RESUMO
No disponible
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Fístula Intestinal/etiologia , Fístula Cutânea/etiologia , Transplante de Coração/efeitos adversos , Coração Auxiliar/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Fibrinolíticos/administração & dosagem , Imunossupressores/administração & dosagem , Ascite/diagnóstico , Bacteriemia/diagnósticoRESUMO
BACKGROUND: Synchronization between the left ventricle and a left ventricular assist device (LVAD) may be important for ventricular unloading and coronary perfusion. We assessed the synchrony between cardiac and LVAD cycles by increasing delays in steps of 100 msec throughout the cycle, under conditions of total and partial left ventricular support. METHODS: We studied 7 healthy minipigs weighing 30-40 kg. A 60-cc Berlin Heart Excor LVAD was implanted and connected to a BCM 1200 console, making it possible to synchronize the LVAD systole and the EKG signal with a prefixed delay. We recorded hemodynamic parameters (including aortic, pulmonary, and left ventricular pressure) and LVAD flow for each delay. RESULTS: Intraventricular pressure during LVAD systole was minimized with delays of around 40-80% of one cycle. In addition, total flow was higher under these conditions. CONCLUSIONS: This study shows that the synchronous mode of LVAD operation is feasible. Moreover, a delay in device contraction until the second half of the cardiac cycle optimizes ventricular unloading and may eventually improve myocardial recovery.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Coração Auxiliar , Função Ventricular Esquerda/fisiologia , Animais , Pressão Arterial/fisiologia , Insuficiência Cardíaca/cirurgia , Hemodinâmica/fisiologia , SuínosRESUMO
We propose a new, low-cost pulsatile ventricular assist device (VAD) for short-term applications. The new device could prove very useful in emergency ventricular failure in which patient survival is not assured. In these cases, the device allows ventricular function to be maintained as the patient's situation is evaluated and a decision is made on whether to perform a heart transplant or to replace the device with a long-term VAD. The device has a pneumatic tubular blood chamber, clip valves over the cannulae, and a compliant input chamber that improves filling of the pump. Clip valves and all other functions of the device are controlled by means of a computerized console. The use of clip valves reduces the cost of the disposable part of the device.
