Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Jul 26, 2021; 13(7): 204-210
Published online Jul 26, 2021. doi: 10.4330/wjc.v13.i7.204
Large eustachian valve fostering paradoxical thromboembolism: passive bystander or serial partner in crime?
Eustaquio Maria Onorato
Eustaquio Maria Onorato, Invasive Cardiology, Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, Milan 20138, Italy
Author contributions: Onorato EM analyzed the literature, prepared the figures and wrote the paper.
Conflict-of-interest statement: There is no conflict of interest associated with any of the senior author or other coauthors contributed their efforts in this manuscript.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Eustaquio Maria Onorato, MD, Consultant Physician-Scientist, Invasive Cardiology, Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, Via C. Parea, 4, Milan 20138, Italy.
Received: December 21, 2020
Peer-review started: December 21, 2020
First decision: December 27, 2020
Revised: January 6, 2021
Accepted: March 26, 2021
Article in press: March 26, 2021
Published online: July 26, 2021

Catheter-based closure of patent foramen ovale (PFO) is more effective than medical therapy in the prevention of recurrent stroke[1]. It is likely that a proportion of patients evaluated for potential transcatheter PFO closure has actually different anatomical variants particularly common in the right atrium such as eustachian valve, Chiari network, Thebesian valve and Crista Terminalis. Notably, the eustachian valve may represent an increased risk factor for left circulation thromboembolism beyond that associated with PFO size and shunting. Such patients may benefit the most from percutaneous closure procedure.

Keywords: Eustachian valve, Chiari’s network, Patent foramen ovale, Right-to-left shunt, Paradoxical embolism, Echocardiography

Core Tip: Eustachian valve is usually considered to be a benign finding in the absence of associated cardiac anomalies. Moreover, eustachian valve is frequently found in adult patients with septal abnormalities mainly patent foramen ovale. It may actively facilitate the mechanism of paradoxical embolism by directing the blood from the inferior vena cava towards the interatrial septum via patent foramen ovale into the left atrium. Therefore, the presence of such anatomic variant may represent per se an increased risk factor for left circulation thromboembolism.