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
A ventricular outflow tract is a portion of either the left ventricle or right ventricle of the heart through which blood passes in order to enter the great arteries.
The right ventricular outflow tract (RVOT) is an infundibular extension of the ...
(LVOT),
carotid artery Carotid artery may refer to:
* Common carotid artery, often "carotids" or "carotid", an artery on each side of the neck which divides into the external carotid artery and internal carotid artery
* External carotid artery, an artery on each side of t ...
, or other blood vessels.
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LVOT VTI can be incorporated into a
POCUS examination to determine the etiology of shock or to predict fluid responsiveness. LVOT VTI can also be used to monitor cardiac output intra-operatively,
[{{Cite journal, last1=Perrino, first1=Albert C., last2=Harris, first2=Stephen N., last3=Luther, first3=Martha A., date=1998-08-01, title=Intraoperative Determination of Cardiac Output Using Multiplane Transesophageal Echocardiography A Comparison to Thermodilution, url=https://anesthesiology.pubs.asahq.org/article.aspx?articleid=2027702, journal=Anesthesiology: The Journal of the American Society of Anesthesiologists, language=en, volume=89, issue=2, pages=350–357, doi=10.1097/00000542-199808000-00010, pmid=9710392, s2cid=38009432, issn=0003-3022, doi-access=free] or as method to precisely quantify cardiac output in patients with advanced heart failure.
See also
*
Cardiac output
In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols Q, \dot Q, or \dot Q_ , edited by Catherine E. Williamson, Phillip Bennett is the volumetric flow rate of the heart's pumping output: t ...
References
Ultrasound
Blood