Brugada syndrome and temperature

Since temperature affects permeability, temperature change forces the Na+channel and other channels to modify their functional state. INa+kinetics depends strongly on temperature. (Nagatomo T, Fan Z, Ye B, Tonkovich GS, January CT, Kyle JW, Makielski JC. Temperature dependence of early and late currents in human cardiac wild-type and long Q-T DeltaKPQ Na+ channels. Am J Physiol 1998; 275:H2016-H2024.)Thus, an increase of 10oC increment the voltage or width by a factor of 1.3 to 1.6 and increases the time of opening and the number of times that the channel is opened by a factor of three. Activation and inactivation kinetics for early INa+are twofold faster at higher temperature, and shift activation and steady-state inactivation. Then,the fever is consideredtriggers to PVT/VF in the BrSjointly with other causes that causing modifcations in the degree ofelevation of the J point and of the ST segment.The other factors capable to get worse the ventricular repolarização are:antimalarial agents;tricyclic antidepressants; class IA (ajmaline and procainamide) and 1C (fecainide, pilsicainide) anti-arrhythmic agents; hyperglycemia; nocturnal bradycardia by vagal predominance; alcohol consumption; mental stress and cocaine use.