Alterations of atrial Ca(2+) handling as cause and consequence of atrial fibrillation

Area of Science:

• Cardiology
• Electrophysiology
• Molecular Biology

Background:

• Atrial fibrillation (AF) is the most common sustained arrhythmia and a major risk factor for stroke.
• Current treatments for AF are challenging, necessitating novel therapeutic strategies.
• Altered intracellular calcium (Ca2+) handling is a critical aspect of AF pathophysiology.

Purpose of the Study:

• To review and critique the role of altered intracellular Ca2+ handling in AF pathophysiology.
• To differentiate Ca2+ handling changes preceding AF onset from those developing after AF onset.
• To examine the contribution of Ca2+ handling to excitation-transcription coupling, atrial contractile dysfunction, and arrhythmogenicity.

Main Methods:

• Literature review and critical analysis of existing research on intracellular Ca2+ handling in AF.
• Focus on the distinct roles of Ca2+ dysregulation in pre-AF conditions versus established AF.
• Examination of Ca2+-dependent signaling pathways, contractile function, and arrhythmogenesis.

Main Results:

• Intracellular Ca2+ handling undergoes significant remodeling in AF due to increased atrial activation and Ca2+ overload.
• Pre-AF Ca2+ homeostasis alterations in predisposing conditions differ from those post-AF onset.
• Altered Ca2+ handling contributes to excitation-transcription coupling, atrial dysfunction, and increased arrhythmogenicity.

Conclusions:

• Targeted therapies addressing specific aspects of altered intracellular Ca2+ handling hold promise for treating different types of AF.
• Distinguishing between pre-AF and post-AF Ca2+ remodeling is crucial for developing effective, individualized treatments.
• Further research into Ca2+-dependent mechanisms is essential for advancing AF management and reducing stroke risk.