QRS pattern and improvement in right and left ventricular function after cardiac resynchronization therapy: a radionuclide study

Table 4 Baseline clinical characteristics according to CRT response at follow-up

	Responders (n= 23)	Non Responders (n= 25)	p
Age (years)	67 ± 11	65 ± 11	0.64
Males	15 (65%)	21 (84%)	0.19
Aetiology of heart failure
Ischaemic	6 (26%)	11 (44%)	0.24
Non-ischaemic	17 (74%)	14 (56%)
NYHA class
III	21 (87%)	23 (92%)	0.67
IV	3 (13%)	2 (8%)
QRS duration (ms)	150 (120-160)	140 (120-180)	0.77
QRS ≥ 150 ms	12 (52%)	12 (48%)	> 0.99
LEFT axis	11 (48%)	14 (56%)	0.77
QRS morphology
LBBB	19 (83%)	9 (36%)	0.001*
RBBB	0 (0%)	3 (12%)	0.24^§
Non-specific IVCD	4 (17%)	13 (52%)	0.017^†
LVEF (%)	23 ± 5	20 ± 6	0.05
RVEF (%)	37 ± 8	36 ± 10	0.74
SD of LV mean phase (°)	43.0 (24.0-73.0)	43.0 (35.5-64.5)	0.48
SD of RV mean phase (°)	28.0 (19.0-40.0)	26.0 (17.5-36.5)	0.40
Interventricular delay (°)	21.0 (8.0-38.0)	20.0 (8.5-27.5)	0.56
Intra LV dyssynchrony	20 (87%)	24 (96%)	0.34
Intra RV dyssynchrony	16 (70%)	13 (52%)	0.25
Interventricular dyssynchrony	16 (70%)	15 (60%)	0.56

*LBBB vs. RBBB and non-specific IVCD; §RBBB vs. LBBB and non-specific IVCD; † non-specific IVCD vs. LBBB and RBBB.
NYHA class, New York Heart Association class; LBBB, left bundle branch block; RBBB, right bundle branch block; IVCD, intraventricular conduction disturbance; LVEF, left ventricular ejection fraction; RVEF, right ventricular ejection fraction; SD, standard deviation; LV, left ventricular; RV, right ventricular

ISSN: 1471-2261