AVP and Arrhythmia: AVP is directly involved in the regulation of the electrophysiological properties of the pulmonary vein, calcium homeostasis, and the identification of the underlying mechanisms.60 In the same way, Weiss et al. stated that centrally liberated AVP elevated sympathetic outflow to the cardiovascular system and could increase the risk of arrhythmia and sudden death.61 The relationship between AVP and AF has not yet been elucidated.