Emerging concepts in arrhythmogenic dilated cardiomyopathy

Area of Science:

• Cardiology
• Genetics
• Molecular Biology

Background:

• Dilated cardiomyopathy (DCM) is a primary cardiomyopathy often leading to heart failure and sudden death.
• Ventricular arrhythmias were previously attributed solely to left ventricular systolic dysfunction.
• Recent findings reveal heritable DCM phenotypes with disproportionate arrhythmias, suggesting arrhythmogenic origins.

Purpose of the Study:

• To emphasize the importance of genetic profiling in DCM patients with significant arrhythmic burden.
• To explore the phenotypic and genotypic overlap between arrhythmogenic DCM and left dominant arrhythmogenic cardiomyopathy (LDAC).
• To identify red flags for early diagnosis and prevention of sudden cardiac death in arrhythmogenic DCM.

Main Methods:

• Review of genetic profiles in DCM patients with disproportionate ventricular arrhythmias.
• Analysis of phenotypic and genotypic overlaps with LDAC.
• Evaluation of diagnostic tools including ECG, cardiac MRI, Holter monitoring, and family history.
• Assessment of myocarditis as a common disease expression.

Main Results:

• Specific genes (LMNA, SCN5A, FLNC, TTN, RBM20, DSP, DES, PLN) are implicated in arrhythmogenic DCM and LDAC.
• Patients with arrhythmogenic DCM may exhibit arrhythmias exceeding morphological abnormalities.
• Phenotypic and genotypic similarities exist between arrhythmogenic DCM and LDAC.
• Myocarditis is a shared feature in both conditions.

Conclusions:

• Genetic profiling is vital for identifying arrhythmogenic DCM phenotypes.
• Early detection of red flags through comprehensive evaluation aids in preventing sudden cardiac death.
• Understanding the overlap with LDAC is crucial for accurate diagnosis and management.