RESUMO
We describe a technique for mechanical cardiac assistance in an acute model of severe cardiac failure. Cardiac dysfunction was induced by a high dose of halothane in 13 dogs. Seven served as controls. Following median sternotomy, a pneumatically driven device was implanted in the other six dogs in a para-aortic position, using a simple surgical technique without cardiopulmonary bypass. The aorta was cross-clamped during cardiac assistance. During hemodynamic studies, the seven control animals with induced cardiac failure showed high end-diastolic left ventricular and right atrial pressures with low cardiac index and systolic left ventricular and aortic pressures. All dogs in this group died within 30 minutes. Use of a monovalvular cardiac assist device in the experimental group of six dogs to pump blood from the aortic root to the descending aorta in a counterpulsation manner, confirmed good preservation of systemic hemodynamic parameters after induction of heart failure. All animals in this treated group survived more than 45 minutes. Hemodynamically, the device acts as a new ventricle and the impaired left ventricle functionally becomes a left atrium. This condition is clinically appropriate for recovery of left ventricular function in severe acute myocardial failure.
Assuntos
Contrapulsação/instrumentação , Insuficiência Cardíaca/terapia , Coração Auxiliar , Hemodinâmica/fisiologia , Animais , Cães , Desenho de Equipamento , Halotano , Insuficiência Cardíaca/induzido quimicamenteRESUMO
The results with the use of this device in patients who develop Low Cardiac Output Syndrome after cardiac surgery with extracorporeal circulation are analyzed. Special emphasis is given to the development of the opportune indication of this procedure, on the basis of a comparison of the results of the first few years to the most recent ones. Finally, the advantages of the prophylactic use of the Intraaortic Balloon Pump are commented.