Table 3.

Correlations Between Midexposure Change in HRV and Postexposure Change in ECG Measures of Ventricular Repolarization (ECG Values Limited to 1–4h of Postexposure)

HRV parameter	Exposure hour	ECG parameter	Postexposurea hour	r	p value
	3	Tp-Te	1	0.7	0.03
SDNN	Recovery	Tp-Te	2	0.66	0.04
		ST area	2	0.62	0.06
	4	Tp-Te	1–4	0.67	0.03
Triangular index		ST amplitude	1–4	0.6	0.06
		Tp-Te	4	0.74	0.01
		T amplitude	4	0.69	0.03
		ST amplitude	4	0.66	0.04
	Recovery	T amplitude	1–4	0.63	0.05
		Tp-Te	1–4	0.61	0.06
		T amplitude	2	0.67	0.03
		ST area	4	0.66	0.04
		Tp-Te	4	0.62	0.05

Notes. Change in HRV during individual hours of exposure (relative to baseline) significantly correlated with a subsequent change in ECG during 1–4h of postexposure. r indicates Pearson correlation coefficient. N = 5–6 per group.

^aWhen animals were monitored in home cages.