TABLE 1.

Summary of echocardiographic parameters in WT and R21C mice

Data are mean ± S.E. and are derived from nine male R21C and nine WT littermates from each age group. HR, heart rate; SV, stroke volume; CO, cardiac output; ET, aortic ejection time; LV, left ventricular; EF, ejection fraction; FS, fractional shortening; M, mitral; E, passive LV filling peak velocity; A, atrial contraction flow peak velocity; EDV, end-diastolic volume; ESV, end-systolic volume; IVRT, isovolumetric relaxation time; IVCT, isovolumetric contraction time; PWd, posterior wall thickness at diastole; PWs, posterior wall thickness at systole. *, p < 0.05 versus WT. †, p < 0.01 versus WT.

Parameter	Young (6 months)		Old (12 months)
	WT	R21C	WT	R21C
HR (bpm)	458 ± 9	450 ± 10	430 ± 9	476 ± 6†
R-R interval (ms)	131 ± 2	131 ± 3	140 ± 3	126 ± 2†
SV (μl/beat)	40.5 ± 3.5	41.0 ± 1.7	40.3 ± 3.2	28.5 ± 4.0*
CO (ml/min)	18.6 ± 1.8	18.5 ± 0.9	17.5 ± 1.5	13.7 ± 1.9
ET (ms)	48.0 ± 1.9	50.0 ± 1.9	47.0 ± 3.1	37.9 ± 2.7*
%ETa	29.9 ± 1.2	28.1 ± 0.8	33.7 ± 1.8	30.1 ± 2.3
LV mass (mg)	116.1 ± 4.8	115.1 ± 5.2	152.3 ± 11.8	218 ± 20.1*
EF (%)	71.9 ± 3.0	70.7 ± 4.0	62.1 ± 2.6	65.6 ± 2.1
FS (%)a	41.3 ± 2.8	40 ± 2.3	33.5 ± 1.8	35.7 ± 1.6
M E (cm/s)	60 ± 3	70 ± 3*	50 ± 4	45 ± 3
M A (cm/s)	41 ± 3	54 ± 4†	31 ± 3	45 ± 4*
M E/A	1.5 ± 0.2	1.3 ± 0.1	1.8 ± 0.3	1.0 ± 0.1*
E deceleration time (ms)	12.4 ± 0.7	11.9 ± 0.4	13.7 ± 0.7	14.9 ± 0.3
%E deceleration timea	10.8 ± 0.6	12.9 ± 0.4	9.7 ± 0.5	11.9 ± 0.3†
EDV (μl)	63.4 ± 7.3	58.5 ± 7.4	66.7 ± 7.6	44.2 ± 6.9*
ESV (μl)	24.8 ± 4.5	26.4 ± 2.7	26.5 ± 4.8	15.7 ± 3.11
IVRT (ms)	24.1 ± 1.7	23 ± 1.7	22.4 ± 1.7	22.4 ± 1.7
%IVRTa	17.5 ± 1.1	17.1 ± 1.4	15.9 ± 1.1	17.8 ± 1.4
IVCT (ms)	18.1 ± 1.8	19.3 ± 1.6	22.2 ± 3.8	16.9 ± 1.7
%IVCTa	14.0 ± 1.1	14.1 ± 1.2	16.1 ± 2.9	13.3 ± 1.2
PWd (mm)	1.1 ± 0.1	0.9 ± 0.2	0.9 ± 0.1	1.6 ± 0.2*
PWs (mm)	1.3 ± 0.1	1.3 ± 0.1	1.2 ± 0.1	1.9 ± 0.2*

^a %, denotes the temporal parameter was normalized to the R-R interval and expressed as percentage of the cardiac cycle.