Heart failure due to systolic dysfunction is characterized by high morbidity and mortality even with maximal medical therapy. Another approach to cardiac replacement is needed because cardiac transplantation remains available only to very select group of patients. Research on the development of mechanical cardiac support has been conducted for more than four decades and has led to development of three types of ventricular assist devices (VAD) which are now available for clinical use: namely, volume-displacement pumps, axial-flow pumps and centrifugal pumps. A competent native aortic valve is essential for the use of all left ventricular assist devices. The decision about the kind of device that will be the best for a given patient is dictated by clinical indicators such as the need for short vs. long term support, emergent vs. elective implantation, indication for left ventricular vs. biventricular support and patient’s body size. In general, patients can have three clinical indications for VAD implantation: namely, “bridge to recovery”, “bridge to transplant” and “destination therapy”.

“Bridge to recovery”

When the recovery of native heart function is anticipated, as it is for some patients with acute myocarditis or postcardiotomy cardiogenic shock,
a device is said to be used as a “bridge to recovery”. Ventricular assist devices have beneficial effects on myocardial function, which include reversal of the downregulation of beta receptors seen in heart failure and the restoration of the ability of the heart to respond to the inotropic effects of sympathetic stimulation [1]. They also improve geometry of the heart, permitting
a process of reverse ventricular remodeling. In patients who require only temporary cardiac support,
a percutaneous device or a paracorporeal device, which will not require an extensive explantation procedure, is most appropriate. Recovery of the heart may be monitored by echocardiography and hemodynamic measurements but the decision to explant ventricular assist device is usually quite challenging because there are no widely agreed criteria regarding explantation. There are conflicting data regarding the durability of recovery and the long term outcome of these patients.
Recent data suggest that recovery is also possible in patients with advanced chronic heart failure when medical therapy with intense...


Pełna treść artykułu...