Table 1.

Demographic characteristics and echocardiographic data

Mdx mouse groups:	Vehicle (n = 10)	Nicorandil (n = 10)	Isoproterenol (n = 14)	Nicorandil + Isoproterenol (n = 14)
Baseline characteristics
Age at study end (weeks)	13.0 ± 0.52	13.4 ± 0.44	13.4 ± 0.47	13.4 ± 0.51
Body weight at study end (g)	25.8 ± 0.53	26.2 ± 0.45	26.4 ± 0.46	25.1 ± 0.45
Echocardiographic measurements
Heart rate (beats per minute)
Baseline	419 ± 16	472 ± 16	394 ± 19	451 ± 14
Day 10	501 ± 11*	485 ± 14	454 ± 14*	489 ± 13*
Ejection fraction (%)
Baseline	71.3 ± 1.8	75.9 ± 2.1	75.2 ± 1.6	75.9 ± 1.6
Day 10	71.9 ± 2.3	72.6 ± 2.5	68.1 ± 2.6*	74.8 ± 1.6
Fractional shortening (%)
Baseline	35.3 ± 1.5	39.2 ± 1.8	38.6 ± 1.3	39.2 ± 1.4
Day 10	36.0 ± 1.8	36.6 ± 2.0	33.4 ± 1.9*	38.2 ± 1.5
Left ventricular end systolic volume (mL)
Baseline	0.030 ± 0.003	0.027 ± 0.004	0.028 ± 0.003	0.025 ± 0.003
Day 10	0.040 ± 0.007	0.040 ± 0.005	0.047 ± 0.005*	0.030 ± 0.003*
Left ventricular end diastolic volume (mL)
Baseline	0.116 ± 0.008	0.190 ± 0.011	0.111 ± 0.005	0.099 ± 0.007
Day 10	0.119 ± 0.015	0.128 ± 0.011	0.144 ± 0.007*	0.114 ± 0.009
Stroke volume (mL)
Baseline	0.083 ± 0.006	0.080 ± 0.007	0.083 ± 0.003	0.074 ± 0.005
Day 10	0.083 ± 0.008	0.093 ± 0.008	0.096 ± 0.005*	0.082 ± 0.007

Echocardiograms were performed at baseline and at 10 days. Isoproterenol induced left ventricular dilation and a mild cardiac injury with a decrease in ejection fraction and fractional shortening and an increased end systolic volume. Nicorandil was protective against left ventricular dilation and isoproterenol-induced injury. (*p < 0.05 vs same group baseline measurement)