Growth Potential and Left Ventricular Diastolic Function in Cardiomyoplasty

Background. Dynamic cardiomyoplasty is an experimental operation for advanced heart failure. Current clinical results bring the possibility of its application to children. This study was designed to obtain information about the relationship between cardiomyoplasty and growth of the heart. Methods. Six beagles, 9 to 10 weeks old, underwent cardiomyoplasty without electric stimulation (cardiomyoplasty group), and another 5 beagles underwent median sternotomy and pericardiotomy (control group). Six months later, weights of hearts, wrapped latissimus dorsi muscles, and unwrapped right latissimus dorsi muscles and pressure–volume relationships were obtained. Results. Wrapped latissimus dorsi muscles weighed 33 ± 3 g (mean ± standard deviation), and unwrapped muscles weighed 68 ± 5 g. The heart weight was 82 ± 3 g in the cardiomyoplasty group and 89 ± 7 g in the control group. Left ventricular maximum elastance was 3.8 ± 0.8 mm Hg/mL in the cardiomyoplasty group and 3.9 ± 0.9 mm Hg/mL in the control group. End-diastolic pressure versus end-diastolic volume ratios were 0.52 ± 0.03 and 0.54 ± 0.05, respectively. Pathologic examination showed fat infiltration and muscle fiber atrophy in the cardiomyoplasty group. Conclusions. The wrapped latissimus dorsi muscle flaps were growing and the diastolic function was not impaired. This indicates a potentially safe clinical application of dynamic cardiomyoplasty for children.