Heart failure epicardial fat increases atrial arrhythmogenesis

Area of Science:

• Cardiology
• Electrophysiology
• Obesity Research

Background:

• Obesity is a significant risk factor for atrial fibrillation (AF) and heart failure (HF).
• The specific impact of epicardial fat on atrial electrophysiology, particularly in the context of HF, remains unclear.

Purpose of the Study:

• To investigate whether heart failure (HF) modulates the effects of epicardial fat on atrial electrophysiology.
• To evaluate the arrhythmogenic potential of epicardial fat in a heart failure model.

Main Methods:

• Conventional microelectrode recordings were used to assess action potentials in the left and right atria of control and HF rabbits.
• Epicardial fat from control or HF rabbits was applied to healthy rabbit atria.
• Adipokine profiles of epicardial fat from control and HF rabbits were analyzed.

Main Results:

• Epicardial fat from both control and HF rabbits prolonged left atrial action potential duration.
• HF epicardial fat significantly increased left atrial contractility and induced spontaneous activity and burst firing.
• HF epicardial fat exhibited altered adipokine profiles, with lower resistin, C-reactive protein, and serum amyloid A compared to control fat.

Conclusions:

• Heart failure-associated epicardial fat enhances atrial arrhythmogenesis.
• These findings suggest a mechanism linking obesity, HF, and increased atrial arrhythmias.