RESUMO
Based on a multichannel synchronous mapping of heart electric potentials, the sequence in time of the ventricle myocardium depolarization was compared with dynamics of distribution of cardioelectric potentials on the body surface in a dog. The cardioelectric field on the dog body surface at the period of the initial ventricular activity has been shown to be characterized by the presence of two inversions of the mutual disposition of areas of positive and negative potentials. Contribution to formation of distribution of the cardioelectric potentials on the body surface at each moment of the period of initial ventricular activity was made by all myocardial layers involved by excitation.
Assuntos
Sistema de Condução Cardíaco/fisiologia , Modelos Cardiovasculares , Animais , Mapeamento Potencial de Superfície Corporal , Cães , Técnicas Eletrofisiológicas Cardíacas , Feminino , Masculino , Função VentricularRESUMO
Experimental and theoretical methods were employed to study the effects of torso shape and heart orientation in the thoracic cavity on peculiarities of the formation cardiac electric field on the body surface in dogs. It was found that heart orientation to a greater extent than torso shape affected projections of cardiac electric potentials from the epicardium onto the body surface.
Assuntos
Miocárdio/metabolismo , Animais , Mapeamento Potencial de Superfície Corporal , Simulação por Computador , Cães , Eletrocardiografia , Campos Eletromagnéticos , Eletrofisiologia , Modelos TeóricosRESUMO
In anaesthetised rabbits at normal body temperature, the earliest ventricles' epicardial recovery occurs at the heart apex and adjacent left ventricle's surface whereas the latest one occurs at the epicardium of the right ventricle's base. A decrease in the mediastinum temperature to 32 degrees C reversed the recovery sequence. Following the cooling of the heart, the longest prolongation of the activation-recovery interval occurred at the heart apex area and the lowest one--at the right ventricle base.