Heart rate variability (HRV) is a critical vital sign that can predict a number of different disease states, including heart attack and probably recovery from heart attack—but it’s not one of the things your doctor measures (at least our doctor doesn’t). You know your weight, blood pressure and cholesterol levels. Why don’t you know your HRV levels? To download a short PDF explaining HRV, go to http://beathealthy.com/education/hrvbackground.pdf