such features are the treppe phenomenon and captured beats in escape rhythm , fixed coupling intervals in extrasystoles , partial or complete atrioventricular block in very premature atrial extrasystoles , prolongation of the period following an atrial extrasystole , interpolated premature beats , complete compensatory pause and the rule of bigeminy in ventricular extrasystoles , slight instability of the parasystolic period , multiple length parasystolic periods slightly different from the exact multiples of the parasystolic idioperiod , preference of the parasystoles for certain phase in the sinus cycle , synchronization at a phase difference and fluctuation repeatedly and without interruption from a parasystolic to an extrasystolic rhythm and synchronization in escape rhythm with isorrhythmic dissociation .
C0033036
atrial extrasystole
C0340464
premature beats