Advanced HF Flashcards
what are two options for palliative inotropes
dobutamine and milrinone
what drug class is dobutamine
beta adrenergic beta1 receptor agonist
what drug class is milrinone
phosphodiesterase inhibitor (PDE3)
what is the dosing for dobutamine
2.5-25 mcg/kg/min (usually 10)
what is the dosing for milrinone
0.125-0.5 mcg/kg/min
which has a longer half life, dobutamine or milrinone?
milrinone, and it is prolonged in renal dysfunction
which is a more potent vasodilator, dobutamine or milrinone?
milrinone is a more potent vasodilator, it can cause hypotension
how is milrinone beneficial in patients with RV dysfunction
decrease in pulmonary pressures
dobutamine on B1 receptors causes ____
increased contractility (CO)
dobutamine on B2 receptors causes ____
vasodilation (decreased MAP)
what is required for palliative inotropes?
go home with an implantable defibrillator because they can cause Vtach/VFib
palliative inotropes are associated with NO difference in ____
mortality
palliative inotropes are only to improve ____
functional status/quality of life
name 3 complications with palliative inotropes
central line infections, defibrillator shocks for VT/VF, cost
what are some considerations for dobutamine
use with beta blockers is controversial, may worsen tachycardia
what are some considerations for dobutamine
use with beta blockers is controversial; may worsen tachycardia
what are some considerations for milrinone
hypotension especially with renal dysfunction, may worsen ventricular dysrhythmias
name 3 risks for mechanical support
bleeding, thrombosis, infection
what is the intra aortic balloon pump (IABP)
inflatable balloon inserted into the descending aorta (femoral or axillary insertion) that is set to inflate in ratio to ventricular contractions
what are the pharmacological considerations for IABP
there is an anticoagulation debate but most centers use parenteral heparin or DTI
what are the settings for IABP
1:1 which is one inflation for every contraction, and 1:3 which is one inflation for every 3 contractions
what are the indications for IABP
temporary support during cardiogenic shock, PCI, acute ischemia (MI, unstable angina), bridge to transplant/device
what are 2 advantages for IABP
relatively quick insertion, hemodynamic improvements
what are the hemodynamic improvements from IABP
increased diastolic BP, decreased myocardial oxygen demand, improved coronary perfusion, afterload reduction, modest improvement in CO
what is a contraindication to IABP
aortic disease
what are some complications from IABP
infection, hematoma/bleeding (device requires heparin), thrombocytopenia, vascular complications, aortic dissection
what is the impella heart pump
a percutaneous LVAD with femoral or axial insertion
what are the four different impella device types
2.5, 5.5, CP, RP
what is the impella 2.5
delivers 2.5 L/min of CO`
what is the impella 5.5
delivers 5.5 L/min of CO
what is the impella CP
delivers 3.5 L/min of CO
what is the impella RP
delivers 4 L/min of flow for RV
indications for impella
6 hours or less for support during PCI, 6 days or less for support during cardiogenic shock, often used for much longer when patients are bridge to transplant
femoral insertion of impella
can be done in the cath lab by interventional cardiologist
axillary insertion of impella
must be done by cardiothoracic insertion
advantage to axillary insertion of impella
patients can mobilize
what is unique about impella pharmacotherapy
need a dextrose based purge solution (with either heparin or sodium bicarb) as well as parenteral anticoagulation with heparin or DTI
how should you titrate anticoagulation for impella
anti-Xa target range of 0.2-0.4 IU/mL or corresponding institutional aPTT range
improper anticoagulation or purge solution with impella can result in?
device failure and hemolysis
what is the ECMO
extracorporeal membrane oxygenation: percutaneous support by where blood is pumped through an extracorporeal oxygenator (supplies blood with oxygen, removes carbon dioxide)
2 major types of ECMOs
vevovenous (v-v) and venoarterial (v-a)
v-v ECMO
provides only PULMONARY support
with the v-v ECMO, deoxygenated venous blood is pumped through the oxygenator and returned oxygenated to ______
venous circulation
the v-v ECMO is used in _______
respiratory distress syndrome (ARDS)- lung failure
the v-a ECMO provides ______
cardiopulmonary support
with the v-a ECMO, deoxygenated venous blood is pumped through the oxygenator and returned oxygenated to ____
arterial circulation
the v-a ECMO is used in ______
cardiogenic shock
what pharmacotherapy is required with ECMO
anticoagulation with heparin or DTI
it is imperative to monitor for _______ with the ECMO
peripheral limb ischemia
what else should you treat with the v-a ECMO
it provides retrograde blood flow into the aorta resulting in increased afterload so you should treat with an afterload decreasing agent such as vasodilators
what are two types of total artificial hearts
syncardia, carmat
what is syncardia
pneumatic (air-driven) implantable device that provides biventricular support)
total artificial hearts are _____ ONLY
bridge to transplant
you can have a stroke volume of ___ or ___ with syncardia
50cc or 70cc
the contraction frequency with syncardia is adjusted to provide _____
appropriate cardiac output
what thrombotic prophylaxis does syncardia require
multi-modal: aspirin, heparin transitioned to warfarin, dipyramidole, pentoxifylline
what does the carmat provide
hydroelectric ventricular contraction
why does carmat have less intense anticoagulation needs than syncardia
it has 4 biological valves (bovine), biocompatible ventricular lining
what pharmacotherapy is used for carmat
treatment dose LMWH until hospital d/c then prophylactic dose LMWH
types of LVAD flow
continuous flow, pulsatile
types of LVAD continuous flow
axial flow, centrifugal flow
what is the name of the pulsatile LVAD
heartmate XVE, it’s off the market
what is the name of the axial flow LVAD
heartmate II, it’s off the market
what is the name of the centrifugal flow LVAD
heartmate III (only one on the market)
definition of left ventricular assist device (LVAD)
serves as a permanent prosthetic left ventricle to deliver oxygenated blood to peripheral circulation
components of LVAD
pump, driveline (delivers power and settings to pump), external battery
pharmacologic considerations for LVAD
prosthetic device (infection, thrombosis), requires anticoagulation/antiplatelet therapy (bleeding, thrombosis), blood pressure management (don’t have a pulse)
blood from the _____ enters the LVAD. the LVAD then pumps blood into ____
left ventricle. aorta (to the body).
what pharmacotherapy did heartmate XVE require when it was on the market
only aspirin 325 mg daily
what were some complications with heartmate XVE
infection, bleed, thrombosis (pump, stroke), pump failure
what pharmacotherapy did heartmate II require when it was on the market
aspirin 325 mg daily and warfarin titrated to goal INR 2-3, antibiotics around the time of implant
what advantage did heartmate II carry over heartmate XVE
it was a smaller pump, simpler surgical procedure, improved device durability
what are the three components of virchow’s triad
hypercoagulable state, circulatory stasis, vascular wall injury
how do LVADs cause a hypercoagulable state
increased thrombin production by interaction between blood and device components (blood touches metal, wants to clot)
how do LVADs cause circulatory stasis
LVAD recipients may have stasis due to lack of LV function
how do LVADs cause vascular wall injury
the implantation requires major surgery
how do LVAD recipients have circulatory stasis
due to lack of LV function
how can LVADs lead to clot
platelet activation through tissue injury, clotting cascade activation
what drugs are needed to prevent clots for LVAD
antiplatelet (aspirin, p2y12, dipyramidole) to prevent platelet thrombus, anticoagulant (heparin, LMWH, warfarin, DOACs?) to prevent platelet thrombus
aspirin mechanism
inhibits COX-1 resulting in lack of thromboxane A2 production
P2Y12i mechanism
prevent platelet activation downstream of aspirin; inhibit ADP production resulting in reduction of platelet-based thrombin
dipyramidole mechanism
inhibits breakdown of cAMP resulting in reduced activation and aggregation
what is the primary antiplatelet choice in LVAD
aspirin (given the increased risk of bleeding with P2Y12i)
when is DAPT reserved for with LVAD
patients with history of pump thrombosis
anticoagulation for LVAD
heparin infusion w/ low aPTT goal (50-80s) for bridging to therapeutic warfarin (goal INR=2-3 regardless of device)
when is INR goal for LVAD different?
patients with GI bleeding, patients with history of pump thrombosis
what is INR goal for LVAD patients with GI bleeding
1.8-2.5
what is INR goal for LVAD patients with history of pump thrombosis
2.5-3.5
how do you monitor for hypertension with continuous flow devices??
the patients do not have a pulse so you monitor by MAP
MAP=
1/3(SBP) + 2/3(DBP)
what is considered HTN based on MAP?
anything above 85/90? is considered hypertension with a VAD and may increase stroke risk
how do axial flow pumps work
they have an impeller (similar to a boat propeller) that helps draw blood from LV through a cannula into the aorta)
how do centrifugal flow pumps work
they use magnetic levitation (mag-lev) with a bladed disk in the pump cavity to deliver blood from LV to aorta)
stroke risk factors with LVAD
MAP > 85 mmHg, INR<2, aspirin dose <81 mg daily
how was HVAD better than heartmate II
pump size was smaller, further simplification of the surgical procedure, less pump thrombosis risk, but similar to increased stroke risk
heartmate III advantages
fully magnetized levitation technology, results in improved hemo-compatibility with patients (reduced pump thrombosis)
LVAD complications
hemocompatibility (bleeding, thrombosis), infectious, right ventricular failure, pump malfunctions
bleeding complications with LVAD
hemorrhagic stroke, GI bleeding, epistaxis
thrombosis complications with LVAD
ischemic stroke, pump thrombosis
infectious complications with LVAD
driveline infection, infected device