scholarly journals A Validated Smartphone-based Electrocardiogram Reveals Severe Bradyarrhythmias during Immobilizing Restraint in Mice of Both Sexes and Four Strains

2021 ◽  
Vol 60 (2) ◽  
pp. 201-212
Author(s):  
Rachael N Labitt ◽  
Eva M Oxford ◽  
Allyson K Davis ◽  
Scott D Butler ◽  
Erin K Daugherity
Keyword(s):  
Heart Rate ◽  
Animal Welfare ◽  
Atrioventricular Block ◽  
Cardiovascular Effects ◽  
Average Decrease ◽  
Reflex Bradycardia ◽  
Severe Bradycardia ◽  
Different Strains ◽  
Telemetry Ecg ◽  
Third Degree Atrioventricular Block

Mouse handling and restraint affect behavior, physiology, and animal welfare, yet little information is available on how various mouse restraint methods affect cardiovascular parameters. We validated the use of a smartphone-based ECG sys- tem in mice by performing simultaneous smartphone and telemetry ECG recordings in conscious, restrained mice and in anesthetized mice. We observed that mice held in standard immobilizing restraint ("scruffing") experienced severe bradycardia. Mice of both sexes and 4 different strains (BALB/cJ, C57BL/6J, DBA/2J, and FVB/nJ) were restrained by 3 handlers using 3 different restraint methods: light restraint; 3-finger restraint, which creates a dorsal transverse fold of skin; and the standard immobilizing restraint, which creates a dorsal longitudinal fold of skin that results in a crease on the ventral neck. Regardless of the handler, immobilizing restraint, but not 3-finger restraint, produced severe bradycardia with irregular rhythm in all 4 strains and both sexes, with an average decrease in heart rate of 31%, or 211 bpm, and a maximal decrease of 79%, or 542 bpm. When evaluated using telemetry, immobilizing restraint produced severe arrhythmias such as junctional and ventricular escape rhythms, and second- and third-degree atrioventricular block. Sinus pauses were observed for an average of 4 min, but up to 6.8 min after release from immobilizing restraint. Atropine administration to C57BL/6J mice attenuated immobilizing restraint-induced bradycardia, supporting the hypothesis that pressure on cervical baroreceptors during stretching of the neck skin results in a vagally-mediated reflex bradycardia. Because of these profound cardiovascular effects, we recommend using the light or 3-finger restraint and avoiding or minimizing the use of immobilization restraint while handling mice.

scholarly journals Third‐degree atrioventricular block and pacemaker implantation in a man with severe hemophilia A: A case report

2021 ◽  
Vol 37 (2) ◽  
pp. 460-461
Author(s):  
Ricardo Mesquita Camelo ◽  
Bruna Pontes Duarte ◽  
Antônio Macedo do Nascimento ◽  
Ana Maria Vanderlei
Keyword(s):  
Case Report ◽  
Atrioventricular Block ◽  
Hemophilia A ◽  
Pacemaker Implantation ◽  
Severe Hemophilia ◽  
Third Degree Atrioventricular Block

Thalidomide-induced symptomatic third-degree atrioventricular block

2006 ◽  
Vol 95 (9) ◽  
pp. 474-476 ◽  
Author(s):  
Martin Hinterseer ◽  
Alexander Becker ◽  
Stefan Kääb ◽  
Nicola Lang ◽  
Michael Näbauer ◽  
...  
Keyword(s):  
Atrioventricular Block ◽  
Third Degree Atrioventricular Block

Increased Pressor Responsiveness to Enkephalin in Spontaneously Hypertensive Rats: The Role of Vasopressin

1980 ◽  
Vol 59 (s6) ◽  
pp. 235s-237s ◽  
Author(s):  
R. W. Rockhold ◽  
J. T. Crofton ◽  
L. Share
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressor Response ◽  
Cardiovascular Effects ◽  
Hypertensive Rats ◽  
Methionine Enkephalin ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Wistar Kyoto

1. The cardiovascular effects of an enkephalin analogue were examined in spontaneously hypertensive and normotensive Wistar-Kyoto rats. (D-Ala2)-methionine enkephalin caused a biphasic increase in blood pressure and an increase in heart rate after intracerebroventricular injection. 2. The initial pressor response to (D-Ala2)-methionine enkephalin was greater in hypertensive than in normotensive rats. No difference was noted between groups during the secondary pressor response. Heart rate increases paralleled the secondary increase in blood pressure. 3. Naloxone pretreatment abolished the secondary increase in blood pressure and the tachycardia, but did not blunt the initial pressor response in female Wistar-Kyoto rats. 4. Plasma levels of arginine vasopressin were depressed during the plateau phase of the pressor response in hypertensive rats given intracerebroventricular (d-Ala2)-methionine enkephalin. 5. The results suggest that the cardiovascular effects of central enkephalin are not due to vasopressin, but may involve activation of the sympathetic nervous system.

Effects of temperature and wind on facial temperature, heart rate, and sensation

1976 ◽  
Vol 40 (2) ◽  
pp. 127-131 ◽  
Author(s):  
J. LeBlanc ◽  
B. Blais ◽  
B. Barabe ◽  
J. Cote
Keyword(s):  
Heart Rate ◽  
Skin Temperature ◽  
Subjective Evaluation ◽  
Temperature Measurements ◽  
Wind Speeds ◽  
Reflex Bradycardia ◽  
The Face ◽  
Cooling Effects ◽  
Effects Of Temperature ◽  
Cold Wind

Skin temperature measurements of the face have shown that the cheek cools faster than the nose and the nose faster than the forehead. The cooling effect of wind is maximum at wind speeds between 4.5 and 6.7 m/s. Cold winds produce significant bradycardia, which is, however, much more pronounced during the expiratory phase of respiration. A significant correlation was noted between cooling of face and the reflex bradycardia observed. Similarly, a very significant correlation was noted between drop in skin temperature and subjective evaluation of cold discomfort. Consequently, the drop in skin temperature, reflex bradycardia, and subjective evaluation are parameters which are directly affected by cold wind and can be used as adequate indicators of the degree of discomfort. When comparing the present results with the windchill index, it was found that in the zone described as “dangerously cold” the index fits well with the physiological measurements. In the zone described as “bitterly cold,” the index by comparison with actual skin temperature measurements and subjective evaluation underestimates the cooling effects of combined temperature and wind by approximately 10 degrees C.

Cardiovascular Effects of Aerobic Exercise With Self-Selected or Predetermined Intensity in Adolescents With Obesity

2021 ◽  
pp. 1-7
Author(s):  
Tércio A.R. Barros ◽  
Wagner L. do Prado ◽  
Thiago R.S. Tenório ◽  
Raphael M. Ritti-Dias ◽  
Antônio H. Germano-Soares ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Heart Rate ◽  
Pulse Pressure ◽  
Exercise Intensity ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Cardiovascular Effects ◽  
Heart Rate Reserve ◽  
Central Pulse Pressure

This study compared the effects of self-selected exercise intensity (SEI) versus predetermined exercise intensity (PEI) on blood pressure (BP) and arterial stiffness in adolescents with obesity. A total of 37 adolescents, 14.7 (1.6) years old, body mass index ≥95th percentile were randomly allocated into SEI (n = 18; 12 boys) or PEI (n = 19; 13 boys). Both groups exercised for 35 minutes on a treadmill, 3 times per week, for 12 weeks. The SEI could set the speed at the beginning of the sessions and make changes every 5 minutes. The PEI adolescents were trained at an intensity set at 60% to 70% of heart rate reserve. Brachial and central BP, pulse pressure, augmentation index, and carotid–femoral pulse wave were determined at baseline and after 12 weeks. Both groups reduced brachial systolic BP (SEI, Δ = −9 mm Hg; PEI, Δ = −4 mm Hg; P < .01), central systolic BP (SEI, Δ = −4 mm Hg; PEI, Δ = −4 mm Hg; P = .01), and central pulse pressure (SEI, Δ = −4 mm Hg; PEI, Δ = −3 mm Hg; P = .02) without differences between groups. No changes in the augmentation index and carotid–femoral pulse wave were observed in either group. The SEI induced similar changes in various cardiovascular outcomes compared with PEI in adolescents with obesity.

scholarly journals Cardiovascular effects of lumbar epidural anaesthesia in isoflurane-anaesthetised pigs during surgical removal of the liver

2009 ◽  
Vol 80 (1) ◽  
Author(s):  
G.F. Stegmann
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Abdominal Surgery ◽  
Epidural Anaesthesia ◽  
Cardiovascular Effects ◽  
Surgical Removal ◽  
Arterial Blood ◽  
Combined Administration ◽  
Lumbar Epidural Anaesthesia ◽  
Surgical Preparation

In humans the combined administration of epidural anaesthesia and inhalation anaesthesia may result in cardiovascular instability associated with decreases in heart rate and blood pressure. Anaesthesia was induced with a combination of midazolam / ketamine in 18 female pigs with a mean body weight of 24.9±5.9 kg scheduled for surgical removal of the liver. After tracheal intubation, anaesthesia was maintained on a circle rebreathing circuit with isoflurane. Epidural anaesthesia was administered with ropivacaine (AL-group, n=8) at 0.2 mℓ / kg of a 7.5 mg / mℓ solution to the anaesthetised animals. The A-group (n = 10) received isoflurane anaesthesia only. The vaporiser was set at 2.5 % for the A-group and 1.5 % for the AL-group. Heart rate, invasive systolic, diastolic, and mean arterial blood pressure were monitored. Comparisons were made between treatments and within treatments comparing variables during surgical preparation and abdominal surgery. Differences between treatments were not statistically significant (P > 0.05) during surgical preparation or during abdominal surgery. For within treatment groups, the differences between surgical preparation and abdominal surgery were statistically significant (P < 0.05) for heart rate in the A-group, but not statistically significant (P > 0.05) for the other variables. It is concluded that abdominal surgery may be associated with statistically significant changes in heart rate in isoflurane-anaesthetised pigs and that the combined administration of epidural ropivacaine may prevent statistically significant changes in HR during abdominal surgery.

scholarly journals Tai-chi-chuan and yoga onpostexercise hypotension: comparison to aerobic and resistance exercise

2016 ◽  
Vol 29 (3) ◽  
pp. 543-552
Author(s):  
João Douglas Alves ◽  
Jorge Luiz de Brito Gomes ◽  
Caio Victor Coutinho de Oliveira ◽  
José Victor de Miranda Henriques Alves ◽  
Fabiana Ranielle de Siqueira Nogueira ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Young Women ◽  
Tai Chi ◽  
Cardiovascular Effects ◽  
Cardiovascular Responses ◽  
Tai Chi Chuan ◽  
Post Exercise ◽  
Significant Difference ◽  
Apparently Healthy

Abstract Introduction: Tai-Chi-Chuan and Yoga have becoming popular practices. However is unclear the cardiovascular effects, and if they present similar behavior to aerobic and resistance sessions. Objective: To evaluate the cardiovascular responses during the session and post-exercise hypotension (PEH) of Tai Chi Chuan (TS) and Yoga (YS) in comparison to aerobic (AS) and resistance (SR) exercises. Methods: Fourteen young women (22.3 ± 2 years) apparently healthy performed four sessions (AS, RS, TS and YS). The heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) were recorded at resting, during (every 10 minutes) and until 50 minutes of recovery. Results: AS, RS, TS e YS showed significant increase in HR compared to resting.AS at 10, 30 e 50 minutes in relation to RS, TS e YS. The RS in relation to TS and YS at 10, 30 and 50 minutes. No significant difference between TS and YS. SBP was significantly increased in AS, RS, TS e YS at 10, 30 e 50 minutes during the session, in relation to rest. AS was significantly higher at 30 e 50 minutes than RS and higher than TS and YS at 10, 30 e 50 minutes. No significant difference in DBP. For PEH, AS, RS and TS significantly reduced at 10, 30 and 50 minutes. YS reduced at 50 minutes. No significant diastolic PEH. Conclusion: TS and YS showed as safe alternatives of exercising in the normotensive young adult woman, despite having lower values, they promote similar hemodynamic behavior to AS and RS.

Isoflurane Depresses Baroreflex Control of Heart Rate in Decerebrate Rats

2002 ◽  
Vol 96 (5) ◽  
pp. 1214-1222 ◽  
Author(s):  
Jong S. Lee ◽  
Don Morrow ◽  
Michael C. Andresen ◽  
Kyoung S. K. Chang
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Baroreflex Sensitivity ◽  
Baroreflex Control ◽  
Beta Adrenoceptor ◽  
Reflex Bradycardia ◽  
Reflex Tachycardia ◽  
Map Data ◽  
Regulatory Sites

Background Isoflurane inhibits baroreflex control of heart rate (HR) by poorly understood mechanisms. The authors examined whether suprapontine central nervous system cardiovascular regulatory sites are required for anesthetic depression. Methods The effects of isoflurane (1 and 2 rat minimum alveolar concentration [MAC]) on the baroreflex control of HR were determined in sham intact and midcollicular-transected decerebrate rats. Intravenous phenylephrine (0.2-12 microg/kg) and nitroprusside (1-60 microg/kg) were used to measure HR responses to peak changes in mean arterial pressure (MAP). Sigmoidal logistic curve fits to HR-MAP data assessed baroreflex sensitivity (HR/MAP), HR range, lower and upper HR plateau, and MAP at half the HR range (BP50). Four groups (two brain intact and two decerebrate) were studied before, during, and after isoflurane. To assess sympathetic and vagal contributions to HR baroreflex, beta-adrenoceptor (1 mg/kg atenolol) or muscarinic (0.5 mg/kg methyl atropine) antagonists were administered systemically. Results Decerebration did not alter resting MAP and HR or baroreflex parameters. Isoflurane depressed baroreflex slope and HR range in brain-intact and decerebrate rats. In both groups, 1 MAC reduced HR range by depressing peak reflex tachycardia. Maximal reflex bradycardia during increases in blood pressure was relatively preserved. Atenolol during 1 MAC did not alter maximum reflex tachycardia. In contrast, atropine during 1 MAC fully blocked reflex bradycardia. Therefore, 1 MAC predominantly depresses sympathetic components of HR baroreflex. Isoflurane at 2 MAC depressed both HR plateaus and decreased BP50 in both groups. Conclusions Isoflurane depresses HR baroreflex control by actions that do not require suprapontine central nervous system sites. Isoflurane actions seem to inhibit HR baroreflex primarily by the sympathetic nervous system.

scholarly journals Does 20 mg long-acting methylphenidate alter blood pressure and heart rate in children with ADHD?

2011 ◽  
Vol 51 (5) ◽  
pp. 282
Author(s):  
Tjhin Wiguna ◽  
Sasanto Wibisono ◽  
Sudigdo Sastroasmoro ◽  
Fransiscus D. Suyatna
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular Effects ◽  
Children With Adhd ◽  
Normal Ranges ◽  
Blood Pressures ◽  
Drug Naïve ◽  
Repeated Analysis ◽  
Long Acting

Objective To identify the cardiovascular effects of long-acting methylphenidate administered for twelve weeks in Indonesian children with ADHD.Methods This was an 18-week, time series study on children with ADHD who were given 20 mg of long-acting methylphenidate for twelve weeks. During the study period we made ten serial observations of the subjects, including before, during and 6 weeks following drug administration. We included drug naive children with ADHD between the ages of 7 – 10 years. Children with mental retardation and chronic physical or mental disorders were excluded. Blood pressure was measured by sphygmomanometer with a child’s cuff at the brachial artery. We also collected data on heart rate, side effects, complaints and other medications used during the study. Repeated analysis was performed on the data with a P level of 0.05.Results Twenty-one subjects were recruited for this study. Mean blood pressure fluctuated insignificantly during the research period, for both mean systolic and mean diastolic blood pressures (P=0.115 and P=0.059). Mean heart rate also fluctuated insignificantly (P=0.091). All fluctuations were within the normal ranges. During the study, there were complaints of dizziness, nausea, and gastrointestinal upset, but they were reportedly mild and disappeared before the second week of observation.Conclusion Administration of 20 mg long-acting methylphenidate for twelve weeks in children with ADHD altered mean blood pressures and heart rates, but within the normal range for children of their age. However, cardiovascular risk observation is still needed when administering methylphenidate to children with ADHD, especially for those using the medication long-term.[Paediatr Indones. 2011;51:282-7].

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