sudden, terrifying disconnect. You're in a high-stakes meeting—the kind you’ve navigated a thousand times—but this time, your mind is  blank. The data on the screen blurs, the confident point you were about to make is gone

when people think about heart health, they picture numbers like blood pressure, cholesterol, or maybe their resting heart rate. But there’s another number—one that’s less talked about but arguably just as important: heart rate variability, or HRV.