Proteomics Study of the Effect of Left Atrial Appendage Resection on the Energy Metabolism of Atrial Muscle in Beagle Dogs with Rapid Atrial Pacing

Aims: The myocardial energy metabolism during atrial fibrillation（AF） is a research hotspot. Proteomics provides a new method for the study of atrial fibrillation; however, there are no related studies of the effect of the left atrial appendage（LAA） on the energy metabolism of the atrial muscle. We use proteomics to analyze the effect of resection of the LAA on the energy metabolism of the left atrial myocardial cells in beagle dogs with rapid atrial pacing. METHODS Nine beagle dogs were divided into three groups: the model group (rapid atrial pacing/LAA resection), the positive control group (rapid atrial pacing/LAA preservation), and the negative control group (sinus rhythm). Twelve weeks later, the atrial tissues were resected for proteomics study. Parallel Reaction Monitoring (PRM) was used for the validation of the targeted proteomics. RESULTS 55 proteins were upregulated and 68 proteins were downregulated in the experimental vs. the positive control group. Proteins related to glucose and lipid metabolism were mainly downregulated, and mitochondria-related proteins were mainly downregulated during rapid atrial pacing compared with sinus rhythm. After resection of the LAA, glucose-metabolism-related proteins showed a significant upregulation trend, lipid metabolism-related proteins were further downregulated, whereas mitochondria-related proteins were upregulated compared with rapid atrial pacing with LAA preservation. PRM confirmed the reliability of the proteomics results. CONCLUSION In the setting of AF, the resection of the LAA had a relatively large effect on the energy metabolism structure by affecting the quantity and functions of mitochondria.