Table 3.

Cardiac function during aortic pressure manipulation

Left atrial filling pressure (cm H2O)	13.5	13.5	13.5	13.5
Aortic pressure (cm H2O)	60	70	80	90
HR (beats × min−1)
Sham	279 ± 10	281 ± 11	287 ± 9	284 ± 10
AI	276 ± 23	282 ± 22	289 ± 19	278 ± 16
CO (mL × min−1 × g heart mass−1)
Sham	28 ± 3	28 ± 3	31 ± 3	27 ± 3**
AI	14 ± 2*	14 ± 3*	17 ± 3*	15 ± 4*
Coronary flow (mL × min−1 × g heart mass−1)
Sham	8.5 ± 0.9**	9.6 ± 1.0**	11.4 ± 1.0	11.5 ± 1.2
AI	5.9 ± 1.3**	6.7 ± 1.4	8.0 ± 1.3	7.5 ± 1.9
Systolic pressure (mmHg)
Sham	76 ± 1**	82 ± 1**	90 ± 2	95 ± 2**
AI	59 ± 3*,**	64 ± 2*,**	74 ± 3*	80 ± 3*,**
Diastolic pressure (mmHg)
Sham	29 ± 2**	33 ± 2**	37 ± 2	45 ± 2**
AI	35 ± 1**	40 ± 2**	45 ± 2*	52 ± 3**
Cardiac work (SP × CO)
Sham	2086 ± 202**	2321 ± 227**	2813 ± 292	2321 ± 228
AI	842 ± 165*	935 ± 184*	1244 ± 263*	1254 ± 369*
RPP (HR × SP)
Sham	21 095 ± 644**	22 964 ± 967**	25 743 ± 884	27 266 ± 1265**
AI	16 220 ± 1324*,**	17 972 ± 1299*,**	21 290 ± 1286*	22 296 ± 1667*
Maximum rate of ΔP (+dp/dt; mmHg × s−1)
Sham	1312 ± 49	1415 ± 62	1442 ± 80	1431 ± 58
AI	827 ± 65*	825 ± 48*	923 ± 67*	919 ± 111*
Minimum rate of ΔP (−dp/dt; mmHg × s−1)
Sham	−1052 ± 49	−1127 ± 93	−1103 ± 51	−1078 ± 48
AI	−607 ± 58*	−645 ± 56*	−687 ± 65*	−687 ± 99*

Different measures of cardiac function in sham (n = 7) and 5/6 ablation–infarction (AI; n = 6) rats in response to altering aortic pressure. Data collected at 100-cm H₂O are not included due to the inability of some AI animals (n = 3) to achieve aortic overflow, and AI animals unable to achieve aortic overflow during the entirety of afterload manipulations (n = 1) have been excluded.

Values are mean ± SEM; SP, systolic pressure; CO, cardiac output; RPP, rate pressure product; HR, heart rate; ΔP, change in pressure.

*P < 0.05 versus sham, **P < 0.05 versus 80-cm H₂O atrial filling pressure value.