Spontaneous Atrial Fibrillation in Transgenic Goats With TGF (Transforming Growth Factor)-β1 Induced Atrial Myopathy...

Area of Science:

• Cardiology
• Exercise Physiology
• Biomarkers

Background:

• Growing evidence links endurance exercise to increased atrial fibrillation (AF) risk.
• The role of underlying atrial myopathy in this association remains unclear.

Purpose of the Study:

• To investigate if endurance exercise exacerbates AF risk in the presence of atrial myopathy.
• To explore the impact of endurance exercise on AF inducibility and associated biomarkers.

Main Methods:

• Utilized cardiac-specific TGF-β1 transgenic goats (atrial myopathy model) and wild-type (WT) controls.
• Implanted pacemakers for arrhythmia monitoring and assessed AF inducibility via atrial pacing.
• Subjected animals to 3 months of progressive endurance exercise and analyzed circulating microRNAs and inflammatory biomarkers.

Main Results:

• Transgenic goats showed higher baseline AF inducibility compared to WT controls.
• Spontaneous AF developed in transgenic goats during exercise, while AF inducibility increased in both groups initially.
• Exercise altered microRNA and MMP9 levels, suggesting a role in AF susceptibility.

Conclusions:

• Endurance exercise in conjunction with atrial myopathy increases spontaneous AF incidence.
• Exercise-induced AF inducibility may be linked to altered profibrotic biomarkers, independent of myopathy.