Table 4.

Selected ex vivo and in vivo cardiac parameters in canines and humans. Right ventricular trabeculae from mixed-breed canines and human (2 females, 3 male) were stimulated at 1 Hz and 0.5 Hz, respectively. Temperature of 37 °C in both groups. Calcium concentrations (in mM) were 2 (canine) and 1.75 (human). TTP (time to peak: time from stimulation to peak force) and (dF/dt_max)/F (maximal velocity of contraction divided by developed force) represent contraction kinetics. RT₅₀ (Relaxation time 50%: time from peak force to 50% relaxation) and (dF/dt_min)/F (maximal velocity of relaxation divided by developed force) represent relaxation kinetics. dF/dt_max and dF/dt_min (not shown) values were divided by the developed force yielding (dF/dt_max)/F and (dF/dt_min)/F, respectively. Cardiac catheterization measurements performed in control humans (4 females/8 males) and conscious standing canines (mongrel). LVSP: left ventricular systolic pressure. LV τ: left ventricular isovolumic relaxation time constant. LV dP/dt_max left ventricular maximal rate of pressure rise. LV dP/dt_min left ventricular maximal rate of pressure decline.

Parameter	Caninea,b	Humanc,d	Ratio
			Canine/Human
Ex Vivo Right Ventricular Trabeculae
Force (mN/mm2)	15.8	16.7	0.95
TTP (ms)	110.7	235	0.47
RT50 (ms)	61.4	153	0.40
dF/dtmax/F (s −1)	17.6	7.7	2.29
dF/dtmin/F (s −1)	−11.9	−5.9	2.02
In Vivo Catheterization
LVSP (mmHg)	120	115	1.04
LV τ(ms)	28	43	0.65
LV dP/dtmax (mmHg/s)	2,948	1,491	1.98
LV dP/dtmin (mmHg/s)	−2,454	−1,869	1.31

References:

^aModified from subset of data reported in (Billman, et al., 2010),

^b(Cheng, Igarashi, & Little, 1992),

^c(Rossman, et al., 2004),

^d(Kasner, et al., 2007).