CrossTalk opposing view: Heart rate variability as a measure of cardiac autonomic responsiveness is fundamentally flawed.

The article discusses the study of heart rate variability (HRV) as a measure of cardiac autonomic responsiveness. Topics discussed include determination of HRV by heart rate; association of autonomic nerve activity with HRV; and relationship between high frequency power and heart rate. It notes that the data was collected from healthy conscious human, athletically trained conscious human, and conscious human exposed to autonomic blockade.