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HeartMate II Left Ventricular Assist Device (LVAD). Courtesy University of Washington Medical Center. BACKGROUND. Ventricular assist devices (VADs) are a proven therapy as bridge-to-cardiac transplantation in Class IIIB and Class IV heart failure patients
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HeartMate II Left Ventricular Assist Device (LVAD) Courtesy University of Washington Medical Center
BACKGROUND • Ventricular assist devices (VADs) are a proven therapy as bridge-to-cardiac transplantation in Class IIIB and Class IV heart failure patients • The dramatic increase in the use of VADs has been unavoidable for those patients suffering end-stage heart failure due to the consistent shortage of donor organs • As mean support duration for VADs increases, more VAD patients will be living in the community • HeartMate LVAD is approved as Destination Therapy (DT)
HM II CANDIDATES FDA Approved 4.21.08 • Bridge-to-Transplant (BTT) FDA Approved 1.20.10 • Destination Therapy (DT)
HM II Cored into LV Outflow to aorta Percutaneous tube System Controller Batteries
FUNCTION & CAPABILITY • Axial (continuous) flow: ?NO PULSE/ ?BP • One moving part: Rotor • Small • 400 gm • 125 cc • 60% smaller than HM I (XVE) • Quiet • Flows: 3 – 10 lpm • Anticoagulation required
ADVANTAGES • Size: Potential BSA of .8 m2 • Only one moving part • Blood lubricated bearings • Designed for long term support • Lower infection rates (smaller perc tube)
Pump Housing Rotor
PUMP ROTOR and STATORS BLOOD FLOW Inflow Bearings Inflow Stator Outflw Stator Outflow Bearins Rotor
SYSTEM CONTROLLER Controller + Back-up Controller
POWER MODULE Supplies main power to LVAD Provides 30 minutes of backup power Repeats alarms generated by the System Controller Serves as the electrical interface between the System Controller and the Display Module
BATTERIES • 14v Li-Ion • 6 – 10 hours of support *Patients report up to 15 hrs of battery power • Up to 4 hour recharge for fully discharged battery • 3 years or 360 charges
DISPLAY MODULE • Pump Mode • Fixed • Power Saver • Pump Speed (rpm) • Pulse Index • Estimated Flow (lpm) • Too low “---” • Too high “+++” • Power (watts) • Alarm Conditions • Highest priority displayed
EMERGENCY POWER PACK (EPP) • Single use battery pack in a plastic carrying case with a shoulder strap • Provides battery power in the event of extended power outage • Approximately 12 hours of support • Must be replaced if used for a period exceeding three hours
BATTERY ALARMS ADVISORY ALARMS HAZARD ALARM
BATTERY ALARMS BATTERY < 15 minutes of power BEEP Q SEC BATTERY < 5 minutes of power STEADY TONE Defaults to ‘Power Saver Mode’ • Pump defaults to Fixed Rate Mode of 8000 rpm, or fixed speed setpoint if lower • System will return to set speed once adequate power is restored ACTION • Replace batteries or switch to alternate power source
SYSTEM DRIVER CELL LOW VOLTAGE SYSTEM CONTROLLER CELL LOW VOLTAGE • Yellow cell symbol • Beep every 4 seconds ACTION • Replace cell battery and perform System Controller self test
POWER CABLE DISCONNECTED and FLASHING POWER CABLE DISCONNECTED • Flashing green power symbol & battery power bars • Beep every second ACTION • Check cable connections to power source • Check power leads for damage, replace if necessary
LOW FLOW; NO OPERATION or INCORRECT OPERATION LOW FLOW < 2.5 lpm • Pump not operating or not operating correctly • Decreased preload (right heart failure, tamponade, hypovolemia, bleeding, etc) • Obstruction of pump inflow or outflow • Systemic hypertension ACTION • Assess patient • Monitor
DRIVELINE DISCONNECTED FROM CONTROLLER • Check connections ACTION • Reconnect driveline to controller
STEADY TONE andNO SYMBOL • NO POWER TO PUMP ACTION • Check system driver connections to pump • Check system driver power connections to power source • If persist, seek additional help immediately
CPR SHOULD NOTBE PERFORMED ON HEARTMATE LVAD PATIENTSUNLESS DIRECTED
VT or VF • STABLE • Patient may “feel funny” “light headed” or “different” • Pump speeds and flows are normal, low normal, or very low • Consider cardioversion after consultation with Mechanical Assist Device Coordinator • UNSTABLE • Patient unresponsive • Treat as unstable VT/VF
LVAD PATIENT TRANSPORT • Transport to assigned facility • Spare batteries, PBU and the display module should be brought to the hospital with the patient • PBU weighs 29 pounds without batteries • All modes of emergency transportation are acceptable • Aviation electronics will NOT interfere with LVAD and visa versa