Transesophageal echocardiographic demonstration of distinct mechanisms for right to left shunting across a patent foramen ovale in the absence of pulmonary hypertension

• Published in: Journal of the American College of Cardiology 1991-10, Vol.18 (4), p.1112-1117
• Main Authors: Langholz, David, Louie, Eric K., Konstadt, Steven N., Rao, T.L.K., Scanlon, Patrick J.
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Cardiac Catheterization; Cardiology. Vascular system; Congenital heart diseases. Malformations of the aorta, pulmonary vessels and vena cava; Coronary Circulation - physiology; Echocardiography - methods; Female; Heart; Heart Septal Defects, Atrial - complications; Heart Septal Defects, Atrial - diagnostic imaging; Heart Septal Defects, Atrial - physiopathology; Humans; Hypertension, Pulmonary; Intracranial Embolism and Thrombosis - etiology; Male; Medical sciences; Middle Aged; Monitoring, Intraoperative - methods; Pulmonary Wedge Pressure - physiology; Sodium Chloride
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(91)90775-5

The optimal visualization of the atrial septum and fossa ovalis by transesophageal echocardiography was utilized to demonstrate saline contrast transit across the atrial septum and to relate it to the motion of the flap valve (septum primum) of the fossa ovalis. In three cases, three distinct mechanisms of right to left interatrial shunting in the absence of right ventricular systolic hypertension were identified: 1) transient spontaneous reversal of the left to right atrial pressure differential with each cardiac cycle; 2) sustained elevation of right atrial pressure above left atrial pressure induced by respiratory maneuvers; and 3) aberrant flow redirection across the foramen ovale due to a large right atrial mass. Any of these three mechanisms may be operative during paradoxic embolism in the absence of elevation of right ventricular pressures.