The ‘dreaded PFO’: anatomical and functional features of high risk for stroke

Patent foramen ovale (PFO) has a high prevalence in general population and can be implicated in cryptogenic stroke among young people. Recent trials have shown that transcatheter PFO closure is superior to medical treatment in the secondary prevention of ischaemic stroke. The benefit in the reduction of stroke recurrence is particularly evident in patients who have documentation of a PFO with high-risk characteristics. Therefore, after the assessment of a clear causal relationship with the event, a thoughtful documentation of anatomic (height, length, presence of an aneurysmatic or a floppy atrial septum, a prominent Eustachian valve or Chiari’s network, an acute angle with the inferior vena cava) and functional high-risk characteristics is mandatory.

Accidental Entrapment of Electrical Mapping Catheter by Chiari’s Network in Right Atrium during Catheter Ablation Procedure

A 78-year-old male was admitted to our hospital due to frequent palpitation. His electrocardiogram (ECG) presented regular narrow QRS tachycardia with 170 bpm, and catheter ablation was planned. During electroanatomical mapping of the right atrium (RA) with a multiloop mapping catheter, the catheter head was entrapped nearby the ostium of inferior vena cava. Rotation and traction of the catheter failed to detach the catheter head from the RA wall. Exfoliation of connective tissue twined around catheter tip by forceps, which were designed for endomyocardial biopsy, succeeded to retract and remove the catheter. Postprocedural echocardiography and pathologic examination proved the existence of Chiari’s network. The handling of complex catheters in the RA has a potential risk of entrapment with Chiari’s network.