Atrial fibrillation

Cardiac rehabilitation for heart failure and atrial fibrillation: a propensity- matched study

BACKGROUND

Atrial fibrillation (AF) is common in individuals with heart failure (HF). Individuals with HF and AF may have a reduced functional capacity and quality of life (QoL) which leads to hospital admission and burden on clinical services. Evidence supported the effect of exercise training in individuals with HF. However, there is no existing data on the effectiveness of comprehensive cardiac rehabilitation (CR) in individuals with coexisting HF and AF.

AIM

To explore the effect of CR in individuals with HF and AF compared with those with HF and no-coexisting AF.

METHODS

Using CR database, individuals with HF and AF were identified and propensity matched to those with no coexisting AF. The change in incremental shuttle walking test, Heart Disease Quality of Life questionnaire, Hospital Anxiety and Depression Scores were compared between groups pre-CR and post-CR.

RESULTS

149 individuals were propensity matched from each group. The mean±SD age of the matched sample was 73.4±8 years, body mass index 29±5.5 kg/m2, left ventricular ejection fraction 35.2±9.8% and 56% were male.A statistically significant improvements in exercise capacity, heart disease QoL, anxiety and depression scores were observed within each group. There were no significant differences between groups for any of these outcome measures.

CONCLUSIONS

Individuals with HF and AF gain a similar improvement in exercise capacity and health related QoL outcomes as individuals with no coexisting AF following CR. The presence of AF did not compromise the effectiveness of CR.

Transcriptome Discovery of Genes in the Three Phases of Autophagy That Are Upregulated During Atrial Fibrillation

Background: Autophagy may contribute to the maintenance of atrial fibrillation (AF), but no previous study has concurrently surveyed all 3 phases of autophagy, namely autophagosome formation, lysosome formation, and autophagosome-lysosome fusion. Here we aimed to identify disorders involving various phases of autophagy during AF. Methods and Results: We used bioinformatic techniques to analyze publicly available DNA microarray datasets from the left atrium (LA) and right atrium (RA) of 7 patients with AF and 6 patients with normal sinus rhythm who underwent valvular surgeries. We compared gene expression levels in the LA (AF-LA) and RA of patients with AF with those in the LA and RA of patients with normal sinus rhythm. Several differentially expressed genes in the AF-LA sample were significantly associated with the Gene Ontogeny term 'Autophagy', indicating that the expression of autophagic genes was specifically altered in this dataset. In particular, the expression of genes known or suspected to be involved in autophagosome formation (autophagy related 5 [ATG5], autophagy related 10 [ATG10], autophagy related 12 [ATG12], and light chain 3B [LC3B]), lysosome formation (lysosomal associated membrane protein 1 [LAMP1] and lysosomal associated membrane protein 2 [LAMP2]), and autophagosome-lysosome fusion (synaptosome associated protein 29 [SNAP29], SNAP associated protein [SNAPIN], and syntaxin 17 [STX17]) was significantly upregulated in the LA-AF dataset. Conclusions: Autophagy is activated excessively in, and may perpetuate, AF.