Velocity time integral
Velocity Time Integral is a clinical Doppler ultrasound measurement of blood flow, equivalent to the area under the velocity time curve. The product of VTI (cm/stroke) and the cross sectional area of a valve (cm2) yields a stroke volume (cm3/stroke), which can be used to calculate cardiac output. VTI can be performed across the left ventricular outflow tract (LVOT), carotid artery, or other blood vessels.
LVOT VTI can be incorporated into a POCUS examination to determine the etiology of shock[1] or to predict fluid responsiveness.[2] LVOT VTI can also be used to monitor cardiac output intra-operatively,[3] or as method to precisely quantify cardiac output in patients with advanced heart failure.
See also
[edit]References
[edit]- ^ Blanco, Pablo; Aguiar, Francisco Miralles; Blaivas, Michael (2015). "Rapid Ultrasound in Shock (RUSH) Velocity-Time Integral". Journal of Ultrasound in Medicine. 34 (9): 1691–1700. doi:10.7863/ultra.15.14.08059. ISSN 1550-9613. PMID 26283755.
- ^ Miller, Ashley; Mandeville, Justin (June 2016). "Predicting and measuring fluid responsiveness with echocardiography". Echo Research and Practice. 3 (2): G1 – G12. doi:10.1530/ERP-16-0008. ISSN 2055-0464. PMC 4989101. PMID 27249550.
- ^ Perrino, Albert C.; Harris, Stephen N.; Luther, Martha A. (1998-08-01). "Intraoperative Determination of Cardiac Output Using Multiplane Transesophageal Echocardiography A Comparison to Thermodilution". Anesthesiology: The Journal of the American Society of Anesthesiologists. 89 (2): 350–357. doi:10.1097/00000542-199808000-00010. ISSN 0003-3022. PMID 9710392. S2CID 38009432.