Evaluation of pulmonary venous obstruction
Computed tomography (CT) of the chest and transthoracic echocardiography were performed pre- and postoperatively for all patients. PVO was comprehensively defined by the shape that is clearly narrower on the heart side than on the periphery on computed tomography, continuous flow pattern, and mean pressure gradient greater than 8 mmHg at the atrial entrance on echocardiography (5). We diagnosed seven patients with PVO (PVO group) and 11 patients without PVO (non-PVO group) according to these diagnostic criteria.