Related Experiment Video
Updated: May 8, 2026

Left Atrial Stenosis Induced Pulmonary Venous Arterialization and Group 2 Pulmonary Hypertension in Rat
Published on: November 18, 2018
Platypnea-orthodeoxia syndrome caused by a latent atrial septal defect
Hiroto Takiguchi1, Kyoko Niimi, Takuya Aoki
1Department of Pulmonary Medicine, Tokai University School of Medicine, Japan.
Abstract:
A 79-year-old woman presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome). A (99m)Tc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 25.5% in the supine position and 32.3% in the sitting position. A dynamic CT scan and a transoesophageal echocardiogram confirmed the presence of a shunt across an atrial septal defect (ASD). A percutaneous transcatheter closure of the defect significantly improved the patient's blood oxygenation levels when she was in the upright position. An ASD should therefore be included in the differential diagnosis of platypnea-orthodeoxia syndrome, regardless of the patient's age.
More Related Videos
13:10Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)
Published on: April 24, 2017
07:41Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure
Published on: February 8, 2022
Related Concept Videos
Atelectasis II: Pathophysiology
Pneumothorax-I
Pneumothorax can be even further classified as spontaneous, traumatic, and tension pneumothorax.
Mitral Stenosis I: Introduction
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Dysrhythmias II: Classification of Tachyarrhythmias