Mechanism of atrioventricular conduction: study on an analogue.

A simple analogue of the heart, consisting of neon relaxation oscillators, is presented. The analogue may display several disturbances of the A-V conduction, like normal atrioventricular (A-V) conduction, first-degree heart block, Wenckebach periods, Mobitz II type block, supernormal conduction, complete A-V block, the phenomenon of accrochage in complete A-V block and the absolutely arrhythmic response of the ventricles to a very high atrial rate. The analogue was constructed in the simplest possible way, i.e., using the least possible number of variables. The striking similarities between the properties of relaxation oscillators and cardiac pacemakers on the one hand and between the behavior of the analogue and manifestations of the A-V conduction abnormalities on the other might possibly permit a hypothesis about the mechanism of A-V conduction abnormalities based on the analogue. This mechanism is discussed in detail.