title: Transesophageal echocardiographic demonstration of distinct mechanisms for right to left shunting across a patent foramen ovale in the absence of pulmonary hypertension.
abstract: 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.
authors.affiliation: Department of Medicine, Loyola University Medical Center, Maywood, Illinois 60153.
authors.forename: D
authors.initials: D
authors.lastname: Langholz
authors.forename: E K
authors.initials: EK
authors.lastname: Louie
authors.forename: S N
authors.initials: SN
authors.lastname: Konstadt
authors.forename: T L
authors.initials: TL
authors.lastname: Rao
authors.forename: P J
authors.initials: PJ
authors.lastname: Scanlon
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization; D003326:Coronary Circulation / Q000502:physiology; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D006976:Hypertension, Pulmonary; D002542:Intracranial Embolism and Thrombosis / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012965:Sodium Chloride
chemical_list: D012965:Sodium Chloride