Can lanoxin (digoxin) be used in a patient with Tricuspid Valve Atresia, hypoplastic right ventricle, and severe Pulmonic Stenosis not yet on Prostaglandin E1 (PGE1)?

Digoxin Should Be Avoided in This Clinical Scenario

Digoxin is not recommended for a patient with tricuspid valve atresia, hypoplastic right ventricle, and severe pulmonic stenosis not yet on PGE1, as there is no specific medical therapy for pulmonary stenosis and digoxin has limited efficacy in right-sided heart failure. 1

Rationale for Avoiding Digoxin

Limited Evidence for Right-Sided Heart Failure

• There are few data to support the efficacy of digoxin in right-sided heart failure associated with pulmonary stenosis or right ventricular dysfunction 1
• Digoxin's primary role is in left ventricular systolic dysfunction and atrial fibrillation, not in congenital right-sided obstructive lesions 2

Contraindications in Obstructive Physiology

• Digoxin should be avoided in patients with obstructive physiology where positive inotropic effects may be detrimental 1
• In hypertrophic cardiomyopathy with left ventricular outflow tract obstruction, digoxin is specifically contraindicated due to its positive inotropic effects that can worsen obstruction 1
• While this guideline addresses left-sided obstruction, the same physiologic principle applies to severe right ventricular outflow tract obstruction

Appropriate Management Strategy

Immediate Stabilization

• Prostaglandin E1 (PGE1) infusion is the critical first-line therapy for ductal-dependent lesions like tricuspid atresia with severe pulmonic stenosis to maintain pulmonary blood flow 1
• Patients with severe cyanosis due to obstruction to pulmonary flow require urgent intervention to augment pulmonary blood flow 1

Medical Management

• If right-sided heart failure develops, diuretics are the primary medical therapy, not digoxin 1
• Oxygen supplementation should be provided to maintain adequate saturations 1
• Avoid dehydration and maintain adequate preload 1

Definitive Treatment

• Surgical or catheter-based intervention is required for definitive management of severe pulmonary stenosis 1
• Options include systemic-to-pulmonary artery shunt procedures (modified Blalock-Taussig shunt) for initial palliation 1
• Right ventricular outflow tract stenting may be considered as a palliative procedure in neonates with tricuspid atresia and critical pulmonic stenosis 3
• Staged palliation toward eventual Fontan completion is the typical pathway for tricuspid atresia with hypoplastic right ventricle 1

Clinical Pitfalls to Avoid

Common Misdiagnoses

• Do not misdiagnose pulmonary arterial hypertension in these patients - PAH is very rare in isolated pulmonary stenosis and tricuspid atresia 1
• Cyanosis in right ventricular outflow tract lesions should prompt evaluation for the underlying obstructive lesion, not empiric medical therapy 1

Inappropriate Medication Use

• Avoid vasodilators (nitrates, phosphodiesterase inhibitors) that can worsen hemodynamics in obstructive lesions 1
• Do not use digoxin as first-line therapy for symptoms in this population - it will not address the underlying pathophysiology 1

Urgent Consultation Required

• Surgeons with training and expertise in congenital heart disease should be consulted immediately for operative planning 1
• These complex lesions require specialized care at centers with expertise in adult congenital heart disease 1