Atrial fibrillation (AF) is the most common arrhythmia affecting 1.3 million people in the UK. AF causes an irregular and fast heartbeat, which makes the heart pump poorly. As a result, blood clots may form inside the heart and, if they travel to the brain, can lead to an AF-related stroke. Patients with AF have a risk of stroke five-times higher than patients with normal rhythm.

Anticoagulants make the blood less likely to clot and, thus, reduce the chances of an AF-related stroke. For most people, once anticoagulation is started it must be taken for the rest of their lives irrespective of the amount of AF someone has. However, anticoagulants make patients more prone to bleeding.

New studies have reported a lower stroke risk in patients with short and infrequent AF episodes. If there are long time gaps in between AF episodes, short periods of anticoagulation around the time of AF may be enough to avoid clots from forming and reducing the overall risk of bleeding. To use anticoagulants only when needed will require an accurate and reliable way to detect AF when it occurs and alert patients. New technologies, such as small heart monitors placed under the skin, watches and rings, can track the heart rhythm continuously and send real-time alerts to patients via mobile phone message if AF is detected.

The purpose of this study is to investigate if implantable cardiac monitors (LINQ II) and wearable devices (Apple Watch and CART-I ring) can detect AF episodes, send real-time alerts to patients and who will respond to these alerts within a short timeframe. The investigators will recruit 50 patients and follow them for six months. All participants will receive a LINQ II and a wearable device.

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the trial.
• Male or Female aged 18 years or above.
• Paroxysmal AF with symptoms, Holter recording and/or implantable device evidence of >1 but <15 episodes of AF in the last 3 months.
• Persistent AF scheduled for repeat cardioversion (i.e. having had at least one prior cardioversion).
• Currently have an Apple IOS or Android smartphone.

Exclusion Criteria:

• Diagnosis of permanent AF.
• Contra-indications for implantable cardiac monitor.
• Visual or physical impairment that prevents ability to read and acknowledge smartphone/watch notifications.
• Unable to comply with the follow-up schedule.
• Do not have Apple IOS or android smartphone.