This paper presents a new efficient DCT-IV-based ECG compression algorithm with a higher Quality Score (QS) and a better Compressing Ratio (CR). The ECG signals sourced from MIT-BIT arrhythmia database with a sampling rate of 360 Hz are employed to be the test patterns for the evaluating the proposed compression algorithm. The simulation results show that the averages of CR, Percent RMS Difference (PRD), and QS are, respectively, 5.267, 0.187, and 28.223 for all 48 lead-V1 patterns of MIT-BIH database. Compared with Lee et al.'s algorithm, the QS value of the proposed method has a great improvement by 25.1%. Additionally, we use DCT-IV to be a unified transform kernel for ECG signal encoding and decoding because the formula of forward DCT-IV is same to its inverse. Also, we realize it to be a compact hardware accelerator with a fewer hardware resources. Therefore, it would be a better choice for realizing the ECG compressor in the future.