Table 6.

Effect of zilpaterol hydrochloride (ZH) supplementation (8.33 mg/kg on a DM basis) on heart measurements following 20-d ZH supplementation, 3-d withdrawal period, and a corticotropin-releasing hormone and vasopressin challenge administered on d 24

Heart parameter1	CON2	ZIL2	SEM	P-value
Aortic valve to left atrial ventricular valve diameter ratio	0.71	0.73	0.03	0.64
Aortic valve to pulmonary valve diameter ratio	0.98	1.04	0.03	0.16
Aortic valve circumference, cm	11.61	11.60	0.38	0.98
Aortic valve to right atrial ventricular valve diameter ratio	0.69	0.69	0.04	0.96
Interventricular septum thickness, cm	4.12	4.29	0.12	0.30
Left atrial ventricular valve circumference, cm	16.53	16.13	0.61	0.64
Left atrial ventricular valve to right atrial ventricular valve diameter ratio	0.97	0.95	0.03	0.64
Left ventricle free wall thickness, cm	3.54	3.54	0.08	0.97
Left ventricle + interventricular septum to right ventricle weight ratio	3.28	3.57	0.13	0.14
Left ventricle + interventricular septum/total heart weight, g	0.58	0.61	0.05	0.07
Left ventricle free wall thickness/right ventricle free wall thickness, cm	1.68	1.79	0.05	0.13
Left ventricle thickness/septal thickness, cm	0.86	0.82	0.03	0.36
Left ventricle + septum weight, g	1.53	1.53	0.06	0.97
Pulmonary valve to left atrial ventricular valve ratio	0.72	0.70	0.02	0.47
Pulmonary valve to right atrial ventricular valve ratio	0.70	0.66	0.03	0.30
Pulmonary valve circumference, cm	11.89	11.20	0.30	0.11
Right atrial ventricular valve circumference, cm	17.14	17.08	0.60	0.94
Right ventricle free wall thickness, cm	2.11	1.99	0.05	0.09
Right ventricle free wall weight, g	467.60	436.60	22.40	0.33
Right ventricle free wall to interventricular septal thickness ratio	0.51	0.47	0.02	0.04
Right ventricle to total heart weight ratio	0.18	0.17	0.06	0.72

¹β ≥ 0.91.

²Treatment groups: CON = control (no ZH); ZIL = zilpaterol.