The tricuspid regurgitation jet velocity shown was used in a critical care patient to estimate RV systolic pressure:
Vol control – tvol 420ml PEEP 10cmH20
Cardiovascular: MAP 67mmHg on Noradrenaline 0.3mcg/kg/min
2/13
His TRVmax is high:
Why should I not diagnose this patient with pulmonary hypertension in my echo report?
2 are correct:
a. not steady state
b. Off axis cursor
c. Echo cannot diagnose it
d. Poor 2D view
3/13
Answer:
a, c and possibly b!
Lets start with what TR vmax means and how it is calculated
How do they calculate: 1. Valve area 2. Mean AV gradient 3. Max AV gradient
2/14
Essential Principles: 1. The effective orifice area is always smaller than the anatomical orifice area
This effective orifice area is what is calculated
It is the key determinant of survival 2. Continuity equation
Conservation of mass
3/14
Continuity equation:
A2 X V2 = A1 x V1
(AVA) x (AV VTI) = (LVOT CSA) x (LVOT VTI)
AVA = [(LVOT CSA) x (LVOT VTI)]/ AV VTI
And for those of you who still auscultate the precordium you would have heard the elusive 'tumour plop'....of course you would.
But lets get back to the basics of M- Mode use in the PLAX view
2/6
Firstly the AV:
Here is a normal m-mode image through the AV during the cardiac cycle - note: 1. How systole and diastole are identified by ECG 2. Opening of the RCC and NCC to form the 'envelope' 3. Symmetry of the envelope 4. Closure line at end syst.
3/6
Compare this to m mode in severe AS where there is no identifiable opening of the cusps: