Detecting Patent Foramen Ovale after Cryptogenic Stroke - A Single Center Experience in Taiwan

BACKGROUND

Cryptogenic strokes related to a patent foramen ovale (PFO) in young patients have been reported. Percutaneous transcatheter occlusion is considered a safe and effective method for achieving PFO closure. Here, we present our experience of PFO closure in a series of young patients diagnosed with cryptogenic stroke.

METHODS

This was a retrospective study of 62 patients who were younger than 60 years of age and previously diagnosed with cryptogenic stroke. They underwent cardiac catheterization for the diagnosis of PFO and/or device closure. Bubble and echocardiography studies, the patients' characteristics, complications, and recurrence of stroke were recorded. The Risk of Paradoxical Embolism (RoPE) score index was also calculated.

RESULTS

Patients with a bubble study grade greater than grade I were likely to have PFO (odds ratio: 22.2 [95% confidence interval: 1.2-412.3]). The mean RoPE score in the PFO closure group was 7.18. Two patients (3.9%) developed atrial fibrillation during the procedure. Ischemic stroke recurred in two patients (3.3%).

CONCLUSIONS

Combining a bubble study with transcranial Doppler ultrasound or transthoracic echocardiography may increase the validity of PFO diagnosis. Because of the low recurrence rate of stroke and low complication rate, it is important to identify PFO patients with a bubble study grade greater than grade I. Closure of PFO may be a good strategy for preventing recurrent stroke among such patients.

Diagnosis of patent foramen ovale using maximum intensity T-projection imaging

Accurate diagnosis of patent foramen ovale (PFO) and grading of right-to-left shunt severity by the standard method of transthoracic or transesophageal echocardiography (TEE) with bubble injection is often challenging. We proposed the novel Maximum Intensity T-Projection (MIP) Imaging method as a complementary or alternative approach for simplified diagnosis and grading of PFO. MIP Imaging represents the superimposition of all frames of an echocardiographic video onto one image. Thus, all bubbles passing from right to left atrium are represented in this single image. Diagnosis and quantification of PFO by MIP Images were compared to those obtained by standard echocardiographic methods, using the same echocardiography video loops. We applied the MIP Imaging approach to 122 echo examinations (75% of them TEE studies), performed to rule out PFOs. The average time needed to manually analyze video loops taken during bubble injection was 102 ± 52 s vs. less than 1 s using the MIP Imaging method. There was good concordance between the conventional echo method and MIP Imaging in the diagnosis and quantification of PFOs. MIP Imaging for diagnosis and quantification of PFOs was much less time consuming than the classical method and at least as accurate as the classical method. Thus MIP Imaging may be used initially as an adjunct method for PFO diagnosis and quantification and may eventually replace the classical method.

Agitated Saline Contrast Echocardiography in the Identification of Intra- and Extracardiac Shunts: Connecting the Dots

Agitated saline contrast studies are an essential component of contemporary echocardiography. Agitated saline contrast plays a critical role in the elucidation of intracardiac versus intrapulmonary shunting and can have major therapeutic implications, particularly in light of the evolution of percutaneous treatment options for atrial septal defects or a patent foramen ovale. Despite their perceived simplicity, however, there are numerous pitfalls of these investigations that can occur during their performance and interpretation. As such, the authors review the "bubble study" in identifying intracardiac and extracardiac shunts, including the history of its development, the physics and physiology of contrast enhancement, how to optimally perform and interpret an agitated saline contrast study, and its safety in unique populations.

Ischaemic Stroke and the Echocardiographic "Bubble Study": Are We Screening the Right Patients?

BACKGROUND

Patent foramen ovale (PFO) is a potential mechanism for paradoxical embolism in cryptogenic ischaemic stroke or transient ischaemic attack (TIA). PFO is typically demonstrated with agitated saline ("bubble study", BS) during echocardiography. We hypothesised that the BS is frequently requested in patients that have a readily identifiable cause of stroke, that any PFO detected is likely incidental, and its detection often does not alter management.

METHODS

This was a retrospective observational study of patients with recent ischaemic stroke/TIA referred for a BS. Patient demographics, stroke risk factors, vascular/cerebral imaging results and transoesophageal echocardiogram (TOE) reports were recorded. A "modified" Risk of Paradoxical Embolism (RoPE) score was calculated. Change in management was defined as antiplatelet/anticoagulant therapy alteration or referral for PFO closure. Bubble Study complications were recorded.

RESULTS

Among 715 patients with ischaemic stroke/TIA referred for a BS, 8.7% had atrial fibrillation and 9.2% had carotid stenosis ≥70%. At least three stroke risk factors were present in 39.3% and only 47.1% of patients screened had a "modified" RoPE score of >5. A PFO was detected in 248 patients of whom only 31% (77/248) had a subsequent change in management. Of BS performed, 1/924 patients (0.1%) suffered a TIA as a complication.

CONCLUSIONS

The echocardiographic BS is frequently performed in patients that have a readily identifiable cause of stroke and whose PFO unlikely relates to the stroke/TIA. Bubble Study findings resulted in a change in management in the minority. The procedure is safe but the complication rate warrants informed consent.

Transcatheter closure of unroofed coronary sinus using covered stents in an adult with drainage of the coronary sinus to the right ventricle after supra-annular tricuspid valve replacement

We present a rare case of unroofed coronary sinus in a patient who underwent supra-annular tricuspid valve replacement with consequent drainage of the coronary sinus to the right ventricle. It is unclear whether the coronary sinus was unroofed congenitally or iatrogenically. This rare setup resulted in significant cyanosis. The abnormal drainage was successfully closed via trans-catheter delivery of covered stents with resolution of the cyanosis. © 2017 Wiley Periodicals, Inc.

Identification and Quantification of Patent Foramen Ovale-Mediated Shunts: Echocardiography and Transcranial Doppler

Once deemed benign, patent foramen ovale (PFO)-mediated right-to-left shunting has now been linked to stroke, migraine, and hypoxemia. Contrast transesophageal echocardiography is considered the standard technique for identifying a PFO, allowing visualization of the atrial septal anatomy and differentiation from non-PFO right-to-left shunts. Transthoracic echocardiography is the most common method for PFO imaging, being cost-effective, but has the lowest sensitivity. Transcranial Doppler is highly sensitive but is unable to differentiate cardiac from pulmonary shunts; it is the best method to quantitate shunt severity, being more sensitive than transthoracic or transesophageal echocardiography so is our preferred screening method for PFO.