Arrhythmogenic right ventricular dysplasia (ARVD) is a clinical and pathologic entity whose diagnosis rests on electrocardiographic and angiographic criteria; pathologic findings, replacement of ventricular myocardium with fatty and fibrous elements, preferentially involve the right ventricular (RV) free wall. There is a familial occurrence in about 50% of cases, with autosomal dominant inheritance with variable penetrance and polymorphic phenotypic expression, and is one of the major genetic causes of juvenile sudden death. When the dysplasia is extensive, it may represent the extensive form of ARVCM (arrhythmogenic right ventricular cardiomyopathy). In this review, we focus on the some candidate genes mutations and information on some genotype-phenotype correlation in the ARVD. Our findings are in agreement with those of European Society of Cardiology who stated that: genetic analysis is usefull in families with RV cardiomyopathy because whenever a pathogenetic mutation is identified, it becomes possible to establish a presymptomatic diagnosis of the disease among family members and to provide them with genetic counseling to monitor the development of the disease and to assess the risk of transmitting the disease offspring. On the basis of current knowledge, genetic analysis does not contribute to risk stratification of arrhythmogenic RV cardiomyopathy.

Isolated non-compaction of the ventricular myocardium (INVM), sometimes referred to as ‘spongy myocardium’, is a congenital and exceedingly rare cardiomyopathy. Isolated ventricular non-compaction occurs in the absence of other structural heart diseases and, hypothetically, it is due to the arrest of myocardial morphogenesis. Isolated non-compaction of the ventricular myocardium may manifest itself from infancy to young adulthood with a high mortality rate. Both sexes are affected. In our study, we present a case of INVM (left and right ventricles) in a 3-year-old girl, diagnosed by two-dimensional echocardiography. The anomaly presented as a restrictive cardiomyopathy. The girl was admitted to our hospital with heart failure, when she was 10 months old. She was treated with dopamine, digoxin, furosemide, spironolactone, and acenocoumarol and her condition improved. Presently, the girl remains asymptomatic and for 3 years of follow-up, her development has been almost normal. We here describe the genetic background of this disorder (based on a literature review).

Aberrant expression of various miRNA species has been implicated in numerous cardiac diseases, e.g., heart failure, hypertrophy, conduction disturbances, and arrhythmogenesis. The aim of this study was to determine whether miR-1, miR-133a, and miR-133b can serve as biomarkers in the diagnosis of ventricular (Va) and supraventricular (SVa) arrhythmias in pediatric patients. Molecular analysis included 30 patients with SVa or Va (13-17.5 years; 14 boys/16 girls) and 20 non-arrhythmic controls. Arrhythmia was confirmed by 24-h Holter ECG recording. miRNA was extracted from serum using the miRNeasy^R Serum/Plasma Kit. miScript SYBR Green PCR Kit (Qiagen) was used to quantify miRNA expression. The levels of miR-1 and miR-133a expression were significantly higher in the SVa group than in the controls (p ​= ​0.0327 and p<0.0001, respectively). Additionally, both groups of patients with arrhythmia presented significantly lower expression levels of miR-133b than the controls (p<0.01 for both comparisons). The level of miR-133a expression in the SVa group was significantly higher than in the Va group (p ​= ​0.0124). ROC analysis demonstrated that the expressions of miR-1 and miR-133a could differentiate between the SVa patients and arrhythmia-free controls (AUC ​= ​0.7091, p ​= ​0.07 and AUC ​= ​0.8021, p ​= ​0.007, respectively). Furthermore, the expression of miR-133b was shown to distinguish patients with SVa and Va from the arrhythmia-free controls (AUC ​= ​0.7273, p ​= ​0.07 and AUC ​= ​0.8030, p ​= ​0.04, respectively). miR-1, miR-133a, and miR-133b have the potential to become diagnostic biomarkers of arrhythmia in pediatric patients.

Introduction: The main goal of this study was to examine the patient age and sex dependent expression of KCNQ1 and HERG genes that encode potassium channels responsible for the occurrence of long QT syndrome (LQTS). Material and methods : The study enrolled 43 families whose members...