ± 79.88	0.559
SDNN (ms)	125.76 ± 33.54	154.82 ± 39.72	0.003
SDANNindex (ms)	113.24 ± 33.71	141.65 ± 36.28	0.002
SDNN index (ms)	49.71 ± 17.92	65.26 ± 16.87	< 0.001
RMSSD (ms)	28.33 ± 11.72	37.29 ± 13.20	0.006
pNN50%	8.48 ± 8.97	14.13 ± 9.41	0.016
Total power (ms2)	2683.56 ± 2081.23	4446.65 ± 2151.45	0.001
VLF (ms2)	1851.73 ± 1318.44	2964.81 ± 1557.53	0.004
LF (ms2)	615.72 ± 624.36	1048.73 ± 462.23	0.001
HF (ms2)	197.15 ± 203.88	408.51 ± 291.02	0.002

¹t-test. SDNN: Standard deviation of all the RR intervals; SDNN index: Mean of standard deviation of all RR intervals for all 5-min segments of the entire recording; RMSSD: Square root of the mean of squared differences of two consecutive RR intervals; pNN50%: Percent of beats with consecutive RR interval difference of more than 50 ms; VLF: Very low-frequency interval, LF: Low-frequency interval; HF: High-frequency interval.