This paper presents the implementation of an ambulatory electrocardiogram (ECG) monitoring system. The proposed system comprises current trends on ambulatory ECG monitoring like integration of the hardware in clothing, the use of low power components, wireless data transmission via Bluetooth and the use of a PDA Differing from other approaches the signal processing was located close to the sensor. Thus, more variability in further data handling and therefore a more efficient operation is possible. Employing adequate hardware components on the one hand and adapting a wavelet based signal processing method to the applied components on the other hand, we realized a system optimized in terms of suitability for daily use, energy efficiency and reliability.