Cardiovascular Psychiatry and Neurology

Research Article

Obesity in American Indian and Mexican American Men and Women: Associations with Blood Pressure and Cardiovascular Autonomic Control

Table 3

Intercorrelations between metrics of mean HR, overall HRV, cardiovagal control, and cardiac sympathetic activity.


	Mean HR	SDNN	CSI	RSA	RMSSD	pNN50	HF-HRV	LF-HRV	HR_DB

Mean HR	—
SDNN	−0.465**	—
CSI	0.543**	−0.266*	—
RSA	−0.519**	0.864**	−0.542**	—
RMSSD	−0.590**	0.867**	−0.609**	0.841**	—
pNN50	−0.662**	0.788**	−0.670**	0.857**	0.922**	—
HF-HRV	−0.252*	0.822**	−0.344**	0.737**	0.815**	0.679**	—
LF-HRV	−0.206*	0.677**	0.028	0.467**	0.450**	0.356**	0.428**	—
HR_DB	0.075	0.494**	−0.158	0.553**	0.413**	0.407**	0.433**	0.344**	—

Note: Mean HR: mean heart rate; SDNN: standard deviation of interbeat interval (IBI); CSI: Toichi cardiac sympathetic index (sympathetic-related variability); RSA: natural log of variance of filtered (0.12–0.40 Hz) IBI; RMSSD: root mean square of successive differences between IBIs; pNN50: the percentage of the absolute differences between consecutive IBIs that are greater than 50 ms; HF-HRV: high frequency (HF)-heart rate variability (HRV) power (0.12–0.40 Hz); LF-HRV: low frequency (LF)-HRV power (0.04–0.12 Hz); HR_DB: the HR response to deep breathing at 6 breaths per minute. Indicates that Pearson’s correlation is significant at P < 0.05. Indicates that Pearson’s correlation is significant at P < 0.001.