Heart Failure in Children

Introduction & Etiology - Tiny Tickers Trouble

• Heart Failure (HF): Clinical syndrome where the heart cannot pump enough blood to meet the body's metabolic demands or can do so only at elevated filling pressures.
• Etiology (Common Causes):
  • Congenital Heart Defects (CHD): Predominant cause in infancy.
    • Volume Overload: Ventricular Septal Defect (VSD), Patent Ductus Arteriosus (PDA).
    • Pressure Overload: Aortic Stenosis (AS), Coarctation of Aorta.
  • Myocardial Dysfunction: Cardiomyopathies (dilated, hypertrophic), myocarditis.
  • Arrhythmias: Persistent tachyarrhythmias or bradyarrhythmias.
  • High-Output States: Severe anemia, large AV malformations.

⭐ In infants, the most common cause of heart failure is a large left-to-right shunt, such as a Ventricular Septal Defect (VSD).

Pathophysiology & Classification - Pump Under Pressure

• Heart failure (HF): Heart unable to meet body's metabolic demands.
• Pathophysiology: ↓ Cardiac Output (CO) triggers neurohormonal activation (SNS, RAAS).
  • Initially adaptive; chronic activation → maladaptive ventricular remodeling (hypertrophy, dilation), worsening HF.
• Classification based on:

⭐ BNP & NT-proBNP are key biomarkers; levels ↑ with ventricular wall stress, aiding diagnosis & severity assessment.

Clinical Features & Severity - Spotting the Signs

• Infants & Young Children (Ross Classification):
  • Poor feeding, failure to thrive (FTT)
  • Tachypnea (>60/min), diaphoresis (esp. with feeds)
  • Hepatomegaly (>2-3 cm BCM), irritability
  • Ross Class III/IV: Marked symptoms, FTT, symptoms at rest (e.g., grunting)
• Older Children (NYHA-like):
  • Dyspnea on exertion, orthopnea
  • Fatigue, exercise intolerance
  • Peripheral edema, persistent cough
• General Signs: Tachycardia (>160/min infant, >100/min child), S3 gallop, cool extremities, cardiomegaly.

⭐ > In infants, diaphoresis during feeding is a classic sign of heart failure, often mistaken for normal sweating.

Diagnostic Approach - Cracking the Case

• Clinical suspicion: Poor feeding, tachypnea, FTT, tachycardia, hepatomegaly.
• Key Investigations:
  • CXR: Cardiomegaly (CTR > 0.6 infants, > 0.5 children), pulmonary venous congestion/edema.
  • ECG: Ventricular hypertrophy, arrhythmias.
  • Echocardiography: Gold standard. Confirms diagnosis. Assesses structure, function (EF), etiology.
  • Biomarkers: ↑ BNP or NT-proBNP levels.

    ⭐ Elevated BNP/NT-proBNP aids differentiating cardiac vs. non-cardiac dyspnea & correlates with severity.

Management Strategies - Mending Little Hearts

• Primary Goals: Improve symptoms & quality of life, slow progression, ↑survival. Always treat underlying cause.
• General Measures: Oxygen PRN, optimal nutrition (caloric density), judicious Na+/fluid restriction.
• Pharmacotherapy (Chronic HF):
  • Diuretics: Furosemide (loop); Spironolactone (K-sparing, anti-remodeling).
  • ACE inhibitors (e.g., Captopril 0.1-0.3 mg/kg/dose TID initially) or ARBs: ↓afterload & ↓preload.
  • Beta-blockers (e.g., Carvedilol): Only in stable, euvolemic patients. Start low, titrate slow.
  • Digoxin: Positive inotrope for symptomatic relief. Narrow therapeutic index. 📌 Monitor levels & for toxicity (nausea, vomiting, arrhythmia).
• Acute Decompensated HF (ADHF):
  • IV loop diuretics (Furosemide).
  • IV inotropes (e.g., Milrinone, Dobutamine).
  • Oxygen; consider non-invasive/invasive ventilation.

⭐ In ADHF with low output ("cold & wet"), Milrinone (inodilator) is often preferred for reducing preload/afterload.

High‑Yield Points - ⚡ Biggest Takeaways

• Congenital Heart Defects (CHD), especially VSD & PDA, are the primary cause in infants.
• Myocarditis and cardiomyopathies are key acquired causes.
• Clinical signs: Infants show poor feeding, tachypnea, diaphoresis; older children exhibit dyspnea, edema.
• Failure to thrive (FTT) is a common presentation in infants.
• Echocardiography is crucial for diagnosis and assessing cardiac function.
• Mainstay treatment: Diuretics (Furosemide), ACE inhibitors, Digoxin (monitor toxicity).
• Address underlying causes and precipitating factors like anemia or infection.