We examined the hemodynamic effects of a new, implantable, direct cardiac assist device in an ovine heart failure model.
Description
The device, which encompasses both left and right ventricles, is inserted through the pericardial apex and self-expands to encompass the heart without suturing. The intact pericardium anchors the device in place. The device has 2 concentric chamber layers: an internal chamber layer filled with fluid to conform to the heart and an external chamber layer filled with air that provides external compression and negative pressure to aid relaxation.
Evaluation
The device was implanted in 7 sheep with heart failure induced by microsphere embolization. Cardiac performance was assessed for 6 to 8 hours. The cardiac assist device provided cardiac systolic and diastolic assistance, as shown by pressure tracings of the left ventricle and aorta, pulmonary artery flow, and +dP/dt. Central venous pressure decreased during cardiac assistance. No anatomic damage was noted postmortem.
Conclusions
Systolic and diastolic cardiac assistance can be achieved with this device that compresses and relaxes in synchrony with the native cardiac cycle.
