Ventricular Assisting Devices in the Cathlab Unrestricted
What is a VAD? A single system device that is surgically attached to the left ventricle of the heart and to the aorta for left ventricular support For Right Ventricular support, the device is attached to the right atrium and to the pulmonary artery
Ventricular Assist Device (VAD) A mechanical pump that is surgically attached to one of the heart s ventricles to augment or replace native ventricular function Can be used for the left (L VAD), right (R VAD), or both ventricles (Bi VAD) Are powered by external power sources that connect to the implanted pump via a percutaneous lead (driveline) that exits the body on the right abdomen Pump output flow can be pulsatile or nonpulsatile
Why Do We Need VADs? Heart disease is the leading cause of death in the Western world ~5 million people in the US have congestive heart failure (CHF) 250,000 are in the most advanced stage of CHF ~500,000 new cases each year ~50,000 deaths each year only effective treatment for end stage CHF is heart transplant
Why Do We Need VADs? But, in 2008: 7318 people were waiting for a heart 2210 received one 623 died waiting ~1200-1500 VAD implanted in 2008
Indications for VAD Bridge to transplant (BTT) most common allow rehab from severe CHF while awaiting donor Bridge to recovery (BTR) unload heart, allow reverse remodeling can be short- or long-term Destination therapy (DT) permanent device, instead of transplant currently only in transplant-ineligible patients Bridge to candidacy (BTC)/ Bridge to decision (BTD) when eligibility unclear at implant not true indication but true for many pts
Types of VADs Pulsatile and Non Pulsatile
Pulsatile Ventricle-like pumping sac device. Blood enters via the inflow cannula and fills a flexible pumping chamber. Electric motor or pneumatic (air) pressure collapses the chamber and forces blood into systemic circulation via the outflow cannula. Can be LVAD, RVAD, or BiVAD First-generation devices (in use since early 1980s) Patients will have a palpable pulse and a measurable blood pressure. Both are generated from the VAD output flow.
Pulsatile VAD Key Parameters Pump Rate: How fast the VAD is pumping (filling & emptying) Can be set at a fixed rate or can automatically adjust Pulsatile VADs are loud and the rate can be assessed by listening Output: The amount of blood ejected from the VAD Measured is liters per minute Is dependent upon preload, afterload, and pump rate
Non-Pulsatile Continuous-flow devices Impeller (spinning turbine-like rotor blade) propels blood continuously forward into systemic circulation. Axial flow: blood leaves impeller blades in the same direction as it enters (think fan or boat motor propeller). Most implanted devices are LVADs only Are quite and cannot be heard outside of the patient s body. Assess VAD status by auscultation over the apex of the LV. The VAD should have a continuous, smooth humming sound. The Patient may have a weak, irregular, or non-palpable pulse The Patient may have a narrow pulse pressure and may not be measurable with automated blood pressure monitors. This is due to the continuous forward outflow from the VAD. The Mean Arterial Pressure is the key in monitoring hemodynamics. Ideal range is 65-90 mmhg.
Non Pulsatile VAD Key Parameters Flow: Measured in liters per minute Correlates with pump speed ( speed= flow, speed= flow) Dependent on Preload and Afterload Speed: How fast the impeller of the internal pump spins Measured in revolutions per minute (rpm) Flow speed is set and determined by VAD clinical team and usually cannot be manipulated outside of the hospital
VADs commonly seen in the community
Thoratec VAD (pvad/ivad) Pneumatic, external(pvad) or internal (ivad), pulsatile pump(s) right-, left-, or bi-ventricular support (RVAD/LVAD/BiVAD) up to ~7.2 lpm flow Short- to medium-term use (up to ~1-2 years) bridge to recovery bridge to transplant hospital discharge possible ivad pvad
Thoratec pvad
Axial-flow (non-pulsatile) pump electric, intra-ventricular left heart support only Speed: 8000-12000 rpm flow: ~3-5 lpm Jarvik 2000 LVAD Medium- to long-term therapy (months to years) bridge to transplant (investigational)
WHAT REALLY HAPPENS IN THE CATH LAB?
Myocardial infarction is the leading cause of death in the United States and in most industrialized nations throughout the world. Approximately 450, 000 people in the United States die from coronary disease per year. 5 The survival rate for U.S. patients hospitalized with MI is approximately 95%. This represents a significant improvement in survival and is related to improvements in emergency medical response and treatment strategies.
Complications Vascular Complications Recurrent ischemia Recurrent infarction Mechanical Complications Left ventricular free wall rupture Ventricular septal rupture Papillary muscle rupture with acute mitral regurgitation Myocardial Complications Diastolic dysfunction Systolic dysfunction Congestive heart failure Hypotension/cardiogenic shock Right ventricular infarction Ventricular cavity dilation Aneurysm formation (true, false)
SURVIVAL OF CANDIDATES IN MYOCARDIAL INFARCTION DEPENDS ON RAPID REVASCULRIZATION ULTIMATE GOAL PREVENTION OF MULTIORGAN FAILURE DUE TO DECREASED CO
INOTROPES
RAPID SOLUTION ARE RQUIRED
Intra-Aortic Balloon Pump (IABP) Copyright 2008 Perfusion.com, Inc.
The role of IABP in assisting the LV: Preload (slight decrease) Afterload (decreases) Coronary flow (increases) Myocardial oxygen (decreases) Cardiac output (increases)
Timing of Counterpulsation Electrocardiographic Arterial pressure tracing
WHAT IF MYOCARDIAL FUNCTION IS DRAMATICALLY DECREASED?
IMPELLA: T H E I M P E L L A 2. 5 I S A N I N T R AVA S C U L A R M I C R O A X I A L B L O O D P U M P T H AT S U P P O RT S A PAT I E N T S C I R C U L ATO RY S Y S T E M. T H E C AT H E T E R I S I N S E RT E D P E R C U TA N E O U S LY T H R O U G H T H E F E M O R A L A RT E RY A N D I N TO T H E V E N T R I C L E. T H E I M P E L L A I N C R E A S E S C O R O N A RY F L O W, S Y S T E M I C F L O W, C A R D I A C O U T P U T W H I C H D I R E C T LY C O R R E L AT E S TO M O RTA L I T Y. T H E I M P E L L A R E M O V E S B L O O D F R O M LV, R E D U C I N G WA L L T E N S I O N A N D M Y O C A R D I U M O 2 D E M A N D, W H I L E I N C R E A S I N G O 2 S U P P LY. N O T I N O T R O P E D E P E N D E N T.
Impella System Fundamentals Moving the Blood Rotation of the Impeller pulls blood through the cannula Impella Console controls how fast the Impeller rotates Rotation speed is proportional to flow Blood Flow Motor Impeller Cannula
Principles of Impella Design Inflow (ventricle) Outflow (aortic root) EDV, EDP AOP Flow O 2 Demand Myocardial Protection O 2 Supply Cardiac Power Output Systemic Hemodynamic Support
Safety & Ease-of-Use World s smallest heart pump Percutaneous placement Single vascular access point 9 Fr catheter No cardiac wall puncture No valve damage* Active hemodynamic support Not dependent on Inotropes Designed to: Reduce Complications Reduce Mortality Reduce Complexity No physiologic timing needed ECG Pressure * Dixon et al, J Am Coll Cardiol Interv 2009;2:91 6
DO YOU THINK THAT IT CAN HELP IN MASSIVE RV INFARCTION WITH HEMODYNAMIC JEOPARDY?
S H I F T I N G T O F U L L B Y P A S S M A Y B E T H E S O L U T I O N I N P A T I E N T S W I T H A C U T E M Y O C A R D I A L I N F A R C T I O N W I T H S I G N I F I C A N T L Y I M P A I R E D V E N T R I C U L A R F U N C T I O N O R C A R D I O G E N I C S H O C K.
CARDIOHELP SYSTEM L I F E S A V I N G T H E R A P I E S
The CARDIOHELP System is the world s smallest and lightest life support system. The portable system provides ECLS to replace or support the patient s circulation and respiration.
Message to take home: Don t hesitate to suggest the utilization of ant support system that you believe appropriate to help your patient. You can be the strongest link in line of patient s survival chain.grab it. The earlier the better
Thank you