MATLAB: How to detect pacing pulses in ECG signal

Question

I have downloaded this ecg database from physionet – https://physionet.org/physiobank/database/mitdb/. The recordings of my interest are 107.dat, 107.atr, 107.hea I have plotted the signals correctly and can make out from the annotations that there are paced pulses. But, I am unsure whether what I feel are pacing pulses are correct or not. I have attached an image file showing the peaks of what I feel are pacing pulses. Please can anyone tell if it is right?

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Also, I want to know what is the wave following the pacing pulse? (Q,R,S??) Any help would be appreciated. Thank You.

Answer 1

You are correct. The spikes that you have identified with the black dots are pacing spikes. You should see them in all leads. I have never done any frequency-selective signal processing on a paced EKG.