Right-to-Left Shunt During Transseptal Mitral Valve-in-Valve Replacement: A Case Report

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiac Surgery

Background:

• An 88-year-old woman presented with severe mitral stenosis and moderate mitral regurgitation, experiencing worsening dyspnea on exertion.
• The patient had a history of coronary artery bypass graft and prior mitral valve replacement 14 years earlier, posing high risk for redo sternotomy.
• Transcatheter mitral valve-in-valve replacement was considered as a less invasive alternative.

Observation:

• The transseptal mitral valve-in-valve replacement procedure was initiated.
• Intraoperative hypoxia and hypotension occurred following the creation of an atrial septal defect for valve deployment.
• A right-to-left shunt was identified as the cause, attributed to the patient's pre-existing pulmonary hypertension.

Findings:

• The intraoperative hypoxia and hypotension were directly linked to the right-to-left shunt.
• Prompt closure of the atrial septal defect effectively resolved the hemodynamic instability.
• The patient tolerated the procedure and subsequent recovery well.

Implications:

• Transseptal mitral valve-in-valve replacement can be a viable option for high-risk patients with degenerated mitral valves.
• Careful management of atrial septal defect creation and closure is crucial to mitigate shunt-related complications.
• This case highlights the importance of addressing underlying pulmonary hypertension and shunt physiology during transcatheter valve interventions.