Abstract
The present study investigated the mechanism of diving bradycardia. A group of 14 healthy untrained male subjects were examined during breath-holding either out of the water (30-33 degrees C), in heat-out immersion, or in whole-body submersion (27-29 degrees C) in a diving pool. Blood velocity, blood volume flow in the carotid artery, diastolic blood pressure and electrocardiogram were measured and recorded during the experiments. The peak blood velocity increased by 13.6% (P < 0.01) and R-wave amplitude increased by 57.1% (P < 0.005) when the subjects entered water from air. End-diastolic blood velocity (Ved) in the carotid artery increased significantly during breath-holding, e.g. Ved increased from 0.20 (SD 0.02) m.s-1 at rest to 0.33 (SD 0.04) m.s-1 (P < 0.001) at 50.0 s in breath-hold submersion to a 2.0-m depth. Blood volume flow in the carotid artery increased by 26.6% (P < 0.05) at 30 s and 36.6% (P < 0.001) at 40 s in breath-hold submersion to a 2.0-m depth. Diastolic blood pressure increased by 15.4% (P < 0.01) at 60 s during breath-holding in head-out immersion. Blood volume flow, Ved and diastolic blood pressure increased significantly more and faster during breath-holding in submersion than out of the water. There ...Continue Reading
Citations
Feb 27, 2003·Archives of Medical Research·Nadan M Petri, Dejan Andrić
Oct 7, 2003·Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology·Guido Ferretti, Mario Costa
Mar 4, 2009·Acta Physiologica·Fabrice JouliaP Barthelemy
Jul 11, 2013·PloS One·Troy J CrossZeljko Dujic
Dec 20, 2007·Respiratory Physiology & Neurobiology·Johan P A AnderssonErika K A Schagatay
Mar 17, 2007·Respiratory Physiology & Neurobiology·Ivan PaladaZeljko Dujic
Feb 1, 2005·Scandinavian Journal of Medicine & Science in Sports·G E Foster, A W Sheel
Jun 1, 2017·Physiological Reports·Howard H CarterDaniel J Green
Apr 17, 2010·Research in Sports Medicine·Teresa C AlentejanoGordon J Bell
May 12, 2012·Sports Medicine·Zeljko Dujic, Toni Breskovic
Oct 10, 2013·Journal of Strength and Conditioning Research·Alexandre GuimardKatia Collomp
Oct 28, 2003·Journal of Applied Physiology·Johan P A AnderssonErika K A Schagatay
Feb 19, 2011·Journal of Cardiovascular Medicine·Paolo AlboniLorella Gianfranchi
Mar 13, 2020·Experimental Physiology·Sultan E AlSalahiJames P Fisher
Dec 11, 2013·American Journal of Physiology. Heart and Circulatory Physiology·Hardikkumar M PatelMatthew D Muller
Jan 24, 2015·Journal of Applied Physiology·Teelkien R van VeenMichael A Belfort
Aug 13, 2003·Renal Failure·Igor RoudenkoKonstantinos Mavromatidis