Dynamic cardiomyoplasty is based upon the use of electrostimulated Latissimus Dorsi muscle (LDM) to reinforce the ventricular wall of heart in patients with end-stage heart failure. In the present study we induced a preoperative reinforcement of LDM in 3 male patients selected for cardiomyoplasty, by means of a physiokinesiologic training. The application of morphometric techniques was useful to analyze the modifications in fibre type diameter and composition, in number and distribution of mitochondria and in number of capillaries in LDM needle biopsies performed before and after training. The preoperative muscle training induces trophic modifications in muscle fibres with increase in fibre diameter, in capillarity and in number and size of mitochondria. These parameters indicate that a preoperative training of LDM before cardiomyoplasty may be useful for muscle reinforcement and for preparation to the electrostimulation program in the postoperative cardiac assistance.