Imaging Features of Arrhythmogenic Cardiomyopathies

Area of Science:

• Cardiology
• Genetics
• Medical Imaging

Background:

• Arrhythmogenic cardiomyopathy (ACM) is a genetic disease involving fibrofatty myocardial replacement, leading to arrhythmias and sudden cardiac death.
• Most ACM cases link to desmosomal gene variants, affecting cell-to-cell adhesion in cardiac and skin tissues.
• ACM can affect the right ventricle, left ventricle, or both, evolving beyond its initial right-dominant description.

Purpose of the Study:

• To introduce the Padua criteria as an update to the 2010 task force criteria for diagnosing arrhythmogenic cardiomyopathy.
• To provide updated diagnostic criteria for the right-dominant ACM phenotype and introduce criteria for left-predominant and biventricular phenotypes.
• To highlight the role of cardiac MRI, particularly late gadolinium enhancement, in diagnosing and characterizing ACM.

Main Methods:

• Review and comparison of the 2010 task force criteria and the new Padua criteria for ACM diagnosis.
• Inclusion of updated criteria for structural, tissue characterization, repolarization, depolarization, arrhythmic, and family history components.
• Emphasis on cardiac MRI findings, including ventricular dilatation, dysfunction, wall motion abnormalities, and late gadolinium enhancement for tissue characterization.

Main Results:

• The Padua criteria offer updated diagnostic standards for right-dominant ACM and new criteria for left-predominant and biventricular forms.
• Cardiac MRI, especially late gadolinium enhancement, is emphasized as a key diagnostic and tissue characterization tool.
• Differential diagnoses for right-dominant ACM include shunts and normal variants; left-dominant ACM can mimic myocarditis, sarcoidosis, or dilated cardiomyopathy.

Conclusions:

• The Padua criteria represent a significant advancement in diagnosing arrhythmogenic cardiomyopathy, accommodating a broader understanding of its phenotypes.
• Enhanced utilization of cardiac MRI, particularly late gadolinium enhancement, improves diagnostic accuracy and characterization of ACM.
• Accurate diagnosis of ACM phenotypes is crucial for appropriate management and differentiating from other cardiac conditions.