How have LVADs been used?
- as a bridge to transplantation
- as destination therapy
- as a bridge to transplant candidacy
- as a bridge to recovery
What are the 2 TYPES of CF LVADS? Where is the impeller located?
- Heart Mate II: below the diaphragm
- HVAD: implanted above the diaphragm within pericardial sac
List the types of temporary forms of cardiac mechanical support in cardiogenic shock
- Intra-aortic balloon pump
- ECMO
- Impella
- Tandem
What is more COMMON to occur when AV remains CLOSED POSTOPERATIVELY?
- aortic thrombus
- new onset “de novo” AI
How can you view TERMINAL portion of OUTFLOW CANNULA?
high left parasternal long axis view
How can you view MID portion of OUTFLOW CANNULA?
right parasternal view with patient in right lateral decubitus position
What is the velocity norm for OUTFLOW grafts?
- normal ≤ 2m/s
- > 2 at any level may represent obstruction
What is the velocity norm for INFLOW HEART MATE II?
normal < 1.5 m/s
What is the velocity norm for HVAD?
can’t be performed due to color and doppler artifact caused by closeness of the impeller
When is BP taken?
Pre exam BP and BP after any pump speed changes.
What is being determined when checking the BP?
mean arterial pressure = cuff pressure is gradually reduced until a constant sound is heard
What MAP NORM is recommended?
MAP BP < 85 mmHg
What MAP NORM indicates hypertension and what does this mean?
- MAP BP > 85 mmHg
- too high speed pump
What MAP NORM indicates hypotension and what does this mean?
- MPAP < 60 mmHg
- too low speed pump
What are reasons to stop a SPEED CHANGE TEST?
- completion of test
- suction event occurs
- symptoms of hypertension
- symptoms of hypotension
- cannula flow reversal
Describe a SUCTION EVENT?
when high pump speeds, malplaced cannula or hypovolemia pulls LV segment obstructing flow into the cannula: very critical as dangerous arrhythmia occur and cardiac outflow is impeded
What are SIGNS of too LOW of speed?
- LVIDd increased
- Right ward shifted IVS
- More prominent MR
- Frequent AV opening
- RA and RVSP increased
What are SIGNS of too HIGH of speed?
- leftward shifted IVS and/or impedes flow into cannula
- Worsening TR and AR
What is an OPTIMAL speed?
- speed just below the maximum speed that keeps the AV closed or only intermittent opening depending on institution
- Typically at least 400 and 40 below maximal speedster HMII and HVAD
