Editorials

An Analysis of Platypnea-Orthodeoxia Syndrome Including a “New” Therapeutic Approach

History

The original description of patients with platypnea-orthodeoxia dates back to 1949 when Burchell et al² described a patient with an atrial septal defect manifesting platypnea-orthodeoxia and subsequently described the reversal of both following closure of a patent foramen ovale. “Platypnea” and “orthodeoxia” were not used to describe the manifestations of this syndrome until they became commonly accepted in 1969 and 1976, respectively.

In 1956, two patients with upright dyspnea and oxygen

Clinical Features

Table 1 outlines the etiologic background of the platypnea-orthodeoxia syndrome. It is not surprising that interatrial communications are the most common etiologic association. The population at risk is huge. Approximately 25% of the general population have a patent foramen ovale.⁷ Platypnea-orthodeoxia may theoretically occur with other sites of intracardiac right-to-left shunting, but this occurrence has not been documented thus far.

There are no data which can be used to estimate the

Physiologic Features

The precise mechanisms for both platypnea and orthodeoxia are unknown. In the several isolated case reports, speculation over mechanisms is often geared to whatever special features were found in the patient being reported.

This is particularly puzzling in patients with the syndrome related to interatrial communications. What is the mechanism for a right-to-left shunt in patients without pulmonary hypertension and normal hemodynamics? This puzzle has been restated as a question: “What causes

A New Therapeutic Approach

Given a patient with an interatrial communication and platypnea-orthodeoxia, the current approach is to consider surgical closure of the communication, say a patent foramen ovale. Indeed, investigation of the possibility of an interatrial communication is commonly justified by the availability of a surgical remedy, including new techniques using percutaneous catheters. The attractiveness of surgical closure is enhanced by the possibility of preventing paradoxical emboli. As a result, aged