Skip to Main Content

INTRODUCTION

Mechanical circulatory support devices include implanted devices that assist the left ventricle (LVAD), the right ventricle (RVAD), and both ventricles (BiVAD), as well as the total artificial heart (TAH). Most devices in current use are LVADs, and these are discussed in this chapter.

LVADs are used in the management of refractory heart failure with reduced ejection fraction (HFrEF) in children and adults, either as permanent (destination) therapy or as a bridge to heart transplant.1 In the United States, LVAD-related ED visits increased 16-fold between 2010 and 2017 due to rising use of LVADs and 2-year survival >70% in patients with newer-generation devices.2 Nearly half of patients with LVADs seek medical care at the ED within the first month following implantation and, on average, patients come to the ED seven times in the first year following LVAD placement.3,4 LVAD risks include mechanical complications, conditions exacerbated by long-term anticoagulation and arterial remodeling from continuous-flow devices, and infections.

Early-generation LVADs were pulsatile-flow LVADs that produced a peripheral pulse in the patient. Continuous-flow LVADs, which generally do not produce a pulse, are currently the most widely used. The Heartmate 3 (HM3) and HeartWare devices, both continuous-flow pumps, are most popular in the United States and are also used in the Asia-Pacific regions.5,6 The Medtronic HeartWare Ventricular Assist Device (HVAD) was discontinued in 2021 due to mechanical and medical issues, but some patients may still have these in place. The Berlin Heart is used for children as a bridge to transplant. LVAD use in Europe varies with country and funding.

DEVICE COMPONENTS

The HM3 will be used to illustrate the components of the LVAD device. The HM3 basic parts are the internal pump, controller, external power source, and percutaneous driveline (Figure 55A-1).7,8 The only moving part of the HM3 is the pump, which draws blood from the left ventricle and delivers up to 10 L/min to the ascending aorta. The LVAD power source is two or more rechargeable battery packs. The percutaneous driveline is tunneled through the anterior abdominal wall and provides a conduit for electrical wiring, connecting the external system controller to the internal pump.

Figure 55A-1.

LVAD components (HeartMate III). Specific components include the inflow cannula positioned at the left ventricular apex, pumping chamber, outflow cannula connected to the ascending aorta, percutaneous driveline, controller unit, and power source.

The LVAD controller regulates the LVAD function, including power source monitoring, system monitoring, data collection, and alarms.7 The controller has a display panel that provides important information about LVAD function (Figure 55A-2). The HM3 controller has three alarm icons: Low Battery Alarm, Device Malfunction Alarm, and Device Function Warning Alarm (Figure 55A-2). Audible and visual alarms can indicate ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.