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

Relative levels of the full length mRNA isoform, E28A, were decreased by 24.7% in patients with CHF compared to control. --- E28A ---

Previously, we showed that the least sensitive measure was a reduction in E28A abundance by 24%. --- E28A ---

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

The full length SCN5A mRNA (E28A) was decreased by 24.7% in patients with CHF compared to control. --- E28A ---