scholarly journals Potential remdesivir‐related transient bradycardia in patients with coronavirus disease 2019 (COVID‐19)

2021 ◽  
Author(s):  
Carlo Pallotto ◽  
Lorenzo Roberto Suardi ◽  
Andrea Gabbuti ◽  
Sara Esperti ◽  
Lorenzo Mecocci ◽  
...  
Keyword(s):  
Transient Bradycardia

Upper Gastrointestinal Endoscopy in Infants: Diagnostic Usefulness and Safety

PEDIATRICS ◽  
1984 ◽  
Vol 74 (5) ◽  
pp. 828-831
Author(s):  
Charles B. Hargrove ◽  
Martin H. Ulshen ◽  
Mitchell D. Shub
Keyword(s):  
Gastroesophageal Reflux ◽  
Gastrointestinal Hemorrhage ◽  
Gastrointestinal Endoscopy ◽  
Diagnostic Technique ◽  
Upper Gastrointestinal Endoscopy ◽  
Upper Gastrointestinal Hemorrhage ◽  
Diagnostic Aid ◽  
Diagnostic Usefulness ◽  
Transient Bradycardia ◽  
Upper Gastrointestinal

Although fiberoptic, upper gastrointestinal (UGI) endoscopy has become an accepted diagnostic technique in the older child and adult, concerns about safety have limited the use of this procedure in infants. A 1-year experience with 49 upper gastrointestinal endoscopies in infants less than 25 months of age is reported. There were varied indications for the procedures, including upper gastrointestinal hemorrhage and obstruction, but evaluation for esophagitis secondary to gastroesophageal reflux was most common. Procedures were performed without sedation in 45% of all infants studied, including 87% of infants less than 3 months of age; procedures were well tolerated. General anesthesia was used on only three occasions. A thorough examination was always possible, and biopsies were taken whenever indicated. Only one complication, transient bradycardia, occurred in a critically ill infant. This experience demonstrates that upper gastrointestinal endoscopy is a safe and effective diagnostic aid in infants, and it can often be performed with little or no sedation.

Early Intubation and MAS

PEDIATRICS ◽  
1991 ◽  
Vol 87 (2) ◽  
pp. 269-269
Author(s):  
LIONEL D. TRAVERSE
Keyword(s):  
Vagal Stimulation ◽  
Meconium Aspiration Syndrome ◽  
Meconium Aspiration ◽  
Early Intubation ◽  
Transient Bradycardia

To the Editor.— I was particularly interested by the article by Wiswell et al, entitled "Meconium Aspiration Syndrome: Have We Made a Difference?"1 because it is one of the few articles that has addressed issues of direct interest for the "trenches paediatrician." I would like to propose the following comments to the authors. Intubation of a newborn, by an experienced and trained person, is a benign gesture. Except for the occasional vagal stimulation and very transient bradycardia associated, and the potential trauma to cords (which in good hands is probably easy to avoid), I am not aware of any medium- or long-term sequelae of intubating an infant once or twice.

Large-magnitude, transient, bradycardic events in rabbits

1999 ◽  
Vol 277 (1) ◽  
pp. R243-R249
Author(s):  
Daniel Roach ◽  
Ela Thakore ◽  
Robert S. Sheldon
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Adult Female ◽  
Heart Period ◽  
Shape Parameters ◽  
Large Magnitude ◽  
Central Statistical ◽  
Distinct Word ◽  
Transient Bradycardia

We propose that heart period sequences are organized similarly to sentences, with a lexicon of recurrent, similarly shaped words. These words should fulfill four criteria: universality, nonrandomness, central statistical tendencies, and specific associated physiology. Here we describe a large-magnitude, transient bradycardia (LMTB) and assess whether it constitutes a word. LMTBs were seen in 11 of 12 adult female rabbits. All shape parameters were different than those of the beat-randomized and phase-randomized surrogate sequences ( P < 0.05–0.001). LMTBs were 8.4 ± 2.9 beats and 2.64 ± 0.87 s long and were characterized by bradycardia of 77 ± 49 ms over 1.09 ± 0.49 s with a recovery to baseline over 1.56 ± 0.61 s. The LMTBs had a slower recovery than onset in 9 of 11 rabbits and were highly peaked in 10 of 11 rabbits ( P< 0.05). Scalar, magnitude, and shape parameters had values with central statistical tendencies. About 76% of LMTBs were accompanied by hypotension (mean −6.1 ± 3.9 mmHg) that lagged 2 beats behind the onset of the bradycardia and that correlated with the bradycardia (−10.5 ± 4.1 ms/mmHg). Thus transient bradycardic events are a distinct “word” in the lexicon of heart rate variability.

Metabolic and cardiorespiratory responses to hypoxia in fetal sheep: adenosine receptor blockade

1999 ◽  
Vol 276 (6) ◽  
pp. R1805-R1811 ◽  
Author(s):  
Andrew Chau ◽  
Brian J. Koos
Keyword(s):  
Adenosine Receptors ◽  
Low Voltage ◽  
Specific Inhibitor ◽  
Cardiovascular Responses ◽  
Inhibitory Effects ◽  
Fetal Sheep ◽  
Fetal Breathing ◽  
Phasic Rem Sleep ◽  
Transient Bradycardia

8-Phenyltheophylline (PT), a potent and specific inhibitor of adenosine receptors, was infused intra-arterially into unanesthetized fetal sheep to determine the role of adenosine in hypoxic inhibition of fetal breathing. PT in normoxic fetuses increased heart rate and the incidence of low-voltage electrocortical activity, rapid eye movements (REM), and breathing. Mean breath amplitude increased by 44%. Hypoxia (preductal arterial[Formula: see text] = 14 Torr) induced a metabolic acidemia, a transient bradycardia, and hypertension while virtually eliminating REM and breathing. PT administration during hypoxia enhanced the metabolic acidemia, blocked the bradycardia and hypertension, increased the incidence of REM and breathing, and elevated mean breath amplitude. The results indicate that 1) adenosine is involved in fetal glycolytic and cardiovascular responses to hypoxia, 2) activation of central adenosine receptors mediates about one-half the inhibitory effects of hypoxia on REM and breathing, and 3) the depression of breathing may critically depend on a hypoxia-induced reduction in phasic REM sleep.

Pressor effect of arginine vasopressin in progressive autonomic failure

1986 ◽  
Vol 71 (2) ◽  
pp. 173-178 ◽  
Author(s):  
T. D. M. Williams ◽  
D. DaCosta ◽  
C. J. Mathias ◽  
R. Bannister ◽  
S. L. Lightman
Keyword(s):  
Blood Pressure ◽  
Arginine Vasopressin ◽  
Autonomic Failure ◽  
Pressor Response ◽  
Normal Subjects ◽  
Pressor Effect ◽  
Normal Volunteers ◽  
Pressor Responses ◽  
Transient Bradycardia ◽  
Related Increase

1. The blood pressure (BP) and heart rate (HR) responses to 5 min incremental intravenous infusions of noradrenaline (NA) and arginine vasopressin (AVP) were investigated both in patients with progressive autonomic failure (PAF) and in normal volunteers. 2. Stepwise infusion of NA at rates of 300–3000 pmol min−1 kg−1 produced a bradycardia and a dose related increase in BP in normal subjects. In subjects with PAF there was no significant HR response but the dose-BP response was shifted to the left with significant pressor responses at infusion rates of 60–300 pmol min−1 kg−1. 3. Stepwise infusion of AVP at 0.2–5.0 pmol min−1 kg−1 caused transient bradycardia but no pressor response in seven normal volunteers. Further increases in AVP infusion in three other subjects achieved plasma AVP levels as high as 3000–4000 pmol/l, and still no significant pressor response was observed. 4. Stepwise infusion of AVP at 0.05–2.0 pmol min−1 kg−1 in the eight subjects with PAF resulted in a pressor response without any change in HR. During this infusion plasma AVP increased from 0.8 ± 0.2 (mean ± se) to 30 ± 2 pmol/l. A significant pressor response was already apparent at a plasma AVP level of 5.5 ± 1.8 pmol/l.

Behavioural, physiological and morphological adaptations of the shanny (Blennius pholis) to the intertidal habitat

1982 ◽  
Vol 62 (2) ◽  
pp. 329-338 ◽  
Author(s):  
P. R. Laming ◽  
C. W. Funston ◽  
D. Roberts ◽  
M. J. Armstrong
Keyword(s):  
Locomotory Activity ◽  
Intertidal Habitat ◽  
Aerial Respiration ◽  
Morphological Adaptations ◽  
Transient Bradycardia ◽  
Cutaneous Respiration

Immersed shannies (Blennius pholis) showed peak locomotory activity coincident with daylight high tides. Emersion caused cessation of breathing and bradycardia though Q02 was little affected. Q02 fell, however, when the abdomen was enclosed in an impermeable sheath to block cutaneous respiration. Gulping of air into the extensively vascular oesophagus probably also acts as a means of aerial respiration. Reimmersion of fish caused a transient bradycardia followed by a tachycardia and a fall in Q02 followed subsequently by a rise. The results are discussed in relation to the behavioural, circulatory, respiratory and morphological adaptations of the shanny to the intertidal habitat.

Quantitative evaluation of ontogenetic change in heart rate and its autonomic regulation in newborn mice with the use of a noninvasive piezoelectric sensor

2008 ◽  
Vol 294 (4) ◽  
pp. H1708-H1715 ◽  
Author(s):  
Shinichi Sato
Keyword(s):  
Heart Rate ◽  
Restraint Stress ◽  
Piezoelectric Sensor ◽  
Autonomic Control ◽  
Adrenergic Stimulation ◽  
Newborn Mice ◽  
Autonomic Blockade ◽  
Freely Moving ◽  
First Time ◽  
Transient Bradycardia

A reliable basal heart rate (HR) measurement in freely moving newborn mice was accomplished for the first time by using a novel noninvasive piezoelectric transducer (PZT) sensor. The basal HR was ∼320 beats/min at postnatal day (P)0 and increased with age to ∼690 beats/min at P14. Contribution of autonomic control to HR was then assessed. Sympathetic blockade with metoprolol significantly reduced basal HR at both P6 (−236 ± 23 beats/min; mean ± SE) and P12 (−105 ± 8 beats/min), but atropine was without effect, indicating the predominant tonic adrenergic stimulation and absence of vagal control for basal HR in newborn mice. In contrast to stable basal HR during 5-min recording, HR measured by ECG (ECG-HR) was markedly decreased because of the restraint stress of attaching ECG electrodes, with accompanying freezing behavior. ECG-HR lowered and further decreased gradually during 5 min (slow cardiodeceleration) at P0–P3 and rapidly decreased and gradually recovered within 5 min (transient bradycardia) at P9–P14. The response was not uniform in P4–P8 mice: they showed either of these two patterns or sustained bradycardia (9–29%), and the number of mice that showed transient bradycardia increased with age (30–100%) during the period. Studies with autonomic blockade suggest that the slow cardiodeceleration and transient bradycardia are mediated mainly by withdrawal of adrenergic stimulation and phasic vagal activation, respectively, and the autonomic control of HR response to restraint stress is likely to change from the withdrawal of adrenergic stimulation to the phasic vagal activation at different stages during P4–P8 in individual mice. The PZT sensor may offer excellent opportunities to monitor basal HR of small animals noninvasively.

scholarly journals The characteristics of cardiac vagal preganglionic motoneurones in the dogfish

1985 ◽  
Vol 117 (1) ◽  
pp. 459-470 ◽  
Author(s):  
D. J. Barrett ◽  
E. W. Taylor
Keyword(s):  
Horseradish Peroxidase ◽  
Mechanical Stimulation ◽  
Efferent Activity ◽  
Conduction Velocities ◽  
Antidromic Stimulation ◽  
Hrp Histochemistry ◽  
Transient Bradycardia ◽  
Stimulation Of

Preganglionic vagal motoneurones supplying the heart of the dogfish have been located in the medulla by antidromic stimulation of the central cut end of the branchial cardiac branch of the vagus. They supplied axons with conduction velocities between 4.75 and 16.3 m s-1, which is similar to mammalian B fibres. Motoneurones were found in two locations: the rostromedial (N = 5) and lateral (N = 12) divisions of the vagal motor column. Their measured depths and rostrocaudal distributions with respect to obex corresponded with the location of branchial cardiac motoneurones determined by horseradish peroxidase (HRP) histochemistry. All the neurones located in the rostromedial division of the vagal motor column were spontaneously rhythmically active. Their activity contributed to the rhythmic, respiratory-related bursts in peripheral recordings of efferent activity from the branchial cardiac vagus. They could be induced to fire in a prolonged burst by mechanical stimulation of the gill arches. The neurones located lateral to the rostromedial division of the vagal motor column could be divided into three categories: (1) spontaneously, continuously active cells which could be induced to fire more frequently by mechanoreceptor stimulation, (2) silent cells which could be induced to fire by mechanoreceptor stimulation, (3) silent cells which did not respond to mechanoreceptor stimulation. It is concluded, from the response of the medial and two categories of lateral cells to mechanoreceptor stimulation (which results in a transient bradycardia), that branchial cardiac motoneurones from both these central locations exert a chronotropic influence on the heart.

Cardiac response to startle stimuli in larval zebrafish: sympathetic and parasympathetic components

2010 ◽  
Vol 298 (5) ◽  
pp. R1288-R1297 ◽  
Author(s):  
Kara D. Mann ◽  
Carlton Hoyt ◽  
Shaina Feldman ◽  
LaChelle Blunt ◽  
Aaron Raymond ◽  
...  
Keyword(s):  
Heart Rate ◽  
Nervous System ◽  
Cardiac Output ◽  
Autonomic Nervous System ◽  
Sudden Onset ◽  
Cardiac Response ◽  
Autonomic Nervous ◽  
Repeated Stimulation ◽  
Larval Zebrafish ◽  
Transient Bradycardia

Central regulation of cardiac output via the sympathetic and parasympathetic branches of the autonomic nervous system allows the organism to respond to environmental changes. Sudden onset stimuli, startle stimuli, are useful probes to study central regulatory responses to the environment. In mammals, startle stimuli induce a transient bradycardia that habituates with repeated stimulation. Repeated presentation of the stimulus results in tachycardia. In this study, we investigate the behavioral regulation of heart rate in response to sudden stimuli in the zebrafish. Larval zebrafish show a stereotyped heart rate response to mild electrical shock. Naïve fish show a significant increase in interbeat interval that resolves in the 2 s following stimulation. This transient bradycardia decreases on repeated exposure to the stimulus. Following repeated stimulation, the fish become tachycardic within 1 min of stimulation. Both the transient bradycardia and following tachycardia responses are blocked with administration of the ganglionic blocker hexamethonium, demonstrating that these responses are mediated centrally. The transient bradycardia is blocked by the muscarinic antagonist atropine, suggesting that this response is mediated by the parasympathetic system, while the following tachycardia is specifically blocked by the beta-adrenergic antagonist propranolol, suggesting that this response is mediated by the sympathetic nervous system. Together, these results demonstrate that at the larval stage, zebrafish actively regulate cardiac output to changes in their environment using both the parasympathetic and sympathetic branches of the autonomic nervous system, a behavioral response that is markedly similar to that observed in mammals to similar sudden onset stimuli.

Fetal cardiovascular reflex responses to hypoxaemia

1994 ◽  
Vol 6 (1) ◽  
pp. 17-37 ◽  
Author(s):  
Dino A Giussani ◽  
John AD Spencer ◽  
Mark A Hanson
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Cardiovascular Response ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Intrauterine Environment ◽  
Fetal Sheep ◽  
Arterial Blood ◽  
Cardiovascular Reflex ◽  
Transient Bradycardia

The fetus mounts a coordinated cardiovascular response to an insult of acute hypoxaemia which involves neural and endocrine components. During acute hypoxaemia in late pregnancy there is a transient bradycardia, a gradual increase in arterial blood pressure and an increase in heart rate variability. In addition, there is a redistribution of the combined ventricular output favouring the cerebral, myocardial and adrenal circulations by shunting blood away from the peripheral circulations. A component of the increase in peripheral vascular resistance and the increase in arterial blood pressure during acute hypoxaemia is mediated via increases in plasma concentrations of vasoconstrictor hormones such as vasopressin, angiotensin II and neuropeptide Y. Whilst an increase in plasma ACTH and cortisol is also seen during acute hypoxaemia, their contribution to cardiovascular control in fetal sheep is less clear.Evidence has been presented to suggest that a number of these cardiovascular and endocrine responses to acute hypoxaemia are chemorefiex in nature, mediated principally by carotid chemoreceptor afferents. In addition, this reflex may be modifiable in terms of changes in magnitude and gain: first, by an influence of the intrauterine environment during chronic hypoxaemia and second, through genetic influences, in animals adapted to life at high altitude.

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