The purpose of this research is to see if investigators can detect truncated mRNA splice variants of the cardiac voltage-gated sodium (Na+) channel gene, SCN5A, in patients with a weak heart (Heart Failure) with or without an implantable cardioverter-defibrillator (ICD) and compare them to patients with a normal heart. Hypothesis: 1. Patients with reduced left ventricular ejection fraction have increased abundances truncated mRNA splice variants of the SCN5A gene, which portends to sodium channel dysfunction and an increased risk for sudden cardiac death. 2. Patients with implantable cardioverter-defibrillator devices (ICDs) who have experienced shock therapy have increased abundances of truncated mRNA splice variants of the SCN5A gene compared to similar congestive heart failure patients who have not experienced shock therapy.

NCT01185587

Conditions

1. Atrial Fibrillation
2. Atrial Flutter
3. Heart Failure

MeSH:Heart Failur Heart Failure Atrial Fibrillation Atrial Flutter

HPO:Abnormal left ventricular function Atrial fibrillation Atrial flutter Congestive heart failure Paroxysmal atrial fibrillation Right ventricular failure

These three splicing variants for the nonfunctional sodium channel gene product were denoted E28B, E28C, and E28D. --- E28C ---

At the same time, the E28C and E28D mRNA abundances were increased 14.2 fold and 3.8 fold respectively in CHF patients compared to controls. --- E28C ---

This study is designed to test whether SCN5A mRNA processing is altered in OSA patients, which may contribute to their increased arrhythmic risk, and whether processing of SCN5A mRNA is modulated by CPAP treatment. Specific aims: 1. Compare sodium channel splicing variants in mild, moderate, or severe OSA patients at baseline to at 1 month after CPAP treatment. In addition, the baseline splicing variants of SCN5A in the OSA patients will be compared to an age-matched control group. 2. Hypoxia-associated upstream regulators of SCN5a mRNA splicing, Hypoxia-inducible factor 1-alpha (HIF-1α), RNA Binding Motif Protein 25 (RBM25) and LUC7-Like 3 Pre-MRNA Splicing Factor (LUC7L3), will be examined in OSA patients before and after 1 month of CPAP treatment.

NCT02725632

Conditions

1. Sleep Apnea Syndromes

Interventions

1. Device: CPAP

MeSH:Apnea Sleep Apnea Syndromes Sleep Apnea, Obstructive

HPO:Apnea Obstructive sleep apnea Sleep apnea

Three truncated SCN5A mRNA splicing variants were identified (denoted variant B (E28B), variant C (E28C), and variant D (E28D)). --- E28C ---

Among them, E28C and E28D abundances were increased 14.2 fold and 3.8 fold respectively in CHF patients compared to controls. --- E28C ---