Cardiomyoplasty: latissimus dorsi muscle function with training

Cardiomyoplasty is a new surgical treatment for heart failure in which skeletal muscle assists the heart. However, for the first 2 weeks postoperatively, the latissimus dorsi muscle (LDM) remains unstimulated, and during the next 2 weeks, the LDM is stimulated with only one pulse every other heart beat. Thus, for the initial 4 postoperative weeks, minimal systolic assistance is provided. This study determined if the LDM is capable of providing early assistance after 4 weeks of training. Cardiomyoplasty surgery involves severing the perforating intercostal arteries to the LDM, detaching the LDM from its distal insertion, and wrapping it around the heart. At each of these steps, we measured LDM global shortening in 6 dogs with 4 weeks training of the LDM. By training the LDM a significant functional improvement was seen with a preserved capability to sustain contraction even after raising the muscle