A filtering unit for an electrocardiograph device, the filtering unit comprising: - a digital signal input interface for receiving a digital electrocardiographic signal sampled at a predetermined sampling frequency (F s) between 300 and 8000 Hz; - a storage unit connected to the digital signal input interface and configured to store a predetermined number of consecutive recent samples of the digital electrocardiographic signal; - a finite impulse response filter unit connected to the storage unit and configured to generate and provide a filtered digital electrocardiographic signal using the stored samples, the finite impulse response filter unit having an impulse response h [ n] consisting of a finite ordered sequence of between 900 and 160000 consecutive Kronecker delta pulses δ [ n], wherein n is an order of a respective Kronecker delta pulse in the finite ordered sequence, the impulse response formed by - at least three consecutive sets of one or more consecutive scaled Kronecker delta pulses, all of the scaled Kronecker delta pulses within a respective set having a respective constant amplitude, wherein - a modulus of the sum of the amplitude of all the Kronecker delta pulses of the impulse response is smaller than 0.1; - a number of the scaled Kronecker delta pulses of at least one of the sets of Kronecker delta pulses is equal to or higher than a minimum number of Kronecker delta pulses resulting from multiplying the sampling frequency by a time span of 10 -2 seconds; and wherein - the storage unit is configured to store at least a number of the consecutive recent samples of the digital electrocardiographic signal that is equal to the number of Kronecker delta pulses of the impulse response. - a digital signal input interface for receiving a digital electrocardiographic signal sampled at a predetermined sampling frequency (F s) between 300 and 8000 Hz; - a storage unit connected to the digital signal input interface and configured to store a predetermined number of consecutive recent samples of the digital electrocardiographic signal; - a finite impulse response filter unit connected to the storage unit and configured to generate and provide a filtered digital electrocardiographic signal using the stored samples, the finite impulse response filter unit having an impulse response h [ n] consisting of a finite ordered sequence of between 900 and 160000 consecutive Kronecker delta pulses δ [ n], wherein n is an order of a respective Kronecker delta pulse in the finite ordered sequence, the impulse response formed by - at least three consecutive sets of one or more consecutive scaled Kronecker delta pulses, all of the scaled Kronecker delta pulses within a respective set having a respective constant amplitude, wherein - a modulus of the sum of the amplitude of all the Kronecker delta pulses of the impulse response is smaller than 0.1; - a number of the scaled Kronecker delta pulses of at least one of the sets of Kronecker delta pulses is equal to or higher than a minimum number of Kronecker delta pulses resulting from multiplying the sampling frequency by a time span of 10 -2 seconds; and wherein - the storage unit is configured to store at least a number of the consecutive recent samples of the digital electrocardiographic signal that is equal to the number of Kronecker delta pulses of the impulse response.