Pediatrics
A 3-year-old child presents with new-onset exertional dyspnea and palpitations following a viral URI 3 weeks…
A 3-year-old child presents with new-onset exertional dyspnea and palpitations following a viral URI 3 weeks ago. Exam shows tachycardia, tachypnea, and gallop rhythm. What is the most appropriate diagnostic test?
Explanation
Core Concept: Acute viral myocarditis leading to dilated cardiomyopathy and heart failure in a pediatric patient.
Clinical Presentation:
- Recent viral prodrome followed by signs of heart failure: tachycardia out of proportion to fever, tachypnea, exertional dyspnea, gallop rhythm (S3), hepatomegaly, poor feeding.
- Complications: Cardiogenic shock, fatal arrhythmias, need for heart transplantation.
Diagnosis:
- First-line & Gold standard: Echocardiography to assess ventricular function (depressed ejection fraction), chamber dilation, and rule out structural congenital heart disease.
- Adjuncts: ECG (sinus tachycardia, ST-T wave changes), chest X-ray (cardiomegaly), troponin/BNP, and cardiac MRI. Endomyocardial biopsy is the definitive gold standard but rarely performed in children unless specific indications exist.
Management:
- Acute: Hemodynamic support, diuretics, inotropes, and sometimes mechanical circulatory support (ECMO).
- Long-term: Guideline-directed heart failure medications (ACE inhibitors, beta-blockers); heart transplant if refractory.