1482 Sensitivity of the mean heart rate range and the E:I ratio in assessing the heart rate response to deep breathing

1. Disorders of the autonomic nervous system are frequently diagnosed by measuring heart rate changes in response to deep-breathing and lying-to-standing manoeuvres. The heart rate changes in these manoeuvres are quantified in measures using various units, like beats per minute, seconds and dimensionless ratios. 2. In the present study we mathematically derived relationships between the measures which quantify heart rate changes in beats per minute, seconds and dimensionless ratios. The theoretical outcomes were experimentally confirmed by the results of the deep-breathing and the lying-to-standing test in 525 healthy and diabetic subjects. The measures were found to be non-equivalent, because the mean RR interval duration influenced the measures in different ways. 3. It is argued that measures in seconds are preferable to measures in beats per minute or ratios, because the physiological interpretation of this measure is easier, and the sensitivity of measures in seconds is expected to be greater. 4. Finally, we recommend that measures of heart rate variation in the deep-breathing and lying-to-standing manoeuvre are accompanied by information on the mean RR interval duration or mean heart rate to allow correct interpretation of the measures.

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Heart rate responses and plasma cortisol concentrations in ewes: comparison between cervical and laparoscopic intrauterine insemination and their associated handling procedures

Animal Science ◽

10.1017/s1357729800009516 ◽

1998 ◽

Vol 66 (2) ◽

pp. 383-387 ◽

Cited By ~ 1

Author(s):

M. Khalid ◽

W. Haresign ◽

D. G. Bradley

Keyword(s):

Heart Rate ◽

Stress Responses ◽

Plasma Cortisol ◽

Intrauterine Insemination ◽

Management Practice ◽

Treatment Groups ◽

Cortisol Responses ◽

The Mean ◽

Pre Treatment ◽

Mean Heart Rate

AbstractThis study consisted of two experiments. In experiment 1, stress responses of sheep which were restrained either in a laparoscopy cradle or a roll-over cradle were compared. The results of this experiment indicated that restraint in roll-over cradle is less (P < 0·05) stressful than that in a laparoscopy cradle when assessed in terms of the elevation and duration of both the mean heart rate and plasma cortisol responses. Experiment 2 compared the stress responses of sheep subjected to restraint in a laparoscopy cradle, restraint in a laparoscopy cradle with intrauterine artificial insemination (AI) by laparoscopy, minimal restraint with cervical AI or restraint in a roll-over cradle plus foot-trimming. All treatments resulted in significant elevations in both heart rate and plasma cortisol concentrations (F < 0·001). The peak heart rate was significantly (P < 0·05) higher in ewes subjected to cervical AI than in those subjected to intrauterine insemination, with other treatments intermediate. The peak cortisol response did not differ among different treatments. The duration over which both the mean heart rate and -plasma cortisol concentrations remained significantly elevated above pre-treatment concentrations did not differ among treatment groups. The results of this study suggest that while restraint using a laparoscopy cradle is more stressful than that using a rollover cradle, the stress inflicted by intrauterine insemination by laparoscopy itself is no greater than that due to restraint using the laparoscopy cradle alone, cervical AI or the management practice offoot-trimming using a rollover cradle.

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Effect of ouabain on pressor responsiveness in normal man

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1994.267.5.e642 ◽

1994 ◽

Vol 267 (5) ◽

pp. E642-E647

Author(s):

G. B. Pidgeon ◽

A. M. Richards ◽

M. G. Nicholls ◽

R. R. Bailey ◽

K. L. Lynn ◽

...

Keyword(s):

Heart Rate ◽

Healthy Volunteers ◽

Plasma Levels ◽

Plasma Renin ◽

Ang Ii ◽

Short Term ◽

Vasoactive Hormones ◽

Normal Man ◽

The Mean ◽

Mean Heart Rate

To assess the effects of ouabain on pressor and vasoactive hormone responsiveness, 10 healthy volunteers were pretreated with ouabain (0.5 mg i.v. 42 and 18 h before study) or placebo before pressor challenge with angiotensin II (ANG II; 2, 4, and 8 ng.kg-1.min-1 for 30 min/dose) and norepinephrine (NE; 5, 15, and 45 ng.kg-1.min-1 for 15 min/dose). There were no differences at baseline between the two study days regarding mean arterial pressure (MAP) or heart rate. Baseline pulse pressure, however, was significantly greater after ouabain (47 +/- 3 vs. 41 +/- 1 mmHg; P < 0.05). The mean maximum increments in MAP during ANG II and NE infusions were 17.5 +/- 1.1 and 10.5 +/- 1.3 (SE) mmHg, respectively, after ouabain and 19.2 +/- 1.3 and 10.4 +/- 1.5 mmHg after placebo (not significant). The mean heart rate was lower during both infusion periods on the ouabain study day compared with control (P < 0.05). Baseline plasma levels of ANG II, aldosterone, plasma renin activity, atrial and brain natriuretic peptide, guanosine 3',5'-cyclic monophosphate, NE, and epinephrine and achieved levels during the two infusions were similar on the two study days. We conclude that short-term ouabain administration does not alter pressor responsiveness or plasma levels of vasoactive hormones in healthy volunteers.

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Etorphine-halothane anaesthesia in two five-year-old African elephants (Loxodonta africana) : clinical communication

Journal of the South African Veterinary Association ◽

10.4102/jsava.v70i4.789 ◽

1999 ◽

Vol 70 (4) ◽

Cited By ~ 2

Author(s):

G.F. Stegmann

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Systolic Pressure ◽

Loxodonta Africana ◽

African Elephants ◽

Clinical Communication ◽

Dental Surgery ◽

Blood Pressures ◽

The Mean ◽

Mean Heart Rate

Anaesthesia of 2 five-year-old femaleAfrican elephants (Loxodonta africana) was required for dental surgery. The animals were each premedicated with 120 mg of azaperone 60 min before transportation to the hospital. Before offloading, 1 mg etorphine was administered intramuscularly (i.m.) to each elephant to facilitate walking them to the equine induction / recovery room. For induction, 2 mg etorphine was administered i.m. to each animal. Induction was complete within 6 min. Surgical anaesthesia was induced with halothane-in-oxygen after intubation of the trunk. During surgery the mean heart rate was 61 and 45 beats / min respectively. Systolic blood pressures increased to 27.5 and 25.6 kPa respectively, and were treated with intravenous azaperone. Blood pressure decreased thereafter to a mean systolic pressure of 18.1 and 19.8 kPa, respectively. Rectal temperature was 35.6 and 33.9 oC at the onset of surgery, and decreased to 35.3 and 33.5 oC, respectively, at the end of anaesthesia. Etorphine anaesthesia was reversed with 5mg diprenorphine at the completion of 90 min of surgery.

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Cardiac autonomic dysfunction in obese subjects

Clinical Science ◽

10.1042/cs0760567 ◽

1989 ◽

Vol 76 (6) ◽

pp. 567-572 ◽

Cited By ~ 65

Author(s):

Marco ROSSI ◽

Giuliano Marti ◽

Luigi Ricordi ◽

Gabriele Fornasari ◽

Giorgio Finardi ◽

...

Keyword(s):

Blood Pressure ◽

Body Mass Index ◽

Heart Rate ◽

Autonomic Dysfunction ◽

Cross Correlation ◽

Heart Rate Response ◽

Valsalva Manoeuvre ◽

Deep Breathing ◽

Cardiac Autonomic Dysfunction ◽

Obese Subjects

1. The prevalence of cardiac autonomic alterations was evaluated in 23 obese subjects with body mass index 37.2 ± 3.03 kg/m2 (mean ± sd), compared with 78 controls with body mass index 22.5 ± 2.6 kg/m2 (P < 0.001). 2. Cardiac autonomic function was assessed by four standard tests (heart rate response to deep breathing and to the Valsalva manoeuvre, systolic blood pressure fall after standing and diastolic pressure rise during handgrip) and by the cross-correlation test, a new method of computerized analysis of respiratory sinus arrhythmia based on spectral analysis of electrocardiographic and respiratory signals. 3. Considering tests indicative of parasympathetic function, only the heart rate response to the deep breathing and the cross-correlation test were significantly lower in the obese than in the control group [deep breathing = 13.95 ± 8.65 beats/min (mean ± sd) vs 24.5 ± 7.65, P < 0.001; cross-correlation 4.28 ± 0.74 units vs 5.14 ± 0.63, P < 0.001]. Deep breathing and/or cross-correlation were abnormal in 10 (43.5%) obese subjects (deep breathing: seven subjects, cross-correlation: eight subjects). No significant difference between groups was found for the response to the Valsalva manoeuvre: the Valsalva ratio was 1.69 ± 0.45 in obese subjects and 1.88 ± 0.33 in controls (P = NS). The Valsalva ratio was abnormal in three obese subjects. 4. No significant differences were found between groups for tests indicative of sympathetic function. The rise in diastolic blood pressure after handgrip was 12.6 ± 6.2 mmHg (1.67 ± 0.82 kPa) in obese subjects and 18.2 ± 4.9 mmHg (2.42 ± 0.65 kPa) in controls (P = NS), and the fall in systolic blood pressure after standing was −6.8 ± 8.6 mmHg (−0.90 ± 1.14 kPa) in obese subjects and −6.9 ± 10.4 mmHg (−0.91 ± 1.38 kPa) in controls (P = NS). The handgrip test was abnormal in four obese subjects, while no obese subject had an abnormal blood pressure response to standing. 5. Our findings suggest a high incidence of cardiac autonomic dysfunction in obese subjects. Since cardiac autonomic alterations have been shown to be involved in the mechanisms of cardiac sudden death, our data suggest a possible role of autonomic dysfunction in the increased risk for sudden death in obesity.

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Factors Related to the Dive Reflex in Harbor Seals: Respiration, Immersion Bradycardia, and Lability of the Heart Rate

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y74-034 ◽

1974 ◽

Vol 52 (2) ◽

pp. 248-258 ◽

Cited By ~ 15

Author(s):

Robert W. Dykes

Keyword(s):

Heart Rate ◽

Individual Differences ◽

Time Course ◽

Breathing Pattern ◽

Mean Amplitude ◽

Harbor Seals ◽

Normal Heart ◽

Normal Heart Rate ◽

The Mean ◽

Mean Heart Rate

The normal heart rate of young breathing harbor seals, 130.1 beats/min (S.E.M. = 22, n = 33), decreases by 50% during periods of spontaneous apnea in air and by 69% during 2 min of forced apnea in air. Apneic bradycardia develops five times more slowly than bradycardia observed during immersion. During forced apnea the heart rate drops to 31% of the value observed during periods of breathing in 200 s while during immersion the heart rate drops to this value only after 20 s. Since the bradycardia during apnea has a slower time course, apnea alone cannot account for the bradycardia observed during immersion.In quietly resting seals, the apneustic breathing pattern consisted of periods of breathing (duration of 10–115 s) interrupted by apneic pauses (duration of 19–104 s). During the breathing periods successive breaths tended to be smaller so that at the end of a breathing period the mean amplitude of a respiratory movement was only 57% of the mean amplitude of the first inspiration. Tracheostomy altered the breathing pattern and lowered the mean heart rate during breathing to 43% of the rate observed in intact animals. Under controlled conditions immersion bradycardia was highly reproducible and showed no signs of conditioning to the experimental regime. Data from 56 immersions on three animals illustrated minor individual differences in the time course of the immersion bradycardia and provided the basis for an estimate of the average time course of immersion bradycardia in young harbor seals.

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Use of Heart Rate Response for the Assessment of Hearing in Infants

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348947808700217 ◽

1978 ◽

Vol 87 (2) ◽

pp. 243-247 ◽

Cited By ~ 1

Author(s):

Tokuro Suzuki

Keyword(s):

Heart Rate ◽

Clinical Utility ◽

Heart Rate Response ◽

Tone Burst ◽

Individual Variability ◽

Prominent Component ◽

Msec Duration ◽

Subjective Threshold ◽

The Mean ◽

Normal Adults

The clinical utility of the heart rate (HR) response as an index of hearing in infant children under 12 months of age was investigated. The most prominent component of the averaged HR response elicited with a short tone burst of 100 msec duration was a brief HR deceleration which mostly occurred between the first and second beats after stimulation. The mean response detectability for tones of 250 Hz and 1 kHz were 50, 82 and 100%, with stimulations of 40, 60 and 80 dB above subjective threshold of normal adults, respectively. The detectability decreased a little at 4 kHz stimulation. Though there was an individual variability in the appearance of the response, the method was considered to be useful as a supplementary tool for evaluating hearing in infant children.

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Cluster Headache: Heart Rate and Blood Pressure Changes During Spontaneous Attacks

Cephalalgia ◽

10.1046/j.1468-2982.1982.0202061.x ◽

1982 ◽

Vol 2 (2) ◽

pp. 61-70 ◽

Cited By ~ 19

Author(s):

David Russell ◽

Are von der Lippe

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cluster Headache ◽

Diastolic Blood Pressure ◽

Head Pain ◽

The Mean ◽

Significant Change ◽

Pressure Changes ◽

Change In Mean ◽

Mean Heart Rate

The ECG findings before, during and following 81 spontaneous attacks of cluster headache in 24 patients have been recorded using a Holter cardiography system. No significant change in mean heart rate was found during attacks, when all attacks were considered as a group. Attacks which began when patients were awake differed from those which began during sleep as regards changes in mean heart rate. The mean heart rate decreased during the majority (61%) of attacks which began when patients were awake, whereas it remained unchanged or increased during the majority (67.5%) of attacks which began during sleep. The attacks which began when patients were awake also had higher absolute mean heart rate values before, during and following attacks compared to similar values for those attacks which began during sleep. Blood pressure was measured during 11 attacks and showed a significant increase in both systolic and diastolic blood pressure. The heart rate and blood pressure in six patients usually increased during induced head pain.

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Heart rates and abdominal temperatures of free-ranging South Georgian shags, Phalacrocorax georgianus

Journal of Experimental Biology ◽

10.1242/jeb.200.4.661 ◽

1997 ◽

Vol 200 (4) ◽

pp. 661-675 ◽

Cited By ~ 12

Author(s):

R M Bevan ◽

I L Boyd ◽

P J Butler ◽

K Reid ◽

A J Woakes ◽

...

Keyword(s):

Heart Rate ◽

Dive Depth ◽

Dive Duration ◽

Diving Behaviour ◽

The South ◽

Data Logger ◽

Heart Rates ◽

The Mean ◽

Free Ranging ◽

Mean Heart Rate

The South Georgian shag (Phalacrocorax georgianus) shows a remarkable diving ability comparable to that of penguins, yet nothing is known of the physiology of these birds. In this study, heart rates and abdominal temperatures were recorded continuously in four free-ranging South Georgian shags using an implanted data-logger. A timedepth recorder was also attached to the back of the implanted birds to record their diving behaviour. The diving behaviour of the birds was essentially similar to that reported in other studies, with maximum dive durations for individual birds ranging between 140 and 287 s, and maximum depths between 35 and 101 m. The birds, while at the nest, had a heart rate of 104.0±13.1 beats min-1 (mean ± s.e.m.) and an abdominal temperature of 39.1±0.2 °C. During flights of 221±29 s, heart rate and abdominal temperature rose to 309.5±18.0 beats min-1 and 40.1±0.3 °C, respectively. The mean heart rate during diving, at 103.7±13.7 beats min-1, was not significantly different from the resting values, but the minimum heart rate during a dive was significantly lower at 64.8±5.8 beats min-1. The minimum heart rate during a dive was negatively correlated with both dive duration and dive depth. Abdominal temperature fell progressively during a diving bout, with a mean temperature at the end of a bout of 35.1±1.7 °C. The minimum heart rate during diving is at a sub-resting level, which suggests that the South Georgian shag responds to submersion with the 'classic' dive response of bradycardia and the associated peripheral vasoconstriction and utilisation of anaerobic metabolism. However, the reduction in abdominal temperature may reflect a reduction in the overall metabolic rate of the animal such that the bird can remain aerobic while submerged.

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Does Nasal Obstruction Increase Heart Rate?

Bengal Journal of Otolaryngology and Head Neck Surgery ◽

10.47210/bjohns.2017.v25i3.132 ◽

2017 ◽

Vol 25 (3) ◽

pp. 124-129

Author(s):

Venkatesha Belur Keshavamurthy ◽

Munish Kambathatti Shekharappa ◽

Yogeesha Beesanahalli ◽

Nagaraj Maradi ◽

Priya Rani Kori

Keyword(s):

Heart Rate ◽

Nasal Obstruction ◽

Sleep Apnoea ◽

Cardiovascular Morbidity ◽

Obstructive Sleep ◽

Significant Difference ◽

Obstruction Group ◽

The Mean ◽

Mean Heart Rate

Introduction Nasal obstruction is implicated in the etiopathogenesis of Obstructive Sleep Apnea (OSA). OSA is associated with mean heart rate (HR) variations in wakefulness and in sleep. Early intervention has proven to reduce cardiovascular morbidity in OSA patients. In spite of various confounding factors HR measurement has been utilised as an independent predictor of mortality. The influence of severity of nasal obstruction on HR has not been studied in the literature. This study aims to clarify the influence of severity of nasal obstruction on HR. Materials and Methods We examined 55 patients aged less than 50 years with no previous cardiac complaints, who underwent overnight oxygen saturation and HR monitoring. The patients were divided into Mild, Moderate and Severe Nasal Obstruction group depending on NOSE scale grading. Results There was no statistically significant difference in the Mean HR, Min HR, Max HR, and Max-Min HR in mild, moderate or severe nasal obstruction groups. Discussion The role of nasal obstruction in Obstructive Sleep Apnoea and the importance of HR as predictor of cardiovascular morbidity have been discussed. The studies on the heart rate in nasal obstruction and OSA were reviewed. Conclusion Nasal obstruction does not influence the heart rate.

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