Autonomic pathways responsible for bradycardia on facial immersion.

J Appl Physiol Respir Environ Exerc Physiol

Published: December 1979

The autonomic pathways mediating the bradycardia response to facial immersion (FI) have not been fully elaborated in man. By means of parasympathetic and sympathetic blockade we studied the heart rate response to FI in nine highly trained young swimmers, at rest and during dynamic cycle exercise. With no blockade, heart rate at rest declined with FI 36 +/- 18%. Under beta-blockade with propranolol or alpha-blockade with phentolamine FI produced a similar decrement. Atropine reduced the response. During exercise FI produced 48 +/- 9% decline without blockade. The response was similar with beta-blockade, but was completely abolished with atropine. Systolic blood pressure responses to FI measured by cuff in three subjects were small and bore no relation to the heart rate response. The results are compatible with parasympathetic efferent mediation of the heart rate response to FI. They are incompatible with a role for sympathetic mediation except as a complex interaction between parasympathetic and sympathetic influences. Hypertension and other sympathetic responses to FI do not play a role in production of bradycardia, but are apparently incidental effects. The heart rate decrement produced by FI increases with greater steady-state heart rate.

Download full-text PDF

Source
http://dx.doi.org/10.1152/jappl.1979.47.6.1218DOI Listing

Publication Analysis

Top Keywords

heart rate
24
rate response
12
autonomic pathways
8
facial immersion
8
parasympathetic sympathetic
8
response
6
heart
6
rate
6
pathways responsible
4
responsible bradycardia
4

Similar Publications

Objectives: This study aimed to assess the outcomes of heterotaxy patients undergone the Fontan operation, focusing on morphological features and surgical techniques.

Methods: Eighty-two consecutive heterotaxy patients who underwent the Fontan operation from 1985 to 2021 were compared to 150 patients with tricuspid atresia (TA) and 144 patients with hypoplastic left heart syndrome (HLHS). The Kaplan-Meier method and Cox proportional hazard model were used to analyze transplant-free survival and predictor of outcomes.

View Article and Find Full Text PDF

Down the Rabbit Hole: A Large-Scale Survey of Psychedelic Users' Patterns of Use and Perceived Effects.

J Psychoactive Drugs

January 2025

Department of Psychiatry, Mathison Centre for Mental Health Research and Education, and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.

The ever-changing landscape surrounding legality and accessibility of psychedelics and their increasing popularity make it imperative to better understand the nature of psychedelic use by the general population. To this end, 1,486 eligible respondents ( = 29.58, 67.

View Article and Find Full Text PDF

Aim: To evaluate whether integrating Apolipoprotein B (ApoB) into the SCORE2 cardiovascular risk prediction framework improves its predictive accuracy and clinical applicability within the UK Biobank population.

Method: A 10-year prospective cohort study was conducted with 448,303 UK Biobank participants eligible for SCORE2 calculation. Three approaches were employed: (1) threshold analysis to determine the optimal ApoB cutoff for cardiovascular disease (CVD) risk prediction using Youden's Index, (2) assessment of the synergistic effect of SCORE2 and ApoB through concordant and discordant classifications, and (3) recalibration of the SCORE2 model by incorporating ApoB as an additional predictor.

View Article and Find Full Text PDF

Evaluation of the Effect of Virgin Rice Bran Oil (VRBO) on DoxorubicinInduced Cardiotoxicity in Wistar Rats.

Curr Cardiol Rev

January 2025

Department of Nutrition, Société Francophone de Nutrithérapie et de Nutrigénétique Appliquée, Villeurbanne, France.

Objective: The usage of doxorubicin (DOX), an antineoplastic drug that is frequently used for the cure of cancer, is restricted to maximal doses due to its cardiac toxicity. Reactive oxygen species produced by DOX result in lipid peroxidation and organ failure, ultimately resulting in cardiomyopathy. Due to its high polyphenol content, virgin rice bran oil (VRBO) is a diet nutritional supplement with a strong antioxidant.

View Article and Find Full Text PDF

Measuring the heart rate of sea turtles is important for understanding their physiological adaptations to the environment. Non-invasive methods to measure the electrocardiogram (ECG) of sea turtles have been developed by attaching electrodes to their carapace. However, this method has only been applicable to sea turtles with sparse keratin on their shell surfaces, such as loggerhead turtles, and it is difficult to detect heartbeats in sea turtles with dense keratinous scutes, including green sea turtles.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!