What is the most appropriate management for a 2-year-old boy with a history of hypertrophic cardiomyopathy (HCM) and aortic stenosis, presenting with increased shortness of breath during physical activity, diastolic murmur, and severe aortic stenosis (68%) with left ventricular hypertrophy?

Management of 2-Year-Old with HCM, Severe Aortic Stenosis, and Progressive Symptoms

This child requires urgent mechanical aortic valve replacement combined with septal myectomy. 1

Rationale for Surgical Intervention

The combination of symptomatic severe aortic stenosis (68%) and hypertrophic cardiomyopathy in a pediatric patient is life-threatening and demands definitive surgical correction. 1 The presence of increasing dyspnea during physical activity indicates hemodynamic compromise from dual left ventricular outflow tract obstruction—both fixed (valvular stenosis) and dynamic (HCM-related). 2

Why Combined Surgery is Optimal

• Single-stage correction addresses all structural abnormalities: Surgical myectomy combined with aortic valve replacement corrects both the fixed valvular stenosis and the dynamic septal obstruction in one procedure. 1

• The modified Konno procedure is specifically designed for young children with basal obstruction, allowing simultaneous aortic valve replacement while addressing septal hypertrophy with satisfactory long-term results. 1

• Transaortic septal myectomy adds minimal additional risk to valve replacement and critically prevents postoperative hemodynamic instability by relieving the left ventricular outflow tract obstruction. 1

Why Other Options Are Inappropriate

Reassurance is contraindicated: This child has symptomatic severe aortic stenosis with progressive dyspnea, indicating advanced disease that will not improve without intervention. 1 The natural history of untreated severe aortic stenosis in children includes sudden death risk and progressive heart failure. 2

TAVR is not appropriate for pediatric patients: This 2-year-old requires a mechanical valve for durability given decades of expected lifespan, and TAVR technology is neither designed nor approved for toddlers. 1 Additionally, TAVR does not address the septal hypertrophy component of HCM. 3

Activity restriction alone is inadequate: While appropriate for managing HCM symptoms in stable patients 2, this child already experiences symptoms at baseline activity levels, indicating advanced disease requiring definitive treatment. 1 Restriction does not address the fixed severe aortic stenosis. 1

Post-Operative Management Requirements

• Intraoperative transesophageal echocardiography must assess adequacy of septal myectomy and valve function immediately. 1

• Follow-up transthoracic echocardiography within 3-6 months to evaluate procedural results, then serial imaging every 1-2 years to monitor for residual obstruction, valve function, and hypertrophy progression. 1

• Beta-blocker therapy post-operatively to manage residual HCM symptoms and reduce arrhythmia risk. 1

• Lifelong restriction from competitive sports given the underlying HCM diagnosis, even after successful surgical correction. 2, 1

• Mechanical valve anticoagulation management with appropriate INR monitoring and warfarin dosing for pediatric patients. 1

Critical Pitfalls to Avoid

Do not attempt medical management alone with beta-blockers or calcium channel blockers—these agents do not address fixed valvular stenosis and will not prevent progression in severe disease. 1 Medical therapy is appropriate for obstructive HCM without valvular pathology 2, but this child has dual pathology requiring surgical correction.

Do not underestimate the complexity: The combination of HCM and aortic stenosis creates challenging hemodynamics where the severe afterload from aortic stenosis may mask the dynamic obstruction from HCM. 4 Both must be addressed surgically to prevent postoperative complications. 5