Gastrointestinal and liver diseases and atrial fibrillation: a review of the literature

Figures

• 

  Figure 1.. The bidirectional relationship between atrial fibrillation and gastrointestinal and liver diseases. Gastrointestinal conditions may directly relate to atrial fibrillation through a variety of proposed mechanisms or through multiple shared risk factors. Additionally, complications of atrial fibrillation and the treatment of atrial fibrillation may cause gastrointestinal diseases. AF, atrial fibrillation; GI, gastrointestinal.

• 

  Figure 2.. Anatomic relationship between the heart and the esophagus and stomach. The juxtaposition of the esophagus to the left atrium and the parasympathetic innervation may be important factors that promote a bidirectional relationship of gastrointestinal diseases and AF. L., left; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; R., right; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein.

• 

  Figure 3.. Proposed mechanisms for the association between gastrointestinal cancer and atrial fibrillation. AF, atrial fibrillation; GI, gastrointestinal.

• 

  Figure 4.. Proposed mechanisms for the interaction between the gut microbiome and atrial fibrillation. Gut microbes convert dietary choline and L-carnitine, from red meat and eggs, to trimethylamine, which is oxidized to trimethylamine N-oxide in the liver. Trimethylamine N-oxide is associated with atherosclerosis, cardiovascular events, and an increased susceptibility to atrial fibrillation. Trimethylamine N-oxide may initiate atrial electrical remodeling, autonomic remodeling, and an upregulation of pro-inflammatory signaling pathways that may initiate atrial fibrillation. Lipopolysaccharides, which are derived from the outer membrane of Gram-negative bacteria, may enter the circulation through the gut mucosa and contribute to atrial fibrillation risk by increasing inflammatory cytokines and by altering the structural and electrical remodeling of the left atrium. The Mediterranean diet may favorably alter the gut microbiome and lower markers of oxidative stress and lipopolysaccharide levels, which may decrease atrial fibrillation risk. LPS, lipopolysaccharides; TMA, trimethylamine; TMAO, trimethylamine N-oxide.