Cardiac autonomic dysfunction in patients with gastroesophageal reflux disease

Table 1 Distribution of autonomic dysfunction among patients with reflux and controls n (%)

	Parasympathetic damage			Sympathetic damage	Combined damage
	Without	Early	Definitive
Reflux	4 (21.1)	7 (36.8)	8 (42.1)	17 (94.4)	10 (58.8)
Control	24 (31.2)	43 (55.8)	10 (13.0)	55 (72.4)	8 (10.7)

For parasympathetic damage: χ² = 8.48, df = 3, P = 0.014.

Table 2 Autonomic cardiovascular tests reflecting parasympathetic damage n (%)

Autonomic cardiovascular reflex tests	Reflux(n = 19)	Controls (n = 77)	P value1
Valsalva maneuver	8 (42.1)	18 (23.4)	0.015
Heartrate variation during deep breathing	10 (52.6)	8 (10.4)	< 0.001
Heart rate response to standing test	6 (31.6)	36 (47.4)2	0.028
Vagal dysfunction	8 (42.1)	10 (13.0)	0.014

¹Mann-Whitney test;

²Data from one patient missing.

Table 3 Autonomic cardiovascular tests reflecting sympathetic damage n (%)

Autonomic cardiovascular reflex tests	Reflux(n = 18)	Controls(n = 77)	P value1
Orthostatic hypotension	1 (5.3)	2 (2.6)	0.822
Hand grip test	16 (88.9)	59 (76.6)	0.481
Sympathetic dysfunction	17 (94.4)	55 (72.4)2	0.047

¹Mann Whitney test;

²Data from one patient missing.

Table 4 Complete autonomic dysfunction n (%)

Complete autonomic dysfunction	Reflux	Controls	P value1
Absent	7 (41.2)	67 (89.3)	< 0.001
Present	10 (58.8)	8 (10.7)	< 0.001
Total	17 (100)	75 (100)	< 0.001

¹Mann-Whitney test.

Table 5 Degree of autonomic dysfunction n (%)

Degree ofautonomic dysfunction	Reflux	Controls	P value1
Normal	0 (0.0)	0 (0.0)	< 0.001
Mild	1 (5.6)	22 (28.9)	< 0.001
Moderate	9 (50.0)	48 (63.2)	< 0.001
Severe	8 (44.4)	6 (7.9)	< 0.001
Total	18 (100)	76 (100)	< 0.001

Table 6 Short term heart rate variability analysis (mean ± SD)

Parameter	Reflux	Controls	P value1
Average dRR (ms)	15.67 ± 10.35	27.80 ± 17.49	0.003
SD dRR (ms)	12.48 ± 7.63	22.42 ± 13.87	0.001
MD dRR (ms)	9.76 ± 6.36	17.10 ± 10.25	0.002
pNN50%	3.62 ± 6.26	9.82 ± 10.29	0.009
RMSSD (ms)	19.81 ± 12.81	35.87 ± 21.78	0.001
VLF (ms2)	67.76 ± 65.56	129.33 ± 129.19	0.036
LF (ms2)	56.29 ± 65.64	135.07 ± 142.90	0.015
HF (ms2)	35.62 ± 51.27	102.52 ± 115.53	0.011
LF/HF	3.07 ± 2.34	2.27 ± 2.82	0.225

¹t-test. SD dRR: Standard deviation of normal RR intervals (SD); MD dRR: Absolute mean of standard deviation; pNN50%: Percentage of adjacent RR intervals differing > 50 ms; RMSSD: Mean square root of the mean of the sum of the squares of differences between adjacent RR intervals; VLF: Very low-frequency power; LF: Low-frequency power; HF: High-frequency power.

Table 7 Beat-to-beat heart rate variability and baroreflex sensitivity (mean ± SD)

Parameter	Reflux	Controls	P value1
Heart rate variability
LFnu-RRI (%)	63.85 ± 17.27	59.74 ± 15.98	0.280
HFnu-RRI (%)	36.15 ± 17.27	39.98 ± 15.37	0.298
VLF-RRI (ms2)	132888.77 ± 56675.91	745.72 ± 2409.152	0.021
LF-RRI (ms2)	319.18 ± 347.13	864.78 ± 1036.92	0.016
HF-RRI (ms2)	225.73 ± 263.42	656.44 ± 996.35	0.047
Total power (ms2)	1383.55 ± 65646.66	2264.58 ± 3231.24	0.034
LF/HF	3.32 ± 2.88	2.83 ± 3.72	0.561
Baroreflex sensitivity (ms/mmHg)
Minimal slope	3.62 ± 3.99	4.43 ± 3.32	0.317
Maximal slope	40.50 ± 31.57	47.06 ± 32.29	0.385
Mean slope	12.11 ± 7.00	17.11 ± 9.77	0.024

¹t-test. HF: High-frequency power; LF: Low-frequency power; LFnu-RRI: Percent of normalized LF interval component; Hfnu-RRI: Percent of normalized HFinterval component; VLF-RRI: Very low-frequency interval component of heart rate variability; LF-RRI: LF interval component of heart rate variability; HF-RRI: HF interval component of heart rate variability.

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.

Table 9 Twenty-four-hour ambulatory blood pressure monitoring (mean ± SD)

Parameter	Reflux	Controls	P value1
Systolic BP (mmHg)
24 h	125.65 ± 14.47	116.17 ± 8.73	< 0.001
Awake	127.80 ± 13.57	118.79 ± 9.02	< 0.001
Sleep	117.11 ± 17.03	105.64 ± 11.83	0.001
Diastolic BP (mmHg)
24 h	74.80 ± 7.92	72.36 ± 6.21	0.138
Awake	76.65 ± 7.49	74.46 ± 6.23	0.178
Sleep	68.58 ± 9.51	64.64 ± 7.04	0.046
Standard deviation of BP
Awake systolic BP	14.52 ± 4.04	12.29 ± 3.15	0.008
Awake diastolic BP	11.12 ± 3.65	9.25 ± 1.95	0.002
Sleep systolic BP	13.14 ± 5.38	9.29 ± 4.41	0.002
Sleep diastolic BP	10.21 ± 2.53	8.41 ± 3.34	0.031
Pulse pressure
24 h	50.72 ± 9.52	43.72 ± 5.20	< 0.001
Awake	51.14 ± 9.26	44.51 ± 5.55	< 0.001
Sleep	48.57 ± 10.77	40.95 ± 7.59	0.001

¹t-test. BP: Blood pressure.