Heart rate variability and electrocardiogram waveform as predictors of morbidity during hypothermia and rewarming in rats

2002 ◽  
Vol 80 (9) ◽  
pp. 925-933 ◽  
Author(s):  
C B Matthew ◽  
A M Bastille ◽  
R R Gonzalez ◽  
I V Sils
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Wave Amplitude ◽  
Sodium Pentobarbital ◽  
Sprague Dawley ◽  
T Wave ◽  
Sprague Dawley Rats ◽  
Copper Tubing ◽  
Electrocardiogram Ecg

This study examined electrocardiogram (ECG) waveform, heart rate (HR), mean blood pressure (BP), and HR variability as potential autonomic signatures of hypothermia and rewarming. Adult male Sprague–Dawley rats had telemetry transmitters surgically implanted, and 2 weeks were allowed for recovery prior to induction of hypothermia. Rats were lightly anesthetized (sodium pentobarbital, 35 mg/kg i.p.) and placed in a coil of copper tubing through which temperature-controlled water was circulated. Animals were cooled to a core temperature (Tc) of 20°C, maintained there for 30 min, and then rewarmed. Data (Tc, BP, HR from ECG, and 10-s strips of ECG waveforms) were collected every 5 min throughout hypothermia and rewarming. Both HR and BP declined after initial increases with the drop in HR starting at a higher Tc than the drop in BP (29.6 ± 2.4°C vs. 27.1 ± 3.3°C, p < 0.05). Animals that were not successfully rewarmed exhibited a significant (p < 0.05) increase in the normalized standard deviation of interbeat intervals (IBI) throughout cooling compared with animals that were successfully rewarmed. The T wave of the ECG increased in amplitude and area with decreasing Tc. T-wave amplitude and IBI variability show potential as predictors of survival in hypothermic victims.Key words: hypothermia, rewarming, heart rate variability, ECG, blood pressure.

scholarly journals Differential effects of the blood pressure state on pulse rate variability and heart rate variability in critically ill patients

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Elisa Mejía-Mejía ◽  
James M. May ◽  
Mohamed Elgendi ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Pulse Rate ◽  
Pulse Transit Time ◽  
Pulse Rate Variability ◽  
Physiological Factors ◽  
Ecg Signals ◽  
Non Invasive ◽  
Electrocardiogram Ecg

AbstractHeart rate variability (HRV) utilizes the electrocardiogram (ECG) and has been widely studied as a non-invasive indicator of cardiac autonomic activity. Pulse rate variability (PRV) utilizes photoplethysmography (PPG) and recently has been used as a surrogate for HRV. Several studies have found that PRV is not entirely valid as an estimation of HRV and that several physiological factors, including the pulse transit time (PTT) and blood pressure (BP) changes, may affect PRV differently than HRV. This study aimed to assess the relationship between PRV and HRV under different BP states: hypotension, normotension, and hypertension. Using the MIMIC III database, 5 min segments of PPG and ECG signals were used to extract PRV and HRV, respectively. Several time-domain, frequency-domain, and nonlinear indices were obtained from these signals. Bland–Altman analysis, correlation analysis, and Friedman rank sum tests were used to compare HRV and PRV in each state, and PRV and HRV indices were compared among BP states using Kruskal–Wallis tests. The findings indicated that there were differences between PRV and HRV, especially in short-term and nonlinear indices, and although PRV and HRV were altered in a similar manner when there was a change in BP, PRV seemed to be more sensitive to these changes.

A STANDARDIZED METHOD FOR THE PRODUCTION OF HEMORRHAGIC SHOCK IN THE RAT

1955 ◽  
Vol 33 (3) ◽  
pp. 436-447 ◽  
Author(s):  
H. G. Downie ◽  
J. A. F. Stevenson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mortality Rate ◽  
Hemorrhagic Shock ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Standardized Method

Although the blood pressure is one of the important criteria in the standardization of hemorrhagic shock in the dog, it has rarely been used for this purpose in the rat. A method resembling the reservoir technique developed by Wiggers and Werle (1942) for the dog using blood pressure as the criterion has been modified for use with the rat. Male Sprague-Dawley rats weighing approximately 400 gm. were used. In the standardization of this technique the blood pressure was reduced to 30 mm. Hg in a 10-min. period of hemorrhage and then maintained at this level by subsequent small hemorrhages into the reservoir until reinfusion indicated the beginning of vascular collapse, at which time all the blood in the reservoir was returned. Considering that those animals which lived longer than 48 hr. were survivors, in a series of 27 animals, 21 died and 6 survived—a mortality rate of 78%.During the hypotensive period there was a consistent and steady drop in the respiratory rate and rectal temperature. The heart rate declined initially and tended to recover as the hypotensive period progressed. After reinfusion the blood pressure rose but. did not reach prehemorrhage levels. Hemorrhage into the bowel and convulsions were significant postreinfusion findings.

scholarly journals Cooling-Evoked Hemodynamic Perturbations Facilitate Sympathetic Activity with Subsequent Myogenic Vascular Oscillations via Alpha2-Adrenergic Receptors

2017 ◽  
pp. 449-457 ◽  
Author(s):  
Y.-H. LIN ◽  
Y.-P. LIU ◽  
Y.-C. LIN ◽  
P.-L. LEE ◽  
C.-S. TUNG
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressor Response ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Sprague Dawley ◽  
Cold Stimulation ◽  
Very Low Frequency ◽  
Power Spectral ◽  
Sprague Dawley Rats

This study extends our previous work by examining the effects of alpha2-adrenoceptors under cold stimulation involving the increase of myogenic vascular oscillations as increases of very-low-frequency and low-frequency of the blood pressure variability. Forty-eight adult male Sprague-Dawley rats were randomly divided into four groups: vehicle; yohimbine; hexamethonium+yohimbine; guanethidine+yohimbine. Systolic blood pressure, heart rate, power spectral analysis of spontaneous blood pressure and heart rate variability and spectral coherence at very-low-frequency (0.02 to 0.2 Hz), low-frequency (0.2 to 0.6 Hz), and high-frequency (0.6 to 3.0 Hz) regions were monitored using telemetry. Key findings are as follows: 1) Cooling-induced pressor response was attenuated by yohimbine and further attenuated by hexamethonium+yohimbine and guanethidine+yohimbine, 2) Cooling-induced tachycardia response of yohimbine was attenuated by hexame-thonium+yohimbine and guanethidine+yohimbine, 3) Different patterns of power spectrum reaction and coherence value compared hexamethonium+yohimbine and guanethi-dine+yohimbine to yohimbine alone under cold stimulation. The results suggest that sympathetic activation of the postsynaptic alpha2-adrenoceptors causes vasoconstriction and heightening myogenic vascular oscillations, in turn, may increase blood flow to prevent tissue damage under stressful cooling challenge.

A STANDARDIZED METHOD FOR THE PRODUCTION OF HEMORRHAGIC SHOCK IN THE RAT

1955 ◽  
Vol 33 (1) ◽  
pp. 436-447
Author(s):  
H. G. Downie ◽  
J. A. F. Stevenson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mortality Rate ◽  
Hemorrhagic Shock ◽  
Respiratory Rate ◽  
Rectal Temperature ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Standardized Method

Although the blood pressure is one of the important criteria in the standardization of hemorrhagic shock in the dog, it has rarely been used for this purpose in the rat. A method resembling the reservoir technique developed by Wiggers and Werle (1942) for the dog using blood pressure as the criterion has been modified for use with the rat. Male Sprague-Dawley rats weighing approximately 400 gm. were used. In the standardization of this technique the blood pressure was reduced to 30 mm. Hg in a 10-min. period of hemorrhage and then maintained at this level by subsequent small hemorrhages into the reservoir until reinfusion indicated the beginning of vascular collapse, at which time all the blood in the reservoir was returned. Considering that those animals which lived longer than 48 hr. were survivors, in a series of 27 animals, 21 died and 6 survived—a mortality rate of 78%.During the hypotensive period there was a consistent and steady drop in the respiratory rate and rectal temperature. The heart rate declined initially and tended to recover as the hypotensive period progressed. After reinfusion the blood pressure rose but. did not reach prehemorrhage levels. Hemorrhage into the bowel and convulsions were significant postreinfusion findings.

scholarly journals Antagonism of orexin receptors in the posterior hypothalamus reduces hypoglossal and cardiorespiratory excitation from the perifornical hypothalamus

2013 ◽  
Vol 114 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Georg M. Stettner ◽  
Leszek Kubin
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Respiratory Rate ◽  
Receptor Antagonist ◽  
Hypoglossal Nerve ◽  
Posterior Hypothalamus ◽  
Sprague Dawley ◽  
Arterial Blood ◽  
Orexin Receptors ◽  
Sprague Dawley Rats

The perifornical (PF) region of the posterior hypothalamus promotes wakefulness and facilitates motor activity. In anesthetized rats, local disinhibition of PF neurons by GABAA receptor antagonists activates orexin (OX) neurons and elicits a systemic response, including increases of hypoglossal nerve activity (XIIa), respiratory rate, heart rate, and blood pressure. The increase of XIIa is mediated to hypoglossal (XII) motoneurons by pathways that do not require noradrenergic or serotonergic projections. We hypothesized that the pathway might include OX-dependent activation locally within the PF region or direct projections of OX neurons to the XII nucleus. Adult, male Sprague-Dawley rats were urethane anesthetized, vagotomized, paralyzed, and ventilated. Gabazine (GABAA receptor antagonist, 0.18 mM, 20 nl) was injected into the PF region, and ∼2 h later, a second gabazine injection was performed preceded by injection of a dual OX1/2 receptor antagonist (almorexant; 90 mM) either into the XII nucleus (40–60 nl at 2–3 rostrocaudal levels; n = 6 rats), or into the PF region (40–60 nl; n = 6 rats). XIIa, respiratory rate, heart rate, and arterial blood pressure were analyzed for 70 min after each gabazine injection. The excitatory effects of PF gabazine on XIIa, respiratory, and heart rates were significantly reduced by up to 44–82% when gabazine injections were preceded by PF almorexant injections, but not when almorexant was injected into the XII nucleus. These data suggest that a significant portion of XII motoneuronal and cardiorespiratory activation evoked by disinhibition of PF neurons is mediated by local OX-dependent mechanisms within the posterior hypothalamus.

scholarly journals The Effect of Subdiaphragmatic Vagotomy on Heart Rate Variability and Lung Inflammation in Rats with Severe Hemorrhagic Shock

2021 ◽  
Author(s):  
Fateme Khodadadi ◽  
Farzaneh Ketabchi ◽  
Zahra Khodabandeh ◽  
Alireza Tavassoli ◽  
Gregory F. Lewis ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Hemorrhagic Shock ◽  
Hemodynamic Parameters ◽  
Sprague Dawley ◽  
Inflammatory Reactions ◽  
Sprague Dawley Rats ◽  
Tnf Α

Abstract Background The role of the sub-diaphragmatic branch of the vagus nerve in mediating heart rate variability (HRV) and inflammatory reaction to long term hemorrhagic shock has not been determined prior to this study. Methods Male Sprague-Dawley rats were divided into four groups of Sham, sub-diaphragmatic vagotomized (Vag), long term (130±2 minutes) hemorrhagic shock (LHS), and sub-diaphragmatic vagotomized with LHS (Vag+LHS). Hemodynamic parameters were recorded and HRV calculated during multiple phases of hemorrhagic shock. The expressions of TNF-α and iNOS were measured in the spleen and lung tissues at the conclusion of the protocol. Results Decreases in blood pressure during blood withdrawal were identical in the LHS and Vag+LHS groups. However, heart rate only decreased in the Nadir-1 phase of the LHS group. HRV indicated increased power in the very-low, low, and high (VLF, LF, and HF) frequency bands during the Nadir-1 phase of the LHS group and decreased power in the Vag+LHS group. There was metabolic acidosis partially compensated with respiratory system in the LHS and Vag+LHS groups. Increases of TNF-α and iNOS expression in the spleen and lung of the LHS group were reversed in the Vag+LHS group. Conclusion This study indicates that sub-diapragmatic vagotomy increases lung inflammatory reactions and blunts the cardiac vagal tone surge in response to severe hemorrhagic shock.

Parathyroidectomy significantly decreases hypertension in spontaneously hypertensive and deoxycorticosterone plus saline treated rats

1982 ◽  
Vol 60 (2) ◽  
pp. 208-212 ◽  
Author(s):  
Alexis Gairard ◽  
Alain Berthelot ◽  
René Schleiffer ◽  
Fanny Pernot
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Normal Serum ◽  
Male Rats ◽  
Shr Rats ◽  
Sprague Dawley ◽  
Spontaneously Hypertensive ◽  
Sprague Dawley Rats ◽  
Normal Serum Calcium

In male Sprague–Dawley rats, hypertensive development was diminished for 10 weeks when parathyroidectomy (PTX) was performed 1 week before deoxycorticosterone plus saline (DOCA + NaCl) treatment. In young spontaneously hypertensive male rats (SHR, Okamoto strain) parathyroidectomy performed after weaning lessened hypertensive levels and lowered heart rate for 24 weeks. When mineralocorticoid or genetic hypertension was established, parathyroidectomy did not significantly change blood pressure levels. High dietary calcium in PTX–SHR rats reestablished normal serum calcium but not systolic blood pressure to the level of sham SHR. From our present and previously reported results, it appears that the parathyroid gland is necessary for the total development of hypertension in both models.

scholarly journals Effectiveness of Interstitial Laser Acupuncture Depends upon Dosage: Experimental Results from Electrocardiographic and Electrocorticographic Recordings

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Wei He ◽  
Gerhard Litscher ◽  
Xiang-Hong Jing ◽  
Hong Shi ◽  
Xiao-Yu Wang ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Acupuncture Therapy ◽  
Experimental Results ◽  
Time Dependent ◽  
Laser Acupuncture ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Interstitial Laser ◽  
Electroencephalogram Eeg

The purpose of this study was to evaluate the influence of the duration of interstitial laser acupuncture therapy effects on neurovegetative and neurobioelectrical parameters like heart rate (HR), heart rate variability (HRV), and electroencephalogram (EEG). We investigated 6 male Sprague-Dawley rats. They underwent 10 min, 20 min, and 30 min interstitial laser acupuncture (in randomized order, with a break of at least 30 min between the different measurement conditions) at the acupoint Neiguan. HR changed significantly only during 20 min red laser stimulation, whereas 10 and 30 min stimulation did not induce significant changes. HRV did not change significantly during any of the different durations; however, an increase was found during 20 min irradiation. Neither the LF/HF ratio of HRV nor the integrated EEG showed significant changes. In this study, it could be experimentally proved that some effects of laser acupuncture are time dependent, and therefore the dosage, as well known from theory, also depends on the time factor. We could especially demonstrate that different treatment times lead to different effects on neurovegetative and neurobioelectrical parameters. Further studies are needed to verify or refute these results.

Changes in the arterial blood pressure, heart rate and normal ECG parameters of rat after envenomation with Egyptian cobra (Naja haje) venom

1997 ◽  
Vol 16 (6) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamed Alaa A Omran ◽  
Ismail M Abdel-Nabi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Electrical Activity ◽  
Arterial Blood Pressure ◽  
Wave Amplitude ◽  
Low Dose ◽  
High Dose ◽  
T Wave ◽  
Arterial Blood ◽  
Naja Haje

1 The effect of Egyptian cobra (Naja haje) venom on the normal electrical activity of the cardiac muscles (ECG) and arterial blood pressure of envenomated rats were investigated in this study. 2 Rats were divided into three groups. The first group was injected im with saline and considered as control group. Rats of the second and third groups were injected IM with 0.02 μg and 0.04 μg cobra venom/ gim b.wt, respectively. 3 Mean blood pressure (MBP), heart rate (HR) and four different ECG parameters (PR and QT intervals, R and T wave amplitudes) were measured over 1 h following envenomation. 4 The low dose (0.02 μg/g) of N. haje venom caused hypotension accompanied by an increase in the HR, whereas hypertension and bradycardia developed after injection of the high dose (0.04 μg/g) of venom. 5 There was a decrease in the P-R interval after administration of the low dose and prolongation of it after the high dose. The Q-T interval and R-wave amplitude were significantly increased after injection of both doses. T-wave amplitude was significantly elevated only after injection of the high dose. 6 The present results indicate that the Egyptian cobra (N. haje) venom significantly alters the arterial blood pressure and ECG parameters of envenomated rats. This suggests that impairment of the electrical activity of cardiac muscle may be one of the reasons why victims of cobra bite die.

Sign in / Sign up

Export Citation Format

Share Document