Severe mitral valve regurgitation in a preschool boy following blunt abdominal trauma: a case report.

Background: Mitral valve injuries typically result from high-energy chest trauma, with occurrences following blunt abdominal trauma being exceptionally rare. To date, no cases of mitral valve injury caused by isolated blunt abdominal trauma in paediatric patients have been reported. Case summary: A 4-year-old boy presented with laboured breathing, tachypnoea, and tachycardia after sustaining localized blunt force abdominal trauma caused by an unintentional knee impact from an adult. Despite the absence of external signs of trauma and unremarkable findings on initial imaging, worsening symptoms and elevated cardiac biomarkers prompted echocardiography, which revealed severe mitral regurgitation due to a torn papillary muscle. Prompt surgical intervention, including chordal reattachment and mitral valve reconstruction with posterior 'split' annuloplasty, led to full recovery, with minimal residual regurgitation at 1-year follow-up. Conclusion: Isolated blunt abdominal trauma can result in severe cardiac injuries, even in the absence of clinical or radiographic signs of trauma. Early echocardiography and prompt surgical management were crucial for a favourable outcome.