Patent Foramen Ovale—Assessment and Treatment

Abstract

SUMMARYA Patent Foramen Ovale (PFO) is detectable in 20-25% of the population. Some, but not all, case control studies have found an increased incidence of PFO in patients with cryptogenic stroke. Prospective cohort studies have failed to convincingly demonstrate a link between PFO and first stroke, and evidence linking PFO to recurrent stroke is far from compelling. The rate of recurrent stroke in medically treated patients is low, but the development of devices for PFO closure has lead to enthusiasm in some quarters to pursue a strategy of device closure. Nonrandomized studies have suggested a lower risk of recurrent events with device closure but the data are heterogeneous, and potentially prone to bias. Device implantation is associated with a risk of major adverse events of between 1.5% and 2.3%, and there is a significant rate of failure to close shunts. The results of randomized trials of device closure are keenly awaited. Migraine with aura has been linked with PFO. A recent metanalysis suggested an association, but the one prospective population study did not. The well-publicized and controversial MIST Trial is the only randomized trial of device closure in migraineurs yet published, and failed to demonstrate a convincing benefit from device closure. Other conditions such as platypnea-orthodeoxia syndrome and prevention of decompression sickness in divers, may justify device closure. Evidence for a role of PFO in the etiology of cryptogenic stroke and migraine is contradictory. It is possible that some patients might benefit from PFO closure but there is scant evidence of sufficient quality to justify routine PFO closure in either group. It is essential that ongoing randomized trials of device closure are completed. Prevalence and DetectionA patent foramen ovale (PFO) is a slit or tunnel like passage in the interatrial septum (IAS) formed by failure of postnatal fusion of the septum primum and septum secundum. Persistent PFO occurs in around 20-25% of the adult population, the exact frequency dependent on the method of detection. An autopsy based study suggested that the prevalence of PFO decreased with age implying either spontaneous closure or, intriguingly, a significant early death rate in those with PFOs [1]. However recent evidence from a large surgical series suggests that this is not the case and prevalence does not relate to age [2].Transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), and transcranial Doppler (TCD) can all be used to detect . TOE has traditionally been regarded as the gold standard but has some significant disadvantages. Whilst in some individuals a PFO is obvious on 2D echo or color flow on TOE, injection of bubble contrast is needed in many to clearly demonstrate a right to left shunt (see Figure 1). Patient sedation, positioning in the left decubitus position and the inability to perform a complete Valsalva may make it more difficult to visualize a shunt with bubbles on TOE than on TTE where the patient is semiupright and able to perform a good Vals...

Platypnea-Orthodeoxia Syndrome in Review: Defining a New Disease?

“…It is currently known that the frequency of PFO is significantly greater among patients with cryptogenic infarcts (about 45%), even though the directives for PFO closure in patients with stroke are still controversial [30,31]. …”

Massive pulmonary thromboembolism after intravenous stroke thrombolysis

“…The role of the PFO in the aetiology of stroke is confusing and contradictory 1. PFO is common in the general adult population and normally is not harmful.…”

“…PFO is associated with a higher incidence of ischaemic stroke and systemic embolism 4. In addition, ASA is often associated with PFO, and the mechanism for stroke in ASA is due to concomitant PFO, and a tendency toward atrial arrhythmias such as AF and thrombus formation 1. In some cases, diagnosis of paradoxical embolism is not an easy task.…”

“…Several cases of concomitant pulmonary embolism (PE) and ischaemic stroke1 2 and an ischaemic stroke following PE3 4 have been described in the literature. We present a patient who suffered a massive PE after intravenous thrombolysis for an ischaemic stroke.…”

En mann i 40-årene med residiverende hjerneinfarkt

“…Dette er den hyppigste medfødte hjerteabnormiteten, da den persisterer som en potensiell forbindelse hos ca. 25 % av befolkningen i voksen alder (2,3). Luftboblekontrast i perifer vene brukes for å visualisere høyre-til-venstre-shunting gjennom intraatriale septum.…”