Jugular venous reflux is a potential pitfall of using the transcranial Doppler bubble test to detect patent foramen ovale

Introduction

Patent foramen ovale (PFO) – one type of right-to-left shunt (RLS) – is a congenital cardiac lesion between the two atria that persists into adulthood. PFO contributes to distinct types of ischemic vascular diseases, stroke, possibly migraine, and decompression illness. Nearly 1/4 of all adults have a PFO, and it is responsible for 40–50% of cryptogenic strokes (M.K. Mojadidi et al. J Am Coll Cardiol 2018; 71: 1035–1043).

There are several screening methods to detect PFO, with varying degrees of sensitivity and invasiveness, including transthoracic and transoesophageal echocardiography and transcranial Doppler bubble test (TCD-BT) (M.N. Rubin et al. Stroke 2023; 54: 2842–2850). TCD-BT is a sensitive (96.1%) and specific (92.4%) screening test that can detect RLS. TCD-BT is minimally invasive and does not require sedation, resulting in better patient compliance and a more accurate examination. However, TCD-BT alone does not reveal whether the RLS is intracardiac or pulmonary, and further assessment by TEE or TTE is advised to determine its anatomic origin.

In this case series, we evaluated whether the fully autonomous, robotic, NG2 Intelligent Ultrasound from NeuraSignal could detect PFO in a group of healthy volunteers with unknown PFO status. Our study revealed a vascular phenomenon that is not well described in literature, namely jugular venous reflux (JVR), and its potential impact on the use of TCD-BT for PFO detection.

Publication History

Received: 06 June 2025

Accepted after revision: 06 October 2025

Accepted Manuscript online:
06 October 2025

Article published online:
09 December 2025