. Author manuscript; available in PMC: 2009 Sep 25.

Published in final edited form as: Am J Hypertens. 2008 Sep 25;21(12):1324–1329. doi: 10.1038/ajh.2008.292

Table 2.

Univariate linear correlations between breathing rate (RMSSD = root mean square of successive mean differences), tidal volume (TV), ventilation, end tidal CO₂ (PetCO₂), low frequency heart rate variability (LF HRV in lnmsec²), high frequency heart rate variability (HF HRV in lnmsec²), and the ratio of low to high frequency heart rate variability (LF/HF).

	TV (RMSSD)	Ventilation (RMSSD)	PetCO₂ (RMSSD)	LF HRV (lnmsec²)	HF HRV (lnmsec²)	LF/HF
Breathing rate (RMSSD)	.53^**	.55^**	.53^**	−.16	−.20	.34^*
Tidal Volume (RMSSD)		.83^**	.44^**	−.29	−.40^**	.37^*
Ventilation (RMSSD)			.42^**	−.35^*	−.39^**	.14
End tidal CO₂ (RMSSD)				−.34^*	−.43^**	.34^*
LF HRV (lnmsec²)					.93^**	−.12
HF HRV (lnmsec²)						−.38^**

= p <.05;

^**

= p <.01