Stroke volume

Hello Pablo! Sorry for the late answer. I reply your very good explanation regarding LVOT-VTI. You are very right: we can use LVOT-VTI in critical ill patients to evaluate stroke volumen or to approach haemodynamic conditions in icu- or ER-settings to choose our treatment (CO-calculation, VTI-variability to evaluate fluid responsiveness). In aortic stenosis there is one more aspect for using LVOT-VTI: you can use it for examination dimensionless graduation of aortic stenosis: pressure gradient - measured with cw in aortic valve position- is dependend on ejection fraction/ myocardial contractility, and continuity equation is sometimes not reliable because of unreliable measurement of LVOT-diameter (for example: PGmean 30 mmHg, EF 30% > PGmean of 30 means aortic stenosis 2. class, but in the context of EF 30% that means high grade aortic valve stenosis). VTI gives us a good evaluation of dimensionless index of aortic stenosis NOT dependent on EF/ myocardial contractility based on a simplified continuity equation: LVOT-VTI/ Aortic valve-VTI (measured with CW). Quotient < 0,25 means high grade aortic stenosis. In my opinion it is a good methode for quick and simple measurement of aortic valve stenosis. You are very right with aortic insufficiency (you know I don´t "like" aortic insufficiency, it is - in my opinion - the most difficult valve disorder for correct measurement). But for haemodynamic measurement without calculation of stroke volume you could use LVOT-VTI (like VTI-variance, assumed the aortic insuffficiency is being "constant"). One mopre point: I use VTI in LVOT and midventricular for demonstration whether the patient is in a hyperdynamic state. And... concerning your excelent article ("Usefullness of stroke distance by echocardiography as a surrogate marker of cardiac output that is independent of gender and size in a normal population."): It is a very good approach with a simple calculation and quick and simple measurement with following rules: heart rate < 55/min and LVOT-VTI 95/min and LVOT-VTI > 22 cm means hyperdynamic state (Thanks a lot again for that article!!!!!). Regarding to your last comment in EchoJournal concerning you interesting vid "stroke volume" I have learned a new feature of using VTI in aortic descendens (30/70-rule!!) to calculate stroke volume or/ and to evaluate heamodynamic state of patient. But in using that I´m still in my learning curve. One could think one would only need systemic VTI to measured the "needfull things" for treatment in critical care medicine. Anyone in that community with one new interesting aspect in using VTI? Best greetings to you Palbo! Jörg.