For centuries, doctors have turned to a variety of vital signs to quickly assess the well-being of patients. A visit to the ER these days might result in as many as five measurements being taken, each offering unique clues as to what’s going inside the complex human body. Recently, though, a new number has popped up that may turn out to be the single most useful piece of information available to understand someone’s underlying health condition.
Heart rate variability (HRV) offers insights into recovery from illness, injury or exercise, can track levels of physical and emotional stress, and even act as a predictor of cardiac failure. Advances in technology, including image sensors, now make HRV measurement accessible to anyone with a chest strap or smartphone.