The sequence of activation of ventricular myocardium in Atlantic cod (Gadus morhua marisalbi)

Electrophysiological studies were carried out to establish the sequence of depolari- zation of intramural layers of ventricular myocardium of the Atlantic cod ( Gadus morhua marisalbi, n = 5) at 12°C. The heart rate of cod is 34 ± 5 bpm. The first foci of myocardial activation appear in the subendocardial layers near the atrioven- tricular orifice, and the later - in the subepicardial layers of the apex. The excita- tion wave in the myocardium of cod ventricle moves from the zone of atrioventricu- lar orifice to the region of the apex (p