Potential Role of Patent Foramen Ovale in Exacerbating Hypoxemia in Chronic Pulmonary Disease

Abstract

Patent foramen ovale has been associated with multiple pulmonary diseases, such as pulmonary hypertension, platypnea-orthodeoxia syndrome, and chronic obstructive pulmonary disease. A connection between patent foramen ovale and chronic pulmonary disease was first described more than 2 decades ago in case reports associating patent foramen ovale with more severe hypoxemia than that expected based on the severity of the primary pulmonary disease. It has been suggested that patients with both chronic pulmonary disease and patent foramen ovale are subject to severe hypoxemia because of the right-to-left shunt. Furthermore, investigators have reported improved systemic oxygenation after patent foramen ovale closure in some patients with chronic pulmonary disease. This review focuses on the association between chronic pulmonary disease and patent foramen ovale and on the dynamics of a right-to-left shunt, and it considers the potential benefit of patent foramen ovale closure in patients who have hypoxemia that is excessive in relation to the degree of their pulmonary disease.

Keywords: Diagnostic imaging; exercise tolerance; foramen ovale, patent/complications/diagnosis/diagnostic imaging/physiopathology/surgery/therapy; heart septal defects, atrial/prevention & control; hemodynamics; hypertension, pulmonary/complications/etiology/physiopathology; hypoxia/complications/diagnosis/etiology; pulmonary disease, chronic obstructive/complications/physiopathology/therapy; recovery of function; risk factors.

Fig. 1.

Patient 1. Transesophageal echocardiograms (mid-esophageal, bicaval view) show an interatrial right-to-left shunt in a patient whose hypoxemia was out of proportion to his chronic obstructive pulmonary disease. A) Color-flow Doppler mode shows flow across the patent foramen ovale (PFO) from the right atrium (RA) to the left atrium (LA). B) Agitated-saline contrast injection reveals shunting of bubbles from the RA to the LA through the PFO. C) After patent foramen ovale closure with a Gore Helex septal occluder (arrow), color-flow Doppler mode reveals no residual flow.

Fig. 2.

Patient 1. Three-dimensional, volume-rendered, transesophageal echocardiograms show A) the interatrial shunt before closure of the patent foramen ovale (arrow), and B) no residual shunting after closure with a Gore Helex septal occluder (arrow), upon agitated-saline contrast injection (oval).

Fig. 3.

Patient 2. Fluoroscopic image shows balloon sizing for patent foramen ovale (PFO) closure. The balloon catheter was placed over a guidewire and passed across the PFO and into the left atrium. The balloon was inflated gently until an indentation was seen at the level of the PFO (arrows) and there was no flow around the balloon, as determined by Doppler-flow imaging through an intracardiac echocardiographic catheter (oval).

Fig. 4.

Patient 2. Fluoroscopic image shows a 19-mm Amplatzer Atrial Septal Defect Occluder (arrow) in place across the interatrial septum, after release from the delivery cable. An intracardiac echocardiographic catheter (oval) is also seen.