Electrocardiogram (ECG) transmission in real time could involve some problems with the quality of services and security. This paper aims to evaluate a none compressed 12-lead ECG transmission using the Secure Internet Protocol (IPSec), compared with the popular Internet Protocol (IP). Using an analytical model, the transmission performance is estimated in terms of end-to-end delay and loss rate. Our results show that ECG transmission could be assured both security and quality of services.