Left Ventricular Device Emergencies

Basics

Description

Left Ventricular Assist Device (LVAD)
  • Portable mechanical pump support for the patient with heart failure (HF)
  • Components
    • Inflow cannula from the left ventricle
    • Outflow cannula to the aorta
    • Pump: Continuous flow
      • Axial or centrifugal
      • Patient has no palpable pulse due to LVAD continuous blood flow
    • Percutaneous driveline: Connects pump to system control
    • System controller:
      • Regulates motor power and speed
      • Performs diagnostic monitoring
      • Alarm display
      • Stores data for download
    • Batteries: Powers system control and pump
    • Power base unit: Charges batteries and powers control and pump
  • Goals of VAD therapy:
    • Bridge to transplantation (BTT): Support cardiac function prior to heart transplant
    • Destination therapy (DT): Support cardiac function for the rest of a patient's life
    • Bridge to recovery (BTR): Support cardiac function temporarily to give the heart recovery time

Epidemiology

  • 23 million patients with HF worldwide
  • 5.1 million patients with HF in the U.S.
  • Up to 150,000 patients classified with severe HF, with heart transplant being treatment of choice when medical management has failed
  • <3,000 heart transplants performed annually in the U.S.
  • Annual mortality rate for patient awaiting heart transplant has dropped continuously from 17% in 2001 due to LVAD as BTT

Etiology

Common LVAD-associated emergencies
  • Anemia (0.5–18% of patients)
    • Acquired von Willebrand disease type 2A due to shear stress on red blood cells
    • Anticoagulation
  • Bleeding
    • Intracranial hemorrhage (ICH) (11%)
    • Gastrointestinal (22–40%)
      • Arteriovenous malformations (AVMs)
      • Angiodysplasias
    • Hematuria
    • Epistaxis
  • Infection (30–50% of patients)
    • Driveline: Most common (17–30%)
    • Pump pocket (2–10%)
    • Cannula or device (0.6%)
    • Bloodstream (20–27%)
  • Thrombosis (35%)
    • Pump thrombosis can result in pump/device failure

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