Heart rate variability in patients with essential tremor: A cross sectional study

ObjectiveTo investigate heart rate variability (HRV) in patients with Essential Tremor (ET) in comparison with patients with Parkinson's Disease (PD).MethodsThis is a cross sectional control study including 10 patients with ET, 10 patients with PD and 10 age-sex-matched controls. In patients and controls, we measured the components of HRV analysis in the frequency domain during a daytime period of 12-h. Selected HRV variables were low-frequency (LF) and high-frequency (HF), conventionally considered to be influenced by the sympathetic system and the parasympathetic system respectively.ResultsHRV variables, in patients with ET, were significantly different from those detected in PD patients and similar to those of controls while in PD patients, they were significantly different from those of controls. At cut off level of 654 ms², LF component correctly distinguished ET patients versus PD with sensitivity, specificity, PPV and accuracy of 100%. By contrast, at cut off level of 737 ms², HF component showed sensitivity, specificity, PPV and accuracy of 80%, 100%, 100%, and 86.67% respectively. DAT-SPECT and cardiac MIBG uptake were both normal in ET patients whereas they were markedly decreased in those with PD.ConclusionsIn our study, the LF component of HRV analysis distinguishes ET patients from those with PD on an individual basis, thus representing a valid help in everyday clinical practice for differentiation between these patients in absence of scintigraphic investigations.     

Heart rate variability in patients with idiopathic Parkinson's disease with and without obstructive sleep apnea syndrome

BackgroundObstructive sleep apnea syndrome (OSAS) is associated with repeated apnea-induced sympathetic surges leading to specific alterations of the power spectrum of heart rate variability (HRV). Sympathetic dysfunction evolves early in idiopathic Parkinson’s disease (PD), but the consequences on cardiac autonomic response to OSAS have not been studied so far in PD patients.MethodsSixty-two patients with PD (35 without OSAS (PD-wo), 27 with OSAS (PD-OSAS)) and 62 age-matched control subjects (25 without OSAS (Co-wo), 37 with OSAS (Co-OSAS)) were included. HRV variables – including mean R–R interval, standard deviation of all normal-to-normal R–R intervals (SDNN), both low frequency (LF) and high frequency (HF) power bands, and the LF/HF ratio – were computed automatically from full-night polysomnography and calculated separately for each sleep stage.ResultsHRV variables were similar in PD-wo and PD-OSAS. In contrast, Co-OSAS showed significantly higher LF power in NREM1 and NREM2 sleep and higher LF/HF ratio in NREM1, NREM2 and slow wave sleep than Co-wo. Similarly, correlations between HRV variables and parameters of OSAS severity were found only in controls but not in PD patients.ConclusionOur results suggest that the sympathetic response to OSAS is blunted in PD, giving further clinical evidence of the sympathetic denervation commonly observed in this neurodegenerative disorder.     

Abnormal heart rate variability in a subject with second degree atrioventricular blocks during sleep.

OBJECTIVE: We compare the profiles of heart rate variability (HRV) during sleep stages in 9 healthy controls and one subject with second degree atrioventricular blocks (AVB), investigating the role of sympathovagal balance in such pathology. METHOD: Sleep and cardiac records were taken for one night in 9 male subjects from 21:00 to 07:00 h and for two nights in a male subject with AVB. Time and frequency domain indexes of HRV were calculated over 5 min-periods. RESULTS: In one subject without any daytime heart disease, 253 and 318 AVB of type 2 (Mobitz 2) were observed during the two experimental nights, predominantly during rapid eye movement (REM) sleep and the surrounding sleep stage 2 in the second half of the night. In the 9 control subjects, absolute HRV indexes and low frequency (LF)/(LF+high frequency, HF) (where LF and HF are low frequency and high frequency power) were low during slow wave sleep, and significantly increased during REM sleep and the preceding sleep stage 2. In the subject with AVB, these HRV indexes were abnormally low during all sleep stages, with a predominant increase in parasympathetic activity as inferred from low LF/(LF+HF). During wake, however, LF/(LF+HF) normally increased, and the tachycardia observed with the arousal that terminates SWS was preserved in the subject with AVB. CONCLUSION: These results suggest that in the subject with second degree atrioventricular blocks, sleep processes, particularly during REM sleep, create a specific neurological background that prevents an increase in sympathetic tone and triggers cardiac pauses.     

帕金森病患者RR间期频谱分析

测定20例帕金森病患者的ECG,应用微机处理显示RR间期变化的频谱曲线.结果发现,帕金森病患者与健康对照组比较,RRI较小,LF较高,HF也较高,LF/HF比值较大.这提示患者支配心脏的迷走和交感神经均受损害.     

Cardiac autonomic impairment during sleep is linked with disease severity in Parkinson’s disease

ObjectiveCardiac physiology during sleep in Parkinson’s disease (PD) remains poorly explored. We studied heart rate variability (HRV) across sleep stages in PD patients and correlated the results with clinical features.MethodsCross-sectional study comprising 33 patients with PD and 29 controls matched for age, gender, and number of apneas/hypopneas per hour. HRV measures, (mean R–R interval, SDNN, ULF, VLF, LF, HF and LF/HF) were calculated separately for all sleep stages as well as wakefulness just before and after sleep during one-night polysomnography. Correlation analysis was performed between HRV values and PD patients’ characteristics.ResultsThe mean R–R interval was lower in all sleep stages in PD patients when compared with controls. VLF and LF were lower during REM sleep in PD patients. HF during N1–N2 stage was higher in PD. We found inverse correlations between VLF and LF during REM sleep and UPDRS-ON and UPDRS-OFF.ConclusionVLF and LF during REM sleep might constitute surrogate markers of disease severity.SignificanceThese findings provide additional clinical evidence of the autonomic impairment commonly observed in PD, and prove that cardiac autonomic dysfunction during REM sleep is correlated with disease severity.     

Autonomic function in the early stage of panic disorder: power spectral analysis of heart rate variability

Previous studies of autonomic nervous system (ANS) function in panic disorder (PD) patients have yielded conflicting results. We speculate that these differences might result from the variety of clinical stages of PD. In order to investigate this, we compared ANS activity in untreated patients in the early stage of PD with control subjects using power spectral analysis of electrocardiogram R-R intervals (PSR-R) in supine rest and during head-up tilt, which was performed according to the maximum entropy method (MEM). It recognizes two main components: high-frequency power (HF), which mainly reflects cardiac parasympathetic activity, and low-frequency power (LF), which reflects both cardiac sympathetic and parasympathetic activity. The patients with PD had significantly higher values for all components of PSR-R only in tilt position total power (TP), LF, and HF than did the control subjects (P<0.01, <0.01, <0.02, respectively). However, the LF/HF ratio which indicated sympathovagal balance did not differ significantly between the two groups in tilt position. Our findings suggest that patients with PD in the early stage of illness have co-activation of sympathetic and parasympathetic nervous systems, which might act to maintain a balance between the two autonomic systems.     

Cardiac autonomic dysfunction in drug naïve hot water epilepsy

PurposeThis study aimed to characterize the role of autonomic nervous system dysfunction in hot water epilepsy (HWE). Heart rate variability (HRV) has been established as a good index of cardio-autonomic regulation.MethodologyForty-five patients with HWE (age: 24.6 ± 10.1 years; M:F = 37:8) and 45 age and gender matched controls (age: 24.17 ± 10.37 years; M:F = 37:8) were studied. Five minutes resting lead II electrocardiogram (ECG) was obtained (AD instruments) under standard conditions and analyzed for time and frequency domain HRV parameters using LabChart software.ResultPatients with hot water epilepsy showed significant increase in LF nu (Low frequency normalized unit) and LF/HF denoting an interictal increase in sympathetic activity. In addition, reductions were noted in parasympathetic function [RMSSD (root mean square successive difference of RR intervals), HF (High frequency) nu and LF/HF].ConclusionThis study has demonstrated an impaired sympatho-vagal balance characterized by increased sympathetic activity and reduced parasympathetic activity in patients with HWE. The present study supports the notion that the hypothalamus is involved in both, the pathogenesis of HWE and autonomic regulation.     

Heart rate variability in childhood obesity

Obesity is characterized by hemodynamic and metabolic alterations. Autonomic control on cardiac function involvement is controversial. The aim of the study was to assess early sign of cardiac autonomic dysfunction in obesity, using time- and frequency-domain heart rate variability (HRV) analysis in a pediatric population. Methods: 32 obese children (OB) (17 M, 15 F; 13.9±1.7 y) were compared with 13 healthy lean subjects (7M, 6F; 12.9±1.6y). For each participant, the authors performed a clinical examination, laboratory testing, blood pressure (BP) measurements, and 24-hour electrocardiograph/ambulatory BP monitoring. The spectral power was quantified in total power, low-frequency (HF) power, index of sympathetic tone, high-frequency (HF) power, index of vagal tone, and LF/HF ratio. Low frequency and HF were averaged to obtain 3 measures: 24-hour, daytime, and nighttime levels. Total, long-term, and short-term time-domain HRV values were calculated. Results: The obese children had higher casual and ambulatory BP, and higher fasting glucose, insulin, and triglyceride levels. Overall HRV values were not significantly lower in OB. The obese children had significantly lower 24-hour and nighttime high-frequency normalized units, and time-domain measures of vagal activity. Low-frequency power showed an inverse but not significant pattern. The OB group had significantly greater 24-hour and nighttime LF/HF ratios. Conclusions: The authors found an increase in heart rate and in BP associated with parasympathetic heart rate control decrease in stabilized obese normotensive children.     

Relationship between ischemic stroke location and autonomic cardiac function

Autonomic cardiac dysfunction is a common complication after acute ischemic stroke (IS). We recruited 75 patients with acute IS with measurements of autonomic cardiac function, including heart rate variability (HRV) and associated parameters, and compared them with 81controls. Of the 75 patients, 28 had right hemispheric infarctions (RH), 29 had left hemispheric infarctions (LH), and 18 had brainstem infarctions (BS). A comparison of HRV in all patients with stroke and in control subjects showed significant differences between IS subgroups and controls in low frequency (LF), high frequency (HF), normalized LF, normalized HF, and LF/HF ranges. A post-hoc comparison identified significant differences between patients with IS with BS infarctions and the control group in LF, HF, and LF/HF ranges. BS infarction may cause a much greater increase in sympathetic modulation and reduced vagal activity compared to RH or LH infarction. Our findings provide evidence that acute IS causes significant damage to the cardiovascular autonomic system, manifesting as abnormalities of HRV. BS stroke might correlate with a significant reduction in parasympathetic and an increase in sympathetic influence on HRV.     

Heart rate variability remains reduced and sympathetic tone elevated after temporal lobe epilepsy surgery

PurposeThere is evidence of autonomic dysregulation in temporal lobe epilepsy. The structures removed during temporal lobectomy are important centers of central cardiovascular control; therefore surgery may conceivably alter the cardiovascular autonomic function. The effects of temporal lobectomy on autonomic cardiac control are controversial. We investigated the effects of temporal lobectomy on heart rate variability (HRV) in the early and late postoperative periods.MethodsWe used 1-h ECG recordings to assess heart rate variability by spectral analysis in 24 consecutive patients who underwent temporal lobectomy due to intractable temporal lobe epilepsy. ECG recordings were performed before and twice (early and late) after surgery. The results were compared with age and sex matched controls.ResultsWhen compared with controls, all the time and frequency domain indices (SDRR, RMSSD, TP, LF and HF) were significantly lower in the patient group before surgery. Findings were similar in the early and late post-operative periods except that the LF/HF ratio increased in the patient group after the late post-operative period. Within the patient group, compared to pre-operative results, normalized HF was increased in the early post-operative period; however in the late post-operative period, LF/HF ratio was increased.ConclusionsThese findings show that in patients with intractable temporal lobe epilepsy, HRV is decreased globally in both sympathetic and parasympathetic domains. While the total HRV remains reduced throughout the postoperative periods, the LF/HF ratio, i.e., sympathovagal balance is altered, in favor of parasympathetic side early after surgery, but towards the sympathetic side after the first postoperative month.     

Heart rate variability in coronary artery disease patients with and without panic disorder

Panic disorder (PD) and coronary artery disease (CAD) often co-occur, and CAD patients with comorbid PD suffer greater cardiovascular morbidity and mortality relative to CAD patients without PD. However, the mechanisms underlying these associations are still unknown. Reduced heart rate variability (HRV), a non-invasive measure of cardiac autonomic modulation, is an important predictor of adverse cardiac events. Interestingly, reduced HRV has been observed in patients with panic-like anxiety and PD, as well as in various CAD populations. However, the extent to which HRV is altered in patients with both PD and CAD is unknown. This study evaluated HRV in 42 CAD patients with (n=20) and without (n=22) PD. Patients underwent 48-h electrocardiographic monitoring. Power spectral analysis of HRV indicated that CAD patients with PD exhibited significantly lower LF/HF ratios, which may reflect lower sympathetic modulation, compared with non-PD patients. Additionally, total power in PD patients was made up of a significantly higher proportion of HF power and a significantly lower proportion of VLF power than in non-PD patients. No other significant differences in HRV indices were observed. Results suggest that contrary to what has been observed in the majority of PD-only and CAD-only populations; patients with both PD and CAD appear to exhibit lower sympathetic modulation during ordinary daily life conditions. Though preliminary, these findings suggest that changes in HRV may not be the mechanism underlying greater cardiovascular morbidity and mortality among CAD patients with PD.     

Effect of aging on autonomic function in individuals with severe motor and intellectual disabilities

Autonomic nervous function is often abnormally regulated in individuals with severe motor and intellectual disabilities (SMID). In this study, we assessed autonomic nervous function of patients with SMID and determined how it was influenced by age. The study included 21 individuals with SMID and 15 healthy adolescents (control). To determine the effect of aging, the patients with SMID were divided into an older age group (Old) and younger age group (Young). Autonomic nervous function was assessed using power spectral analysis of heart rate variability (HRV) for 24-h Holter electrocardiogram recordings. The low- and high-frequency components (LH and HF) of HRV were calculated. The ratio between LF and HF (LF/HF) was used as an indicator of sympathetic modulation, while HF alone was used as an indicator of parasympathetic modulation. The LH/HF in the control group was higher in the daytime than at nighttime, while HF had an opposite pattern of change. Therefore, circadian rhythms were observed in the control group for both sympathetic and parasympathetic nervous activities. In contrast, the LF/HF in patients with SMID had no circadian rhythm. The HF was higher in the Old SMID group than in the Young group, and it exhibited a circadian rhythm in eight patients in the Old SMID group versus none of the patients in the Young group. These findings suggest that the sympathetic nervous system is suppressed in both old and young patients with SMID. However, while the parasympathetic nervous system is suppressed in younger patients with SMID, it is activated with increasing age.     

Heart rate variability in patients with frontal lobe epilepsy

ObjectiveTo identify autonomic dysregulation in frontal lobe epilepsy (FLE).MethodsWe studied 14 male and 11 female subjects with FLE and an equal number of matched healthy control subjects. Lead I electrocardiograms were obtained for 5 min in the interictal state during daytime. Frequency-domain analysis of heart rate variability was performed and the data subsequently converted to heart rate interval and high frequency (HF; 0.15–0.45 Hz) power which representing vagal or parasympathetic regulation, as well as low frequency (LF; 0.04–0.15 Hz) power and LF/(HF + LF) expressed in normalized units (LF%) (considered to mirror sympathetic regulation). Differences in data between groups were compared using t-test.ResultsThe epilepsy group had a lower mean heart rate interval and a lower high frequency power.ConclusionsPatients with FLE have interictally faster heart rates, attributed to lower parasympathetic drive, which may contribute to the higher incidence of sudden death that is seen in this group of patients. This suggests that the mechanism of decreased HRV in patients with FLE is probably different from that in patients with temporal lobe epilepsy.     

Estimating cardiac autonomic activity during sleep: impedance cardiography, spectral analysis, and Poincaré plots.

OBJECTIVE: To compare noninvasive measures of cardiac autonomic activity during sleep. METHODS: The absolute and normalized (n.u.) high and low frequency peaks from the spectral analysis of R-R intervals (HF, LF, HFn.u., LFn.u.), LF/HF ratio, pre-ejection period (PEP) from impedance cardiography, and the autocorrelation coefficient (rRR) as illustrated in Poincaré plots were measured during night-time sleep in 9 young healthy subjects. Heart rate and blood pressure were also recorded. RESULTS: Heart rate was significantly associated with cardiac sympathetic activity (PEP, average r=-0.46), but not with cardiac parasympathetic activity (HF, average r=-0.17). rRR was significantly associated with heart rate (average r=0.41), and LF/HF (average r=0.69), but not with PEP or HF. From NREM to REM sleep, heart rate, LFn.u., LF and rRR significantly increased, HFn.u. significantly decreased, LF/HF showed an increasing trend (P=0.07) and PEP showed a decreasing trend (P=0.06). Blood pressure and HF were highly variable without significant changes from NREM to REM sleep. CONCLUSIONS: Cardiac parasympathetic activity (HF) does not vary greatly between sleep stages. Cardiac sympathetic activity (PEP) decreases linearly during sleep. rRR and LF/HF can track sympathovagal changes during sleep, but cannot differentiate between changes in cardiac parasympathetic and sympathetic activity. The relative advantages and disadvantages of the different measures are discussed.     

Sleep-disordered breathing and cardiac autonomic modulation in children

ObjectivesTo investigate the adverse cardiac autonomic effects of sleep-disordered breathing (SDB) in a large population-based sample and a clinical sample of children.MethodsSubjects included a population-based sample of 700 and a clinically diagnosed sample of 43 SDB children. SDB was defined based on an apnea hypopnea index (AHI) ? 1 during one night of polysomnography. Cardiac autonomic modulation was measured by heart rate variability (HRV) analysis of the beat-to-beat RR interval data collected during polysomnography.ResultsThe mean (SD) age was 112 (21) months, with 49% male and 25% non-white. About 73.0% had AHI < 1 (no SDB), 25.8% had 1–5 AHI (mild SDB), and 1.2% had ?5 AHI (moderate SDB). Among individuals with moderate SDB in the population-based sample and the clinically diagnosed SDB patients, the mean (SE) of HRV-high frequency power (HF) was significantly lower compared to children without SDB [6.00 (0.32) and 6.24 (0.14), respectively, vs. 6.68 (0.04) ms², p < 0.05 and p < 0.01, respectively], whereas the low frequency power to high frequency power ratio (LF/HF) was significantly higher [1.62 (0.20) and 1.74 (0.09), respectively, vs. 0.99 (0.02), both p < 0.01)].ConclusionsSDB in healthy young children and in clinical patients is significantly associated with impaired cardiac autonomic modulation, i.e., sympathetic overflow and weaker parasympathetic modulation, which may contribute to increased risk of acute cardiac events in persons with SDB, even before reaching the “high risk age.”     

Effects of antiepileptic drug therapy on heart rate variability in children with epilepsy

Impaired cardiac autonomic function may contribute to the risk of sudden unexpected death in epilepsy. Heart rate variability (HRV) is a useful tool for the detection of sympathetic-parasympathetic balance of autonomic nervous system. In the present study, epilepsy patients who had never received antiepileptic medication and those whose seizures have been successfully controlled with antiepileptic drugs were compared with each other and a control group in order to investigate the effects of epilepsy and various antiepileptic drugs on HRV. HRV were tested via 5 min ECG monitoring in 92 patients and 83 controls. Time domain parameters including SDNN, RMSSD and the frequency domain parameters including HF (reflects parasympathetic activity) and LF (reflects sympathetic activity) were assessed. In this group, 78 patients were using antiepileptic drugs including valproic acid (n=33), oxcarbazepine (n=19), phenobarbital (n=11), combined regimens (n=10) and other drugs (n=5), while 14 patients had never received antiepileptic medication. For both of the epilepsy patients groups with or without treatment, time domain parameters were found to be significantly suppressed. In addition, parasympathetic activity was found to be decreased (HF was decreased, LF/HF ratio was increased) in epilepsy patients without antiepileptic drug therapy. Our results indicate that seizure control with antiepileptic drugs may help to improve the cardiac autonomic function impairment in epilepsy patients.     

Assessment of autonomic nervous system function in patients with Behçet' s disease by spectral analysis of heart rate variability

The purpose of this study was to evaluate the autonomic nervous system (ANS) function in patients with Behcet's disease by using power spectral analysis of heart rate variability (HRV). The study population consisted of 71 patients with Behcet's disease, and 26 normal volunteers. HRV was measured by power spectral analysis in supine and standing position. In supine position, Behcet's patients had increased low frequency component in absolute (LF) and normalized units (LF nU) but had lower values of high frequency component in absolute (HF) and normalized units (HF nU) than the controls (P < 0.05). In standing position, higher values were obtained in LF and LF nU but lower values of HF and HF nU in Behcet's patients than controls (P < 0.05). LF/HF was significantly higher in patients both in supine (2.5 +/- 1.0 vs. 1.2 +/- 0.8, P = 0.001) and standing (21.9 +/- 7 vs. 1.8 +/- 0.3, P < 0.001) positions. Our data suggest that patients with Behcet's disease may have asymptomatic ANS dysfunction, which is in the form of increased sympathetic and decreased parasympathetic modulation, and power spectral analysis of HRV is beneficial in assessing the ANS function.     

Sudden withdrawal of carbamazepine increases cardiac sympathetic activity in sleep.

OBJECTIVE: To evaluate the cardiac autonomic effects of abrupt withdrawal of carbamazepine (CBZ) during sleep in patients with epilepsy. BACKGROUND: The pathophysiology of sudden unexpected death in epilepsy (SUDEP) is uncertain, with ictal or peri-ictal cardiorespiratory compromise appearing probable. Risk factors for SUDEP include multiple antiepileptic drugs (AED), poor compliance, and abrupt AED withdrawal. The spectral analysis of the beat-to-beat heart rate variability (HRV) displays two main components: low frequency (LF), representing sympathetic and parasympathetic influence and high frequency (HF), representing parasympathetic influence. The LF/HF ratio is commonly regarded as an indicator of sympathovagal balance. METHOD: Twelve patients with medically intractable seizures underwent abrupt withdrawal of CBZ to facilitate seizure recording during controlled circuit TV-EEG monitoring. Continuous EKG recording was begun 24 hours before CBZ reduction. Spectral analysis of the HRV was performed during selected samples of non-REM sleep before and after CBZ reduction. Analyses were made at least 6 hours after from (complex) partial and 12 hours from generalized seizures. RESULTS: The mean LF/HF ratio before withdrawal of CBZ was 2.15 compared with a ratio of 2.65 on day 4 after withdrawal, an increase of 19% (geometric mean; 95% CI, 2% to 34%; Wilcoxon test, z = 2.36; p = 0.018). The ratio increased in 10 patients compared with a decrease in only one patient. CONCLUSION: Abrupt withdrawal of CBZ leads to enhanced sympathetic activity in sleep as evidenced by increased LF/HF ratios. Increased sympathetic activity in the setting of seizure-induced hypoxia could predispose to SUDEP.     

Functional evaluation of central cholinergic circuits in patients with Parkinson’s disease and REM sleep behavior disorder: a TMS study

Central cholinergic dysfunction has been reported in patients with Parkinson?s disease (PD) and hallucinations by evaluating short latency afferent inhibition (SAI), a transcranial magnetic stimulation protocol which gives the possibility to test an inhibitory cholinergic circuit in the human brain. REM sleep behavior disorder (RBD) was also found to be associated with cognitive impairment in PD patients. The objective of the study was to assess the cholinergic function, as measured by SAI, in PD patients with RBD (PD-RBD) and PD patients without RBD (PD-nRBD). We applied the SAI technique in 10 PD-RBD patients, in 13 PD-nRBD patients and in 15 age-matched normal controls. All PD patients and control subjects also underwent a comprehensive battery of neuropsychological tests. Mean SAI was significantly reduced in PD-RBD patients when compared with PD-nRBD patients and controls. Neuropsychological examination showed mild cognitive impairment in 9 out of the 10 PD-RBD patients, and in 5 out of the 13 PD-nRBD. SAI values correlated positively with neuropsychological tests measuring episodic verbal memory, executive functions, visuoconstructional and visuoperceptual abilities. Similar to that previously reported in the idiopathic form of RBD, SAI abnormalities suggest a cholinergic dysfunction in PD patients who develop cognitive impairment, and present findings indicate that RBD is an important determinant of MCI in PD.     

Combined cardiac sympathetic excitation and vagal impairment in patients with non-organic erectile dysfunction

ObjectivePatients with non-organic erectile dysfunction (ED) frequently present with syndromes involving systemic sympathovagal dysfunction. The linkage of ED to cardiac autonomic regulation is not well understood.MethodsForty-four men with non-organic ED and 38 healthy age-matched control subjects with ages ranging from 40 years to 69 years were recruited. These two groups were divided into three distinct age categories at 10-year intervals. Patients were divided into three different severity categories, among whom 35 patients received a two-month oral treatment of trazodone. Power spectral analysis of successive R-R intervals (RR) was performed to evaluate the variance (variance of RR-interval values), the high-frequency power (HF), and the ratio of low-frequency power to HF (LF/HF) of their heart rate variability (HRV).ResultsPatients exhibited a significantly lower variance and HF, but a higher LF/HF compared to the control group across all age categories. The changes in variance and HF were severity dependent. In addition, all the HRV parameters of the patients with a satisfactory response after treatment have significantly improved.ConclusionThe results indicate that patients with non-organic ED had significant cardiac sympathetic hyperactivity and severity-dependent cardiac vagal impairment.SignificanceNon-organic ED may be accompanied by an abnormality in cardiac autonomic regulation.