Formation of Cardioelectric Field on the Body Surface at a Period of Activation of Ventricular Myocardium in the Chicken Gallus domesticus

Scaling of Ventricular Excitation of Birds

“…One might assume, therefore, that with matched scaling exponents, QRS in mammals is greater than in birds with similar M h . This is in agreement with the multifocal pattern of ventricular excitation in birds (Shmakov et al, 1979;Kharin et al, 2001Kharin et al, , 2006Roshchevsky and Shmakov, 2003). This pattern is particularly due to the spatial organization of the Purkinje system (Davies and Francis, 1946;Truex and Smythe, 1965;Shmakov et al, 1979) and results in a shorter ventricular excitation period in birds than in mammals with similar M b .…”

“…The main result of the study reported here is that the scaling of QRS in avian species encompassing a 1,000-fold M b range (from about 0.1 to approximately 100 kg), has an allometric exponent of 0.18. The scaling exponents for birds and mammals are very similar, although there are differences in cardiac electrophysiological characteristics, such as the ventricular excitation pattern (Shmakov et al, 1979;Kharin et al, 2001Kharin et al, , 2006Roshchevsky and Shmakov, 2003), polarity of the QRS complex, and cardiac morphological characteristics including those underlying ventricular excitation, e.g. expression patterns of gap junction proteins (Minkoff et al, 1993;Becker et al, 1998) and spatial organization of the Purkinje system (Davies and Francis, 1946;Truex and Smythe, 1965;Shmakov et al, 1979).…”

“…In avian hearts, Purkinje fibers penetrate the thickness of the ventricular walls and run close to the epicardium (Davies and Francis, 1946;Truex and Smythe, 1965;Shmakov et al, 1979). Avian hearts are characterized by the multifocal pattern of ventricular excitation (Shmakov et al, 1979;Kharin et al, 2001Kharin et al, , 2006Roshchevsky and Shmakov, 2003) that results in a shorter period of ventricular excitation in birds than in mammals with similar M b . Electrocardiograms of birds are characterized by the predominately negative QRS complex and the opposite directed T wave in the bipolar limb lead II and the lead along the longitudinal heart axis (Machida and Aohagi, 2001; see references in Table 1).…”