Abstract

Function of skeletal muscle powered ventricle made from canine rectus abdominis muscle. We have been focused on the utilization of the rectus abdominis muscle (RAM) for a biomechanical substitute alternative to latissimus dorsi muscle. The primary problem in using RAM is the method of stimulation. Therefore differences between segmental nerve stimulation (SNS) and muscle stimulation (MS) of skeletal muscle powered ventricles (SMV) made from RAM were investigated. Unconditioned left RAMs of seven mongrel dogs (mean 13.2Kg) were used in this study. Pressure generating and pumping capabilities of SNS were superior to that of MS at low stimulating amplitude. The conditioning of RAM was also assessed in another three mongrel dogs (mean 13Kg). Histochemical examination by Myosin ATPase stain (pH4.3) after low frequency (2Hz) electrical preconditioning for eight weeks showed complete transformation to Type I fiber. Pressure generating capability of conditioned SMV decreased to 70% of unconditioned SMV.