Evaluation of left ventricular contractile function using noninvasively determined single-beat end-systolic elastance in mitral regurgitation: experimental validation and clinical application.
OBJECTIVE
We performed this study to validate the single-beat estimation of end-systolic elastance (E(es)) in an animal model of chronic mitral regurgitation (MR) and to use E(es) to predict postoperative left ventricular (LV) systolic function with the noninvasively derived single-beat E(es) (E(es-s)) in patients with MR.


METHODS
Eight sheep with MR were studied under 4 different loading conditions. E(es) was measured as the slope of the end-systolic pressure-volume relationship with a conductance catheter during inferior vena cava occlusion. E(es-s) was calculated using a bilinearly approximated time-varying elastance curve. We also studied 105 patients with MR who had undergone mitral valve repair. All measurements in these patients were performed before surgery and repeated at about 1 week after surgery.


RESULTS
In the animals in a total of 23 different stages, E(es-s) showed a good correlation and agreement with invasively determined E(es) (y = 0.84 x + 0.38; r = 0.8; P < .01, mean difference = 0.1 +/- 0.6 mm Hg/mL). In the clinical study, preoperative E(es-s) (r = 0.77; P < .001) and end-systolic volume index correlated well with postoperative ejection fraction (r = -0.69; P < .001). Multivariate analyses revealed that only E(es-s) was an independent predictor of postoperative LV function. Preoperative E(es-s) less than or equal to 1.0 mm Hg/mL was most predictive for identifying patients with LV dysfunction after surgery (sensitivity 87%; specificity 76%).


CONCLUSIONS
LV end-systolic elastance can be estimated noninvasively and is useful to detect latent LV dysfunction in patients with MR before surgery.
Kim
Yong Jin
YJ
Seoul National University Hospital, Seoul, Korea.
Jones
Michael
M
Greenberg
Neil L
NL
Popovic
Zoran B
ZB
Sitges
Marta
M
Bauer
Fabrice
F
Thomas
James D
JD
Shiota
Takahiro
T
D000328:Adult; D000818:Animals; D019560:Echocardiography, Three-Dimensional; D004548:Elasticity; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009200:Myocardial Contraction / Q000502:physiology*; D012372:ROC Curve; D012189:Retrospective Studies; D034561:Sheep, Domestic; D013599:Systole / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*