Spectral Analysis Of Heart Rate Research Articles

The Role of n-3 PUFAs in Preventing the Arrhythmic Risk in Patients with Idiopathic Dilated Cardiomyopathy

N-3 polyunsaturated fatty acids (n-3 PUFAs) intake is associated with a reduction in sudden cardiac death in patients with ischemic heart disease. Their effects in patients with heart failure caused by idiopathic dilated cardiomyopathy (IDC) are unknown. We compared with placebo the effects of n-3 PUFAs administration in 44 patients with IDC and with frequent or repetitive ventricular arrhythmias at Holter monitoring using a randomized, double-blind design. Arrhythmic risk was assessed by microvolt T-wave analysis (MTWA), signal averaged ECG (SAECG), Holter monitoring, power spectral analysis of heart rate (HR) variability, catecholamine and cytokine plasma levels, at baseline and after 6 months. At MTWA, 7/12 patients (58%) initially positive became negative after n-3 PUFAs while one patient became positive after placebo (p = 0.019). N-3 PUFAs administration was also associated to normalization of SAECG (11/15 patients, p < 0.0015), decrease in non-sustained ventricular tachycardia (NSVT) episodes (p = 0.0002) and NSVT HR (p = 0.0003), improvement in HR variability and decrease in catecholamine and cytokine plasma levels. The ratio of plasma n-6 PUFAs to n-3 PUFAs decreased from 12.01 to 3.48 after n-3 PUFAs. N-3 PUFAs administration is associated with favorable effects on parameters related to arrhythmic risk in patients with idiopathic dilated cardiomyopathy. These results are consistent with antiarrhythmic activity independent from their antiischemic effects.

Baroreflex sensitivity and power spectral analysis in different extrapyramidal syndromes

Cardiac autonomic abnormalities have been described in Parkinson's disease and other extrapyramidal syndromes. To investigate baroreflex sensitivity as an important risk marker of cardiovascular mortality in patients with Parkinson's disease and other extrapyramidal syndromes. We recorded continuously blood pressure, ECG and respiration in 35 patients with multiple system atrophy (MSA), 32 patients with progressive supranuclear palsy (PSP), 46 patients with idiopathic Parkinson's disease (PD) and in 27 corresponding healthy subjects (Con). Recordings of 2 min at rest were used to calculate baroreflex and spectral analysis of heart rate and systolic blood pressure. Resting baroreflex sensitivity (BRS) was significantly lower in the MSA and the PSP group but not in the PD group in comparison to the Con group. With increasing Hoehn & Yahr stage, BRS significantly decreased in all patient groups. In spectral analysis, all patient groups had a significantly lower relative low frequency (LF)-band power than the healthy controls. Patients with extrapyramidal disorders frequently demonstrate pathologically decreased BRS values and abnormalities of spectral analysis. This may have fundamental impact on the cardiovascular prognosis of patients with extrapyramidal disease.

Pharmacokinetic and pharmacodynamic effects of midodrine on blood pressure, the autonomic nervous system, and plasma natriuretic peptides: a prospective, randomized, single-blind, two-period, crossover, placebo-controlled study

Background: Midodrine is an α-agonist prodrug of desglymidodrine (DGM) that has been reported to be of clinical benefit in patients with neurocardiogenic syncope. Its effects may be mediated not only by its hypertensive properties but also by its neurohumoral influences independent of blood pressure (BP). Objective: The present study aimed to simultaneously characterize the effects of midodrine on BP, plasma catecholamines, plasma atrial natriuretic peptide (ANP), and power spectral analysis of heart rate (HR) in healthy volunteers. Methods: This was a prospective, randomized, single-blind, 2-period, crossover study in which a single, oral, 5-mg dose of midodrine was compared with placebo. The washout period between midodrine and placebo was 1 week. The study parameters included plasma DGM (as measured by high-performance liquid chromatography [HPLC]); systolic and diastolic BP (as measured with an oscillometric monitor); HR; plasma catecholamines (measured by HPLC); plasma ANP, also known as venous return (measured by a radio-immunoassay); and low- and high-frequency HR variation (calculated from computerized 5-minute electrocardiographic recordings). All study parameters were measured simultaneously 12 times just before and over a period of 8 hours after drug administration. Results: Fifteen healthy nonsmoking male subjects (14 white, 1 black; mean [SD] age, 28.6 [4.7] years; weight, 74.5 [16.4] kg; seated BP, 109.9 [9.0]/73.6 [9.5] mm Hg; seated HR, 63.8 [8.4] bpm) were randomized. No significant effects of midodrine on BP were observed. At C max, midodrine decreased norepinephrine from 188.4 (30.6) to 162.5 (29.8) pg/mL ( P = 0.011) and HR from 57.2 (7.3) to 54.9 (6.6) bpm ( P = 0.022). A significant correlation was found between DGM concentration and HR ( ϕ -0.61; P = 0.014). A DGM-related increase in plasma ANP (+29.6 [90.0] fmoL/mL) was observed. Conclusion: This study in healthy male volunteers found that midodrine has sympatholytic influences that are independent of BP but related to augmented venous return.

Point:Counterpoint: Respiratory sinus arrhythmia is due to a central mechanism vs. respiratory sinus arrhythmia is due to the baroreflex mechanism

Blood pressure and heart periods fluctuate at respiratory frequencies in healthy humans. Some researchers ([8][1], [23][2]) explain this as a cause-and-effect relation: blood pressure changes trigger baroreflex-mediated R-R interval changes. Here I make the case that respiratory sinus arrhythmia is

Cardiovascular activity during laboratory tasks in women with high and low worry

Worry has been related to delayed stress recovery and cardiovascular disease risk. Cardiovascular responses to a range of laboratory tasks were examined in this study of high and low worriers. Undergraduate women were recruited with the Penn State Worry Questionnaire to form low ( n = 19) and high ( n = 22) worry groups. These individuals engaged in six laboratory tasks (orthostatic stress, supine rest, hand cold pressor, mental arithmetic, and worry and relaxation imagery) while heart rate (HR), HR spectral analysis, impedance cardiography, and blood pressure were acquired. The only significant group difference found was a consistently greater HR across tasks in high worriers ( p < .05). No group by condition interactions emerged. High trait worry in healthy young women appears to be marked by elevated HR in the absence of autonomic abnormalities. These findings are discussed relative to the literature on worry, with particular reference to its health implications.

Effects of glucagon-like peptide-1, yohimbine, and nitrergic modulation on sympathetic and parasympathetic activity in humans

Glucagon-like peptide-1 (GLP-1), an incretin, which is used to treat diabetes mellitus in humans, inhibited vagal activity and activated nitrergic pathways. In rats, GLP-1 also increased sympathetic activity, heart rate, and blood pressure (BP). However, the effects of GLP-1 on sympathetic activity in humans are unknown. Our aims were to assess the effects of a GLP-1 agonist with or without alpha(2)-adrenergic or -nitrergic blockade on autonomic nervous functions in humans. In this double-blind study, 48 healthy volunteers were randomized to GLP-1-(7-36) amide, the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-l-arginine acetate (l-NMMA), the alpha(2)-adrenergic antagonist yohimbine, or placebo (i.e., saline), alone or in combination. Hemodynamic parameters, plasma catecholamines, and cardiac sympathetic and parasympathetic modulation were measured by spectral analysis of heart rate. Thereafter, the effects of GLP-1-(7-36) amide on muscle sympathetic nerve activity (MSNA) were assessed by microneurography in seven subjects. GLP-1 increased (P = 0.02) MSNA but did not affect cardiac sympathetic or parasympathetic indices, as assessed by spectral analysis. Yohimbine increased plasma catecholamines and the low-frequency (LF) component of heart rate power spectrum, suggesting increased cardiac sympathetic activity. l-NMMA increased the BP and reduced the heart rate but did not affect the balance between sympathetic and parasympathetic activity. GLP-1 increases skeletal muscle sympathetic nerve activity but does not appear to affect cardiac sympathetic or parasympathetic activity in humans.

Autonomic cardiovascular function and baroreflex sensitivity in patients with cervical dystonia receiving treatment with botulinum toxin type A

To investigate possible changes in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity in patients with primary cervical dystonia receiving chronic treatment with botulinum toxin type A. Short-term power spectral analysis of heart rate and systolic blood pressure variability, high-frequency and low-frequency oscillations of heart rate variability, low frequency/high frequency ratio and baroreflex sensitivity (alpha index) were measured in 12 patients with cervical dystonia before and 2-4 weeks after botulinum toxin type A injection and compared with normative data. Before treatment, at rest, patients had significantly lower high frequency power than healthy subjects (p < 0.01), whereas no differences were found in low frequency power. Botulinum toxin injection in patients induced no changes in either power frequency. In patients before treatment and healthy subjects the low frequency oscillatory components increased similarly from rest to tilt (p < 0.01), but tilt induced lower low frequency values in patients than in healthy subjects (p < 0.01). In patients before treatment, the high frequency variations from rest to tilt remained unchanged, whereas in healthy subjects they decreased significantly (p < 0.01). Botulinum toxin type A injection in patients induced no changes in low frequency or high frequency powers. In patients before treatment the low frequency/high frequency ratio increased slightly from rest to tilt, but in healthy subjects increased significantly (p < 0.01). Botulinum toxin type A left the pretreatment low frequency/high frequency ratio unchanged. The alpha-index measured at rest in patients before treatment was lower than in healthy subjects (p<0.05), whereas during tilt was similar in both groups. The alpha-index measured after botulinum toxin injection in patients remained unchanged at rest and during tilt. Patients with cervical dystonia receiving treatment with botulinum toxin type A have mild, subclinical abnormalities in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity. These changes do not worsen after acute botulinum toxin type A injection.

Hydrocortisone effects on cardiovascular variability in septic shock: A spectral analysis approach*

Septic shock may be associated with a loss in cardiovascular variability and adrenal dysfunction. To investigate the relationship between cardiovascular autonomic modulation and adrenal function during sepsis. Seventy-five volunteers with septic shock and six healthy volunteers were prospectively included in the study. Cardiovascular variability was assessed by spectral analysis of heart rate and diastolic blood pressure signals, which included computation of normalized low (LF(nu)) and high frequency (HF(nu)) components. Cardiovascular variability was investigated in patients and healthy volunteers immediately before and 1 hr after a single bolus of 50 mg of hydrocortisone (study phase I); in patients according to adrenal function (study phase II); and in patients with septic shock and adrenal insufficiency, before and 72 hrs after a treatment with 50 mg every 6 hrs of hydrocortisone and 50 microg daily of fludrocortisone or their placebos (study phase III). As compared to healthy volunteers, patients had decreased LF(nu)-HR (.16 +/- .05 vs. .23 +/- .07 p = .01) and LF(nu)-DBP (.18 +/- .11 vs. .28 +/- .02 p = .01) and, after hydrocortisone, they had a greater increase in LF(nu)-DBP (p = .01). As compared to patients with normal adrenal function, those with adrenal failure had decreased LF(nu)-HR (.1 +/- .01 vs. .2 +/- .15 p = .01) and LF(nu)-DBP (.008 +/- .01 vs. .14 +/- .22 p = .0003). In patients with adrenal failure, as compared to placebos, hydrocortisone plus fludrocortisone increased significantly LF(nu)-DBP (p = .02) and low frequency/high volume ratio (p = .009). In septic shock, the loss in cardiovascular variability is more marked in patients with adrenal insufficiency and is partly restored by exogenous administration of corticosteroids.

Autonomic dysfunction in experimental sepsis induced by cecal ligation and puncture

A systemic inflammatory response to infection characterizes sepsis which associated to refractory hypotension, turns into severe sepsis. Our aim was to evaluate hormonal and cardiovascular alterations after experimental sepsis induced by cecal ligation and puncture (CLP). Male Wistar rats (200–250 g) were submitted to CLP or sham operation. The animals were decapitated at 0, 2, 4, 6 and 8 h after surgery for collection of blood samples for plasma osmolality, sodium and vasopressin (AVP) measurements. The mean arterial pressure (MAP) and heart rate (HR) were recorded 1 h before and to each 1 h during 5hs after surgery. The spontaneous baroreflex sensitivity and spectral analysis of HR and MAP variability were analyzed after recording. The plasma osmolality and sodium did not show any alterations compared to the sham group. MAP decreased from 3 h (85 vs.103 mm Hg, P < 0.05) to 5 h in the CLP group (76 vs.106 mm Hg, P < 0.05). This was accompanied by an increase in HR. The AVP plasma level was elevated at 4 h (6.0 ± 1.1 vs. 1.1 ± 0.2 pg/mL, P < 0.05) and returned to basal levels at 8 h after CLP (2.3 ± 0.5 vs. 1.9 ± 0.2 pg/mL, P > 0.05). A reduction in baroreflex sensitivity occurred 1 h after injury. The CLP group showed a reduction in overall variability, low-frequency power, and low/high-frequency ratio of HR and low-frequency power of MAP. The data suggest an impairment of autonomic control of the heart and vessels during polymicrobial sepsis. This reduction in autonomic nervous system activity causes the impairment of baroreflex that in turn may contribute to the reduction of vasopressin plasma levels in the late phase of severe sepsis.

Variabilité de la fréquence cardiaque chez des gymnastes rythmiques prépubères : effets d'un entraînement intensif

Introduction The aim of the study was to access the effects of intensive training on autonomic nervous system in prepubertal gymnasts. Synthesis Ten gymnasts have been tested with an orthostatic test (stand test) before and after an intensive training (5 days). The responses of autonomic nervous system were studied with heart rate spectral analysis. Results showed an increase in sympathetic activity after training when vagal control was not modified. Blood pressure (mean, systolic, diastolic) and spontaneous baroreflex were not modified after intensive training. Conclusion Intensive training increased sympathetic activity. But it is difficult to show the impact of mental stress in this increase.

Étude de la variabilité de la fréquence cardiaque au cours d'une course au large en voilier avec privation de sommeil

Introduction The aim of the study was to assess the effects of a 30-hour offshore race with sleep deprivation. Synthesis Seven male sailors volunteered to participate in the race. During this study the subjects were sleep deprived. They were tested 5 times with an orthostatic test (stand test). Responses of the autonomic nervous system were studied through heart rate spectral analysis. Results showed a greater nocturnal parasympathetic activity with no modification for the 4 other test episodes. Conclusion During the night, the parasympathetic activity increase was correlated with the nyctohemeral period and not with sleep deprivation associated with physical activity.

Vagal and sympathetic heart rate and blood pressure control in adult onset PHOX2B mutation–confirmed congenital central hypoventilation syndrome

Children with Congenital Central Hypoventilation Syndrome (CCHS) typically present as newborns with alveolar hypoventilation. With the advent of genetic testing, parents of affected children and other unrelated adults, all heterozygous for the disease-defining PHOX2B polyalanine expansion mutation with the 20/25 genotype, are being identified in adulthood. Though children with PHOX2B mutation-confirmed CCHS demonstrate ANS dysregulation, including altered heart rate and blood pressure control, it is unknown if adults with CCHS have similarly affected autonomic function in blood pressure control. An autonomic profile of blood pressure control has been studied with recording of muscle sympathetic activity and spectral analysis of heart rate and blood pressure variability of one adult patient with alveolar hypoventilation and the 20/25 PHOX2B genotype. All parameters of heart rate variability were reduced. Cardiac baroreflex sensitivity was decreased. Sympathetic responses to Valsalva maneuver, hypoxemia, isometric exercise and cold pressor were blunted. In summary, we found a reduced cardiac baroreflex and a blunted sympathetic mediated response in the individual with adult-onset CCHS, possibly due to dysfunction in the afferent pathway. Our results confirm that PHOX2B affects the development of the autonomic nervous system, possibly causing absence of normal maturation of carotid body and visceral sensory ganglia and leading to autonomic dysfunction in adult-onset CCHS.

Biobehavioural reactivity to pain in preterm infants: a marker of neuromotor development

In this preliminary study, it was examined whether capacity to react to external stress (acute pain) during neonatal intensive care predicts later neuromotor development at 4 and 8 months corrected chronological age (CCA) in high-risk preterm infants. Behavioural and cardiac reactivity to blood collection at 32 weeks postconceptional age (PCA) were recorded in addition to developmental outcomes at 4 and 8 months CCA in 35 preterm infants (17 males, 18 females) born ≤800g and/or ≥25 weeks gestational age (GA). Pain reactivity during routine heel lance for blood collection at 32 weeks GA was measured using a composite score derived from the Neonatal Facial Coding System, change in infant sleep/wake state, and spectral analysis of heart rate. Motor development was assessed using the Movement Assessment of Infants scale and the Bayley Scales of Infant Development. Low biobehavioural pain reactivity at 32 weeks PCA was associated with poorer overall quality of motor function at 8 months CCA, but not at 4 months CCA. It was concluded that pain reactivity before discharge from the neonatal intensive care unit may be a useful marker of neuromotor development in infancy.

Autonomic activity during dexmedetomidine or fentanyl infusion with desflurane anesthesia

Study Objective To evaluate autonomic activity with dexmedetomidine or fentanyl infusion and desflurane anesthesia during laparoscopic gastric banding. Study Design Randomized, single-blinded, open-label study. Setting Operating rooms at a university hospital. Subjects 40 patients scheduled for laparoscopic gastric banding with a mean body mass index of 50 kg/m 2. Interventions Patients received either dexmedetomidine (0.5 μg/kg given intravenously over 10 minutes, 0.4 μg · kg −1 · h −1, n = 20) or fentanyl (0.5 μg · kg −1 bolus, 1 μg · kg −1 · h −1, n = 20) during anesthesia. Response entropy of the electroencephalogram was maintained at 45 ± 5 by adjusting end-tidal desflurane concentration. Measurements In the operating room, blood pressure, heart rate (HR), response entropy, end-tidal desflurane concentration, tone entropy, and power-spectral analysis of HR were measured with the patient awake; 20, 40, and 60 minutes from intubation and the start of drug infusion; and at extubation. Main Results The mean end-tidal desflurane concentration during anesthesia was 4.0% ± 0.6% with dexmedetomidine and 4.1% ± 0.7% with fentanyl, indicating a similar anesthetic requirement in both groups. Autonomic activity, determined by tone entropy and spectral analysis of HR, decreased by 50% during anesthesia in both groups. The dexmedetomidine group showed a greater decrease in sympathovagal balance during anesthesia. Conclusion Both dexmedetomidine and fentanyl facilitated anesthesia and attenuated autonomic activity. Dexmedetomidine produced a greater decrease in sympathovagal balance than fentanyl.

Effects of Short-Term Hypocaloric Diet on Sympatho-Vagal Interaction Assessed by Spectral Analysis of Heart Rate and Blood Pressure Variability during Stress Tests in Obese Hypertensive Patients

We examined the effects of a short-term low-calorie diet on the activity of the autonomic nervous system during stress tests in obese patients with hypertension by analysis of heart rate and blood pressure variability. Eighteen obese inpatients with essential hypertension were given a regular-calorie diet (1,600 kcal, NaCl 7 g) for 4 days, and then a low-calorie diet (1,100 kcal, NaCl 7 g) for 11 days. During both the regular-calorie diet and low-calorie diet, power spectral analysis of heart rate and blood pressure variability at rest and during mental arithmetic test, deep breathing test, isometric handgrip test or cold pressor test was performed. Body weight and 24-h ambulatory blood pressure were significantly lower during the low-calorie diet than during the regular-calorie diet. Systolic and diastolic blood pressure significantly increased over the handgrip test and cold pressor test during both diets. The low frequency component (LF) of systolic blood pressure, a marker of sympathetic activity to the vasculature, during the deep breathing test and cold pressor test were significantly lower on the low-calorie diet than the regular-calorie diet. The blood leptin concentration was also significantly lower on the low-calorie diet than the regular-calorie diet. The decrease in body weight was positively correlated with the decrease in blood leptin concentration. The LF/high frequency component (HF) ratio of the RR interval at rest on the regular-calorie diet was negatively correlated with the decrease in blood leptin concentration. These results suggest that the autonomic nervous function assessed by analysis of heart rate and blood pressure variability during stress tests may be improved by weight loss due to a short-term low-calorie diet in obese patients with hypertension.

Cardiac Nociception

Cardiac Nociception

Parkinson’s Disease

Parkinson’s Disease (PD) is generally considered a movement disorder characterized by loss of dopaminergic neurons in the central nervous system (CNS), most notably in the substantia nigra. The pathogenesis of the neuronal degeneration is not completely understood but is characterized by abnormal protein deposits forming characteristic neuronal inclusions, which are visible by light microscopy of autopsy samples, and termed Lewy bodies. α-Synuclein is one of the proteins found in these inclusions and has attracted interest because mutations of the gene encoding for this protein are found in familiar cases of PD. Most of the disability associated with PD is indeed the result of this CNS defect, and the treatment is aimed at increasing dopamine levels in the CNS, while avoiding as much as possible an increase in the periphery. Less widely recognized is the fact that orthostatic hypotension can occur in PD patients and can become symptomatic and disabling in a significant proportion of patients. The incidence of documented orthostatic hypotension in PD, in community-based studies, ranges from 10% to 40%. Orthostatic hypotension in PD is commonly attributed to the known adverse effects of dopaminergic drugs. However, over the last decade there is growing evidence that peripheral nerves, particularly autonomic neurons, are also involved in PD. Lewy body inclusions, containing α-synuclein, have been found in peripheral autonomic neurons in autopsy cases of otherwise classic PD.1 Microscopically, eosinophilic ubiquitin- and α-synuclein–positive Lewy Bodies and Lewy neurites are not only found in the substantia nigra and locus ceruleus but also are widespread in ganglions cells …

Concomitant Impairment in Endothelial Function and Neural Cardiovascular Regulation in Offspring of Type 2 Diabetic Subjects

Endothelial function is impaired in first-degree relatives (FDRs) of patients with type 2 diabetes. Many states characterized by endothelial dysfunction are associated with increased cardiovascular sympathetic outflow. In this study, we investigated endothelial and autonomic nervous system (ANS) functioning in FDRs and tested the hypothesis that in basal condition, impaired endothelial function is associated with impaired cardiovascular ANS regulation. Flow-mediated endothelium-dependent and -independent vasodilation of the brachial artery was measured with high-resolution ultrasound in 27 otherwise healthy FDRs (14 men and 13 women; mean age 32 years) with normal oral glucose tolerance and in 15 age- and gender-matched control subjects. Cardiovascular ANS regulation was investigated by means of spectral analysis of heart rate and systolic blood pressure (SBP) variability. Baroreflex sensitivity was assessed by the spontaneous baroreflex sequences technique. Flow-mediated endothelium-dependent vasodilation was 9.4+/-1.0% in FDRs and 17.0+/-2.3% in control subjects (P=0.001). Low-frequency oscillations in SBP variability were 8.6+/-2.8 and 2.8+/-0.6 mm Hg in FDRs and controls, respectively (P=0.04). Baroreflex sensitivity was significantly less in FDRs than controls (22.8+/-2.7 versus 37.0+/-5.8, respectively; P=0.01). Change in vessel diameter was inversely correlated with the low-frequency component of SBP variability (r=-0.40; P=0.014). In healthy FDRs of diabetic patients there is a concomitant, possibly related, impairment in endothelial and ANS functioning, which manifests, indirectly, with increase in vascular sympathetic outflow and a depressed baroreflex, vagal, control of heart rate.

Biobehavioural reactivity to pain in preterm infants: a marker of neuromotor development

In this preliminary study, it was examined whether capacity to react to external stress (acute pain) during neonatal intensive care predicts later neuromotor development at 4 and 8 months corrected chronological age (CCA) in high-risk preterm infants. Behavioural and cardiac reactivity to blood collection at 32 weeks postconceptional age (PCA) were recorded in addition to developmental outcomes at 4 and 8 months CCA in 35 preterm infants (17 males, 18 females) born <or=800 g and/or <or=25 weeks gestational age (GA). Pain reactivity during routine heel lance for blood collection at 32 weeks GA was measured using a composite score derived from the Neonatal Facial Coding System, change in infant sleep/wake state, and spectral analysis of heart rate. Motor development was assessed using the Movement Assessment of Infants scale and the Bayley Scales of Infant Development. Low biobehavioural pain reactivity at 32 weeks PCA was associated with poorer overall quality of motor function at 8 months CCA, but not at 4 months CCA. It was concluded that pain reactivity before discharge from the neonatal intensive care unit may be a useful marker of neuromotor development in infancy.

Corrigendum to: “The effect of ventilation on spectral analysis of heart rate and blood pressure variability during exercise” by Matthew N. Bartels, Sanja Jelic, Pakkay Nagi, Gregory Gates, Douglas Newandee, Stanley S. Reisman, Robert C. Basner, Ronald E. De Meersman [Resp. Physiol. Neurobiol. 144 (2004) 91–98

Corrigendum to: “The effect of ventilation on spectral analysis of heart rate and blood pressure variability during exercise” by Matthew N. Bartels, Sanja Jelic, Pakkay Nagi, Gregory Gates, Douglas Newandee, Stanley S. Reisman, Robert C. Basner, Ronald E. De Meersman [Resp. Physiol. Neurobiol. 144 (2004) 91–98