Hemodynamics and physical capacity in patients with left ventricular assist devices. An overview

摘要

In the course of time implantation of left ventricular assist devices (LVAD) has become an alternative to heart transplantation due to the enormous technical developments and miniaturization of these systems. Following implantation most patients show a significant improvement in their clinical condition and exercise capacity as measured by the New York Heart Association (NYHA) classification; nevertheless, exercise tolerance remains clearly limited even after LVAD implantation. The complex physiological and hemodynamic changes in LVAD patients both at rest and during exercise are ultimately not completely understood. The aim of this article is to describe the current state of scientific knowledge with respect to the physical capacity of patients with terminal heart failure after LVAD implantation at rest and during exercise. The influence of increasing the pump speed and continuous physical exercise training on the physical capacity in the long-term course is reviewed. The significance of new diagnostic tools, such as the non-invasive inert gas rebreathing method for measurement of cardiac output and arteriovenous oxygen difference (AVDO(2)) in assessment of the performance of LVAD patients is discussed.