Effect of Atrial Septostomy on Left Ventricular Function in Pediatric Dilated Cardiomyopathy Requiring ECMO

Balloon atrial septostomy (BAS) reduces left ventricular (LV) hypertension during extracorporeal membrane oxygenation (ECMO). However, the acute effect of BAS on LV function as measured by echocardiography is unknown. This was a Retrospective analysis of clinical outcome, LV dimensions, and LV function in dilated cardiomyopathy patients 0-18 years old who underwent BAS on ECMO. In 13 patients with median (IQR) age of 2.3 (0.6-10.9) years, there were no differences in clinical markers of cardiac output at intervals between 12 h before and 6 days after BAS. In addition, BAS was associated with a low rate of periprocedural complications (0.0%), acute kidney injury (7.7%), and worsening radiographic pulmonary vascular congestion (30.7%). There was a significant worsening in LV end systolic diameter (LVIDs; 3.6 [2.9-4.8] cm vs 4.2 [3.2-5.6] cm vs 3.3 [2.6-4.6] cm, p = 0.025), LV end systolic posterior wall thickness (LVPWs; 0.7 [0.5-0.9] cm vs 0.6 [0.5-0.9] cm vs 0.8 [0.6-1.2] cm, p = 0.038), fractional shortening (FS; 17.6% [8.4-20.4%] vs 6.3% [2.0-9.9%] vs 13.2% [3.6-23.4%], p = 0.013), and ejection fraction (EF; 13.1% [8.7-18.9%] vs 5.3% [2.5-11.1%] vs 9.2% [6.0-16.3%], p = 0.039) following BAS that improved in approximately 1 week. There were no differences in LV global longitudinal strain following BAS. We conclude that BAS was associated with low procedural and clinical adverse event rates in our cohort. The worsening LVIDs, LVPWs, FS, and EF seen immediately after the procedure suggests that BAS causes altered loading conditions affecting LV function in pediatric patients with dilated cardiomyopathy requiring ECMO.