A new method of double cardiomyoplasty: “contractile muscular sling”

Background. In several experimental studies, double cardiomyoplasty using both latissimus dorsi muscles did not provide sufficient assist to the failing heart and did not clearly show improvement compared with single cardiomyoplasty. This study demonstrated the superior efficacy of our method of double cardiomyoplasty compared with single cardiomyoplasty. Methods. In 16 dogs, the two latissimus dorsi muscles were crossed in front of the heart and directly sutured to each other behind the heart. Control hemodynamic measurements were obtained, and acute heart failure was induced by intravenous administration of propranolol. After the hemodynamic changes with bilateral latissimus dorsi muscle assistance were measured, single cardiomyoplasty was done in the same dog, and the hemodynamic variables were measured. Results. With our double cardiomyoplasty, aortic systolic pressure increased by 25% (p< 0.001); pulmonary artery systolic pressure, by 40% (p< 0.001); end-systolic elastance, by 155% (p< 0.001); and cardiac output, by 55% (p< 0.001). There were significant increases in aortic pressure, pulmonary artery pressure, end-systolic elastance, stroke volume, and cardiac output with our double cardiomyoplasty compared with single cardiomyoplasty. Conclusions. In this study, our double cardiomyoplasty provided significant hemodynamic improvement compared with single cardiomyoplasty.