Entanglement of a circular mapping catheter in the mitral valve with persistent iatrogenic atrial septal defect after attempted pulmonary vein isolation: a word of caution.

A 34-year-old man presented with pulmonary vein isolation due to paroxysmal atrial fibrillation. During the standard procedure, the circular mapping catheter became dislocated and was caught in the mitral valve apparatus. Following multiple failed attempts to remove the catheter in the catheterization laboratory, the patient needed an emergency operation using the heart-lung machine.