Mechanical Circulatory Support Flashcards
What are the four important characteristics of MCS devices?
1) Location of the pumping chamber
2) Specific ventricle(s) supported
3) Pumping mechanism
4) Indicated duration of support
Typically short-term devices are ______ whereas durable devices are _____ systems.
extracoporeal (or sometimes paracorporeal) pumps
implantable (intracorporeal) systems
Extracorporeal:
Pump located outside the body
Paracorporeal:
Pump located outside but adjacent to the body
Intracorporeal:
Pump implanted within the body
Orthotopic:
In the normal position of the heart (TAH)
LV support:
RV support:
Biventricular support:
Biventricular replacement:
LVAD
RVAD
BiVAD
TAH
List the three major pump mechanisms:
1) Pulsatile flow
2) Continuous-flow rotary pump with axial design (flow of blood is along axis of symmetry of pump)
3) Continuous-flow rotary pump with centrifugal design (flow of blood from center to periphery of pump)
In the pulsatile flow pump mechanism, volume displacement occurs with ____ or ____
pneumatic actuation
electrical actuation
List the three indications for MCS approved by the USFDA and reimbursed by CMS:
1) Bridge to recovery (BTR)
2) Bridge to transplantation (BTT)
3) Destination therapy (DT)
Bridge to recovery (BTR) refers to the use of MCS devices in patients with _______ or ______ that is refractory to _____, but also characterized by a reasonable expectation that the myocardial injury is ____ and that myocardial function will recover during a _____ period of MCS.
acute cardiogenic shock
acutely decompensated HF
optimal medical management
reversible
short
List three types of devices that are generally used for BTR
1) Intra-aortic balloon pump (IABP)
2) Surgically and percutaneously placed extracorporeal/paracorporeal ventricular assist devices (VADs)
3) Extracorporeal life support (previously called extracorporeal membrane oxygenation, ECMO)
IABP is typically positioned in the ______. The IABP is _____ during diastole (increasing diastolic blood pressure and coronary perfusion) and _____ during systole (reducing ventricular afterload).
descending aorta
inflated
deflated
With correct timing, IABP inflation begins immediately after _____, signaled by the dicrotic notch of the arterial waveform. Compared with unassisted ejection, the pump augments diastolic blood flow by increasing _____ during diastole. Balloon deflation before systole decreases ____ with lower _____ and lower _____.
aortic valve closure
peak aortic pressure
ventricular afterload
aortic end-diastolic pressure
peak systolic pressure
The CentriMag is a _______ rotary pump with _____ design and _____ of the internal rotor.
LV support is provided by placing a cannula in the ______ to drain blood from the _____ and pump it into the ____
RV support is provided by placing a cannula in the _____ to drain blood from the _____ and pump it into the ____
continuous flow
centrifugal
full magnetic levitation
right superior pulmonary vein
left atrium
aorta
right atrial appendage
right atrium
main pulmonary artery
The Impella is a ______, microaxial pump designed to propel blood from the _____ into the _____. The tip is positioned within the _____, and blood is pumped from the _____ into the _____. The tip of the catheter is a _____ that stabilizes the device within the _____. The proximal end of the catheter is connected to the external pump.
continuous flow
LV
ascending aorta
LV
LV
ascending aorta
flexible pigtail loop
LV
TandemHeart is a ______ pump with hydrodynamic levitation of the internal rotor positioned on the _____.
centrifugal
right thigh
VA ECMO typically consists of a _____ pump system, ______ and _____. A typical configuration for emergent application of ECMO is percutaneous placement of cannulas in the ______ and _____.
centrifugal
oxygenator
heater-cooler element
femoral vein
femoral artery
In situations where myocardial recovery has not occurred despite an extended period of support, temporary MCS can be continued as a bridge to placement of ______, or as a bridge to _____.
long-term, implantable VAD
heart transplantation
Durable, implantable MCS devices designed for long-term use that permit untethered patient mobility and discharge from the hospital are appropriate devices for ______ indication.
Bridge to Transplantation (BTT)
Durable, implantable MCS devices ideally are placed in patients with significant HF symptoms who are either receiving _______ or who are not on ______ but have limiting symptoms at ____, and in whom hemodynamics are _____ and end-organ function is _____ or _____.
IV inotropes
inotropes
rest
stable
stable
slowly deteriorating
The HeartMate 3 (HM3) is an LVAD with a ________ rotary pump with _______ design and complete magnetic levitation of the internal rotor. The blood pump is positioned within the ______, with its integral inflow conduit in the _____ and outflow graft attached to the _____.
continuous-flow
centrifugal
pericardial space
LV
ascending aorta
The HM3 LVAD uses a continuous flow pump with _____ design that has the capacity to pump blood up to ____ L/min.
centrifugal
10
In the HM3 LVAD, the pump rotor is fully supported by _____, obviating mechanical or fluid bearings and essentially eliminating ______ as a reliability factor.
magnetic levitation
mechanical wear
The HeartMate II (HM2) LVAD is a _______ rotary pump with ____ design and _____ support of the internal rotor. The device is positioned ______ the pericardial space in a ______. The inlet cannula is inserted into the apex of the _____, and the outflow graft is attached to the ____.
continuous flow
axial
mechanical
outside
preperitoneal pump pocket
LV
ascending aorta
The HVAD LVAD is a ______ rotary pump with _____ design and _____ and _____ levitation of the internal rotor. The pump is positioned within the _____ with the integrated inlet cannula positioned within the apex of the ____ and the outflow graft sewn to the ____.
continuous flow
centrifugal
hydrodynamic
magnetic
pericardial space
LV
ascending aorta
Destination Therapy (DT) is the application of MCS in patients with ________ symptoms of advanced HF that result. from irreversible forms of either non-ischemic or ischemic cardiomyopathy and who are _____ for heart transplantation.
chronic refractory
ineligible
The ______ trial evaluated the use of an implantable LVAD compared with OMM for refractory chronic advanced HF. LVAD therapy _____ the mortality seen in the control population treated with OMM.
REMATCH
halved
Patients evaluated for DT must meet specific criteria for reimbursement from CMS that include ____ (list 4)
1) Ineligibility for heart transplantation
2) Significant functional limitations consistent with NYHA Class IIIB or IV symptoms for 45 out of the last 60 days
3) LVEF < 25%
4) Peak VO2 of 14 ml/kg/min or less (unless the patient is on IV inotropes for 14 days or IABP for 7 days)
What are the general guidelines for initiation of MCS? List 4
1) Cardiac index less than 1.8 - 2.2 L/min/m^2
2) SBP < 90 mm Hg
3) PCWP > 20 mm Hg
4) Evidence of poor tissue perfusion reflected by oliguria, rising creatinine and liver transaminases, mental status changes or cool extremities despite the use of OMM
More subtle indications to initiate MCS may be present, particularly in patients with chronic advanced HF who are being evaluated for BTT or DT. These indications include _____, _____ and _____ resulting in limited functional capacity and poor quality of life despite ____, with or without ____.
resting tachycardia
progressive organ dysfunction
persistent significant HF symptoms
OMM
inotrope therapy
A pre-implant creatinine clearance of less than ____mL/min/m^2 is associated with a ___ 3-month mortality in recipients of a continuous-flow LVAD, and this constitutes a ______ to durable LVAD implantation at most centers.
30
22%
contraindication
Heart failure may be associated with a _____ pattern on pulmonary function testing.
restrictive
High fixed PVR (threshold vary form __ to __ Wood units) represents a ______ to heart transplantation and consequently to use LVAD for BTT indication
3 to 6 Wood units
contraindication
Preoperative total bilirubin level and hepatic cellular enzyme levels more than _____ times normal are independent risk factors for RV failure and reduced survival following LVAD implantation.
three
RV failure in most patients is a result of _____.
LV failure
Patients who require BiVAD support have significantly higher preoperative _____ and total ____ levels and a greater need for _____ before MCS device insertion than patients requiring LVAD support only.
creatinine
bilirubin
mechanical ventilation
The presence of _____ with liver cirrhosis is a contraindication to initiating MCS support.
portal hypertension
The need for BiVAD support is associated with substantially ____ survival with both short-term and long-term MCS devices because of a greater degree of compromised _______.
worse
preoperative organ function
RV failure is a prominent factor leading to renal dysfunction after LVAD implantation, because significantly elevated _____ pressures lead to changes in glomerular filtration from ______ to ______ nephrons, with secondary reduction in ______ and resistance to _____ therapy.
right atrial (RA)
cortical
medullary
urine output
diuretic
Preoperative optimization of RV function with a goal RA pressure ideally at ____ mm Hg is important in reducing the need for post-operative RV support.
10
The higher the _____ (or _____ ) at device implantation, the greater is the benefit to the ______ and the _____ pressure when the left ventricle is totally unloaded and LA pressure falls on MCS implantation.
LA pressure (or PCWP)
right ventricle
pulmonary artery pressure
Post-operative recovery of RV function, however, may lag for several days, because total decompression of the left ventricle allows a significant shift of the _____ towards the _____, with further distinction and dysfunction of the _____.
interventricular septum
left ventricle
right ventricle
An abnormal INR may reflect chronically high ____ pressures, leading to hepatic ____ and ultimately to _____ and _____.
right atrial (RA)
congestion
hepatic fibrosis
cirrhosis
List the following for the temporary MCS device - IABP:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Degree of support (?-? L/min)
1) Counterpulsation
2) Pneumatic
3) Percutaneous placement via femoral artery or operative placement in ascending aorta or auxiliary artery
4) LV
5) Partial support device (0.3 - 0.5 L/min)
List the following for the temporary MCS device - VA ECMO:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Degree of support (?-? L/min)
1) Continuous flow rotary pump with centrifugal design
2) Varies
3) Percutaneous operative placement
4) Partial offloading of both RV and LV (reduces preload with oxygenation of blood)
5) Full support device (4-6 L/min)
List the following for the temporary MCS device - CentriMag VAD:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Degree of support (?-? L/min)
1) Continuous flow rotary pump with centrifugal design (magnetic levitation; no bearing)
2) Electric motor
3) Operative placement
4) Right, left or biventricular support
5) Full support device (4-6 L/min)
List the following for the temporary MCS device - TandemHeart pVAD:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Degree of support (?-? L/min)
1) Continuous flow rotary pump with centrifugal design (hydrodynamic support of impeller)
2) Electric motor
3) Percutaneous placement (requires transseptal placement of cannula for left atrial drainage. Arterial return to femoral artery)
4) LV
5) Partial support device (2-4 L/min)
List the following for the temporary MCS device - Impella (2.5, CP, 5.0 or RP):
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Degree of support (?-? L/min)
1) Continuous flow rotary pump with axial design
2) Electric motor
3) Percutaneous through femoral artery or operative placement via aorta or axillary artery
4) LV (Impella RP for RV support)
5) Impella 2.5: Partial device support (1-3 L/min), Full device support for Impella CP (3.5-4 L/min) and Impella 5.0 (5 L/min). Impella RP is for full RV support (4 L/min)
In an IABP, timing of balloon inflation and deflation is based on _____ or ____ triggers.
ECG
pressure
In an IABP, the balloon inflates with the onset of _____, which roughly corresponds with electrophysiologic repolarization or the middle of the _____ wave on the surface ECG, or just after the ______ on the aortic pressure tracing.
diastole
T wave
dicrotic notch
In an IABP, following diastole, the balloon rapidly deflates at the onset of _____, which is timed electrocardiographically to the peak of the _____ on the surface ECG.
LV systole
R wave
The IABP ______ diastolic blood pressure, _____ afterload, _______ myocardial oxygen consumption, ______ coronary artery perfusion and modestly _____ cardiac output.
increases
decreases
decreases
increases
increases
Patients must have some level of _____ and _____ for an IABP to be effective, because any increase in cardiac output depends on the work of the _____ itself.
LV function
electrical stability
heart
ECMO can be either venovenous (VV) for ______ only or venoarterial (VA) for ______ and ______.
oxygenation
oxygenation
circulatory support
In cases of biventricular failure, ______ is the MCS of choice for patients in cardiogenic shock and impaired oxygenation since it provides ______.
VA ECMO
full cardiopulmonary support
Because of the increase in systemic _____, VA ECMO alone may not significantly reduce ventricular wall stress and may result in ____ in cases where residual LV function is inadequate to eject against the increase in systemic _____. This may result in high _______. This may have negative consequences on myocardial recovery unless the LV is unloaded by concomitant ____, LV vent, atrial septostomy, or use of a percutaneous LV-to-aorta ____.
afterload
LV distention
afterload
myocardial oxygen demand
IABP
VAD
The TandemHeart pVAD is a percutaneously inserted extracorporeal ____-____ assist device that pumps blood from the ____ to the ____ through a transseptally placed _____, thereby bypassing the _____ entirely.
left atria-aorta
left atria (LA)
femoral artery
LA cannula
LV
In the TandemHeart pVAD, the redirection of blood from the left atrium reduces LV ____, LV ____, LV ____, LV ____ and ______.
preload
workload
filling pressures
wall stress
myocardial oxygen demand
The flow through the TandemHeart pVAD is _____ to LV output through the aortic valve (parallel circulation). However, the contribution from the native heart is typically _____ as MCS support is increased due to changes in LV loading conditions (____ in preload, _____ in afterload, etc).
additive
reduced
decrease
increase
Coronary flow is driven by perfusion pressure (____ pressure minus _____ pressure)
diastolic
right atrial
In a parallel circuit, such as with the TandemHeart pVAD, LV contraction (native heart output) may be negligible, and systemic perfusion is _____ dependent, with a ______ mean arterial pressure curve. This situation can result in ____ of blood within the aortic root, resulting in _____ and ____.
pump
flat
stasis
thrombus formation
stroke
The Impella is a continuous flow ______ pump designed to pump blood from the ____ into the ____, in series with the LV.
microaxial
LV
ascending aorta
The Impella pumps blood from the LV into the ascending aorta, thereby unloading the ____ and increasing _____. It ____ myocardial oxygen consumption, ______ coronary perfusion, ______ mean arterial pressure, and _____ PCWP.
LV
forward flow
decreases
increases
improves
decreases
List the following for the long-term durable MCS device - HeartMate 3 (HM3):
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Indication
1) Continuous-flow rotary pump with centrifugal design and magnetic levitation of internal impeller
2) Electric motor
3) Operative
4) LV (implantable pump with intrapericardial placement)
5) Long-term support (intended for BTT and DT indication)
List the following for the long-term durable MCS device - HeartMate II (HM2):
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Indication
1) Continuous flow rotary pump with axial design with mechanical pivot support of internal impeller
2) Electric motor
3) Operative
4) LV (implantable pump requiring preperitoneal pocket)
5) BTT, DT
List the following for the long-term durable MCS device - HVAD:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Indication
1) Continuous flow rotary pump with centrifugal design with magnetic and hydrodynamic levitation of internal impeller
2) Electric motor
3) Operative
4) LV (implantable pump with intrapericardial placement)
5) BTT, DT
List the following for the long-term durable MCS device - Syncardia TAH:
1) Pump mechanism
2) Pump energy source
3) Method of placement
4) Ventricle(s) supported
5) Indication
1) Pulsatile, volume displacement
2) Pneumatic
3) Operative
4) Biventricular support (orthotopic placement with removal of both ventricles)
5) BTT, DT
What is the target MAP/Afterload goal for LVAD patients?
80 mmHg (this is essentially the load that the LVAD has to pump against, hence, afterload)
All LVAD patients should be on a minimum of ____ and _____ with an INR goal of __ to __
Aspirin
Warfarin with an INR goal of 2 to 3
