Table 4.

Cardiac parameters in patients with PAH during rest and exercise compared with healthy control subjects in normoxia

	Control Subjects		Patients With PAH		P Values
Variable	Rest	Exercise	Rest	Exercise	Exercise	Between subjects	Interaction
Heart rate and flows
Heart rate, beats/min	61.2 ± 10.8	122.4 ± 12.1‡	63.4 ± 11.5	114.1 ± 15.6‡	<0.0001	0.321	0.022
Aortic stroke volume index, ml/m2	51.4 ± 11.0	61.7 ± 10.4‡	45.7 ± 8.6	46.2 ± 12.1*	<0.0001	0.001	<0.0001
Mean pulmonary artery stroke volume index, ml/m2	51.4 ± 9.9	60.0 ± 9.3‡	40.0 ± 8.0	40.0 ± 13.3*	0.001	<0.0001	<0.0001
Cardiac index, l·min−1·m−2	3.1 ± 0.6	7.6 ± 1.5‡	2.9 ± 0.6	5.2 ± 1.2*‡	<0.0001	<0.0001	<0.0001
Left ventricular parameters
End-diastolic volume index, ml/m2	84.3 ± 14.7	90.1 ± 15.5‡	70.3 ± 14.6†	67.2 ± 16.3*	0.264	<0.0001	0.001
End-systolic volume index, ml/m2	30.4 ± 5.3	25.5 ± 7.0‡	25.7 ± 9.3	18.4 ± 8.8‡	<0.0001	0.005	0.169
Stroke volume index, ml/m2	53.8 ± 10.7	64.6 ± 10.7‡	44.6 ± 6.7†	48.9 ± 9.1*§	<0.0001	<0.0001	<0.0001
Ejection fraction, %	63.7 ± 3.6	71.9 ± 4.5‡	64.3 ± 6.2	73.7 ± 6.7‡	<0.0001	0.363	0.405
Right ventricular parameters
End-diastolic volume index, ml/m2	89.6 ± 2.7	85.8 ± 4.4	88.1 ± 2.5	93.2 ± 4.0*§	0.024	0.890	0.001
End-systolic volume index, ml/m2	38.4 ± 8.5	27.1 ± 8.4‡	40.1 ± 9.5	45.8 ± 15.9†	0.056	0.001	<0.0001
Stroke volume index, ml/m2	51.2 ± 1.6	60.9 ± 1.6‡	45.3 ± 2.6	47.4 ± 2.6*	<0.0001	0.002	<0.0001
Ejection fraction, %	57.1 ± 5.2	69.6 ± 6.1‡	53.6 ± 4.3	51.4 ± 10.7*	<0.0001	<0.0001	<0.0001
Stroke volume index/end-systolic volume index	1.4 ± 0.3	2.4 ± 0.7‡	1.2 ± 0.2†	1.1 ± 0.5*	<0.0001	<0.0001	<0.0001
End-systolic volume/stroke volume	0.8 ± 0.2	0.4 ± 0.1‡	0.9 ± 0.1	1.0 ± 0.5§	0.071	<0.0001	<0.0001

n = 14 patients with PAH and 38 healthy control subjects. PAH, pulmonary arterial hypertension.

Mixed ANOVA for comparing the exercise-dependent change in each variable between groups was used. Simple main effects analysis compared with control was as follows:

^*P < 0.001 and

^†P < 0.05. Simple main effects analysis from rest to exercise was as follows:

^‡P < 0.001 and

^§P < 0.05.