From the Guidelines
Treatment for orthopnea in a patient with a left-to-right shunt (84M) should focus on reducing pulmonary congestion and improving cardiac function, with consideration of shunt closure if the patient is a suitable candidate, as supported by the 2018 AHA/ACC guideline for the management of adults with congenital heart disease 1.
Initial Management
Initial management includes diuretics such as furosemide 20-40mg orally daily or twice daily to reduce fluid overload. Angiotensin-converting enzyme inhibitors like enalapril 2.5-10mg twice daily or lisinopril 5-20mg daily can help reduce afterload and improve cardiac output. Beta-blockers such as metoprolol 25-100mg twice daily may be added cautiously to control heart rate.
Supportive Measures
Elevating the head of the bed 30-45 degrees during sleep will help alleviate orthopnea symptoms. Oxygen supplementation may be necessary if hypoxemia is present. Salt restriction to 2g daily and fluid restriction to 1.5-2L daily are important supportive measures. These interventions work by reducing pulmonary venous pressure, decreasing the left-to-right shunt, and improving overall hemodynamics.
Shunt Closure
In adults with isolated secundum ASD causing impaired functional capacity, right atrial and/or RV enlargement, and net left-to-right shunt sufficiently large to cause physiological sequelae (e.g., Qp:Qs ≥1.5:1) without cyanosis at rest or during exercise, transcatheter or surgical closure to reduce RV volume and improve exercise tolerance is recommended, provided that systolic PA pressure is less than 50% of systolic systemic pressure and pulmonary vascular resistance is less than one third of the systemic vascular resistance, as stated in the 2018 AHA/ACC guideline 1.
Monitoring and Adjustment
Regular monitoring of electrolytes, renal function, and clinical symptoms is essential to adjust medication dosages appropriately. In severe cases unresponsive to medical therapy, surgical correction of the shunt may be considered if the patient is a suitable candidate despite advanced age.
- Key considerations for shunt closure include the presence of significant left-to-right shunting, elevated pulmonary pressure, and pulmonary vascular resistance, as well as the patient's overall clinical status and suitability for the procedure 1.
- Consultation with ACHD and pulmonary hypertension providers is important given the low frequency of this circumstance and the complexity of decision-making 1.
From the Research
Treatment of Left-to-Right Shunt with Orthopnea
- The treatment of left-to-right shunt with orthopnea is primarily focused on reducing the left atrial pressure and improving heart failure symptoms 2.
- ACE inhibitors have been shown to be effective in reducing left-to-right shunt in pediatric patients with heart failure, particularly in those with elevated systemic vascular resistance 3.
- The use of ACE inhibitors, such as captopril, enalapril, and cilazapril, can lower left atrial and right atrial pressures, and decrease pulmonary vascular resistance in pediatric patients with heart failure 3.
- Surgical or trans-catheter repair of the cardiac defect is often necessary to prevent long-term complications, such as increased pulmonary vascular resistance and pulmonary arterial hypertension 4, 5.
- The treatment approach may vary depending on the underlying cardiac defect, left ventricular ejection fraction, pulmonary vascular resistance, and right ventricular structure and function 2, 4.
Management Considerations
- Perioperative anesthetic management is crucial in patients with left-to-right shunt undergoing surgical repair, and requires a thorough understanding of cardiopulmonary changes and treatment options 4.
- The use of diuretics, digoxin, and beta-blockers may be necessary in addition to ACE inhibitors to manage chronic heart failure in children with left-to-right shunt 3.