Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?

Abstract

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and coexistence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari's network. These may act independently or synergistically, multiplying the risk of embolic events. The RoPE score, a scale that includes factors such as young age, cortical infarct location and absence of traditional stroke risk factors, is associated with the probability of a PFO being pathogenic and stroke recurrence risk after the index stroke. Multiple investigators have attempted to correlate other PFO features with the risk of PFO-related stroke, but further investigation is needed before any robust conclusions are reached. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. Caution should be exercised in interpreting the relevance of other PFO features.

Newly-found channels in the interatrial septum of the heart by dissection, histologic evaluation, and three-dimensional microcomputed tomography

“…The characteristics of IACs most different from ASDs and PFOs were the site and course ( Table 2 and Fig 6 ) [ 2 , 4 , 5 , 11 , 15 , 19 – 23 ]. The IAC is the only type of interatrial communication located above the fossa ovalis on the surface of the interatrial septum.…”

The Value of Contrast-Enhanced Transesophageal Echocardiography in the Detection of Cardiac Right-to-Left Shunt Related with Cryptogenic Stroke and Migraine

“…Migraine is a common neurological disorder in clinical practice, which could seriously affect the life quality of patients. So far, contradictory microemboli can cause stroke bypass PFO, and the arteriovenous access with more than 25-50 μ m diameter exists in abnormal status [ 17 , 19 , 20 ]. Migraine is caused by contradictory microemboli and/or the nontangible components of chemical substances that can enter into systemic circulation through the open pulmonary arteriovenous physiological channels [ 21 – 23 ].…”

When orofacial pain needs a heart repair

“…PFO accounts for 95% of all RLS. TEE and c‐TCD are the complementary imaging procedures of choice in adult patients with suspected PFO with RLS (Ioannidis & Mitsias, 2020; Nedeltchev & Mattle, 2006) or in patients at risk of cryptogenic stroke, and provide an indication for the distinction between “innocent” and “suspicious” shunts (Nedeltchev & Mattle, 2006).…”

“…Early detection and treatment is essential in PFO with RLS because this condition has been suggested as a risk factor for cryptogenic stroke in patients younger than 55 years through a mechanism probably consisting in a paradoxical embolism, particularly when a hypercoagulability status is associated. Over a fifth of patients with PFO presented at least one definite abnormality on a thrombophilia test (Ioannidis & Mitsias, 2020). Therefore, it seems reasonable to screen these patients, particularly those with a previous history of thromboembolic events (Rodriguez & Homma, 2003).…”

“…For the majority of people, a PFO will remain undetected or appear only as a chance finding during cardiac investigation. Otherwise, the diagnosis is often made after the patient suffers a stroke, migraine‐like symptoms or decompression sickness while diving (Ioannidis & Mitsias, 2020).…”