Atrial fibrillation, the most common form of heart rhythm irregularity, increases the risk of stroke and is usually prevalent among people above 65 years.
Apple has partnered with Johnson and Johnson to study if the Apple Watch app leads to a lower risk of heart stroke.
A Kentucky woman's Apple Watch notified her that it had detected Atrial Fibrillation, prompting her to seek medical help and thus, saving her life.
Dr Joseph Wiesel was awarded a patent in 2006 for photoplethysmography, which is the same technique used by the Apple Watch to detect atrial fibrillation.
Researchers noted that atrial fibrillation raises the risk of stroke by five-fold. Symptoms include palpitations, racing or irregular pulse, shortness of breath, tiredness, chest pain and dizziness.
The Apple Watch's heart rate sensor picked up the patient's atrial fibrillation symptoms with consistency, leading to a timely checkup and preventing any emergency.