Left ventricular outflow tract obstruction masked by severe aortic stenosis

Area of Science:

• Cardiology
• Cardiac Surgery
• Hematology

Background:

• Aortic valve replacement is a common cardiac surgery.
• Hemolytic anemia is a rare but serious complication following aortic valve replacement.
• Paravalvular leakage is the most common cause of hemolytic anemia post-surgery.

Observation:

• An 81-year-old woman presented with severe hemolytic anemia after aortic valve replacement.
• The anemia was not attributed to paravalvular leakage.
• New-onset left ventricular outflow tract obstruction was identified postoperatively.

Findings:

• The left ventricular outflow tract obstruction was induced by afterload reduction following aortic valve replacement.
• The patient's hemolytic anemia was refractory to medical treatment.
• Dual-chamber pacing, typically used for hypertrophic cardiomyopathy, successfully treated the condition.

Implications:

• This case suggests left ventricular outflow tract obstruction as a potential, albeit uncommon, cause of hemolytic anemia post-aortic valve replacement.
• Dual-chamber pacing may be a viable therapeutic option for drug-refractory hemolytic anemia secondary to this specific obstruction.
• Further research is warranted to understand the mechanisms and incidence of this complication.