gms | German Medical Science

Earlier we have shown that in animals with different types of ventricular excitation the cardioelectric field with similar location of the areas of positive and negative potential is formed on the body surface at period of repolarization of ventricles, and recovery sequences of the epicardium are not the same as the sequences of its depolarization. The sequence of depolarization and recovery properties in intramural layers of sheep heart ventricles under sino-atrial rhythm and under artificial ectopic ventricular foci of different localization was studied. Under sino-atrial rhythm the multiple zones of early and late depolarization, located on the whole myocardial wall (from endocardium to epicardium) are formed in sheep heart ventricles. The initial zones of repolarization were found in the left ventricular free wall, the zones of latest recovery were found in the basal regions, most frequently on the right ventricular epicardium. At ventricular stimulation in animals with “flash” myocardial activation patterns the paced ventricle should be depolarized by a complex way myogenically as well as with the aid of Purkinje fibers. The contralateral ventricle should be excited predominantly by a conduction system. Under artificial stimulation of heart ventricles the non-homogenous change of local repolarization durations in ventricular walls is observed. The work is supported by the grant of RFBR 05 -04-08086