TNF and atrial fibrillation: The involvement of TNF-α in AF involves multiple mechanisms, and TNF-α has been shown to disrupt intracellular calcium homeostasis in atrial myocytes by decreasing the expression of T-type calcium channel α1G subunit (TCCA 1G) and sarcoplasmic reticulum Ca-ATPase (SERCA2a) thereby participating in AF (67, 68).