The aim of this study was to evaluate the functional state of latissimus dorsi muscle (LDM) during electrical stimulation following cardiomyoplasty. Both single pulses and bursts of impulses were used for electrical stimulation. In 15 dogs, studies were carried out for 2 months, while in 19 patients, the follow-up period after cardiomyoplasty was 10 +/- 3.1 months. The LDM was punctured by needle electrodes at various intervals following cardiomyoplasty, and the changes of the rheomyosignal (RMS) curve were registered on the "Reostim-06." During the follow-up study, it was found that: (1) signal amplitude decreased 30%; (2) the contraction duration of LDM increased 38%; (3) the contraction velocity decreased 43%; and (4) relaxation velocity decreased 61%. There is a correlation between LDM mechanical contractile force and RMS indices (r = 0.8). The RMS index was a function of the electrical burst duration and the number of impulses in the bursts. Thus, RMS parameters can characterize the functional state of LDM, and they may be used in designing a new generation of electromyostimulators for optimal LDM stimulation at different periods after cardiomyoplasty.