P01.46. Assessment of autonomic tone at rest and during meditation in a longitudinal study of an eight-week meditation intervention

Purpose Measures of heart rate variability (HRV) and respiratory sinus arrhythmia (RSA), which are the healthy fluctuations in heart rate that reflect autonomic influences on cardiac activity, have been proposed as indicators of physical and psychological health. Previous studies suggest that HRV increases during some meditative states, but it is not clear how autonomic tone is affected either in the short term during meditative states, nor as a long-term result of meditation practice. Here we test two hypotheses: (1) eight weeks of meditation training will improve autonomic tone, in the form of increased overall HRV and decreased low-frequency HRV to highfrequency HRV (LF/HF) ratio; and (2) RSA increases during the meditation state compared to rest.