Table 2 Characteristics comparison between subjects with increase in Q or plateau/decrease in Q (n = 61)

Age (years)

63 ± 10

64 ± 9

n.a.

NS

Gender male/female (%)

33 (83)/7 (17)

18 (86)/3 (14)

0.10 (1)

NS

Etiology ICM/DCM (%)

21 (53)/19 (47)

13 (62)/8 (38)

0.49 (1)

NS

Duration CHF (months)

45 ± 50

46 ± 54

n.a.

NS

Beta blocker (%)

93

95

0.17 (1)

NS

NYHA class II/III (%)

24 (60)/16 (40)

11 (52)/10 (48)

0.33 (2)

NS

LVEF (%)

31 ± 8

33 ± 10

n.a.

NS

Peak VO₂ (mL min⁻¹ kg⁻¹)

19.4 ± 6.0

18.2 ± 5.9

n.a.

NS

Peak Q (L min⁻¹)

11.3 ± 3.6

10.2 ± 5.0

n.a.

NS

Peak SV (mL)

90 ± 24

83 ± 22

n.a.

NS

Plateau/decrease in VO₂

9 (23 %)

11 (52 %)

5.58 (1)

0.02

Plateau/decrease in SV

30 (75 %)

21 (100 %)

6.28 (1)

0.01

Rest HR (beats min⁻¹)

81 ± 16

77 ± 18

n.a.

NS

Peak HR (beats min⁻¹)

126 ± 20

121 ± 35

n.a.

NS

Chronotropic incompetence

1 (2.5 %)

5 (31 %)

7.05 (1)

0.01

Rhythm (SR, Afib, paced) (%)

35 (88)/2 (5)/3 (7)

15 (71)/5 (24)/1 (5)

4.85 (2)

NS

LBBB

19 (48 %)

4 (19 %)

4.84 (1)

0.03

Severe mitral regurgitation

3 (7.5 %)

3 (14 %)

0.72 (1)

NS

Myocardial ischemia

2 (5 %)

0 (0 %)

1.09 (2)

NS