There are multiple media reports about smart watches saving lives after the ECG app alerted the wearer to their cardiac issue.

But the smart watch feature can also be harmful, say Swiss and German doctors, who treated a young man after convincing himself that he was experiencing acute coronary syndrome (ACS).

The fit and healthy 27-year-old became concerned when he developed movement-related, stabbing pain on the left side of his chest following a sports competition.

Fearing an ACS, he recorded multiple, single-lead ECGs with his Apple watch, which he had purchased to monitor his “cardiac health” following media reports of a Danish soccer player’s on-field cardiac arrest.