致命性的心室性心律不整(ventricular arrhythmia，VA)是促成心因性猝死(cardiac sudden death，SCD) 的主因，其存活率之低，發生之突然和快速，總令人措手不及。近年來，許多研究發現心室性心律不整 好發於寒冷的冬天，並陸續提出造成此現象的可能機轉。本文將簡介冬天如何透過氣溫、身體活動量、 曰光曝曬量等來改變人體内分泌系統、凝血機制、氧化壓力及心室重塑(ventricular remodeling)的平衡，導 致自主神經失調、心肌缺血及心臟結構重塑，造成心臟生理電氣不穩，進而引發心室性心律不整。藉由 系統性的文獻整理，期能增加醫療人員對於此議題的了解，並逐步發展相關的預防性措施及衛教，降低 致命性心室性心律不整的發生。

Ventricular arrhythmia (VA) has been considered as a devastating event that mostly contributes to sudden cardiac death (SCD). Its sudden onset and a high mortality have always caught patients off the guard. Previous studies have demonstrated that the incidence of VA has a seasonal variation with higher incidence rates in the winter. Possible mechanisms include winter temperature, physical activity level, and duration of sunshine may change the balance of endocrine system, coagulation, oxidative stress, ventricular remodeling process and thus resulting in autonomic dysfunction, myocardial ischemia, and structure remodeling to increase the risk of VA. This article briefly reviewed the mechanisms underlying winter effect on the incidence of VA. We hope by increasing public understanding of this seasonal variation, preventive strategies and public education will be developed to reduce the incidence of VA and SCD.