Energy efficiency for mobile wireless electrocardiography (ECG) communication is an important issue due to resource constraints in wireless Body Area Sensor Networks (BASNs). Traditional high quality ECG transmission schemes require substantial amounts of energy usage, which may not be available in BASN. Therefore, an adaptive approach is necessary to provide high quality ECG transmission with efficient usage of available energy resources. Related literature mainly focuses on data compression, where transmission energy is saved because the amount of data being transmitted is reduced. However, further reduction of energy consumption based on communication strategy is rarely discussed in literature. In this paper, we analyze the characteristics of compressed ECG data, which show that different parts of the data are unequally important to quality of ECG transmission in BASN. In this work, we propose a new Rate-switching Un-Equal Protection (RUEP) mechanism, which optimizes the distortion reduction of ECG data by adaptively assigning different Rate Compatible Punctured Convolutional (RCPC) codes to protect the different parts of the compressed ECG data. Simulation results demonstrate that our RUEP scheme results in an improved communication energy efficiency by at least 45 percent compared with traditional schemes in the AWGN channel.