Ventricular Assist Device (VAD): Rehab Approach, Opportunities and Challenges Chris Wells, PT, PhD, CCS, ATC
Assistant Professor, University of Maryland--Baltimore School of Medicine

There have been substantial improvements to Ventricular Assist Devices (VAD) since there original introduction as bulky external devices that required a suitcase-sized support device to be moved with the patient. VADs were originally thought of almost exclusively as a bridge to cardiac transplantation. Chris Wells shared that they may now be a bridge to recovery or even destination therapy, that is a long-term management strategy.

Most are left ventricular assist devices (LVAD), although right ventricular units also exist.  All are independent of the cardiac rhythm evident on the EKG. Consequently, one can do therapy when the patient appears by EKG to be in ventricular tachycardia, ventricular fibrillation, or asystole. VADs require a variable range of anticoagulation. All are susceptible to infection, bleeding, thrombosis/stroke and mechanical failure.

The first generation devices were pulsatile units and generated measurable pulses and blood pressures.  More recent versions are non-pulsatile and have no cardiac cycle: no palpable pulse or standard external blood pressure reading can be made. Instead, one usually targets a mean arterial pressure of 70-90 mm Hg.

With VADs, one must avoid suckdown with collapse of the ventricle during too rapid speed of device; treatment is reduction in speed of the device. They may also cause hemolysis, with hemoglobinuria; treat this with speed reduction also. Thrombus occurrence is also a concern and prevented with anticoagulation or anti platelet treatment. A good neurological assessment at baseline is helpful in detecting small changes that may indicate thromboembolic complications.

Examples of non-pulsatile units are the: Jarvik 2000, HeartMate II, Heart Ware and generate flow up to 10L/min.  The internal flow in the devices can be centrifugal or axial, but the clinical relevance of this difference is uncertain.

The six minute walk test or 10 meter walk test, measuring normal and fast pace, are helpful assessments of functional capacity.  Wells says  you should not emphasize energy conservation but push training more aggressively to achieve highest functional status.

Over the last few years, competency in pump management has shifted from company engineers to patient care team.  Wells adds, uperusers, clinicians highly skilled through extensive training, can be very helpful in the support of local clinical personnel, which makes the device an option in a variety of health care situations.

-Contributions from Paul McKinney, MD

Ventricular Assist Device (VAD): Rehab Approach, Opportunities and Challenges