Activity-rest stimulation of Latissimus Dorsi for Cardiomyoplasty: 1-year results in sheep

Ann Thorac Surg. 1998 Dec;66(6):1983-90. Activity-rest stimulation of latissimus dorsi for cardiomyoplasty: 1-year results in sheep. Arpesella G, Carraro U, Mikus PM, Dozza F, Lombardi P, Marinelli G, Zampieri S, El Messlemani AH, Rossini K, Pierangeli A. Source Cardiovascular Surgery, The S. Orsola Hospital, University of Bologna, Italy. Abstract BACKGROUND: In dynamic cardiomyoplasty electro-stimulation achieves full transformation of the latissimus dorsi (LD); therefore, its slowness limits the systolic support. Daily activity-rest could maintain partial transformation of the LD. METHODS: Sheep LD were burst-stimulated either 10 or 24 hours/day. Before and 2, 4, 6, and 12 months after stimulation, LD power output, fatigue resistance, and tetanic fusion frequency were assessed. Latissimus dorsi were biopsied at 6 months, and sheep sacrificed at 12 months. RESULTS: After 1 year of 10 hours/day stimulation LD was substantially conserved and contained large amounts of fast type myosin. From 2 months to 1 year of stimulation the power per muscle of the daily rested LD was greater than that of the left ventricle, being three to four times higher than in the 24-hour/day stimulation. CONCLUSIONS: If extended to humans, these results could be the rationale for the need of a cardiomyostimulator, whose discontinuous activity could offer to patients the long-standing advantage of a faster and powerful muscle contraction. PMID: 9930481 [PubMed - indexed for MEDLINE]