TABLE 2.
Arrhythmias | Autoantibodies | Associated Diseases | Mechanisms |
---|---|---|---|
Supraventricular Tachyarrhythmias | |||
Sinus Tachycardia | Anti-β1 and anti-β2 adrenergic receptors | Inappropriate sinus tachycardia | Agonist-liked activity on β-adrenergic receptors, ↑ cAMP, ↑ chronotropic effect |
Atrial Fibrillation | Anti-myosin heavy chain | Myocarditis, dilated cardiomyopathy, and idiopathic atrial fibrillation | Inflammation |
Anti-Na/K-ATPase | Dilated cardiomyopathy | ↑ [Ca2+]i | |
Anti-M2 receptor | Dilated cardiomyopathy, Grave’s hyperthyroidism | ↑ IKACh, ↓ APD, ↓ AERP, ↑ conduction velocity in atrial myocardium | |
Anti-β1 receptors | Grave’s hyperthyroidism | ↑ hyperpolarization, ↓ APD, ↑ triggered activity | |
Anti-HSP65 | Post-op CABG | Inflammation | |
Ventricular Tachyarrhythmias | |||
Ventricular Tachycardia | Anti-Ro/SSA | Connective tissue diseases | Cross-reaction with hERG K+ channel, ↓ IKr, ↑ QTc |
Anti-β1-adrenergic receptor | Chagas’ disease, idiopathic dilated cardiomyopathy, ischemic cardiomyopathy, viral hepatitis myocarditis | Agonist-liked activity on β-adrenergic receptor, ↑ cAMP, ↑ chronotopic effects, ↑ APD, ↑ QT, ↑ ICa,L, ↓ Ito, ↓ IKs, ↑ EADs, ↑ ERK1/2 | |
Sudden Cardiac Death | |||
Anti-Na/K-ATPase | Dilated Cardiomyopathy | ↑ [Ca2+]i | |
Anti-β1-adrenergic receptor | Dilated Cardiomyopathy | ↑ APD, ↑ QT, and triggered activity | |
Anti-M2 receptor | Chagas’ disease | ↑ QT |
ICa,L, L-type calcium currents; IKACh, acetylcholine-activated potassium currents; IKr, rapid delayed rectifier potassium currents; IKS, slow delayed rectifier potassium currents; Ito, transient outward potassium currents; M2 receptor, muscarinic cholinergic type 2 receptor; Na/K-ATPase, sodium-potassium pump; APD, activation potential duration, AERP, atrial effective refractory period; EAD, early afterdepolarizations; [Ca2+]i, intracellular Ca2+.