Right atrial to left atrial shunt through foramen ovale during pneumoperitoneum for laparoscopic cholecystectomy.

A 62-year old female patient in whom paradoxical right atrial to left atrial shunt flow through the foramen ovale was detected by transesophageal echocardiography during pneumoperitoneum for laparoscopic cholecystectomy was reported. This patient had a history of mitral valve replacement with residual tricuspid valve regurgitation. It was considered that the onset of paradoxical interatrial shunting through the foramen ovale might be caused not only by mechanical ventilation with positive end-expiratory pressure but also by pneumoperitoneum, especially in patients with heart disease, even if the intra-abdominal pressure was maintained at 12 mmHg.