Related Experiment Video
Updated: Dec 9, 2025
Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure
Published on: February 8, 2022
Transcranial Doppler as a Screening Tool for High-Risk Patent Foramen Ovale in Cryptogenic Stroke
Seongho Park1, Jin Kyung Oh2,3, Jae-Kwan Song2
1Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Insights
Transcranial Doppler (TCD) effectively screens for high-risk patent foramen ovale (PFO) in cryptogenic stroke patients. Performing the Valsalva maneuver during TCD significantly improves the detection of high-risk PFO.
Area of Science:
- Cardiology
- Neurology
- Medical Imaging
Background:
- Identifying high-risk patent foramen ovale (PFO) is crucial for preventing recurrent strokes in cryptogenic stroke patients.
- Transesophageal echocardiography (TEE) is the standard for PFO evaluation but is not always feasible.
Purpose of the Study:
- To assess the predictability of transcranial Doppler (TCD) in diagnosing high-risk PFO compared to TEE.
- To determine the role of the Valsalva maneuver (VM) in TCD for PFO risk stratification.
Main Methods:
- Retrospective review of 461 cryptogenic stroke patients who underwent both TEE and TCD.
- High-risk PFO defined by TEE as PFO with atrial septal aneurysm or large PFO (≥2 mm).
- Spencer grading used for TCD shunt assessment, with and without VM.
Main Results:
- High-risk PFO was identified in 26.7% of patients via TEE.
- TCD detected PFO in 72.9% of patients.
- Significant shunt (Spencer grade III+) after VM on TCD identified high-risk PFO in 60.0% of cases, compared to 5.3% without significant shunt.
- TCD with VM showed higher predictability (AUC = .876) for high-risk PFO than TCD at rest (AUC = .718).
Conclusions:
- Transcranial Doppler (TCD) serves as a valuable screening tool for high-risk PFO.
- The Valsalva maneuver is essential for accurate PFO evaluation using TCD.
- Patients with minimal or no shunt on TCD after VM are unlikely to have high-risk PFO.
Background And Purpose:
The identification of high-risk patent foramen ovale (PFO) is important for selecting suitable patients for PFO closure to prevent recurrent stroke in those with cryptogenic stroke. We aimed to evaluate the predictability of transcranial Doppler (TCD) in diagnosing high-risk PFO compared with that of transesophageal echocardiography (TEE), which is not feasible for some stroke patients.
Methods:
We retrospectively reviewed the data of 461 cryptogenic stroke patients who underwent TEE and TCD for PFO evaluation. High-risk PFO on TEE was defined as PFO with atrial septal aneurysm (phasic septal excursion ≥10 mm) or large PFO (≥2 mm). Spencer grading of right-to-left shunt was used to classify the amount of shunt on TCD.
Results:
PFO on TEE was observed for 242 (52.5%) patients, and high-risk PFO was detected for 123 (26.7%) patients. However, PFO on TCD was observed for 336 (72.9%) patients. Among patients with significant shunt (Spencer grade III or higher) who underwent TCD after Valsalva maneuver (VM), 60.0% of patients had high-risk PFO. However, only 5.3% of patients had high-risk PFO among those without significant shunt. Receiver operating characteristic curves showed that significant shunt after VM had higher predictability (AUC = .876, 95% CI: .843-.905) for detecting the high-risk PFO compared with the predictability based on significant shunt at rest (AUC = .718, 95% CI: .674-.759). (P<.0001 for the differences between two AUCs).
Conclusions:
TCD is a good screening tool for evaluating high-risk PFO. VM is important for the evaluation of PFO. Patients with minimal or no shunt on TCD after VM are unlikely to have high-risk PFO.
Related Concept Videos
01:20Imaging Studies for Cardiovascular System II:Types of Echocardiography
Types of Echocardiography
Transthoracic Echocardiography (TTE)
TTE is the most common type of echocardiogram which involves placing a transducer on the patient's chest, emitting sound waves to create heart images. TTE is invaluable for evaluating the heart's size, structure, and motion, making it particularly useful for...
01:21Aneurysm II: Clinical Manifestations and Diagnostic Studies
01:19Assessing Blood pressure using a doppler ultrasound
Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment:
Preparation of Equipment: