Transient biventricular collapse after atrial septal defect closure in an adolescent: a diastolic dysfunction-driven paradox.

While transcatheter atrial septal defect closure is routinely performed, acute biventricular failure is an extraordinary complication in adolescents, with only anecdotal reports in the literature. We present a 16-year-old male with borderline left ventricular systolic function and biventricular diastolic dysfunction who developed transient severe biventricular failure immediately following Amplatzer Septal Occluder (Abbott, Plymouth, MN, USA) deployment. Preprocedural echocardiography revealed right ventricular dilation, a D-shaped septum in diastole. Intraprocedural haemodynamic assessment demonstrated elevated right ventricular diastolic pressures (right ventricular minimal diastolic pressure: 11 mmHg; end-diastolic pressure: 17 mmHg). Haemodynamic collapse occurred within minutes of device release, necessitating emergent dopamine infusion and urgent coronary angiography to rule out device-related complications. Remarkably, ventricular function normalised within 2 hours, enabling extubation the same day. Reports of transient biventricular failure following atrial septal defect closure in adolescents without comorbidities are exceedingly rare, underscoring the critical role of preexisting diastolic dysfunction in precipitating acute decompensation. This case advocates for preprocedural balloon occlusion testing and vigilant haemodynamic monitoring in adolescents with impaired ventricular compliance to mitigate catastrophic outcomes.