What is Left Ventricular Non-Compaction (LVNC) cardiomyopathy?

From the Guidelines

Left Ventricular Non-Compaction (LVNC) cardiomyopathy is a rare cardiac disease characterized by prominent trabeculations within the left ventricular myocardium, separated by deep recesses, often associated with left ventricular dysfunction and a variety of clinical presentations.

Characteristics of LVNC

• LVNC is a relatively novel cardiomyopathy with a genetic basis in some instances and a variety of inheritance patterns 1
• The disease is characterized by a two-layered structure of the myocardial left ventricular wall on imaging testing, with a high ratio of non-compacted to compacted layer of the left ventricle 1
• Common ECG abnormalities in LVNC include T-wave inversion, ST-segment depression, or ventricular conduction delay, mostly left bundle branch block (LBBB) 1

Clinical Presentation

• Clinical presentation of LVNC includes varying degrees of systolic heart failure, ventricular tachyarrhythmias, and/or systemic thromboembolism 1
• The risk of thromboembolism in LVNC cardiomyopathy is increased, with an up to 24% risk of cerebral embolism at follow-up 1
• LVNC can be asymptomatic or present with severe heart failure, ventricular arrhythmias, and thromboembolic events 1

Diagnosis and Genetics

• Diagnosis of LVNC relies on cardiac imaging, including echocardiography and cardiac magnetic resonance (CMR) 1
• Genetic testing in patients with LVNC appears to detect clinically significant variants in 35% to 40% of people, with most-common sarcomere-encoding genes 1
• Multiple genes have been identified as causing LVNC, including mutations in the Z-line protein–encoding ZASP/LDB3 gene, sarcomere-encoding genes, and calcium-handling genes 1

From the Research

Definition and Characteristics of Left Ventricular Non-Compaction (LVNC) Cardiomyopathy

• Left Ventricular Non-Compaction (LVNC) cardiomyopathy is a condition characterized by prominent left ventricular trabeculae separated from deep intertrabecular recesses 2.
• It is a relatively rare congenital condition that results from arrest of the normal compaction process of the myocardium during fetal development 3.
• LVNC shows variability in its genetic pattern, pathophysiologic findings, and clinical presentations 3, 4.

Diagnosis and Clinical Presentations

• LVNC can be diagnosed by echocardiography, cardiac magnetic resonance imaging (CMR), computerized tomography, and left ventriculography 3, 5.
• The clinical presentations of LVNC are variable, ranging from asymptomatic patients to patients who develop ventricular arrhythmias, thromboembolism, heart failure, and sudden cardiac death 3, 5.
• LVNC can occur in isolation or coexist with other cardiac and/or systemic anomalies 3, 5.

Genetic Heterogeneity and Pathogenesis

• LVNC is a genetically heterogeneous disorder that can be associated with other anomalies 3, 4.
• Several candidate causative genes are also mutated in other cardiomyopathies, suggesting a possible shared molecular and/or cellular etiology 4.
• The pathogenesis of LVNC has not yet been fully elucidated, and there is a lack of clarity regarding its significance as a cause of cardiomyopathy 4.

Management and Prognosis

• Management of LVNC is symptom-based, and patients with symptoms have a poorer prognosis 3.
• Accurate diagnosis is key to minimizing risks associated with LVNC, and treatment may involve genetic testing, family screening, implantable cardioverter defibrillator placement, anticoagulation, and prescriptions/restrictions for physical activity 5, 6.