Sequence of ventricular repolarization under body cooling in the frog

Lowering the temperature is known to prolong the repolarization of cardiomyocytes. However, whether the prolongation of action potentials is uniform throughout the myocardium, and whether this prolongation is obvious in ECG, remains unclear. Ventricular repolarization sequences and body surface pote...

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Bibliographic Details
Published inRossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova Vol. 93; no. 10; p. 1123
Main Authors Vaĭkshnoratĭe, M A, Belogolova, A S, Vitiazev, V A, Azarov, A E, Shmakov, D N
Format Journal Article
LanguageRussian
Published Russia (Federation) 01.10.2007
Subjects
Animals
Heart Conduction System - physiology
Hypothermia
Pericardium - physiology
Rana temporaria
Ventricular Function
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Summary:Lowering the temperature is known to prolong the repolarization of cardiomyocytes. However, whether the prolongation of action potentials is uniform throughout the myocardium, and whether this prolongation is obvious in ECG, remains unclear. Ventricular repolarization sequences and body surface potential distributions were studied in 20 frogs Rana temporaria using epicardial and body surface potential mapping. An apex-to-base ventricular repolarization sequence corresponded to the distribution of local repolarization durations was demonstrated at the temperature of 18 degrees C. The body surface potential distribution during the ST-T complex was characterized by the cranial negative and caudal positive potential areas. Under the body cooling to 10 degrees C, repolarization prolonged to a greater extent at the apex that resulted in the base-to-apex repolarization sequence, which, in turn, caused an inversion in the body surface potential distribution with cranial portion of the body being positive and caudal portion being negative.
ISSN:0869-8139