If an ECG was recorded with swapped leads so the R-peak points downwards, the ECG Analysis Module is not able to detect the QRS max correctly. Also using the channel options "invert scale and data" won't help.
An easy solution is to use Channel calculation > Arithmetic... and multiply that channel by -1.
Tip: this can be nested with other functions like low pass filter to become: Lowpass(-1*ch1, 45)
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