Wavelet filter with scalogram for ECG

I need a wavelet filter (preferably in Matlab, but Python can also be used) that can generate a good scalogram for a set of ECGs. In first example, the T wave is not captured by the filter that I used. In the second example, the wavelet filter captures all waves and it is perfect. I need something similar to the second example. You have some ECG tracings attached as well.