In everyday practice (criticalecho) I calculate stroke volume (or surrogate) with LVOT VTI (PW doppler). Practically in all patients it can be measure in A5C view.
In some conditions LVOT VTI is really representative of stroke distance? For example:
In aortic stenosis, is there some problem with LVOT VTI? I assume not because we are measure with PW doppler not in a stenotic area and stroke distance in LVOT still is useful. But of course, measure with CW doppler in an estenotic valve yes will give erroneously LVOT integrals. So, are you agree?
In LVOT dinamic obstruction (hypertrophic miocardiopathy or simply LVH and hypovolemia) we measure in some point of stenotic area with PW doppler…so..this integrals are not valid.! are you agree?
In significant aortic regurgitation…some volume back to LV in every systole so LVOT VTI could appear normal because this regurgitant volume elevate LVEDV and flow by LVOT …but…is not really true because again is lost in every systole…are you agree?
In conclusion, in LVOT dinamic obstruction and in significant aortic regurgitation LVOT VTI are not valid for estimation of stroke volume. In aortic stenosis there will be no problem. What do you think?
And lastly.. in conditions that we can´t measure LVOT VTI… what could it use?
Well, I used supraesteral view and measure VTI with PW doppler in aorta… ascending aorta and descending aorta. In ascending aorta (not always reliable) is better because there is no lost of flow (internal carotid and subclavian) like in descending aorta, but is not always reliable. What do you think about this approach?
In echojournal I will post a clip about it!
Best my friends