1. The Crashing LVAD Chanel Fischetti, MD
Clinical Instructor and Ultrasound Fellow
Department of Emergency Medicine
UC Irvine Health Center

2. Left-sided heart failure
Introduction: The Why?
Left-sided heart failure
So how many of you have seen or worked with LVADs?
In 2018 American Heart Association reported the prevalence of HF to be 5.1 million 
IN 2013, there were an estimated 9000 patients with LVADs
The LVAD basically has become a functional way to be more aggressive in L sided heart failure
forward flowing pump that is indicated when there’s significant heart failure unable to remedied by medications and for people who are waiting for the transplant list or for those just wishing to extend life.
What is the  one year survival rate with LVADs?
In 2001 LVAD = 52% vs Medical Therapy = 25% (Rose et al. 1999)*
In 2013 LVAD = > 90% (Wever-Pinzon et al. 2012)*
Transplant
Nowhere

3. What is an LVAD? Introduction: The What?
So to start, you have an LV with a forward flowing pump with an axial flow device that then goes into the outflow graft which pumps forward into the aorta.
Here you see the line drive, or the link between the battery pack and the flow device, this is what links the power to the LVAD device. The external battery pack is the battery that packs the devices.
batteries — patients carry at least 2 lithium batteries at all times; VAD can be recharged using standard power supply
stabilisation belt — supports and anchors the driveline at the exit site, reduces risk of infection, minimises tissue injury and promotes tissue growth
VADs are preload dependent and afterload sensitive
#goals: make it easily for the heart to “pump”

4. Introduction: The Device

5. HeartWare and HeartMate 3
Types of LVADs
HeartMate I/II
Pulsatile
Continuous
HeartWare and HeartMate 3
MOMENTUM III study: HeartMate 3 vs HeartMate II
HeartMate 1: rarely used anymore, it was a pulsatile flow, but the problem with them was that they often had clotting problems
HeartMate II
Flow type: axial and continuous flow
Backup Method: No external method
Pulse: No palpable pulse or BP. Dopplerable Only
Battery: 14V Li-Ion – 10 hrs
Defib/Cardioversion: No precautions necessary
Anticoagulation: Warfarin

6. HeartWare and HeartMate 3
Types of LVADs
HeartMate I/II
Pulsatile
Continuous
HeartWare and HeartMate 3
MOMENTUM III study: HeartMate 3 vs HeartMate II
HeartWare: Miniaturization of continuous-flow devices is propelled forward with the latest offering from Heartware Inc.
-lighter in weight and doesn’t have the non-wearables
HeartMate 3: centrifugal continuous-flow LVAD:
-goal: several studies have shown reducing adverse events, such as bleeding, stroke, and pump thrombosis.
-HM3 is smaller than HM2 The HM3 is significantly smaller than the HMII
-HM3 incorporates "artificial pulse" technology. Approximately every 2.0 seconds, the rotor speed will briefly drop below the set speed and then increase above the set speed, generating a “flow pulse”.
-this is important, because the largest problem with the HM1/2 is that their pulsatility allowed for more stasis and therefore more clotting risk
-thus this HM3 flow pulse helps reduce stasis within the rotor.
Other HM3 benefits:
-improved ease of surgical implantation
-a modular driveline that can be swapped out in the event of driveline malfunction without necessitating complete pump exchange.
HeartMate 3 is the first fully implantable heart pump that uses magnetic levitation technology and has wide blood-flow passages to reduce shear stress, is frictionless with no mechanical bearings and produces an intrinsic pulse to reduce stasis and avert thrombosis. 
MOMENTUM study: HeartMate 3 provides improvement in clinical outcomes 2/2 reduction in the rate of reoperation for pump malfunction and reduced strokes in patients with advanced heart failure at two years after implantation, according to results of the MOMENTUM 3 trial 
References: Pagani FD, Milano CA, Tatooles AJ, et al. HeartWare HVAD for the treatment of patients with advanced heart failure ineligible for cardiac transplantation: results of the ENDURANCE destination therapy trial. J Heart Lung Transplant 2015;34:S9.
U.S. National Institutes of Health. MOMENTUM 3 IDE Clinical Study Protocol (HM3(TM)) (ClinicalTrials.gov website) Available at:

7. flow/time waveformpulsatility of 2-4 L/min from peak to trough
General LVAD Parameters
Device
Flow Estimate   (L/min)
Speed (RPM)
Power (W)
Pulsatility
HeartWare
4 – 7
2500 – 2900
3 – 7
flow/time waveformpulsatility of 2-4 L/min from peak to trough
HeartMate II
4 – 8
8600 – 9800
6 – 7
4 – 6
HeartMate III
3 – 6
5000 – 6000
1 – 4

8. So how do you measure her vitals?
A 54-year old female, Donna, presents to your E.R. with a complaint of weakness.
So how do you measure her vitals?

9. Vitals HR? Blood Pressure?
You will not hear heart sounds, you will hear a machine like murmur
In terms of HR, you want to ask the patient what their normal baseline HR is as significant changes can occur- think of HR as related to pump flow, they do tend to correlate together.
Automated BP cuffs, rely on biphasic blood flow, can only detect a BP half of the time.
obtain a blood pressure:
-You will need to calculate their mean arterial pressure (MAP) by attaching a manual blood pressure cuff and inflating it to >120 mmHg.
-Then, slowly deflate the cuff while listening for a brachial pulse using a Doppler.2 
-The pressure reading at which arterial flow becomes audible is their MAP (normal: 60–90 mm Hg). 
If a non-pulsatile constant “swoosh” is heard, this number represents MAP and should be between mmHg.
Unstable patients need an arterial line, which will have to be placed using ultrasound guidance, as there will be no pulse to guide you. In the meantime, look for other perfusion indicators such as capillary refill, mottling, extremity temperature and mental status. Oxygen saturation probes similarly rely on pulsatile blood flow and may also be unreliable
assess blood pressure (typically aim for MAP mmHg)
may be difficult or impossible with standard non-invasive blood pressure measurement
intra-arterial line is ideal
can use brachial artery doppler to to detect loud contiuous noise during non-invasive blood pressure measure, this corresponds to the MAP

10. Vitals What do these numbers even mean?
rpm (pump speed — this is set according to ECHO results)
flow (this is calculated from power, rpm and hematocrit/ blood viscosity) — paradoxically increased flow reading can be caused by obstruction as also leads to increased power requirement
PI (pulsatility index — how much cardiac output is provided by the patient vs pump)
power (required by the VAD — averaged over cardiac cycle

11. Important questions to ask
Normal LVAD settings
Goal INR range
Blood loss?
Bowel movement changes?
Compliance with meds
Goal for the LVAD: transplant or bridge?
Normal MAPs
So now that we know how to take the initial LVAD vitals, what history are we looking for?
-Normal LVAD settings
-What's their goal INR range
-Any recent blood loss
-any recent BM changes
-compliance with meds
-goal for their LVAD
-normal MAPs

12. The Labwork INR Haptoglobin LDH CBC Iron studies ECG CXR
INR: you want to know whether or not you’re in the reference range or if your supra or sub-therapeutic
-that’s important because of the clotting risk factors
Haptoglobin: level of hemolysis- all LVADs will have some degree of hemolysis, but it just depends on the degree of hemolysis
LDH: another marker of hemolysis

13. BLEEDING CLOTTING INFECTION MECHANICAL Complications

14. Donna states that she has been feeling very weak and short of breath…
5.0
13,000
2.5
Pump flow is a little less forward flow, her speed is up and her PI is down, but the power is up- meaning that there is more power/energy needed to move flow forward
Think of PI inversely proportional to speed and we remember this because PI (pulsatility index — how much cardiac output is provided by the patient vs pump) 10

15. Clotting Risk of clot within the device and obstruction of flow
Consider changes in LVAD settings
Increase in Power, Decrease in Flow
Consider INR
Can be indicated with change in LVAD settings: increase in power, decrease in flow, increased speed
-could be 2/2 INR changes
-could be volume down and being dry
-Consider missed doses of medications

16. Donna states that she has been feeling very weak and short of breath and stools have been darker recently…
2.7
7,000
6.0
Her flow is down her speed is also down, but her PI is up. Her power is also down, meaning this LVAD is needing less power and speed to lead to equivalent forward flow
3.6

17. Bleeding Supra-therapeutic INR LVAD setting changes
Decreased flow, decreased power
Complications from bleeding
Heyde’s syndrome
So we may see bleeding with supratherapeutic INRs
-Heyde’s syndrome: gastrointestinal bleeding from angiodysplasia- thought to be 2/2 high flow and continuous flow; gastrointestinal angiodysplasia and AV malformations
-these patients can also get acquired von Willebrand factor deficiciency
Complications from bleeding: CVAs/strokes/falls

18. Infective endocarditis Bloodstream infections Mediastinitis
Drive line
Infective endocarditis
Bloodstream infections
Mediastinitis
Drive lines can get infections, fractures/breaks in the lines
-common pathogens
- S. aureus, coagulase negative staphylococci and Corynebacterium spp. However, P. aeruginosa
Targeted abx treament
-risk of development of biofilms
-usually appears as erythema, warmth and redness
No comprehensive guidelines for treatment of LVADIs exist to date, though general guidelines for treatment duration proposed by Nienaber et al. suggest 2-4 weeks of antimicrobial therapy with or without surgical debridement for DLI.
Typically, the driveline exit site is cleansed with an antiseptic agent such as chlorhexidine, hydrogen peroxide, or povidone-iodine and dressed in a sterile fashion either daily or weekly.

19. Drive line – is it intact? Battery LVAD
Mechanical
Drive line – is it intact?
Battery
LVAD
Drive lines can get fractures/breaks in the lines
-describe case from man who cut his own driveline
Battery: malfunction
LVAD: malfunction and flow problems

20. large RV and small LV suggests RV failure or pulmonary hypertension
Applications with Echo
Echocardiography findings
small RV suggests inadequate preload
small LV suggests suckdown
large RV and small LV suggests RV failure or pulmonary hypertension
large RV and large LV suggests pump thrombosis/ obstruction
small RV suggests inadequate preload: so less preload and this would mean give more blood or IVF
small LV suggests suckdown- meaning the pump is sucking too much and almost depleting the afterload and draining the LV- this would mean that maybe the LVAD settings need to be adjusted
large RV and small LV suggests RV failure or pulmonary hypertension
large RV and large LV suggests pump thrombosis/ obstruction

21. Donna comes in with cardiac arrest, what do you do first…
2.7
6.0
3.6

22. CPR To compress or not to compress? Chest compressions if in the field
Look, listen, feel
Chest compressions if in the field
Risks:
Dislodgement
Bleeding
In hospital: no compressions
*LVAD Coordinator?
ACLS with medical interventions
Correct underlying issue: bleeding vs clotting
Look, listen, feel: does it look like the LVAD is functioning? Humming, on?
If there is inadequate perfusion, unresponsiveness, or other altered mental state, the VAD should be assessed for function by looking and listening for alarms, listening for a VAD hum over the left chest and left upper abdominal quadrant, ensuring secure
Check the battery and drive line, do they appear connected or are there problems with the battery, is the drive line fractured or cut?
Consider a fluid bolus as LVADs love fluid and if there’s any reason to be volume down, whether that’s clot or bleeding, fluid will fix it.
Consider CT head

23. Questions?

24. References
Pagani FD, Milano CA, Tatooles AJ, et al. HeartWare HVAD for the treatment of patients with advanced heart failure ineligible for cardiac transplantation: results of the ENDURANCE destination therapy trial. J Heart Lung Transplant 2015;34:S9.
U.S. National Institutes of Health. MOMENTUM 3 IDE Clinical Study Protocol (HM3(TM)) (ClinicalTrials.gov website)
device_after-surgery.aspx
Leuck AM. Left ventricular assist device driveline infections: recent advances and future goals. J Thorac Dis. 2015;7(12):