[Sequential pattern of the propagation of excitation in the heart of the sheep Ovis brachyurae].

With the aid of intramural multipolar technique, the earliest focus of the depolarization is revealed in the myocard thickness of the cranioventral region of the right atrium of the sheep. From there the depolarization wave with a saw-edged front is spread along the thickness of the atria. The chronotopography of the intramural activation wave front shows a more complicated picture of the atrial excitation than a smiply radial one. Apparently it is connected with the presence of the atrial conduction system. The main mass of myocardium of free ventricle walls and the lower two thirds of the septum are activated by means of multifocal depolarization. The base third of the septum is the last to be activated. These features of excitation of the ovine ventricle myocardium can be explained by special character of distribution of the Purkinje fibers in myocardium ventricles.