Public interest in health monitoring devices has increased with the availability of wearable technologies or wearables such as the Apple Watch. These devices are collecting health data that may be useful to health professionals. Most studies to date have been conducted with a limited sample size and with healthy subjects. Recent studies have suggested the usefulness of long-term cardiac monitoring to reveal atrial fibrillation and prevent cryptogenic stroke. Wearable devices may become useful in cardiac monitoring, and further studies are needed.