In today's field of medical technology, the development of Electrocardiogram (ECG) monitoring systems is increasingly receiving attention. ECG, as a crucial tool for assessing cardiac function and heart health, plays an irreplaceable role in clinical diagnosis, health monitoring, and disease prevention. However, ECG signals are inherently low in amplitude and susceptible to interference, making the advancement of ECG electrode technology and Analog Front End (AFE) technology essential for achieving accurate and reliable monitoring. This research underscores the pivotal role of ECG electrode technology and the significance of the Analog Front End (AFE) in enabling efficient wireless ECG monitoring systems. With ECG signals being inherently low amplitude and prone to interference, the technology and choice of electrodes are crucial. This study dives deep into the evolution of ECG electrode technology, reviewing the pros and cons of wet, dry, and capacitive electrodes. The primary focus of the paper revolves around the IA-based pre-amplifier design, detailing its challenges and offering innovative solutions. Novel architectures utilizing capacitors, MOSCAPs, and CMRR improvement techniques are presented. The paper concludes by emphasizing the importance of accurate gain configuration, noise reduction, layout efficiency, and adherence to relevant standards.