The findings prompted Apple to join forces with a Stanford team for their own research on the matter. apple is confident the Apple Watch can detect other common heart conditions.
The study authors wrote that the algorithm could offer a "surprisingly good prediction of hypertension and sleep apnea given that its only inputs are heart rate and step count". Hypertension - also known as high blood pressure - was detected by the Apple wearable with an accuracy of 82 percent.
The study was a partnership between Cardiogram and the UC San Francisco's Health eHeart Study.
An app called Cardiogram implemented technology earlier this year to detect abnormal heart rhythm used to predict and prevent heart disease by tracking heart rate.
It affects 22million adults in the United States and if left untreated the oxygen deprivation from sleep apnea can result in a growing number of health problems, including high blood pressure, stroke, heart failure, diabetes and heart attacks.
Nine to 21 percent of women and 24 to 31 percent of men have sleep apnea, according the American Sleep Association.
Sleep apnea is a potentially serious sleep disorder largely associated with heavy snoring in which breathing repeatedly stops.
Similarly according to the Centers for Disease Control (CDC) more than 75 million adults in the U.S. suffer from high blood pressure (hypertension). "If you have hypertension it can lead to heart attacks, strokes, and kidney disease".
The new N=6,158 study recruited 6,115 participants through the Cardiogram app to test using their Apple Watch over a period of time.
DeepHeart was trained on data from 70 percent of participants, and then tested on the remaining 30 percent who were not used in training, according to Cardiogram co-founder Brandon Ballinger.
More than one billion people globally suffer from hypertension, with 20 percent of these left undiagnosed, the World Health Organization claims.
'The idea here is that by screening continuously you would identify people with hypertension who might not know they have it, ' said Cardiogram's co-founder and study lead Johnson Hsieh.
Data collected from the Apple watches was interpreted by the deep neural network of DeepHeart, which recognized hypertension and sleep apnea.