Date post: | 03-Jul-2015 |
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Like your first colour TVECHO BEYOND POCUS & OTHER APPETIZERS
Dr. P. JANINRoyal North Shore Hospital - Sydney
Some Story
Obese male Poorly documented past medical history No usual medications Elective cystoscopy /GA
Becomes hypoxic 15 min post induction Copious amount of frothy proteaceous liquid in
ETT Rapidly impossible to ventilate Cardiac arrest. Immediate CPR. ROSC. Remains hypoxic on high PEEP / FiO2. High
dose inotropic support Presumed aspiration?
Some Story
Some Question
V-V ECMO Remains on high dose inotropic support Metabolic acidosis. pH 7.18. Relative bradycardia.
The Question
RV dysfunction ?
• Previous RHF• Acidosis / CPR• High PEEP
The Tool
The Problem
2D Areas <> Volumes Volume change <> Contractility Ideal volumes & Starling curve
Geometry
Heart chambers can have a complex geometry.
EF & Simpson’s method make many assumptions.
Right Ventricule
Geometry
EF is not a measure of contractility.
EF is a measure of the global systolic effect, and is highly dependent on load.
Caveats
Echo can only measure deformation.
80% of the systolic work is done during the Isovolumic Contraction Time.
Strain Imaging
Not that new Measures deformation of
ventricular walls: shortening and elongation.
Part of tissue motion tracking. Much more simple than it sounds.
Speckle Tracking
Grayscale pictures consist of a speckled pattern, produced by the interference pattern of reflected ultrasounds.
Each portion of the myocardium has a unique speckle pattern, that can be tracked.
Strain Imaging
Displacement Curve Strain (Deformation) Curve
Strain Imaging
Strain Rate
Rate of relative deformation
Closely related to tissue velocities
Strain Rate
Deformation Imaging
Imaging of wall motion instead of chambers change.
Evolution on the concept of cardiac performance.
Benefits
Strain rate and Tissue velocity are closer to contractility than global measures such as EF, strain, global displacement.
Comparative study of segments. Prognostic value and early detection of cardiomyopathy (heart
failure, Anthracyclines toxicity, MV repair). Synchrony. Some reproducibility for follow-up.
Deformation Imaging
Limited feasibility and accuracy. Relies on high quality pictures (speckle tracking). Challenging interpretation.
3D live: Thin slice mode
3D live: Zoom mode
3D Imaging: Biplane view
3D FV:Tomographic slice
3D FV:Volume rendering
3D FV:Surface rendering
3D FV:Surface rendering
3D FV:Colour Doppler
3D FV:Colour Doppler
3D Echo: Benefits
Multi-plan imaging. Fast acquisition. Volume assessment of complex
chambers. Improved view on complex problems
(valvular lesions, VSD, …).
Contrast Imaging
Contrast Imaging
So What ?
2D echo is not always the straight forward answer to cardiac assessment
What we see is not always unravelling what we need to measure
So What ?
Better technology for more accuracy:
When machines start to properly eyeball the heart, and explore all aspects of its complexity.
Thank you
Thank you to Dr. T. Kapalli (St George Hospital)
Thank you to Dr. Stoylen for his excellent online resource