Patent Foramen Ovale Shunting Induced by Tricuspid Regurgitation: Unusual Cause of Dyspnea After Heart Transplantation.

backgroundPatent foramen ovale (PFO) is a common congenital anomaly that may contribute to hypoxemia and dyspnea. CASE SUMMARY: A 53-year-old woman presented with progressive platypnea and hypoxemia 21 years after orthotopic heart transplantation. Initial assessment revealed moderate tricuspid regurgitation (TR) and a PFO with left-to-right shunting. One year later, worsening dyspnea and desaturation were noted, with imaging confirming severe TR, right atrial dilation, and reversal of shunting to a right-to-left (pulmonary-to -systemic blood flow ratio: 0.79). Surgical tricuspid valve repair and PFO closure were performed, leading to complete symptom resolution and improved oxygenation. DISCUSSION: This case highlights the dynamic relationship between TR and PFO shunt reversal in a cardiac transplant recipient. The literature supports PFO closure in symptomatic individuals, particularly when progressive TR contributes to volume overload and oxygenation impairment. TAKE-HOME MESSAGES: PFO should be considered in cardiac transplant recipients with unexplained dyspnea. Surgical closure is effective when percutaneous intervention is not feasible.