Accepted as an unclassified cardiomyopathy by the American Heart
Association or a genetic cardiomyopathy by the European Society of Cardiology, left
ventricular non-compaction is an intriguing, but poorly understood condition
characterized by the presence of a non-compacted extensive myocardial layer lining the
cavity of the left ventricle which potentially leads to malignant arrhythmias, cardiac
failure, and thromboembolism. Whether it is distinct cardiomyopathy or a
morphological heterogeneous clinical condition with phenotypic morphologic traits
often overlapping other types of cardiomyopathies remains very much debated.
Ventricular trabeculation and compaction are two of the many essential steps for
generating a functionally competent ventricular wall whereas, hyper trabeculation and
the lack of ventricular wall compaction (non-compaction) are also one of the
significant cardio-embryogenic defects associated with left ventricular noncompaction.
This chapter aims to discuss in detail the current knowledge on
embryology, epidemiology, clinical spectrum, genetics as both an isolated trait, and as
part of other cardiac diseases or complex syndromes. It also explains the physiology,
and the present pathophysiological concepts of non-compaction cardiomyopathy,
provide an up-to-date view on imaging and also reevaluate the current diagnostic
criteria and its impact on overdiagnosis of left ventricular non-compaction as well as
the available data on prognosis, and therapy. The chapter will even go further to
describe the challenges, and uncertainties facing the medical community, and the future
directions in diagnosing left ventricular non-compaction.
Keywords: Cardiomyopathy, Congenital heart disease, Cardiac magnetic
resonance, Cardiac computed tomography, Counseling, Diagnosis, Diagnostic accuracy, Epidemiology, Echocardiography, Genetics, Genetic testing, Heart failure,
Heart ventricles, Imaging, Left ventricular non-compaction, Myocardium, Myocardial
fibrosis, Mitochondrial myopathies, Non-compaction, Pathology, Pregnancy, Prognosis,
Right ventricular non-compaction, Spongy myocardium, Trabeculae.