Myths to debunk: the non-compacted myocardium

Area of Science:

• Cardiology
• Human Anatomy
• Medical Diagnostics

Background:

• Left ventricular non-compaction (LVNC) is characterized by prominent trabeculae, a thin compacted layer, and deep inter-trabecular recesses.
• Trabecular anatomy is unique to each individual, acting as a cardiac fingerprint.
• LVNC is observed in healthy individuals, athletes, pregnant women, and patients with various systemic diseases, and can be acquired or reversible.

Purpose of the Study:

• To clarify the diagnostic implications of left ventricular non-compaction (LVNC).
• To differentiate LVNC as a morphological finding from LVNC as a primary cardiomyopathy.
• To guide appropriate terminology and diagnosis when LVNC is associated with other cardiac conditions.

Main Methods:

• Review of existing literature and clinical observations regarding LVNC.
• Analysis of the association between LVNC morphology and various cardiac and systemic conditions.
• Evaluation of the utility of genetic testing in diagnosing LVNC-related conditions.

Main Results:

• LVNC is a common finding in healthy individuals and athletes, and can be reversible.
• Misnaming cardiomyopathies as 'LVNC cardiomyopathy' can obscure the underlying pathology.
• Genetic testing often identifies causes of associated cardiomyopathies rather than LVNC itself.

Conclusions:

• The term 'LVNC cardiomyopathy' should be used cautiously as LVNC describes morphology, not necessarily a functional cardiac disease.
• When LVNC is associated with LV dilation, dysfunction, hypertrophy, or congenital heart disease (CHD), the primary diagnosis should be cardiomyopathy or CHD, with LVNC as a descriptor.
• Accurate diagnosis and terminology are crucial for understanding the prognosis and management of patients with LVNC.