Left ventricular function after plication of the left ventricular free wall in dogs*

Objective: We tested a new surgical technique, the plication of the left ventricular free wall, to reduce left ventricular area and volume and improve left ventricular systolic function, without using a cardiopulmonary bypass. Methods: Dilated cardiomyopathy was induced in eight dogs by the injection of doxorubicin. Plication of the left ventricular free wall was performed in four dogs with induced cardiomyopathy and in five control dogs. Two dogs were not submitted to surgery. The other two dogs died during the induction phase. Cardiac output, 2-dimensional and M-mode echocardiography, arterial blood pressure and electrocardiography were recorded over a 180-day period. Ambulatory electrocardiography of 24 hours was performed during the first postoperative day. Results: The cardiomyopathy-induced group had significant improvements in cardiac output, ejection fraction, shortening fraction and reductions in the left ventricular end-systolic, end-diastolic area and volume after the surgery. One dog died. Electrocardiography and Holter revealed premature ventricular complexes, which improved spontaneously at the first week. The cardiomyopathy-induced dogs that did not undergo surgery deteriorated and died at about 40 days after the induction of cardiomyopathy. Hemodynamic values did not change in the normal dogs submitted to surgery. Conclusion: The plication of the left ventricular free wall reduced the left ventricular area and volume and improved left ventricular systolic function in dogs with doxorubicininduced cardiomyopathy giving low morbidity and mortality. Descriptors: Myocardial diseases, surgery. Cardiomyopathy, congestive, surgery. Heart ventricles, surgery. Doxorubicin. Dogs. Estudo da função ventricular na técnica de plicatura da parede livre do ventrículo esquerdo em cães