1. Effects of endovascular treatment of thoracic aortic diseases on aortic hemodynamics
UNIFESP
Diego Gaia MD PhD

2. Input impedance: in practice ?
Z = P/Q
In practice: Pressure and flow are measured and decomposed in their harmonics, input impedance is calculated for each harmonic as the ratio of pressure and flow components. The result is frequency-dependent modulus and phase angle.
This pattern is not flat! The fact that the phase angle fluctuates between negative and positive values indicates that there are reflections.

3. Wave reflection
explains patho-physiological changes in blood pressure
early return of reflected wave: ‘boost’ of systolic pressure
extra load on the heart
What is the influence of aortic prosthesis / stent-graft placement ?
An early return of the backward wave causes a boost of systolic pressure and thus an extra load on the heart

5. PWV / Impedance / PP / Aix / Reflexion
Type B / DTA
PWV / Impedance / PP / Aix / Reflexion
Day before
During procedure
1 PO
7 PO
30 PO
60 PO
180 PO
360 PO

6. Pulse tonometry

7. Flow: Echocardiogram

8. Pressure and flow: before and after endoprosthesis deployment

9. Type B Dissections
23 %
34 %

10. DTA

11. Pulse Wave Velocity – Femoral / Carotid
20 %

12. Conclusions Aortic stiffness  MACE
Stent-graft can increase aortic stifness and left ventricular afterload (Impedance/PWV)
Negative cardiovascular impact
Device improvementos – compliance / stiffness
O que se sabe do toracico cir[urgicodisquete i dois trabalhos do journal