2. What is a Ventricular Assist Device
(VAD)?
Mechanical circulatory device that is used
to replace the pumping action of a failing
human heart.
Left ventricular failure is primarily treated
using a VAD.
3. Need of Ventricular Assist Device
5 million people suffer from Congestive
heart failure (CHF).
2,50,000 patients are in advanced stage of
CHF.
50,000 deaths are caused due to
ventricular failure alone.
4. Classification of Ventricular Assist
Devices
On the basis of period of use:
a) Temporary, b) Permanent
On the basis of impaired ventricle:
a) LVAD, b) RVAD, c) Bi-VAD
On the basis of Pumping mechanism:
a) Pulsatile b) Non pulsatile
5. On the basis of suspension of rotors:
a) Bearing suspension
b) Electromagnetic or Hydrodynamic
suspension.
6. Advanced Ventricular Assist Device
Termed as “Non pulsatile VAD” because the
main difference between the pulsatile (earlier
version of VADs) and non pulsatile ones is the
pumping mechanism.
Pulsatile VADs emulated the real contraction
phenomenon of ventricles while Advanced VADs
use continuous flow mechanisms.
7. Key features of Advanced VAD
Enabled with continuous flow pumps
ECG independent
Soundless operation
Patient has a weak or non-palpable pulse, which
is normal, owing to the continuous flow
mechanism of the pump
Arterial pressure is in the range of (65-90)mm of
Hg
8.
9.
10. The Pump
Advanced VADs use continuous flow pumps
which are of two types:
a) Centrifugal Flow pump
b) Axial flow pump
11.
12.
13. Key Features of Continuous flow
pumps
Flow:
Measured in liters per minute (lpm): 3 to 10 lpm
Flow is directly proportional to pump speed.
Speed:
Measured in rpm: 8000 to 15000rpm
Power:
14. Pulsatility Index (PI):
Measure of the pressure difference
between VAD’s pump chamber and the
heart’s ventricle (if working, partially).
16. Conclusion
It has been a boon for cardiac patients.
Future of VADs look bright as newer
technologies and methods are being
experimented to make the device
better, lighter and easily portable.
