Table 2 Clinical and functional characteristics at baseline and after 6 months of CRT

NYHA functional class

At baseline

2.6±0.6

2.8±0.6

After 6 months

1.9±0.7^a

2.2±0.9^a

6-min walking distance, (m)

At baseline

329.2±86.0

320.9±98.7

After 6 months

421.5±66.7^a

381.5±112.2^a

LVEF by 3D echocardiography, (%)

At baseline

30.0±2.7

29.6±3.9

After 6 months

40.1±5.4^a

34.4±3.8^a

Mean changes

10[6.2;13.2]

5[3;7]

LVEDV by 3D echocardiography, (ml)

At baseline

233.4±65.0

231.2±65.9

After 6 months

159.1±39.4^a

213.2±63.7^a

Mean changes

−73.0[− 101.0;-51.7]

−15.0[− 31.0;-8.0]

LVESV by 3D echocardiography, (ml)

At baseline

163.4±46.5

163.5±51.3

After 6 months

95.8±27.1^a

140.0±46.7^a

Mean changes

−61.0[−91.0;-47.7]

− 20.0[− 38.0;-12.0]

QRS, (ms)

At baseline

139.1±44.2

141.8±36.7

After 6 months

153.6±26.2

160.2±26.0^a