Oxygen Kinetics and Heart Rate Response during Early Recovery from Exercise in Patients with Heart Failure

Table 2

Results of exercise testing.

(%)	𝑛	AT (mL/min/kg)	Peak VO2 (mL/min/kg)	ΔVO2/ΔWRs (mL/min/W)
FC >90	50	18.4 ± 6	31 ±7	11.6 ± 0.9
FC 70–90	48	14 ± 4	22 ± 4	9.6 ± 0.8
FC 50–70	57	8 ± 3	17 ± 4	8.5 ±1.0
FC <50	31	6 ± 2	10 ± 2	5.2 ± 1.3
(%)	VE/VCO2 Peak ex.	Peak HR (bpm)	TC (VO2) (sec)	TC (HR) (sec)
FC >90	27±2.8	154±22	110±34	148±82
FC 70–90	31±3.5	132±11	197±43^∗	290±65^∗
FC 50–70	37±5.6	123±12	238±80^∗	320±58^∗
FC <50	45±7.2	110±10	278±50^∗	376±55^∗

𝑛∶number of cases, AT: anaerobic threshold, peak VO₂: oxygen uptake at peak exercise, ΔVO₂/ΔWR: ratio of the increase in oxygen uptake to the increase in work rate, VE/VCO₂ peak Ex.: respiratory equivalent for carbon dioxide at peak exercise, peak HR: heart rate at peak exercise, TC (VO₂) and TC (HR): time constant for the postexercise oxygen uptake and heart rate, respectively. 𝑃<0.05 for all parameters of each group compared to the previous group (i.e., FC <50% versus FC 50–70%, FC 50–70% versus FC 70–90%, and FC 70–90% versus FC >90%). Values are expressed as means ± SD. *𝑃<0.05 for the comparison with the previous groups.