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.