Table 2.

In vivo cardiac performance of KO-GFP and KO-S68E mice

	KO-GFP	KO-S68E
Echocardiography
Body weight, g	28.0 ± 0.6 (5)	28.0 ± 0.6 (7)
LVIDD, mm	3.55 ± 0.16	3.40 ± 0.12
LVIDS, mm	2.09 ± 0.13	1.92 ± 0.09
Ant, mm	0.69 ± 0.01	0.71 ± 0.02
PWT, mm	0.74 ± 0.01	0.72 ± 0.02
LV mass, mg	67.2 ± 5.4	62.5 ± 5.0
Heart rate, beats/min	468 ± 19	464 ± 15
Ejection fraction, %	72.6 ± 2.2	75.6 ± 1.0
Fractional shortening, %	41.0 ± 1.8	43.4 ± 0.8
Stroke volume, μl	38.5 ± 4.0	36.1 ± 2.8
Cardiac output, ml/min	18.0 ± 2.0	16.6 ± 1.1
In vivo catheterization
+dP/dt, mmHg/s	6,983 ± 280 (5)	7,584 ± 398* (6)
Max +dP/dt, mmHg/s	13,795 ± 480	14,546 ± 600*
−dP/dt, mmHg/s	7,219 ± 306	7,387 ± 275†
Max −dP/dt, mmHg/s	10,185 ± 156	11,565 ± 951†

Values are means ± SE. Numbers in parentheses are numbers of mice. KO, PLM knockout; S68E, PLM S68E mutant; LV, left ventricle; LVIDD, LV internal dimension at end-diastole; LVIDS, LV internal dimension at end-systole; Ant, anterior wall thickness; PWT, posterior wall thickness; +dP/dt, −dP/dt, 1st time derivatives of LV pressure rise and fall. LV mass is given by the formula LV mass = 1.04[(Ant + LVIDD + PWT)³ − (LVIDD)³]. Maximal +dP/dt and maximal −dP/dt are peak hemodynamic responses after 10 ng isoproterenol infusion.

^*P < 0.047,

^†P < 0.002, KO-GFP vs. KO-S68E.