Percutaneous closure of patent foramen ovale in a patient presenting arterial hypoxaemia and supported with bi-ventricular assist device

Delayed intracardial shunting and hypoxemia after massive pulmonary embolism in a patient with a biventricular assist device

We describe the interdisciplinary management of a 34-year-old woman with dilated cardiomyopathy three months postpartum on a cardiac biventricular assist device (BVAD) as bridge to heart transplantation with delayed onset of intracardial shunting and subsequent hypoxemia due to massive pulmonary embolism. After emergency surgical embolectomy pulmonary function was highly compromised (PaO₂/FiO₂ 54) requiring bifemoral veno-venous extracorporeal membrane oxygenation. Transesophageal echocardiography detected atrial level hypoxemic right-to-left shunting through a patent foramen ovale (PFO). Percutaneous closure of the PFO was achieved with a PFO occluder device. After placing the PFO occluder device oxygenation increased significantly (Δ p_aO₂ 119 Torr). The patient received heart transplantation 20 weeks after BVAD implantation and was discharged from ICU 3 weeks after transplantation.

An increase in pulmonary vascular resistance in patients on BVAD can reopen a PFO resulting in atrial right-to-left shunting and subsequent hypoxemia. The case demonstrates the usefulness of transesophageal echocardiography examinations in the detection of this unexpected event. Percutaneous placement of a PFO occluder device is an appropriate strategy to stop intracardiac shunting through PFO in fixed elevation of pulmonary vascular resistance.

Rescue treatment by percutaneous closure of interatrial septal defect or PFO in infants with Berlin heart

During the past two decades, important progress has been achieved in the treatment of end-stage congestive heart failure in newborns and infants. The use of ventricular assist devices (VAD) in these patients is now available as a bridge to heart transplantation. The use of a VAD may reveal the presence of a silent interatrial septal defect or a patent foramen ovale (PFO), inducing a right to left shunt resulting in systemic desaturation and hemodynamic instability. We present two cases of low weight infants on circulatory support with VADs and right to left shunt through interatrial septum that were successfully treated by percutaneous intervention with an occlusion device.

End-inspiratory occlusion maneuver during transesophageal echocardiography for patent foramen ovale detection in intensive care unit patients

OBJECTIVE

Mechanically ventilated patients in the intensive care unit cannot cooperate to perform the Valsalva maneuver during echocardiography for detection of patent foramen ovale. We evaluated the effectiveness of the end-inspiratory occlusion maneuver to enhance detection of patent foramen ovale in this patient population.

DESIGN

Prospective interventional study.

SETTING

The 40-bed intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

Twenty five sedated and mechanically ventilated intensive care unit patients referred by their attending physician for bedside transesophageal echocardiography and agitated saline contrast study for detection of patent foramen ovale.

INTERVENTION

Agitated saline contrast study with end-inspiratory occlusion maneuver.

MEASUREMENTS AND RESULTS

All patients underwent a complete transesophageal echocardiographic study without any complications. Reduction in right atrial cross-sectional area (from 15.80 +/- 6.08 cm2 to 12.40 +/- 4.63 cm2; p < 0.001) and interatrial septum deviation during the maneuver were recorded in all patients. Microbubbles imaged in the left atrium within three cardiac cycles after injection of agitated saline diagnosed patent foramen ovale in three patients. When end-inspiratory occlusion maneuver was added, patent foramen ovale was diagnosed in seven patients (McNemar chi2 = 9.33, p = 0.0023).

CONCLUSIONS

The end-inspiratory occlusion maneuver enhances the sensitivity of transesophageal echocardiography with agitated saline contrast study for diagnosing intermittent patent foramen ovale in critically ill mechanically ventilated patients.