Studies have demonstrated that the occurrence of a variety of arrhythmias presents an obvious circadian rhythm,which may be regulated by circadian rhythm genes.Circadian cycle and light stimulation can affect circadian rhythm genes and proteins,which constitute a transcription-translation loop that can regulate the ion channels in myocardial cell membrane through nervous-humoral regulation and changes in central clock-sub-clock gene expression,thereby modulating arrhythmia.This article reviews the molecular basis,mechanism,and performance of circadian rhythm in regulating arrhythmia.
Humans ; Circadian Rhythm/genetics* ; Myocytes, Cardiac ; Arrhythmias, Cardiac

Arrhythmias, Cardiac ; Humans ; Potassium Channels, Voltage-Gated ; genetics

Sudden cardiac death (SCD) refers to sudden stop of breath and heartbeat and death within one hour caused by underlying cardiac diseases. Clinical manifestation of inherited arrhythmia is lethal arrhythmia without gross cardiac lesions, which can lead to SCD. The autopsy and pathological examination are difficult to identify the cause of death. Fatal mechanism of inherited arrhythmia is the change in the genes encoding for cardiac ion channel protein, which causes the dysfunctions of cardiac electrical activity. It is very important to detect genetic mutation by the technique of molecular biology in negative autopsy. This review presents the latest research on the relation between SCD and inherited arrhythmia, and the application of molecular autopsy used in identifying SCD due to inherited arrhythmia and its candidate gene.
Arrhythmias, Cardiac/pathology* ; Autopsy/methods* ; Cardiovascular Diseases/genetics* ; Death, Sudden, Cardiac/pathology* ; Humans ; Mutation ; Pathology, Molecular

microRNAs are one kind of endogenous no-encoding RNA with about 22 nucleotides in length, and inhibited the translation of mRNAs by partially complementary binding to the 3' UTR of target mRNAs in the post-transcriptional level. Recent research shows that miRNAs function in the physiological and pathological processes of heart, especially involved in the occurrence and progress of arrhythmias. Abnormal miRNAs alters the protein expression of ion channels, causes the cardiac dysfunction, and triggers heart arrhythmias. The article summarized recent advances about roles of miRNA in arrhythmias and related cardiomyopathy, and discussed the therapeutic potential of miRNAs for heart diseases.
Arrhythmias, Cardiac ; genetics ; metabolism ; Cardiomyopathies ; genetics ; metabolism ; Humans ; MicroRNAs ; genetics ; metabolism

Ion channelopathies are the mainly etiopathogenisis of inherited arrhythmia. Those arrhythmia syndromes are commonly caused by ion channel gene mutation, which can be classified as sodium,potassium and calcium ion channel mutation.Changes in the genes encoding for cardiac ion channel subunits produce modification in the function of the channels, and cause the dysfunctions of cardiac electrical activity; and the clinical manifestation is malignant arrhythmia.
Animals ; Arrhythmias, Cardiac ; genetics ; physiopathology ; Channelopathies ; genetics ; physiopathology ; Humans ; Ion Channels ; genetics ; physiology ; Mutation

OBJECTIVEto investigate the clinical characteristics in two families with early repolarization syndrome (ERS) and recurrent syncope.

METHODall family members including the probands were screened with routine clinical examination, electrocardiography, echocardiography, Holter recording, chest x-ray, head-up tilt test and blood biochemistry.

RESULTSthere was no clinical evidence of organic heart disease in all members from the two families. Proband 1 showed recurrent syncope, ERS and repeated torsade de pointes ventricular tachycardia and ventricular fibrillation were documented with resting ECG. ERS was detected in one brother, one nephew and one son from him and all were free of cardiac events including syncope, cardiac arrest and sudden cardiac death. Proband 2 showed recurrent syncope, ERS and ST segment arched upward elevation in V(1)-V(3) were documented by ECG. His father suffered sudden cardiac death at the age of 65 and asymptomatic ERS was detected in one of his nephew.

CONCLUSIONSERS is not always linked with benign clinical course and can sometimes lead to repeated syncope, torsade de pointes ventricular tachycardia and ventricular fibrillation. Pedigree research is of importance for ERS.

Adult ; Arrhythmias, Cardiac ; genetics ; Asian Continental Ancestry Group ; Humans ; Male ; Pedigree ; Recurrence ; Syncope ; genetics ; physiopathology ; Syndrome

Arrhythmias, Cardiac ; complications ; genetics ; physiopathology ; Atrial Fibrillation ; complications ; genetics ; physiopathology ; Electrophysiology ; Humans

Arrhythmias, Cardiac ; Genetic Diseases, X-Linked/genetics* ; Gigantism/genetics* ; Heart Defects, Congenital/genetics* ; Humans ; Intellectual Disability/genetics* ; Male ; Neuroblastoma

Due to the negative autopsy and without cardiac structural abnormalities, unexpected sudden cardiac death （USCD） is always a tough issue for forensic pathological expertise. USCD may be associated with parts of fatal arrhythmic diseases. These arrhythmic diseases may be caused by disorders of cardiac ion channels or channel-related proteins. Caveolin can combine with multiple myocardial ion channel proteins through its scaffolding regions and plays an important role in maintaining the depolarization and repolarization of cardiac action potential. When the structure and function of caveolin are affected by gene mutations or abnormal protein expression, the functions of the regulated ion channels are correspondingly impaired, which leads to the occurrence of multiple channelopathies, arrhythmia or even sudden cardiac death. It is important to study the effects of caveolin on the functions of ion channels for exploring the mechanisms of malignant arrhythmia and sudden cardiac death.
Arrhythmias, Cardiac/physiopathology* ; Autopsy ; Caveolins/metabolism* ; Channelopathies/genetics* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology ; Humans ; Ion Channels/metabolism* ; Mutation ; Myocardium

OBJECTIVEThe gamma(2) subunit of AMP-activated protein kinase (PRKAG2) located in chromosome 7 plays an important role in regulating metabolic pathways, and patients with PRKAG2 mutations are associated with familial ventricular pre-excitation, hypertrophic cardiomyopathy and AV block. We observed the difference on the phenotypes in a large family with same PRKAG2 mutation.

METHODDirect DNA sequence was performed to screen the exons and exon-intron boundaries of PRKAG2 gene in a large family with 13 affected persons detected by electrocardiography (ECG).

RESULTSSinus bradycardia, short PR interval, right bundle bunch block (RBBB), complete AV block, atrial flutter, atrial fibrillation and sudden cardiac death were identified in this family. Hypertrophic cardiomyopathy was found in one family member. Genetic analysis revealed a missense mutation (Arg302Glu) in all affected family members. This mutation was previous described in patients with Wolff-Parkinson-White (WPW) syndrome and hypertrophic cardiomyopathy.

CONCLUSIONSBesides WPW syndrome and hypertrophic cardiomyopathy, PRKAG2 mutations are responsible also for a diverse phenotypes. PRKAG2 gene mutation should be suspected with familial occurrence of RBBB, sinus bradycardia, and short PR interval.

AMP-Activated Protein Kinases ; genetics ; Arrhythmias, Cardiac ; genetics ; Brazil ; Female ; Genotype ; Humans ; Male ; Mutation ; Pedigree ; Phenotype ; Pre-Excitation Syndromes ; etiology