Chapter 8 - Left Ventricular Noncompaction Cardiomyopathy

Abstract

Left ventricular noncompaction (LVNC), the most recently classified form of cardiomyopathy, is characterized by abnormal trabeculations in the left ventricle (LV), most commonly at the apex. It may be associated with LV dilation or hypertrophy, systolic and/or diastolic dysfunction, or various forms of congenital heart disease (CHD). Affected individuals are at risk of LV or right ventricular failure, or both. Genetic inheritance arises in at least 30–50% of patients, and several genes that cause LV noncompaction have been identified. These genes appear to generally encode sarcomeric (contractile apparatus) or cytoskeletal proteins, although, in the case of LVNC with CHD, disturbance of the Notch signaling pathway appears to be part of a “final common pathway” for this form of the disease. In addition, disrupted mitochondrial function and metabolic abnormalities have a causal role as well. Treatments focus on improvement of cardiac efficiency and reduction of mechanical stress in those with systolic dysfunction. Further, arrhythmia therapy and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death are mainstays of treatment when deemed necessary and appropriate. In this chapter, a current view of left ventricular noncompaction is outlined.