Left Ventricular Assist Device Malfunction
An Approach to Diagnosis by Echocardiography
Steven C. Horton, MD, FACC , ,*,
Reza Khodaverdian, MD*,
Peter Chatelain, BS RDCS,
Marsha L. McIntosh, RDCS,
Benjamin D. Horne, MStat, MPH*,
Joseph B. Muhlestein, MD, and
James W. Long, MD, PhD*,
* Division of Utah Artificial Heart Program, Salt Lake City, Utah
Department of Cardiology, LDS Hospital, Salt Lake City, Utah
University of Utah School of Medicine, Salt Lake City, Utah.
View larger version (36K):
[in a new window]
|
Figure 1 Diagram of Thoratec left ventricular assist device (LVAD). The Thoratec HeartMate LVAD initiates support at the left ventricular apex with a cannula allowing blood to flow across a 25-mm porcine valve, into the LVAD pumping chamber. After the pump fills, it ejects a volume of 83 cc. Blood is ejected across a second 25-mm porcine valve into an outflow graft with a distal anastomosis into the ascending aorta. The pump rhythm is independent of native cardiac rhythm.
|
|
View larger version (85K):
[in a new window]
|
Figure 2 Properly oriented inflow cannula at the apex of the left ventricle.
|
|
View larger version (111K):
[in a new window]
|
Figure 3 Color flow Doppler showing inflow valve regurgitation.
|
|
View larger version (74K):
[in a new window]
|
Figure 4 Pulsed Doppler showing attenuation of inflow valve regurgitation flow during left ventricular (LV) systole and increased flow during LV diastole. IVR = inflow valve regurgitation; LVAD = left ventricular assist device.
|
|
View larger version (89K):
[in a new window]
|
Figure 5 (A) Outflow graft imaged from the right parasternal view. (B) Pulsed Doppler of the outflow graft showing normal flows.
|
|
View larger version (90K):
[in a new window]
|
Figure 6 Pulsed Doppler of inflow cannula. Arrows indicate periods of obstruction to flow from compression of the interventricular septum during left ventricular systole.
|
|
|
