What is the version of the following sentence with correct punctuation?

The electrical conducting pathway of the heart can also become scarred in reactive arthritis leading to irregular heartbeats arrhythmias that may require placement of a pacemaker to regulate the heartbeat
The electrical conducting pathway of the heart can also become scarred in reactive arthritis, leading to irregular heartbeats (arrhythmias) that may require placement of a pacemaker to regulate the heartbeat.