Postoperative Recovery of Left Ventricular Function following Repair of Large Ventricular Septal Defects in Infants

Abstract

Early postoperative left ventricular (LV) dysfunction is observed following repair of large ventricular septal defects (VSDs), but the frequency and rate of recovery of LV function are unknown. This study aims to characterize the incidence and rate of recovery of postoperative LV dysfunction following repair of large VSDs and to improve understanding of LV mechanics before and after VSD repair. Infants who underwent surgical repair of an isolated large VSD were included. Pre- and postoperative echocardiographic images were reviewed, and LV function was assessed by both conventional echocardiography and speckle-tracking strain analyses. Postoperative LV dysfunction was defined as an LV ejection fraction (LVEF)<50% using the 5/6 area-length method. Echocardiograms were reviewed to assess LVEF and LV volume through 1-year follow-up. Of 104 infants evaluated (median age, 0.31 [0.22, 0.56] years), all had normal preoperative LVEF and 39 (38%) had postoperative LV dysfunction. Follow-up echocardiograms were available in 31 (80%) patients, all of whom had LVEF>50% within 9months of surgery. Lower preoperative apical four-chamber longitudinal strain (A4LS) and greater LV end-diastolic volume indexed to body surface area1.38 were independently associated with postoperative LV dysfunction. An absolute preoperative A4LS < 16.7% (area under the curve=0.87; 95% CI, 0.78-0.95; P<.001) was most strongly associated with postoperative dysfunction. Infants with LV dysfunction following repair of large VSDs recover function within 9months. Preoperative A4LS can be helpful to detect subclinical LV dysfunction in the setting of a large hemodynamically significant VSD and guide postoperative expectations for providers and families.