Objectives This study examined the effects of short-term delivery of cardiac contractility modulation (CCM) electric signals on LV function in rabbits with HF.
Methods In one study, rabbits with the transverse ascending aorta constriction-induced HF were randomised to 12 h of active CCM therapy group or to heart failure (HF) group or to a sham-operated control group. left ventricular myocardium RyR2, CX43 was measured by fluorescent quantitation polymerase chain reaction.
Results In CCM treated rabbits, LVEF increased (50±4% vs 36±3%, p<0.0001) compared with HF group and decreased (50±4% vs 67±5%, p<0.001) compared with sham-operated control animals. The increase in EF seen with CCM-treated rabbits was accompanied by reduced LV volumes, improved left ventricular systolic pressure (LVSP) and +LVdP/dtmax. In CCM treated rabbits, the amount of RyR2, CX43 were increased compared with HF group and decreased compared with sham-operated control animals.
Conclusions In rabbits with HF, short-term CCM therapy improves LV systolic function, which is ascribed to the concomitant benefits of CCM therapy on increasing the amount of RyR2, CX43 and improving ventricular excitation-contraction coupling.