HeartMate II

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HeartMate II Left Ventricular Assist System
Clinical Operation and Patient Management
Doc
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Indication for Use

• Bridge to Transplant
• Non-reversible left heart failure
• Imminent risk of death
• Candidate for cardiac transplantation
• For in-patient and out-patient use
• May be transported via ground ambulance, fixed
  wing aircraft or helicopter

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Considerations

• Contraindication
• Inability to tolerate anticoagulation
• Other considerations
• No data on BSA lt 1.3 m², use medical judgment
• Limited data on pediatric patients (Age lt 21
  years)
• Social support
• Acceptance of blood products
• Pregnancy
• Nonreversible end organ failure

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HeartMate II Clinical Experience

• HM II implants
• Worldwide gt 1,300
• U.S. Pivotal Study and CAP
• Bridge to Transplant 456
• Destination Therapy 411
• Number of patients supported (pilot pivotal
  pts)
• 6 months 427
• 1 year 207
• 1.5 years 110
• 2 years 47
• 2.5 years 17
• 3 years 3
• 3.5 years 1

Data as of March 2008
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HeartMate II LVAS System Components

• HM II Components
• Implantable titanium blood pump
• System Controller
• Shared Components
• System Monitor
• Display Module
• Power Sources
• Power Base Unit
• Batteries Clips
• Emergency Power Pack
• Accessories

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HeartMate II LVASKey Design Features

• Relatively Simple Design
• Valveless
• Only one moving part, the rotor
• Blood immersed bearings designed for minimization
  of blood damage
• All motor drive and control electronics are
  outside of the implanted blood pump
• Speed range 6,000 to 15,000 rpm
• Flow range 3 10 L/min

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HeartMate II LVAS Pump

• Flexible inflow conduit
• Textured surfaces
• Inlet cannula, inflow and outflow elbows
• Thrombo-resistant
• Outflow graft with bend relief
• Anastomosed to LV apex and ascending aorta
• Pump output varies over cardiac cycle
• Follows native pulse
• Afterload sensitive

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HM II Pump External View
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Internal View
Rev. 12.0 (3/24/04)
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Volume Displacement vs. Axial Flow

• Volume displacement pumps
• Pulsed (physiologic) flow based on device
  function of positive displacement
• VAD flow beat rate x stroke volume
• Axial flow pumps
• Pump flow follows native cardiac pulse
• Flow increases decreases in response to LV
  pressure
• Sensitive to pressure differential across the
  pump (PAortic- PLV)
• More residual function bigger pulse
• Pump flow determined by pump speed power

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Flow Waveform Comparison Volume Displacement
Axial Flow Pumps
Flow Waveforms for Pulsatile and Axial Pumps
(Both have average flow between 4-5 L/min)
Thoratec IVAD
HeartMate II
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Pump Flow Principles

• Pump flow is a function of
• The speed of the rotor
• ?Speed ? ?Flow
• ?Speed ? ? Flow
• The difference in pressure across the pump
• ? Pressure gradient ? ? Flow
• ? Pressure gradient ? ? Flow

• At any given speed, increased B/P will decrease
  flow

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Flow Estimator Limitations

• A power increase not related to flow will produce
  an inaccurate reading
• Thrombus on rotor
• Flows below 3 L/min are inaccurate and may not be
  displayed

Rev. 12.0 (3/24/04)
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Pump Power

• Measured in watts
• Related to pump speed and flow
• Under normal patient conditions, power should
  remain within a certain range for a specified
  speed
• ? Speed ? ? Power
• Note baseline power for later diagnostic use

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Pulsatility Index

• The Pulsatility Index (PI) is a measurement of
  flow pulse through the pump
• It is determined by the degree of native LV
  contractility and pump speed
• Pump speed determines the amount of LV unloading
• As speed increases the PI goes down
• As speed decreases the PI goes up
• PI is a dimensionless value where
• PI (flow max flow min)/ flow average x10

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Pulsatility Index

• Size of flow pulse reflects degree of LV
  contractility
• When preload increases in the native LV, the
  Frank-Starling curve is impacted and the PI
  increases
• When preload decreases the pulsatility of the LV
  decreases and PI decreases
• Even a severely depressed heart will have some
  residual pulsatility
• Any contraction of the heart will generate a flow
  pulse

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Pulsatility Index

• PI relates to amount of unloading provided by the
  pump therefore the amount of native heart
  function
• The lower the PI? the greater the amount of
  support/unloading being provided by the pump
• The higher the PI? the less the amount of
  support/unloading being provided by the pump
  (more native heart function)
• PI will naturally vary by patient
• Note the baseline PI for later diagnostic use

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Typical Pump Parameters

• Patient parameter seen during trial
• Speed mean (range) 9,400 rpm (8,000 13,000)
• Flow mean (range) 5.5 lpm (3.3 7.8)

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Key Points

• Valveless pump - backward flow will occur if the
  pump stops
• Degree of retrograde flow is determined by
  pressure differential across the pump
• At low speeds, flow can be a combination of
  forward and backward flow
• An average flow does not mean that flow
  throughout the cardiac cycle is forward
• Retrograde flow can occur on a beat by beat basis
• Significant negative pressures can be produced
  when insufficient blood is provided to the pump
• Pump rotor can continue to spin while the inlet,
  outlet or both are obstructed
• If blood does not enter or exit the pump, the
  rotor can continue to operate in stagnate blood
  causing severe hemolysis to the trapped blood
  volume
• Displayed output is inaccurate

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Specific Patient Conditions/Events
Changes Seen Possible Causes to Evaluate
Inflow/outflow obstruction Thrombus/obstruction on inflow or outflow conduits Hypertension (flow will increase with an increased speed)
Return problem/issue with LV filling Evaluate right heart function Evaluate for pulmonary hypertension Patient dehydrated (especially if CVP lt 4) Evaluate for tamponade V Fib or A Fib
Power
Flow
PI
Aortic pulse pressure
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Specific Patient Conditions/Events
Changes Seen Possible Causes to Evaluate
Thrombus on stator or rotor
Evaluate for suction event Suction event will present as pump speed suddenly dropping to auto speed low limit from the higher, fixed speed.
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Specific Patient Conditions/Events
Changes Seen Possible Causes to Evaluate
Clinical need to increase pump speed Long term increase in power No change in patient status Evaluate for device thrombus
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Equipment Overview

• System Controller
• Power Sources
• System Monitor
• Display Module

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HM II System Controller

• Microprocessor that
• Delivers power to the pump
• Controls pump speed and power
• Monitors, interprets responds to system
  performance
• Performs diagnostic monitoring
• Indicates hazard and advisory alarms
• Provides complete backup system
• Event recording capability

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System Controller User Interface
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System Controller Battery Module

• Provides power to the audible alarms when both
  power leads become disconnected
• Lasts approximately one year

WARNING The System Controller alarm battery
module only provides power to the Controllers
audible alarm tones. It does NOT provide power to
the Controller or pump.
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Silencing Alarms

• Advisory Alarms 4 hours
• Alarm resets when
• Alarm condition is resolved
• 4 hour silence period expires
• A hazard or new advisory alarm
• Hazard Alarms and Power Cable Disconnected
  Advisory Alarm 2 minutes
• Alarm resets when
• Alarm condition is resolved or 2 minute silence
  period expire
• New hazard alarm occurs
• Audible advisory alarms will not occur until the
  hazard or power cable disconnected alarm has
  resolved

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System Controller Perc Lock

• Design implemented to prevent accidental
  percutaneous lead disconnects from the system
  controller

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System Controller Perc Lead Connection

• After inserting the perc lead into the
  controller, check the connection by gently
  tugging on the metal end of the Perc Lead to
  ensure proper attachment

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System Controller Perc Lead Connection

• Once connected to a powered controller, the pump
  will automatically start if the fixed speed is
  8,000 rpm
• If fixed speed is lt 8,000 rpm, to start the pump,
  firmly press either the silence alarm or test
  select button on the keypad

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System Controller Event Recorder

• Allows performance data to be collected and
  stored in the
• system controllers memory. Data can be stored
  in 2 ways
• As events occur
• Automatically records data during alarm
  conditions or change in fixed speed setting
• Factory setting On (cannot be turned off)
• At specified record intervals
• Captures and stores data in system controller at
  set time intervals from 30 minutes up to 24 hours
  in hourly increments
• Factory setting Off
• Maximum of 120 events can be stored
• Once full, oldest events are deleted and new ones
  are saved

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System Controller Self Test

• Perform daily, takes approximately 10 seconds
• Pump operation is not affected
• Checks lamps and audio tones only
• To Perform
• Press and hold Test Select button
• After 3 seconds, verify all lamps illuminate and
  unbroken tone
• Release the button. Tone and lamps will remain
  for at least 5 seconds
• Passed all tones and lamps off at completion
  (except solid green power symbol)
• Failed intermittent or absent tone or absent
  lamp during test
• Yellow cell lamp illuminated replace cell
  battery
• Cannot initiate a self test when the controller
  is operating on backup system or any alarms are
  active
• Self test will terminate if any alarm occurs
  during the test in order to sound the alarm

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Common HeartMate Peripherals

• Power sources
• Power Base Unit
• Batteries clips
• Emergency Power Pack
• System Monitor
• Display Module

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Power Base Unit (PBU)

• Supplies mains power to LVAD
• Simultaneously test and charge up to six
  batteries (8 hours)
• Repeats alarms generated by the System Controller
• Alarm reset button will only silence the PBU
  alarm for 5 minutes

• Serves as the electrical interface between the
  System Controller and the System Monitor or
  Display Module
• Data is transmitted through the data link cable
  in the white power lead

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Tethered Operation
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PBU Battery Charge Indicators

• Green battery fully charged and ready for use
• Yellow
• 10 second load test
• Battery is charging
• Red
• Battery improperly positioned in slot or contacts
  dirty
• Clean contacts
• Reinsert into same slot, if red again, insert
  into different slot
• Fails second test, do not use it
• Defective, replace
• If battery red in one slot but yellow or green in
  another, contact biomed department

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Power Base Unit

• Internal battery must be installed and charged
  prior to use
• To verify internal battery is installed, plug
  into outlet and turn unit on
• Unplug from outlet, continuous audio alarm will
  occur 10 seconds
• Contact biomed department if alarm is absent do
  not use
• Provides 30 minutes of backup power
• Takes 12 hours to recharge
• Keep plugged into outlet at all times
• Must be changed yearly

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PBU Alarms

• AC Fail alarm
• Loss of electrical power
• Red light with continuous alarm
• Alarm reset button to silence until lo battery
  alarm occurs
• Batteries in charging slots will cease to charge
  and System Monitor or Display Module will lose
  power
• Low Battery alarm
• Less than 10 minutes of internal battery power
• Red light with continuous alarm that cannot be
  silenced
• Action switch patient to fully charged batteries

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Battery Powered Operation
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Batteries

• 12-volt, sealed lead acid
• 3 5 hours of support on a pair of batteries
• Eight hour recharge for fully discharged battery
• Service life of six months or 120 charge/
  discharge cycles

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Cleaning Battery Battery Clip Terminals

• Clean battery terminals and interior contacts of
  battery clips once a week
• Use alcohol moistened cotton swab or lint free
  cloth
• Allow alcohol to evaporate prior to use
• A contaminating film may rapidly accumulate due
  to frequent handling of the batteries
• Dirty battery terminals may prevent proper
  charging in the PBU

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Emergency Power Pack (EPP)

• Single use battery pack
• EPP cable must be attached to battery pack prior
  to use
• Provides approximately 12 hours of battery power
  in event of extended power outage
• Replace if used 3 hours
• Label on inner lid contains expiration date log
  file to document usage

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System Monitor Functions

• Monitor and adjust system parameters
• Displays current LVAD performance information
• Displays alarms and operating status
• Modification of fixed speed set point and low
  speed limit
• Stop or start pump
• Record data at specified intervals separate from
  system controller
• View and save performance data and waveforms

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System Monitor Software

• Touch screen menu driven tabs across the top of
  the screen
• icon flashes in the lower left corner of
  the screen when the system controller is
  communicating with the system monitor

V3.30
V6.10
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Clinical Screen

• Displays
• Primary operating parameters
• 2 highest priority alarm message banners
• Information updated every second
• Default screen

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Display Module

• Parameters
• Pump Mode
• Pump Speed (rpm)
• PI (Pulsatility Index)
• Estimated Flow (lpm)
• Too low ---
• Too high
• Power (watts)
• Alarm conditions
• Highest priority alarm message alternates with
  flow and power

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ALARMS AND TROUBLESHOOTING

• Advisory, Hazard
• and Battery Alarms

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Advisory Alarms

• Advisory Alarms
• Power Lead Disconnected
• SC Battery Module Low
• Replace System Controller
• Low Speed Operation
• Low voltage

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Advisory AlarmsPower Cable Disconnected

• Power Cable Disconnected
• Visual Flashing 4 green battery fuel gauge
  lights and rapidly flashing green power
  symbol
• Audio One beep every second
• Silence 2 minutes
• Action
• Check power lead connections to power source
• Check PBU cable and system controller power leads
  for damage, replace if necessary

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Advisory AlarmsSC Battery Module Low

• System Controller Battery Module is low
• Visual Yellow cell symbol
• Audio One beep every 4 seconds
• Silence 4 hours
• Action Replace cell battery

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Advisory Alarm Low Voltage

• Low Voltage Advisory Alarm lt 15 minutes of
  power
• Visual Yellow Battery
• Audio One beep every 4 seconds
• Silence Until hazard alarm occurs
• Action immediately replace batteries or switch
  to alternate power source

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Hazard Alarms

• Hazard Alarms
• LOW VOLTAGE
• PERCUTANEOUS LEAD DISCONNECTED
• LOW FLOW
• LOSS OF POWER

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Hazard AlarmLow Voltage

• LOW VOLTAGE HAZARD Alarm lt 5 minutes of power
• Visual Red Battery
• Audio Continuous tone
• Silence 2 minutes
• Defaults to Power Saver Mode
• Pump speed gradually ramps down to 8000 rpm, or
  remains at current speed if set below 8,000 rpm
• System will return to set speed once adequate
  power is restored
• Action immediately replace batteries or switch
  to alternate power source

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Red Heart Hazard AlarmsLow Flow

• Low Flow lt 2.5 L/min
• Visual Red heart
• Audio Steady tone
• Causes
• Decreased preload (right heart failure,
  tamponade, hypovolemia, bleeding, etc)
• Obstruction of pump inflow or outflow
• Systemic hypertension
• Pump off or perc lead disconnected
• Action
• Assess patient
• ECHO to assess RV, LV function, inlet cannula
  obstruction
• If persist, seek additional help immediately

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Red Heart Hazard AlarmsPercutaneous Lead
Disconnected

• Percutaneous lead disconnected from system
  controller

• Visual Red heart
• Audio Steady tone
• Silence 2 minutes
• System Monitor
• PUMP OFF LOW FLOW messages
• Pump Disconnected in pump speed display
• Display Module
• LOW FLOW message

Warning If the pump stops, retrograde flow may
occur and, if blood is stagnant in the pump for
more than a few minutes, there is a risk for
stroke or thromboembolism should the device be
restarted.
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Red Heart Hazard AlarmsPercutaneous Lead
Disconnected contd

• Action
• Check system controller connections to pump
• Reconnect percutaneous lead
• Pump will automatically restart at previous speed
  if fixed speed 8,000 rpm.
• If fixed speed set below 8,000 rpm, restart pump
  by firmly pressing Test Select or Silence Alarm
  button on controller or Pump Start button on
  system monitor.
• If persists, seek additional help immediately

NOTE Simultaneously pressing the Test Select and
Silence Alarm buttons for 2 seconds may restart
the pump using the system controller back up
system. Back up alarm will sound a repeating
cycle of 1 beep per second for 2 seconds followed
by 2 seconds of silence.
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Hazard AlarmLoss of Power

• System Controller disconnected from power
• Visual Absence of green power symbol
• Audio Continuous tone
• Action
• Check system controller connections to power
• Check PBU cable connected to PBU
• Change power source
• Once power is re-established
• Pump will automatically restart if set speed is
  8,000 rpm
• If set speed below 8,000 rpm, firmly press test
  select or silence alarm button to restart pump
• Warning If all power is removed, the pump
  will stop which could result in serious injury or
  death!

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Patient Management
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Patient Assessment

• Patient assessment may include
• Pump function
• Pump speed, flow, motor power, pulse index (PI),
  mode of operation
• System controller settings, alarm status
• Review system controller event recorder log file
• Percutaneous lead connection to system controller
  and perc lock in locked position
• Exit site status, immobilization of percutaneous
  lead
• Vital signs, peripheral circulation
• Mental status, level of consciousness
• 12 lead EKG, ECHO
• Lab work

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Post Op Complications

• Hypovolemia
• Right Heart failure
• Pulmonary hypertension
• Cardiac tamponade
• Bleeding
• Arrhythmia
• Infection
• Hemolysis
• Thromboembolism
• Neurologic dysfunction

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Potential Late Complications

• Hypovolemia
• Arrhythmia
• Thromboembolism
• Infection
• Psycho-social issues
• Neurological dysfunction

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Defibrillation / Cardioversion

• External defibrillation or cardioversion
• Do not stop the pump
• Internal defibrillation or cardioversion
• Disconnect the percutaneous lead from the
  controller
• Consider clamping the outflow graft to prevent
  retrograde flow

Warning In the event that the LVAD stops
operating, retrograde flow may occur and, if
non-circulating blood is in the pump for more
than a few minutes (depending on the coagulation
status of the patient), there is a risk of stroke
or thromboembolism should the device be restarted
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Cardiac Arrest

• Potential risks associated with external chest
  compressions
• Outflow graft LV apex anastomosis
• Clinical judgment should be used
• Direct cardiac massage

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Exit Site Care

• Daily dressing change
• Use aseptic technique
• Sterile gloves, mask, hat
• Antiseptic agent such as chlorhexidine
• Rinse and apply dry, sterile dressing

• Avoid prophylactic application of topical agents
• Utilize stabilization belt
• Dressing supply items should be billed as
  intentional artificial opening

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Care of the Percutaneous Lead

• Damage to the percutaneous lead, depending on the
  degree, may cause the pump to stop
• Do not severely bend, kink or twist the
  percutaneous lead
• Do not catch the percutaneous lead in the
  zipper of the carrying case
• Allow for a gentle curve of the percutaneous
  lead.
• Do not severely bend the lead multiple times or
  wrap it tightly.
• Keep the percutaneous lead clean
• Wipe off any dirt or grime
• If necessary, use a towel with soap and warm
  water to gently clean the percutaneous lead
• Never submerge the lead or other system
  components in water or liquid

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Care of the Percutaneous Lead(contd)

• Do not pull on or move the lead at the exit site
• Gently tug on the metal end of the connector NOT
  the lead when checking percutaneous lead is fully
  inserted into system controller socket
• Wear the HeartMate Stabilization Belt or another
  restraint device AT ALL TIMES to keep the lead
  immobilized
• Be mindful of where the system controller is at
  all times
• Protect the controller from falling or pulling on
  the lead
• Dont allow the percutaneous lead to catch or
  snag on anything that will pull on or move the
  lead
• Check the percutaneous lead daily for signs of
  damage
• Cuts, holes, tears

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Warnings Restrictions

• No excessive jumping or contact sports
• No swimming
• No exposure to MRI
• Avoid strong static discharge (i.e. TV, computer
  screens, vacuuming carpets)
• No pregnancy

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Infection Guidelines
Antibiotic Prophylaxis
Antibiotic Dose Frequency
Vancomycin 15 mg/kg IV Q12H X 48-72
Levofloxacin 500mg IV QD X 48-72
Rifampin 600mg PO 1-2 hours pre-op QD X 48-72
Fluconazole 400mg IV QD X 48-72
Bactroban apply to nostrils evening prior to surgery QD X 5 days

• Antibiotic regimen tailored to institutional
  survelliance cultures and patients culture
  results with doses adjusted for renal and hepatic
  function

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Blood Pressure Monitoring and Management

• In the early post-operative, arterial line
• Goal mean pressure of 70 to 80 mmHg, maximum lt
  90 mmHg
• Once a-line removed, Doppler ultrasound
• Monitoring patients undergoing unconscious
  sedation can be challenging
• Doppler is usually required to monitor blood
  pressure
• Pulse oximetry, if obtainable, may be unreliable
  due to the diminished pulse pressure
• Cerebral oximetry may be useful in assessing
  hemodynamic condition

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Showering

• Allowed once exit site healing
• Keep exit site as clean dry as possible
• Use shower kit to protect external components

• Preparing to shower
• Remove vent connector tubing from inner pouch
  discard
• Hang kit over shoulder or neck adjust strap
• Raise outer skirt
• Lift Velcro tabs open inner pouch

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Showering

• Place system controller, leads connector inside
  inner pouch close pouch
• If using battery power
• Remove one battery at a time insert into
  pockets on either side of inner pouch
• Battery clip at top and facing forward
• If using PBU power
• Place connectors into inner pouch
• Keep away from water shower spray
• Pull outer skirt down over entire pouch
• Press snaps together at bottom of skirt

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Showering

• After showering
• Dry outer skirt and strap
• Lift outer skirt and inner pouch cover
• Transfer equipment to holster or carrying case
• Allow kit to drip dry completely
• Perform exit site care
• Reapply stabilization belt

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Patient Education XVE to HM II Key Points

• No hand pump
• If the pump stops, retrograde flow can occur
• Educate patient not to remove power from both
  power leads simultaneously when changing power
  sources or batteries
• System controller
• Different visual and audio indicators for alarms
• Steps in changing controllers
• Percutaneous lead connection and perc lock
• Defibrillation and cardioversion

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Patient Education XVE to HM II Key Points

• Uses more power, battery support time is less
• PBU internal battery
• Pair of batteries
• Emergency power pack
• Percutaneous lead care is very important
• Blood pressure measurement and management