TABLE 1.

Mechanical and structural characteristics of pig coronary veins and arteries.

	Vein	Artery	Significance
Optimal circumference (Co), mm	7.63 ± 0.52, n = 14	5.92 ± 0.22, n = 16	p < 0.01
Active tension at Co, mN mm−1	2.21 ± 0.38, n = 14	11.8 ± 1.0, n = 16	p < 0.001
Passive tension at Co, mN mm−1	1.03 ± 0.18, n = 14	6.16 ± 0.65, n = 16	p < 0.001
Active stress at Co, mN mm−2	12.9 ± 2.0, n = 14	46.2 ± 4.1, n = 16	p < 0.001
Wall thickness, mm	0.17 ± 0.01, n = 14	0.26 ± 0.02, n = 16	p < 0.001

Optimal circumference (Co) for active tension and the active and passive tension at Co are shown. Wall thickness was determined from vessel dimensions and wet weight. Active stress (i.e., force per cross/sectional area) was calculated from wall thickness and tension. Five and 6 animals were used for veins and arteries, respectively. Statistical comparisons were made using Student’s t-test and Mann-Whitney rank sum test for active tension and stress.