Structural Heart Disease, Acyanotic

Key Features

• Newborn infants who present with serious acyanotic heart disease usually have heart failure secondary to left-sided outflow tract obstruction

• Infants with left-to-right shunt lesions (eg, ventricular septal defect) may have murmurs in the newborn period, but clinical symptoms do not occur until pulmonary vascular resistance drops enough to cause significant shunting and subsequent heart failure (usually at 3–4 weeks of age)

Clinical Findings

• Infants with left-sided outflow obstruction generally do well in the first days of life until the ductus arteriosus—the source of all or some of the systemic flow—narrows

• Tachypnea, tachycardia, heart failure, and metabolic acidosis develop

• On examination, these infants have abnormalities of the pulses

  • In aortic atresia (hypoplastic left-sided heart syndrome) and stenosis, all peripheral pulses are diminished

  • In aortic coarctation, differential pulses (diminished or absent in the lower extremities) are evident

  • SpO₂ and blood pressure may be lower in the legs than in the right upper extremity

Diagnosis

• Chest radiographs show a large heart and pulmonary edema

• Echocardiography confirms diagnosis

Treatment

• Early stabilization includes supportive therapy as needed (eg, intravenous glucose, oxygen, ventilation for respiratory failure, and vasopressor support)

• Specific therapy includes infusions of prostaglandin E₁ (0.0125–0.025 μg/kg/min) to maintain ductal patency