of the ventricle the refractory period of the ventricle in this case refers to that portion of the ventricle to which is delivered the electrostimulatory pulse being refractory it has been found that such stimulation causes an increase in myocardial contractility presumably by increasing intracellular calcium concentration the increase in contractility increases stroke volume so that more blood is pumped in a subsequent systolic contraction the increased stroke volume counteracts the bradycardia and thereby stabilizes cardiac output to either prevent or shorten the duration of a syncopal episode the invention may be a dedicated implantable device or incorporated into an implantable cardiac rhythm management device such as a pacemaker implantable cardioverter defibrillator or combination device sensing of cardiac activity and delivery of ccm stimulatory pulses may be accomplished using sensing pacing channels otherwise used for pacing the ventricles with a bradycardia pacing mode or using channels dedicated for the purpose of delivering ccm pulses in the device shown in fig1 for example any of the ventricular sensing pacing channels may be used for delivering ccm stimulation pulses fig2 illustrates a basic control scheme for carrying out the method as would be implemented by programming the microprocessor 10 in the illustrated.