Coronary air embolism during transcatheter patent foramen ovale closure for platypnea-orthodeoxia syndrome in a patient with severe respiratory disorder: a case report.

In this case with severe respiratory dysfunction, spontaneous deep breathing (spontaneous Valsalva manoeuvre) caused negative intrathoracic pressure and large drops in intravascular pressure. This phenomenon might have induced air contamination during device advancement, either by entrapping or leaving residual air in the gaps between the catheter and the sheath. Additionally, PFO with right-to-left shunts is more likely to cause paradoxical air embolization. Thus, the spontaneous Valsalva manoeuvre should be avoided with appropriate respiratory management to prevent paradoxical air embolization, including CAE, during transcatheter PFO closure under local anaesthesia in severe respiratory dysfunction patients.