ECG for <a href="https://en.wikipedia.org/wiki/Pacemaker_syndrome" class="extiw" title="w:Pacemaker syndrome">Pacemaker syndrome</a>
<a href="//commons.wikimedia.org/wiki/User:GiggsHammouri" title="User:GiggsHammouri">GiggsHammouri</a>
CC BY-SA 3.0
Own work by uploader, drawn from this picture <a rel="nofollow" class="external autonumber" href="http://img.medscape.com/pi/emed/ckb/cardiology/150072-159706-1303.jpg">[1]</a>, empty ECG paper by user <a href="//commons.wikimedia.org/wiki/User:Madhero88" title="User:Madhero88">user:Madhero88</a>