Table 2.

Strain-Differences in Echocardiographic Parameters among S and Congenic Rat Strains Maintained on Elevated Dietary NaCl.

Strain, (n)	LVDd, cm	LVSd, cm	FS, %	Vcf, 1/sec	RWT
S (6)	0.74 ± 0.04	0.42 ± 0.04	44 ± 4	5.48 ± 0.59	0.67 ± 0.01*
RNO3 (7)	0.73 ± 0.04	0.34 ± 0.04	54 ± 3	7.94 ± 0.60	0.67 ± 0.09
RNO3 + RNO7 (7)	0.69 ± 0.02	0.30 ± 0.02	57 ± 3	8.48 ± 0.50	0.85 ± 0.03†
RNO7 (4)	0.86 ± 0.04	0.52 ± 0.05	40 ± 3	5.30 ± 0.78	0.50 ± 0.05
P (overall)	0.036	0.004	0.005	0.002	0.023
P (S vs. RNO3)	NS	NS	NS	0.031	NS
P (S vs.RNO3 + RNO7)	NS	NS	0.039	0.007	0.010
P (S vs. RNO7)	NS	NS	NS	NS	0.041
P (RNO3 vs. RNO3 + RNO7)	NS	NS	NS	NS	NS, 0.08
P (RNO3 vs. RNO7)	NS	0.017	0.035	0.043	NS
P (RNO7 vs. RNO3 + RNO7)	0.024	0.004	0.013	0.012	0.010
P (R3)	0.019	0.001	0.0005	0.0002	0.026
P (R7)	NS	NS	NS	NS	NS
P (R3 × R7)	0.042	NS, 0.08	NS	NS	0.025

Echocardiography was performed on surviving Group 2B rats exposed to a 4% NaCl diet for 40-41 days (i.e., 69-70 days on higher NaCl diets). Numbers of rats per strain studied for each trait are in parentheses, with the following exceptions

^*four S rats

^†six RNO3+RNO7 rats.

NS, not significant (P>0.05). R3, allelic content within the RNO3 congenic interval; R7, allelic content within the RNO7 congenic interval. LVDd: LV end-diastolic diameter, LVSd: LV end-systolic diameter, FS: left ventricular (LV) fractional shortening, Vcf: mean velocity of circumferential fiber shortening, RWT: left ventricular relative wall thickness.