Cardiopulmonary exercise testing and impedance cardiography in the assessment of exercise capacity of patients with coronary artery disease early after myocardial revascularization

Table 3 Correlations between the absolute values of VO₂ at various CPET time points and those of selected hemodynamic parameters, as well as correlations between the relative changes in VO₂ at various CPET time points and those in selected hemodynamic parameters

	HR (bpm)	SV (mL)	CO (L/min)	LCWi (kg*m/m²)
AT values
VO₂ (mL/min/kg)	0.32*	0.17	0.36***	0.33**
O₂ pulse (mL/beat)	− 0.18	0.41**	0.26	− 0.02
Peak values
VO₂ (mL/min/kg)	0.45***	0.03	0.33*	0.40**
O₂ pulse (mL/beat)	− 0.22	0.31*	0.19	− 0.01
Δvalues (peak–rest)
VO₂ (mL/min/kg)	0.47***	0.11	0.41**	0.43***
O₂ pulse (mL/beat)	− 0.17	0.01	0.01	− 0.09
Δvalues (peak–AT)
VO₂ (mL/min/kg)	0.48***	0.03	0.41**	0.44***
O₂ pulse (mL/beat)	− 0.21	0.08	− 0.05	− 0.25

AT anaerobic threshold, CO cardiac output, HR heart rate, LCWi left cardiac work index, peak value at peak exercise, rest value at rest, SV stroke volume, VO₂ oxygen uptake, Δ changes in parameter between its measurements at rest, at peak exercise, and at the anaerobic threshold
^*p < 0.05; ** p < 0.01; ***P ≤ 0.001