A patient diagnosed with rheumatic myocarditis periodically experiences irregular pulse. The ECG reveals irregular occurrence of idioventricular extrasystoles. What mechanism pathogenetic causes compensatory pause in this case?

Answer options

1. Myocardial refractoriness before receiving the next impulse
2. Inhibition of sinus node functioning
3. Delay of excitation in the atrioventricular node
4. Disturbed myocardial contractility
5. Retrograde conduction of excitation to the atria