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The forthcoming smartwatch, due next year, will have a built-in sensor to monitor a wearer's heart rate. Could this information be used to predict a heart attack or warn of the onset of heart disease?

"I think there is the potential out there," Dr. Michael Scott Emery, co-chair of the American College of Cardiology Sports and Exercise Cardiology Council told FoxNews.com in an interview. "It could help in the future."

One common stress test, for example, is to gauge how quickly a patient's heart rate recovers after exercise. After a run on a treadmill, if the patient's heart rate does not fall significantly within the first 2 minutes, it can be an indication that he or she is at an increased risk for a cardiac event within the next 5 or 6 years. There are already a handful of consumer devices on the market that can measure heart rates to take such readings.

Chest straps used by athletes and weekend warriors to track electrical heart readings have been used for years. But these are rapidly being supplanted by more comfortable and convenient runners' watches, fitness trackers, and smartwatches that measure blood flow using LEDs under the wristband. Models such as TomTom's $270 Runner Cardio GPS Watch, Adidas' $400 MiCoach Smart Run Watch, and Samsung's $300 Gear 2 smartwatch calculate the wearer’s pulse rate based on the speed of blood flow in the capillaries. However, these, and similar devices, are intended for sports and fitness use and are not FDA approved as medical devices.

The wrist-based electro-optical heart rate monitors can be as accurate as chest straps, but it depends on "how well they fit, the type of LED configuration, and the algorithms" being used, Liz Dickinson, founder and CEO of heart rate monitoring tech company Mio Global told FoxNews.com. Mio's pulse rate technology is used in the company's $199 Alpha watch, as well as in the TomTom and Adidas watches. Dickinson noted that her firm is focused on delivering accurate heart rate measurements, particularly during exercise, but several medical device makers are focusing on the potential benefits of monitoring patients considered at risk of heart attacks.

In order to give doctors more relevant information about one's heart health, "we need to know what your heart rhythm is," explained Dr. Emery. Such information is usually only available from an electrocardiogram (ECG) administered by a doctor. An ECG can detect coronary heart disease, arrhythmias, or, by comparing it with previous readings, tell a cardiologist that a patient had a heart attack. In the near future, smartphones and watches might be able to gather such information, said Dr. Emery, pointing to one device already available - AliveCor's $199 Heart Monitor.

The AliveCor gadget has two finger sensors and fits onto the back of a smartphone. It measures electrical impulses of the heart and beats per minute. It is what’s known as a single-channel ECG device - the ECG machine in the doctor's office may have as many as 12 channels. AliveCor ECG readings can then be accessed online by a doctor or sent to a hospital as a PDF file.

Furthermore, the growing number of devices available to take other heart-related measurements can be combined to offer a more accurate picture of health - or illness. There are pulse oximeters that measure oxygen saturation in the blood, for example, and wrist collars like Panasonic's $52 EW-BW30S that measure blood pressure for signs of hypertension. Eventually, these digital monitors could be combined into a single device.

Apple already has its corporate eye focused on future healthcare applications. The company's HealthKit software tool is designed to aggregate essential diagnostic information to give doctors an immediate, accurate picture of a patient's health. Apple is involved in at least one research project at Duke University tracking blood pressure and other factors looking for signs of heart disease.

So while the Apple Watch may not be the equivalent of Star Trek's Tricorder, pulse rate monitors are one small step in that direction.

"It's a vital sign we take every day on every patient that walks into the office," said Dr. Emery. "It doesn't necessarily help us predict heart attacks, but can be a sign that something else is going on."