With the upcoming u-healthcare era, a way of measurement for vital sign monitoring of cardiac patients is changing as well. In existing measurement of cardiac patients, various wire in ECG measuring equipment has caused much discomfort and inconvenience. In order to decrease the problem, we are developing an efficient measurement of ECG signal using Wireless sensor network. In this paper, we present a way to reduce amount of data by transmitting ECG data collected from radio electrocardiogram sensor based on Zigbee after calculating cardiac rate. And in order to control the error which can be caused by the different ECG signal intensity each individual can has, we also suggest an adaptive pulse measurement model which can measure heart rate with correcting according to different ECG intensity. To verify the suggested model, sensor application was developed and the data was acquired in TinyOS 2.0 environment and the adaptive pulse measurement model was evaluated through the data from the experiments.