Left Ventricular Assist Device Complications

• These patients MAY NOT HAVE A PULSE
  • May need an ABG since pulse oximetry may be inaccurate without a pulse
• Contact your hospital’s or network’s LVAD Coordinator immediately to help with management and troubleshooting.
• Patients are usually on diuretics, and may be intravascularly depleted or have electrolyte abnormalities

LVAD Patient in Extremis: Step-Wise Diagnostic Approach

Step 1

• Address airway, breathing, circulation
• Obtain IV, O2, monitor
• Measure blood pressure: May need manual cuff with Doppler to obtain mean arterial pressure (MAP), or use arterial line (MAP goal 70-80 mmHg)
• Assign someone to call LVAD Coordinator

Step 2

• A uscultate precordium. Is there a hum?
  • Yes - LVAD is working.
  • No - LVAD is not working.
• B attery: Make sure it is plugged in.
• C ontroller: Check for alarms.
• D riveline: Check device type and evidence of infection or damage
• E chocardiogram

Step 3

• Obtain VAD variables: Flow, Power, Speed, Pulsatility Index

Step 4

• Obtain ECG
• Obtain labs:
  • CBC
  • Electrolytes
  • Coagulation studies
  • LDH
  • Type and screen given GI bleed risk
  • ± Blood cultures if infection concern
  • ± ABG

Echocardiogram Findings - Causes & Management

Big right ventricle, big left ventricle

Potential Causes

• Pump failure
• Pump thrombosis
• Valve disorders

Management

• Heparin
• Antiplatelet agents
• Thrombolytics

Big right ventricle, small left ventricle

Potential Causes

• Right heart failure
• ST-elevation MI
• Pulmonary hypertension
• Note: If LV to outflow cannula size ratio is 1:1, then high risk for suction event

Management

• IV fluids
• ECG
• Consider inotropes

Small right ventricle, small left ventricle

Potential Causes

• Hypovolemia
• Sepsis
• GI bleed

Management

• IV fluids
• Consider blood transfusion
• Antibiotics

LVAD Complications

Arrhythmia

• Up to 50% experience sustained VT/VF in first 4 weeks after LVAD placement
• Difficult to determine primary vs. secondary cause:
  • Primary: Compromised myocardium + scar tissue
  • Secondary: Electrolyte abnormalities, hypotension, suction events
• Management depending on the cause:
  • IV fluid challenge is reasonable
  • Reduce pump speed
  • Correct electrolytes
  • Electrical or pharmacologic: amiodarone, cardioversion

Infection

• Up to 42% experience sepsis within 1 year (REMATCH Study). Most infections are in first 3 months, and 9% are fungal.
• Treat with broad spectrum antibiotics + antifungal

Thrombus (pump thrombus, PE, stroke/TIA)

• High risk despite anticoagulation.
• Pump thrombus suggested by warm device and increased power output.
• Lab finding: Elevated LDH
• Treat with Heparin, thrombolytics, antiplatelet agents

Bleeding

• Patients may have an acquired Von Willebrand Disease coagulopathy.
• If life-threatening, reverse anticoagulation and transfuse as needed.

Suction Event

• An underfilled LV causing suction of myocardium into LVAD
• Can be caused by right heart failure, hypovolemia, sepsis, restrictive cardiomyopathy, arrhythmias
• Treat with IV fluids to increase LV filling.

RV Failure

• Due to acute myocardial infarction (AMI) or previous RV failure
• Treat with IV fluids and consider inotropes.
• Start aspirin and heparin, if AMI.

Cannula Malposition

• Consider in setting of new VT, suction event, chest compressions, or trauma
• Requires surgical exploration

Device Malfunction, Pump Failure

• Suggested if no hum and mean arterial pressure (MAP) <40 mmHg.
• Treat cardiogenic shock: IV fluids, vasopressors, ACLS protocols, consider heparin for thrombosis

Cardiac Arrest

• Multiple potential causes including all those listed above.
• Follow ACLS algorithms EXCEPT:
  • Chest compressions are controversial as they could dislodge the device.
  • Do NOT place defibrillation pads directly over device.
  • Assign one person to assess device placement during and after code.

Altered LVAD Patient

References

• Partyka C, Taylor B. Review article: ventricular assist devices in the emergency department. Emerg Med Australas. 2014;26(2):104-112. [PubMed]
• Andersen M, Videbaek R, Boesgaard S, Sander K, Hansen P, Gustafsson F. Incidence of ventricular arrhythmias in patients on long-term support with a continuous-flow assist device (HeartMate II). J Heart Lung Transplant. 2009;28(7):733-735. [PubMed]
• Greenwood J, Herr D. Mechanical circulatory support. Emerg Med Clin North Am. 2014;32(4):851-869. [PubMed]