Noncompaction cardiomyopathy is caused by a novel in‐frame desmin ( DES ) deletion mutation within the 1A coiled‐coil rod segment leading to a severe filament assembly defect

We sought to describe characteristics and outcome in adults with isolated ventricular noncompaction (IVNC). Isolated ventricular noncompaction is an unclassified cardiomyopathy due to intrauterine arrest of compaction of the loose interwoven meshwork. Knowledge regarding diagnosis, morbidity and prognosis is limited. Echocardiographic criteria for IVNC include-in the absence of significant heart lesions-segmental thickening of the left ventricular myocardial wall consisting of two layers: a thin, compacted epicardial and an extremely thickened endocardial layer with prominent trabeculations and deep recesses. Thirty-four adults (age >16 years, 25 men) fulfilled the diagnostic criteria and were followed prospectively. At diagnosis, mean age was 42 + 17 years, and 12 patients (35%) were in New York Heart Association class III/IV. Left ventricular end-diastolic diameter was 65 + 12 mm and ejection fraction 33 + 13%. Apex and/or midventricular segments of both the inferior and lateral wall were involved in >80% of patients. Follow-up was 44 + 40 months. Major complications were heart failure in 18 patients (53%), thromboembolic events in 8 patients (24%) and ventricular tachycardias in 14 patients (41%). There were 12 deaths: sudden in six, end-stage heart failure in four and other causes in two patients. Four patients underwent heart transplantation. Automated cardioverter/defibrillators were implanted in four patients. Diagnosis of IVNC by echocardiography using strict criteria is feasible. Its mortality and morbidity are high, including heart failure, thrombo-embolic events and ventricular arrhythmias. Risk stratification includes heart failure therapy, oral anticoagulation, heart transplantation and implantation of an automated defibrillator/cardioverter. As IVNC is a distinct entity, its classification as a specific cardiomyopathy seems to be more appropriate.

Left ventricular noncompaction (LVNC) is a reportedly uncommon genetic disorder of endocardial morphogenesis with a reportedly high mortality rate. The purpose of this study was to identify the clinical characteristics of children with LVNC. We retrospectively reviewed 36 children with LVNC evaluated at Texas Children's Hospital (TCH) from January 1997 to December 2002. Five children had associated cardiac lesions. There were 16 girls and 20 boys. The median age at presentation was 90 days (range, 1 day to 17 years). The median duration of follow-up was 3.2 years (range, 0.5 to 12 years). Twenty-seven patients (75%) had ECG abnormalities, most commonly biventricular hypertrophy (10 patients, 28%). Both ventricles were involved in 8 patients (22%) and only the left ventricle in 28 patients (78%). Left ventricular systolic function was depressed in 30 patients (83%), with a median ejection fraction of 30% (range, 15% to 66%) at diagnosis. Nine patients presenting in the first year of life with depressed left ventricular contractility had a transient recovery of function; however, ejection fraction deteriorated later in life, at a median interval of 6.3years (range, 3 to 12 years). Two patients had an "undulating" phenotype from dilated to hypertrophic cardiomyopathy. Two patients (6%) were identified with an underlying G4.5 gene mutation. Five patients (14%) died during the study. LVNC does not have an invariably fatal course when diagnosed in the neonatal period. A significant number of patients have transient recovery of function followed by later deterioration, which may account for many patients presenting as adults, some manifesting an "undulating" phenotype.

Left ventricular (LV) noncompaction (LVNC) is a distinct cardiomyopathy featuring a thickened bilayered LV wall consisting of a thick endocardial layer with prominent intertrabecular recesses with a thin, compact epicardial layer. Similar to hypertrophic and dilated cardiomyopathy, LVNC is genetically heterogeneous and was recently associated with mutations in sarcomere genes. To contribute to the genetic classification for LVNC, a systematic cardiological family study was performed in a cohort of 58 consecutively diagnosed and molecularly screened patients with isolated LVNC (49 adults and 9 children). Combined molecular testing and cardiological family screening revealed that 67% of LVNC is genetic. Cardiological screening with electrocardiography and echocardiography of 194 relatives from 50 unrelated LVNC probands revealed familial cardiomyopathy in 32 families (64%), including LVNC, hypertrophic cardiomyopathy, and dilated cardiomyopathy. Sixty-three percent of the relatives newly diagnosed with cardiomyopathy were asymptomatic. Of 17 asymptomatic relatives with a mutation, 9 had noncompaction cardiomyopathy. In 8 carriers, nonpenetrance was observed. This may explain that 44% (14 of 32) of familial disease remained undetected by ascertainment of family history before cardiological family screening. The molecular screening of 17 genes identified mutations in 11 genes in 41% (23 of 56) tested probands, 35% (17 of 48) adults and 6 of 8 children. In 18 families, single mutations were transmitted in an autosomal dominant mode. Two adults and 2 children were compound or double heterozygous for 2 different mutations. One adult proband had 3 mutations. In 50% (16 of 32) of familial LVNC, the genetic defect remained inconclusive. LVNC is predominantly a genetic cardiomyopathy with variable presentation ranging from asymptomatic to severe. Accordingly, the diagnosis of LVNC requires genetic counseling, DNA diagnostics, and cardiological family screening.