A Constellation of Stroke and Hypoxemia Post ICD Lead Extraction: Role of Patent Foramen Ovale

Keywords
Patent Foramen Ovale; Stroke; Hypoxia

A 78-year-old woman with known ischemic cardiomyopathy underwent elective implantable cardioverter defibrillator (ICD) lead extraction and a new lead implantation. Within 2 hours post-procedure, she experienced expressive dysphasia and right hemiplegia, which was confirmed to be due to an ischemic stroke on a brain CT scan. Additionally, the patient developed resting hypoxemia with oxygen saturation of 87-88% on room air that only partially improved with high-flow oxygen.

Further investigation revealed a right-to-left shunt through a patent foramen ovale (PFO) on a trans-thoracic echocardiogram (TTE). Previous TTE examinations over the past 5 years did not show any valvular pathology or right-to-left shunt through the PFO. The patient was on direct oral anticoagulant therapy for atrial fibrillation, which was electively stopped 2 days before the procedure, and low molecular weight heparin was initiated as a bridging therapy.

The stroke was suspected to be caused by embolization of a blood clot or fibrin from the extracted ICD lead, a known procedural complication. Whereas hypoxemia was thought to be due to distortion of cardiac structure, particularly the relationship between the superior vena cava (SVC) and inferior vena cava (IVC), which can result in altered vortex formation in the right atrium and facilitate right-to-left shunting (Panel A; Video 1).¹

As the patient remained persistently hypoxemic due to the PFO-mediated right-to-left shunt and was bedbound due to the stroke, she underwent transcatheter intervention. The right atrial mean pressure was 8 mmHg, whereas the left atrial mean pressure was 11 mmHg. The right atrial angiogram confirmed the shunting of blood to the left atrium through the PFO (Figure 1A; ^{Video 1}). Bilateral pulmonary venous oxygen saturation was 96-97%, while aortic saturation was 88%, confirming the hypoxemia was due to the right-to-left shunt. Systemic saturation normalized after balloon occlusion of the PFO (Figure 1B; ^{Video 1}). The patient then underwent transcatheter closure of the PFO using an Amplatzer® 25 mm PFO occluder device. A residual leak through the PFO was observed after device deployment, however, her systemic oxygen saturation remained 94-95% on room air (Figure 1C; ^{Video 2}). Especially among patients undergoing transcatheter closure of PFO treating right-to-left shunt, our previous publication described (1) frequent residual leak, (2) normalization of systemic hypoxemia despite the residual leak, (3) frequent need for non-PFO device use, and (4) horizontal device position, likely corroborating with distorted interatrial septal anatomy.²

Figure 1
Transcatheter closure of patent foramen ovale treating right to left shunt mediated hypoxia. Panel A) Right atrial angiogram demonstrating right to left shunting through patent foramen ovale; Panel B) balloon occlusion of patent foramen ovale; Panel C) transcatheter PFO closure. The white broken arrow describes the flow in SVC and IVC; the curved arrow describes the flow in the right atrium and the blue arrow describes the flow through PFO.

Among patients with implantable cardiac devices, the presence of PFO is an independent risk factor for stroke.³ The case highlights a rare occurrence of PFO-mediated right-to-left shunting of blood and its content post-ICD lead extraction that is usually seen after thoraco-abdominal surgeries.² Treating physicians should be cognizant of such PFO-associated pathologies, as transcatheter intervention can effectively eliminate PFO-mediated right-to-left shunt as well as systemic embolization.

• Sources of funding

  There were no external funding sources for this study.

• Study association

  This study is not associated with any thesis or dissertation work.

• Ethics approval and consent to participate

  This article does not contain any studies with human participants or animals performed by any of the authors.

Referências

• ¹
  Shah AH, Ravandi A, Kass M. Platypnea-orthodeoxia Syndrome: Reminder of the In Utero Vena Cava Flow Pattern. JACC Cardiovasc Interv. 2019;12(2):e15-e16. doi: 10.1016/j.jcin.2018.10.040.
  » https://doi.org/10.1016/j.jcin.2018.10.040
• ²
  Shah AH, Osten M, Leventhal A, Bach Y, Yoo D, Mansour D, et al. Percutaneous Intervention to Treat Platypnea-orthodeoxia Syndrome: The Toronto Experience. JACC Cardiovasc Interv. 2016;9(18):1928-38. doi: 10.1016/j.jcin.2016.07.003.
  » https://doi.org/10.1016/j.jcin.2016.07.003
• ³
  DeSimone CV, Friedman PA, Noheria A, Patel NA, DeSimone DC, Bdeir S, et al. Stroke or Transient Ischemic Attack in Patients with Transvenous Pacemaker or Defibrillator and Echocardiographically Detected Patent Foramen Ovale. Circulation. 2013;128(13):1433-41. doi: 10.1161/CIRCULATIONAHA.113.003540.
  » https://doi.org/10.1161/CIRCULATIONAHA.113.003540

Edited by

Editor responsible for the review:

Nuno Bettencourt

Publication Dates

• Publication in this collection
  23 Sept 2024
• Date of issue
  2024

History

• Received
  06 May 2024
• Reviewed
  24 July 2024
• Accepted
  24 July 2024