Cardiomyopathies: is it time for a molecular classification?

Area of Science:

• Cardiology
• Genetics
• Pathology

Background:

• Primary myocardial diseases present complex aetiopathogenesis and historical classification challenges.
• The 1995 World Health Organization (WHO) classification significantly advanced terminology and recognized new entities like arrhythmogenic right ventricular cardiomyopathy.
• Inflammatory heart disease is now definitively classified as a cardiomyopathy.

Purpose of the Study:

• To review the evolving definitions and classifications of primary myocardial diseases.
• To discuss the implications of new definitions encompassing cardiac dysfunction, rhythm disturbances, and arrhythmogenicity.
• To explore the need for a genomics-based classification system for cardiomyopathies.

Main Methods:

• Literature review of historical and current classifications of cardiomyopathies.
• Analysis of the impact of the 1995 WHO classification.
• Discussion of emerging concepts in cardiomyopathy definition and genetic basis.

Main Results:

• The 1995 WHO classification unified terminology and recognized novel cardiomyopathies.
• Current definitions expand beyond contractility and diastolic dysfunction to include rhythm and conduction abnormalities.
• Molecular genetics reveals a genetic background for many previously idiopathic cardiomyopathies.

Conclusions:

• Cardiomyopathy definitions have broadened to encompass a wider spectrum of cardiac dysfunction.
• The discovery of genetic underpinnings necessitates a debate on a genomics-driven classification.
• Future classification systems may integrate genetic information for improved understanding and management of heart muscle diseases.