1. Henry Ford Health System
HENRY FORD HOSPITAL Ventricular Assist Device Program: Emergency Department Education
Henry Ford Health System

2. Agenda Definition of a VAD Current LVADs
Basic LVAD function & Key differences
Stable VAD patient in ED
Unstable VAD patient in ED

3. WHAT IS A VAD?
A Ventricular Assist Device (VAD) is a mechanical circulatory support device used to treat heart failure patients. It helps a weakened heart pump blood throughout the body.
Although VADs can provide right, left, or biventricular support, the LVAD (left ventricular assist device) is the most common.
Patients are usually discharged home on these devices.

4. *
07/16/96
These pumps differ in technical design, but all are continuous-flow pumps and have the following analogous components:
an inflow cannula that is surgically implanted into the left ventricular (LV) apex, serving as a conduit for blood from the LV to the pump; 2) a pump enclosure which houses an impeller that circulates blood; 3) an outflow graft that carries blood from the pump to the systemic circulation; and 4) a surgically tunneled driveline that connects the pump to an external controller that operates and monitors the pump function. The external controller is connected by 2 power cables to a battery powered source or a power module connected to an AC source while batteries are charging. *

5. Basic LVAD function
LVADs move blood from the LV apex to systemic circulation in a continuous manner
Controller: Speed (RPM), Flow (L/min), Power (watts), PI (pulsatility index)
Pump speed is the fundamental parameter that the provider can alter
The system controller monitors power consumption and estimates cardiac output based on speed and power consumption
may not be accurate in the case of physiologic derangements (e.g., AI or LVAD dysfunction including pump thrombosis)
Additionally, the controller measures temporal power fluctuations to give an estimate of pulsatility through the pump, termed pulsatility index for HeartMate devices and represented graphically as the HVAD pump flow waveform for the HeartWare device
Contemporary pump design and operating software are unable to automatically modulate speed or cardiac output based on physiologic demand; therefore, they will operate at the speed the provider sets, consuming as much power as needed to maintain that speed.

6. *
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Key Differences
HVAD and HM 3 provide more accurate CO estimates compared to HM 2
HVAD and HM 3 have a larger change in flow for a given pressure gradient change across the pump than HM 2
centrifugal flow pumps are more sensitive to changes in preload and afterload, and controlling hypertension is a key element of normal centrifugal flow pump function
HVAD and HM 3 have automated speed modulation capabilities to enhance washing of the pump and allow possible intermittent ejection through the native aortic valve. These rapid speed modulations, termed “Artificial Pulse” for HM 3 and “Lavare Cycle” for HVAD may have benefits in preventing pump thrombosis, AV insufficiency and stroke.
-(centrifugal design, and by using the patient’s manually entered hematocrit to estimate the serum viscosity. *

7. HeartMate II Left Ventricular Assist System*
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HeartMate II Left Ventricular Assist System
Implantable
Pump
Batteries
The HeartMate II Left Ventricular Assist System consists of an implantable pump, percutaneous lead, microprocessor-based system controller, and portable power source.
Percutaneous
Lead
Controller *

8. HMII VAD FLOW
Press to see flow
VAD flow is visible on the power module (circled) and the controller.
Click square button on controller to see Liters per min
Flow is like cardiac output (3-6 ok)

9. HeartMate II VAD POWER SOURCES
VAD must be connected to AC power or batteries AT ALL TIMES!
Batteries last ~10-14 hours.
*If patient connected to AC (wall) power and power goes out, power module (PM) will provide only about 20 minutes backup power…switch patient from PM to batteries immediately!
HeartMate II drains both batteries simultaneously.

10. HVAD® System Configuration
Controller
Battery

11. HVAD® System Components
HVAD™ Controller
HVAD™ Pump
HVAD™ Monitor
HVAD™ Controller AC Adapter
HVAD™ Controller DC Adapter
HVAD™ Batteries & Battery Charger

12. HVAD™ Controller Flow and speed on controller screen!
Requires two power sources at all times:
2 batteries
1 battery & AC or DC Adapter
Batteries Hrs
Need Doppler to measure BP
Doppler opening sound approximates mean arterial pressure (70-90 mmHg goal) in most patients
speed
flow

13. HeartMate 3 LVAD
Has engineered pulsatility in pump to “mimic” a pulse.
May or may not get cuff BP:
Goal SBP <110 mmHg
Goal MAP mmHg
Doppler may approximate MAP (if not pulsatile) or SBP!
If Doppler mmHg probably ok.
Doppler here will approximate SBP not MAP because wide pulse pressure in patient

14. GUIDANCE FOR EMERGENCY MEDICAL SERVICES TEAMS
In the event of an emergency, all efforts should be made to direct patients with MCS to their respective MCS/left ventricular assist device (LVAD) centers.
It is crucial that emergency medical services personnel make every effort to bring the patient's peripheral equipment needed to maintain LVAD/TAH function (including the batteries, power base unit, and controllers), even if this entails a slight delay in transporting the patient. This equipment will be needed to support the patient until he or she can be transferred to his or her LVAD center.

15. Major Adverse Events

16. Stable VAD Patient in Emergency Room
Connect patient to power module (PM) to get VAD numbers and obtain basic vital signs.
Doppler BP
O2 saturation may be inaccurate on VAD
Keep patient caregiver with patient.
Follow VAD Emergency Department Algorithm.
Notify cardiology fellow and VAD (313)

17. Clinical Assessment of a Conscious LVAD patient*
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Clinical Assessment of a Conscious LVAD patient
History
Device parameters and alarms
Symptoms of infection; including driveline
Symptoms of HF
Signs of hemoglobinuria (dark urine)
Signs of bleeding
Physical exam:
Cardiac examination!
Measurement of BP
Assessment of perfusion by skin temperature and capillary refill since there is often no palpable pulse
Assessment of signs of right heart failure (JVD, hepatomegaly)
Driveline
Device connections
Document Flow, speed, power, pulsatility index, rate
-no pulse, minimal pulse pressure, and no discernable heart sounds, which makes cardiac assessment difficult *

18. Pulse Underlying LV contractility AV function LVAD pump speed*
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Pulse
Underlying LV contractility
AV function
LVAD pump speed
LVAD preload and afterload
Assessments of heart rate often require telemetry or electrocardiography instead of palpation of a pulse, which is often absent. *

19. *
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Blood Pressure
Propeller inside pump spins blood through providing CONTINUOUS FLOW.
Narrow pulse pressure: These patients may not have a radial pulse!
Carotid pulse is palpable
Due to continuous flow you will likely need a Doppler to get a blood pressure on this patient. The sound you hear when deflating the cuff will often be reflective of the mean arterial pressure (MAP), not systolic.
A “perfect MAP” is mmHg
A dangerously low MAP is ≤50 mmHg
Noninvasive BP measurements are difficult in CF LVAD patients due to diminished pulse pressure, and automated BP monitors may fail to measure BP. Doppler ultrasound is recommended as the most reliable noninvasive method to assess BP in CF LVAD patients.
-The pressure at which the sound of blood flow returns to the brachial artery is recorded and best described as an opening or Doppler pressure, although in practice it is often called a mean arterial pressure (MAP). If a patient has significant pulsatility, then the opening pressure likely represents systolic BP. If there is low pulsatility, then the opening pressure gives a reasonable estimate of the MAP.
Narrow pulse pressure mean Doppler opening pressure is closest to MAP *

20. VAD Patient Transport
Take extra batteries and controller with patient (or just take PM cart with those items inside).
Allow caregiver to stay with patient if possible.
Patients only admitted to P5 or H5.

21. VAD Patient EMERGENCY in ER
VAD TEAM PAGER:
(313)
On call 24 hours, 365 days a year
If no response, keep paging and call attending CHF/Transplant MD on call.

22. VAD EMERGENCY PRECAUTIONS
Feel carotid pulse- radial pulse may not be present.
Be mindful of unique BP measurement needs in VAD patients and pulse ox inaccuracies!
70-90 mmHg perfect for mean arterial pressure
≤50 mmHg is emergent!
CHECK LVAD CONNECTIONS!
Flow of 3-5L usually perfect.
If flow is very low:
Bleeding?
Tamponade?
VAD failure or VAD obstruction?

23. Approach to the Unconscious LVAD patient*
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Approach to the Unconscious LVAD patient
If pulse present and Doppler BP > 50mHg:
Consider non-LVAD causes for unresponsiveness:
- Stroke
- Hypoglycemia
- Overdose
- Hypoxia *

24. Approach to Hypotension in a Conscious LVAD patient

25. ACLS Indications ACLS may be needed if
Not conscious
No carotid pulse
Mean arterial pressure ≤50 mmHg by Doppler
Oxygenation impairment or signs of malperfusion on exam (color, temperature, capillary refill)
Use AHA algorithm on CPR rate, depth, airway management

26. Adult CPR in LVAD patient
VF/VT?
Is there a carotid pulse present? Doppler preferred
Is patient conscious
Check BP: Doppler needed! No No
Yes
VT/VF resolved but unconscious
Yes
NO or Yes: While waiting for Coordinator, begin secondary
assessment
Yes No
Are LVAD controller and Batteries Hooked up?
Doppler or MAP <50
Doppler or MAP ≥50
Shock per ACLS guidelines
No Doppler BP available, Signs of malperfusion or instability No
Begin VAD Arrest:
Standard ACLS
Epi
Chest Compressions
Shock when indicated
Ongoing VT/VF
Call Coordinator and on-call Fellow
Assess BP and VAD flows every 2 min
Call Coordinator
VAD Coordinator: (313)

27. VAD Emergencies
VT/VF: Patient may or may not be stable on LVAD support
Unstable patient: defibrillation ok up to 200 J. Do not disconnect VAD. Don’t stress over pad placement
Stable patient: call cardiology fellow
Can try amio bolus mg.
Risks of persistent VT/VF are device clot, RV failure and cardiogenic shock (RV is impacted by VT/VF and LVAD won’t fill). Would not leave in VT/VF for >30 min, even if stable
OK to sedate and shock if needed.

28. Key Facts on VADs Do not get any part of any VAD wet.
A carotid pulse is palpable. Radial and femoral pulses are often not palpable.
Pulse Ox values are often inaccurate!
Usually need a Doppler to measure blood pressure.
Good number is an opening pressure of
Pump flow is what is supplementing cardiac output.
Good flow is 3-6 L
Defibrillation for VT/VF and CPR is safe. Do NOT disconnect LVAD
CPR is provided according to algorithm.

29. On call 24 hours, 365 days a year
TAKE HOME MESSAGE
VAD TEAM PAGER:
(313)
On call 24 hours, 365 days a year
If no response, keep paging and call attending CHF/Transplant Cardiology on call.
Dr. Cowger is Medical Director of program for any concerns: (cell)

30. References
1. American Heart Association, May Cardiopulmonary Resuscitation in Adults and Children with mechanical Circulatory Support. A Scientific Statement From the American Heart Association. Peberty, M., Gluck, J. et al. Dallas Texas. AMHA. 2. 3. 4.
5. The 2013 International Society for Heart and Lung Transplantation Guidelines for Mechanical Circulatory Support: Executive Summary. The Journal of Heart and Lung Transplantation, Vol 32, No 2, February
6. Waqas M and Cowger JA. Role of Mechanical Circulatory Support. Heart Failure Clinics 2016;12: PMID:
7. Trauma Resuscitation in a Left Ventricular Assist Device Patient: An Emergency Medicine Simulation Scenario. Cureus Oct; 9(10): e doi: /cureus.1773
8. Algorithms to guide ambulance clinicians in the management of emergencies in patients with implanted rotary left ventricular assist devices. Emerg Med J Dec; 34(12): 842–850. doi: /emermed
9. Two-Year Outcomes with a Magnetically Levitated Cardiac Pump in Heart Failure. N Engl J Med 2018; 378: DOI: /NEJMoa
10. Intrapericardial Left Ventricular Assist Device for Advanced Heart Failure. N Engl J Med 2017; 376:
DOI: /NEJMoa