Bilateral carcinoid heart disease secondary to a massive right-to-left shunt through a patent foramen ovale: a case report

To our knowledge, this is the first reported case of bilateral CHD due to a massive right-to-left shunt through a PFO, driven by elevated right atrial pressure and a tricuspid regurgitation jet. This case highlights the importance of assessing for a PFO in patients with carcinoid syndrome and left-sided valvular involvement or unexplained hypoxia. Early recognition and PFO closure may represent a key therapeutic step in selected patients.