Changes in ventricular refractoriness and conduction velocity induced by local hypothermia and hyperthermia

Author

Tormos, A. ; Millet, J. ; Chorro, F.J. ; Such, L. ; Canoves, J. ; Mainar, L. ; Blasco, E. ; Trapero, I.

Author_Institution

Grupo BET, Univ. Politecnica de Valencia

fYear

2005

fDate

25-28 Sept. 2005

Firstpage

531

Lastpage

534

Abstract

VF pattern is related to the electrophysiological parameters of the myocardium. Although the influence of global temperature on these parameters is known, the effects of its regional variations have not been sufficiently studied. We examined the effects of local hypothermia and hyperthermia on refractoriness and conduction velocity (VC), during constant pacing at cycle lengths of 250 ms. In an experimental model (rabbit isolated heart) we used a new method to perform epicardial cooling and heating on the registered surface. The results show that local variations of temperature generate heterogeneity in the electrophysiological properties of the heart. Hypothermia prolongs refractoriness and decreases VC, in a reversible manner. Hyperthermia (42degC) has the opposite effects. The wavelength of the cardiac impulse is not altered because of the opposite and proportional actions on functional refractory period and VC

Keywords

bioelectric phenomena; biomedical electrodes; cardiology; hyperthermia; muscle; 250 ms; 42 C; cardiac impulse; conduction velocity; electrophysiological parameter; epicardial cooling; functional refractory period; hyperthermia; hypothermia; myocardium; pacing; regional variation; stimulation electrode; ventricular refractoriness; Cardiology; Cooling; Electrodes; Heart; Hyperthermia; Myocardium; Rabbits; Silver; Temperature; Virtual colonoscopy;

fLanguage

English

Publisher

ieee

Conference_Titel

Computers in Cardiology, 2005

Conference_Location

Lyon

Print_ISBN

0-7803-9337-6

Type

conf

DOI

10.1109/CIC.2005.1588155

Filename

1588155