Extended patient cardiac function monitoring during normal activity is a growing field in medical research. The research reported in this paper focuses on the development of a portable platform based on Laptop PC for real-time analysis of cardiac oscillations, which can be used as an advanced warning device for heart abnormalities. The emphasis is on algorithms and techniques for QRS complex detection and frequency analysis of heart rate variability. The reliability and effectiveness was quantitatively assessed using simulated and real signals of healthy and pathological cardiac state. The system presents good results on heart rate variability analysis by adapting itself to any electrocardiogram amplitude and frequency.