title: A novel technique to quantify the instantaneous mitral regurgitant rate.
abstract: BACKGROUND
  The systolic variation of mitral regurgitation (MR) is a pitfall in its quantification. Current recommendations advocate using quantitative echocardiographic techniques that account for this systolic variation. While prior studies have qualitatively described patterns of systolic variation no study has quantified this variation.
  
  
  METHODS
  This study includes 41 patients who underwent cardiovascular magnetic resonance (CMR) evaluation for the assessment of MR. Systole was divided into 3 equal parts: early, mid, and late. The MR jets were categorized as holosystolic, early, or late based on the portions of systole the jet was visible. The aortic flow and left ventricular stroke volume (LVSV) acquired by CMR were plotted against time. The instantaneous regurgitant rate was calculated for each third of systole as the difference between the LVSV and the aortic flow.
  
  
  RESULTS
  The regurgitant rate varied widely with a 1.9-fold, 3.4-fold, and 1.6-fold difference between the lowest and highest rate in patients with early, late, and holosystolic jets respectively. There was overlap of peak regurgitant rates among patients with mild, moderate and severe MR. The greatest variation of regurgitant rate was seen among patients with mild MR.
  
  
  CONCLUSIONS
  CMR can quantify the systolic temporal variation of MR. There is significant variation of the mitral regurgitant rate even among patients with holosystolic MR jets. These findings highlight the need to use quantitative measures of MR severity that take into consideration the temporal variation of MR.
authors.affiliation: Department of Medicine, Division of Cardiology, St, Luke's-Roosevelt Hospital Center, 1111 Amsterdam Ave, Cardiology 3rd Floor, New York, NY 10025, USA. suretsky@chpnet.org.
authors.forename: Seth
authors.initials: S
authors.lastname: Uretsky
authors.forename: Farooq A
authors.initials: FA
authors.lastname: Chaudhry
authors.forename: Linda
authors.initials: L
authors.lastname: Gillam
authors.forename: Srinivasa
authors.initials: S
authors.lastname: Gurram
authors.forename: Sri Lakshmi Kala
authors.initials: SL
authors.lastname: Bonda
authors.forename: Harikrishna
authors.initials: H
authors.lastname: Ponnam
authors.forename: Eric
authors.initials: E
authors.lastname: Bader
authors.forename: Naganath
authors.initials: N
authors.lastname: Thota
authors.forename: Randy
authors.initials: R
authors.lastname: Cohen
authors.forename: Azhar
authors.initials: A
authors.lastname: Supariwala
authors.forename: Steven D
authors.initials: SD
authors.lastname: Wolff
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006439:Hemodynamics; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology*; D008944:Mitral Valve Insufficiency / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume; D013599:Systole; D013997:Time Factors; D016277:Ventricular Function, Left