Correcting noise on apparently OK data

[Mehafatima1]

Hello.

Once again, I am taking your precious time to pose my query. My data from one participants appears fine. However, when I apply pan-tompkin algorithm it detects some ectopic beats which do not appear to be R waves. Also, when I preview IBIs, it shows a very noisy signal. I am attaching pictures for review.

[Mehafatima1]

I would like to add that ecgfast and ecgslow give more noise. I have tried 10 Hz low pass filter too. But no filter is working to correct this noise. Can you please suggest what might be the problem possibly?