title: Alternative explanations to the differences of femoral and brachial saline contrast injections for echocardiographic detection of patent foramen ovale.
abstract: Patent foramen ovale (PFO) of the interatrial septum is a cardiac foetal remnant, which frequent persistence in adulthood has important implications in a variety of clinical conditions. Echographic diagnosis of PFO is based on detection of interatrial shunt by means of contrast microbubbles identification after venous injection of a first-generation echographic contrast agent. Current recommendations propose venous femoral injection of contrast for enhanced echographic detection of PFO instead of venous brachial administration, as femoral injection has been shown to have higher sensitivity for PFO detection. Inferior vena cava inflow directed toward interatrial septum has been considered the explanation for increased sensitivity of femoral delivery of contrast. In the present paper, it is hypothesised that the main determinants of these differences between injection sites are technical factors related to right atrial contrast opacification and proper transient right atrial pressure rise, rather than intraatrial flow streaming. Effects of inferior vena cava inflow stream, although significant during foetal life, would be negligible after birth. Rationale and evidence, basis for further research, and practical implications leading to a simpler and safer routine technique for echographic detection of PFO are presented and discussed.
authors.affiliation: Servicio de Cardiología, Hospital Universitario Virgen de la Arrixaca, Carretera Murcia-Cartagena, S/N. 30120 Murcia, Spain. danielsaura@secardiologia.es
authors.forename: Daniel
authors.initials: D
authors.lastname: Saura
authors.forename: Arcadi
authors.initials: A
authors.lastname: García-Alberola
authors.forename: Rafael
authors.initials: R
authors.lastname: Florenciano
authors.forename: Gonzalo
authors.initials: G
authors.lastname: de la Morena
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Sánchez-Muñoz
authors.forename: Federico
authors.initials: F
authors.lastname: Soria
authors.forename: Juan
authors.initials: J
authors.lastname: Martínez-Sánchez
authors.forename: Mariano
authors.initials: M
authors.lastname: Valdés-Chávarri
mesh_terms: D001916:Brachial Artery / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D004452:Echocardiography; D005268:Femoral Vein / Q000000981:diagnostic imaging; D005269:Femur / Q000098:blood supply*; D006344:Heart Septal Defects, Atrial / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006346:Heart Septum / Q000000981:diagnostic imaging; D006801:Humans; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D008955:Models, Cardiovascular; D012680:Sensitivity and Specificity; D012965:Sodium Chloride
chemical_list: D003287:Contrast Media; D012965:Sodium Chloride