Prosthetic valves and VADs Flashcards
Echo assessment of prosthetic valves
2d- type of valve, well seated, leaflets moving, any masses
color doppler- antegrade flow, washing jets, pathologic regurg, paravalvular leak
hemodynamics - velocity, gradients, area calculation
look for colateral damage
anatomic vs antianatomic mitral mechanical valve
anatomic- leaflets in same orientation as native valve
anti-antatomic- leaflets perpendicular (favors symmetric blood flow)
Will protamine fix paravalvular leaks
small low velocity leaks typically resolve
DVI for prosthetic aortic valve
normally .35-.5
medtronic hall tilting disc regurgitant jet
large central, small peripheral
st jude washing jets
directed inward
on x washing jets
directed away (divergent)
Differential for high gradient after replacement
bad measurement - over tracing, MR contamination
bad math
bad physics
bad choices
bad valve
Situations where pressure recovery becomes an issue
Things that favor laminar flow
small ascending aorta <3cm
Bentall
Mechanical AV
Indexed EOA for patient prosthesis mismatch
<0.85 cm2/m2
increased suspicion for valve obstruction
low lvot velocity
dvi <0.25
calculated eoa<predicted>100 ms</predicted>
VADS exam prebypass
AV function (stenosis, insufficiency)
Shunts (interatrial septal defects)
Intracardiac thrombus
Right ventricular function - RVEF , TR >mod?
Mitral valve function - (stenosis)
aortic atherosclerosis for outflow
STAR
Weaning VADS from bypass
evaluate lvad inflow cannula - avoid suckdown, vpeak <2 m/s
adequate flow - appropriate LV vol
AV function- no AI
shunts-interatrial septal defects
De-airing
RV function
VAD post bypass exam
RV function-usually the biggest problem
Unobstructed inflow cannula- vpeak <200m/s
volume status
intact septum
post op vads
hypoxia- look for pfo
cva- look for pfo or thrombus
HD instability - hypovolemia (bleeding) , tamponade, RV failure, infection, device failure
Indications for IABP
LV systolic failure
post bypass HD collapse
unstable angina
preop for high risk pts (LM disease, critical AS)
contraindications to IABP
significant AI
significant aortic disease
aortic dissection
prosthetic graft in descending aorta
aorto-pulmonary shunt (BT shunt)
complications of IABP
ao dissection, arterial perf
limb ischemia
thrombocytopenia
thromboembolic complications
balloon rupture w helium embolus
hematoma
psuedoaneurysm
infection
bleeding
peak velocity cutoff for possible stenosis in prosthetic mitral valve
1.9-2.5 m/s
mean gradient for possible stenosis in prosthetic mitral valve
6-10 mmHg
DVI for possible prosthetic mitral stenosis
2.2-2.5
EOA for possible prosthetic mitral stenosis
1-2
PHT for possible prosthetic mitral stenosis
130-200 msec
What LVAD power and speed likely indicates thrombosis with obstruction
power greater than 10 watts and pump speed remains around 900 rpm (power spike)
lvad low flow alarm differential
suction event
hypovolemia
rv failure
tamponade
malignant hypertension
inflow or outflow obstruction
arrhythmia
lvad high flow alarm differentail
sepsis or medication vasodilation
rotor/bearing thrombosis with pump malfunction
significant AI
North south syndrome
occurs with VA ecmo as heart starts to eject and recover before the lungs recover. Ejects deoxygenated blood and ecmo ejects oxyenated blood
Calculating PAPI and TPG
PAPI= PASP-PADP/ RAP
TPG=MPAP-PCWP
