We report the case of a 57-year-old man who underwent orthotopic heart transplantation because of prior myocardial infarction and cardiogenic shock. The patient developed refractory hypoxemia 7 months after transplantation, secondary to a right to left shunt across a patent foramen ovale related to severe tricuspid regurgitation resulting from repeated control biopsies. Percutaneous closure of the foramen ovale was performed.