Differences between genetic dilated cardiomyopathy and myocarditis in children presenting with severe cardiac...

Area of Science:

• Pediatric Cardiology
• Cardiovascular Pathology

Background:

• Acute myocarditis presents as severe heart failure in children.
• Distinguishing myocarditis from genetic cardiomyopathy is clinically difficult.
• Parvovirus B19 is a primary cause of pediatric myocarditis.

Purpose of the Study:

• Identify clinical presentation patterns differentiating pediatric myocarditis from genetic cardiomyopathy.
• Assess invasive and non-invasive measures for differential diagnosis.
• Evaluate diagnostic utility of endomyocardial biopsy in these conditions.

Main Methods:

• Retrospective descriptive study of pediatric patients (0-16 years) with new-onset heart failure (LVEF < 35%).
• Patients underwent endomyocardial biopsy (EMB) between April 2007 and December 2020.
• Classification into Group 1 (myocarditis, n=18) and Group 2 (genetic cardiomyopathy, n=9).

Main Results:

• Myocarditis cases showed more fulminant/acute presentation (77.8% vs 33.3%), higher cardiac enzyme elevation (p=0.011), lower LV dimension z-score (2.2 vs 5.4), and increased wall thickness (88.8% vs 33.3%).
• Myocarditis group had more frequent edema on EMB.
• Notably, 77.8% of genetic cardiomyopathy patients exhibited inflammation on EMB, meeting criteria for inflammatory cardiomyopathy.

Conclusions:

• Differentiating pediatric myocarditis from genetic cardiomyopathy is challenging, even with endomyocardial biopsy.
• Some genetic cardiomyopathies fulfill diagnostic criteria for inflammatory cardiomyopathy.
• Developing predictive models using invasive/non-invasive measures is crucial for accurate diagnosis.