Cardiac assistance by atrial or ventricular cardiomyoplasty.

Abstract

Dynamic cardiomyoplasty was conceived to enhance cardiac performance by assisting myocardial contraction. Technically, this procedure consists of placing a pedicled latissimus dorsi muscle flap around the heart and subsequent muscle electrostimulation in synchrony with ventricular systole. Three types of dynamic cardiomyoplasty can be considered. (1) Atrial or ventricular reinforcement is accomplished by wrapping the latissimus dorsi muscle flap around the heart to support hypokinetic or akinetic areas secondary to congenital or acquired diseases. The atrial reinforcement may be performed to improve atrial output after Fontan-type procedures. (2) Ventricular substitution is performed to replace a portion of the ventricular wall. Autologous pericardium is used to create a neoendocardium and facilitate hemostatic closure of the ventricle. The pedicled latissimus dorsi is then secured to replace the resected myocardium. (3) The two previous techniques of ventricular substitution and reinforcement are combined. This reconstructive procedure, which normalizes the ventricular geometrical shape, is particularly useful after extended cardiac resections, such as is done in treatment of large ventricular aneurysms, cardiac tumors, or echinococcal cyst formations. At present, improvement in ventricular function has been obtained in 12 patients at our institution. Preoperative severe cardiac dysfunction was present in all of these patients (New York Heart Association functional class III or IV). Postoperative echocardiography, multigated acquisition scan, and hemodynamic studies demonstrate an improvement in ventricular function and no impairment of ventricular compliance by the muscle flap. After a mean follow-up period of 18 months, all patients are in functional class I or II. We believe that dynamic cardiomyoplasty prolongs and improves the quality of life of patients suffering from severe chronic and irreversible myocardial dysfunction by improving ventricular contraction and limiting cardiac dilatation.