Treatment of Heart Failure in Neonates
Neonatal heart failure requires immediate echocardiographic diagnosis to guide etiology-specific treatment, with management varying dramatically based on whether the underlying cause is congenital heart disease with left-to-right shunt, systemic outflow obstruction, or cardiomyopathy. 1, 2
Immediate Diagnostic Approach
The essential first step is transthoracic echocardiography, which categorizes neonatal heart failure into five management-determining patterns 1, 2:
- Congenital heart disease with left-to-right shunt (VSD, ASD, PDA) - typically presents after first few weeks of life 1
- Systemic outflow obstruction (hypoplastic left heart, coarctation, interrupted aortic arch) - presents early with shock 1
- Normally functioning heart with dilated chambers - suggests arteriovenous fistula (cerebral or hepatic) or severe anemia 1
- Pericardial effusion with tamponade 1
- Dilated, poorly functioning heart - cardiomyopathy, myocarditis, or anomalous coronary artery 1
Before echocardiography, examine pulse volume in all four limbs, measure blood pressure in all extremities to rule out coarctation, and obtain ECG to identify arrhythmias (chronic tachyarrhythmias cause cardiomyopathy) 2.
Etiology-Specific Acute Management
For Left-to-Right Shunt Lesions
Administer intravenous furosemide initially and withhold oxygen therapy 1, 2. Oxygen causes pulmonary vasodilation and systemic vasoconstriction, worsening the left-to-right shunt 1. Start furosemide at 1 mg/kg/dose IV or orally every 12-24 hours 3. At doses ≤2 mg/kg/day, potassium supplementation is typically unnecessary 3. If inadequate response, increase by 1 mg/kg increments up to maximum 10 mg/kg/day, though never exceed 6 mg/kg/day for longer than 1 week due to ototoxicity risk 3.
Digoxin use remains controversial in neonates with structurally normal ventricular function, but may benefit those with reduced contractility or persistent symptoms despite furosemide 3. The combination of digoxin and furosemide increases contractility over baseline 3.
For Systemic Outflow Obstruction
Immediately administer prostaglandin E1 to maintain ductal patency and withhold oxygen 1, 2. Oxygen constricts the ductus arteriosus, which is the only source of systemic blood flow in these lesions 1. These neonates require urgent surgical or catheter-based intervention 4.
For Cardiomyopathy/Myocarditis
Follow adult heart failure principles with cautious diuretic administration, as acute preload reduction may cause hypotension 1. Use intravenous inotropes (dobutamine, dopamine, epinephrine, isoproterenol) similar to adults 1. Dobutamine increases cardiac output in pediatric patients of all ages, though it is less effective than dopamine in premature neonates for raising systemic blood pressure 5.
Critical consideration: Rule out anomalous left coronary artery from pulmonary artery by echocardiography or cardiac catheterization, as this is surgically correctable 1. Screen for metabolic causes (carnitine deficiency, selenium deficiency) which are more common in neonates than adults 1.
Chronic/Subacute Management
For ongoing management after stabilization:
- Furosemide: Continue at lowest effective dose (1-2 mg/kg/day for mild heart failure) 3
- Add spironolactone if furosemide alone inadequate at 2 mg/kg/day, rather than increasing furosemide dose 3. This decreases potassium excretion and may eliminate need for supplementation 3
- ACE inhibitors (enalapril, captopril): Use for refractory symptoms despite digoxin and furosemide 1
- Digoxin: Consider for symptomatic heart failure with reduced ventricular function 3
Critical Pitfalls to Avoid
Do not administer oxygen to neonates with undiagnosed heart failure before echocardiography - oxygen worsens left-to-right shunts and can close the ductus arteriosus in duct-dependent lesions 1, 2.
Do not use aggressive diuresis in acute presentation - neonates are preload-dependent and excessive diuresis causes hypotension 1.
Do not miss high-output heart failure from arteriovenous malformations - cerebral or hepatic AVMs present with dilated right heart chambers and biventricular dysfunction despite structurally normal heart 1, 6. These require embolization, not standard heart failure therapy 6.
Monitor for hypovolemia, electrolyte disturbances (especially hypokalemia), and ototoxicity with furosemide 3. Target urine output >1 mL/kg/hour and monitor renal function, blood pressure, and weight 3.
Surgical Considerations
For large VSDs, approximately 50% spontaneously decrease in size, so surgery is typically deferred if the infant gains weight and remains free of respiratory infections 1. However, if large left-to-right shunt persists after 6 months with elevated pulmonary artery pressure, surgical repair becomes necessary 1. Neonates with Down syndrome require earlier intervention due to accelerated pulmonary vascular disease development 7.
Heart transplantation should be considered for refractory cardiomyopathy with poor prognosis 1.