Echocardiographic Measures Associated With Early Postsurgical Myocardial Dysfunction in Pediatric Patients With Mitral Valve Regurgitation

Abstract

The assessment of left ventricular (LV) systolic function using conventional echocardiographic measures is problematic in the setting of mitral regurgitation (MR) given that altered loading conditions can mask underlying ventricular dysfunction. The purpose of this study was to characterize LV function and deformation before and after effective mitral valve repair or replacement to determine echocardiographic measures associated with early postoperative myocardial dysfunction. Baseline LV function was assessed retrospectively by conventional echocardiography and speckle-tracking strain analysis pre- and postoperatively in patients diagnosed with MR between January 2000 and March 2013, excluding patients with less than mild to moderate MR preoperatively, left-sided obstructive lesions, large septal defects, or more than mild MR postoperatively. Forty-six pediatric patients were evaluated (average age, 8.2 ± 6.4 years). Thirteen patients had normal preoperative ejection fractions but significant postoperative dysfunction (defined as an ejection fraction < 50%). Compared with the 33 patients with normal postoperative function, age (11.5 ± 7.1 vs 7.3 ± 5.7 years, P = .04), global circumferential strain (-13.2 ± 5.6% vs -17.1 ± 4.6%, P = .02), and global circumferential strain rate (-0.94 ± 0.40 vs -1.36 ± 0.42 sec(-1), P = .004) were found to be statistically different. Using receiver operating characteristic curves, an older preoperative age (area under the curve, 0.67; P = .03), lower global circumferential strain magnitude (area under the curve, 0.74; P = .007), and lower global circumferential strain rate magnitude (area under the curve, 0.80; P = .0004) were determined to be factors associated with early postoperative LV dysfunction after surgical repair of MR. Strain measurements may be useful as part of the echocardiographic assessment of patients with MR and can guide timing for surgical repair in the pediatric population.