Table 1.

Comparison of baseline ECG restitution findings for QT/TQ interval ratios in healthy humans, dogs and monkeys and humans during autonomic challenge or disease states

Subject	Measurement period	Average study values		References
		QT/TQ 50	QT/TQ 98
Healthy humans	10 s at supine resting baseline	0.73–0.76	1.14	Fossa et al. (2014), Gross, (1952)
	2‐hr supine resting baseline	0.63	1.11	Fossa and Zhou (2010)
	2 hr at sleep	0.65–0.70	1.11–1.23	Fossa et al. (2007), Fossa and Zhou (2010)
	24‐hr baselines	0.70–0.85	1.09–1.52	Fossa and Zhou (2010), Fossa et al. (2007, 2014)a
	Baseline:10‐min exercise (walking)	0.94:1.33	NA	Yu et al. (1950)
	Bike exercise (maximum burst)	2.13	3.25	Fossa and Zhou (2010)
	Supine to standing	1.09	1.80	Fossa and Zhou (2010)
	Phenylephrine bolus challenge during supine rest	0.63	0.92	Fossa and Zhou (2010)
	Isoproterenol bolus during rest	1.79	2.63	Fossa and Zhou (2010)
Rheumatic carditis	10‐s baseline	1.46	NA	Taran and Szilagyi (1947)
Hypertension	Baseline:10‐min walk	1.16:1.67	NA	Taran and Szilagyi (1947)
Congenital heart disease	Baseline:10‐min walk	1.44:1.72	NA	Taran and Szilagyi (1947)
Pulmonary disease	Baseline:10‐min walk	1.08:1.34	NA	Taran and Szilagyi (1947)
Monkey	24‐hr ambulatory baseline	1.01	1.85	b
Canine	24‐hr ambulatory baseline	0.41–0.69	1.20–1.60	b

^aRegulatory TQT studies submitted to FDA.

^bRegulatory toxicology studies submitted to FDA.