Abstract: Heart Rate Variability (HRV) is a very important measure that helps in understanding how the nervous system controls blood circulation (symptho-vagal balance at the sinus node). HRV is currently estimated using frequency domain based methods such as Fast Fourier Transform (FFT). In this paper we propose a novel method based on the Wavelet Transform (WT). This proposed method is applied to the detection of the Tachycardia, Bradycardia and the irregularity of R-R interval.