Table 1.

Characteristics of the study population.

	Strict LBBB (n=31)	Non-strict LBBB (n=19)	Non-LBBB (n=14)	P-value (Strict vs. Non-strict)	P-value (Non-strict vs. Non)
Age, y (SD)	58 ± 11	63 ± 15	52 ± 11	0.07	0.012
Female, n (%)	10 (32)	4 (21)	1 (7)	0.39	0.27
Ischemic etiology, n (%)	8 (26)	12 (63)	8 (57)	0.003	0.73
NYHA, n (%)
Class I	2 (6)	4 (21)	7 (50)	0.12	0.005
Class II	12 (39)	3 (16)	6 (43)
Class III	17 (55)	12 (63)	1 (7)
LVEF (%)	25.2 ± 8.4	23.8 ± 8.2	27.9 ± 7.5	0.76	0.23
LVEDV (ml)	289.0 ± 109.3	287.0 ± 128.4	247.5 ± 74.1	0.76	0.51
LVESV (ml)	221.3 ± 105.0	221.3± 111.3	182.0 ± 62.9	0.98	0.49
Scar size (% LV)	4.2 ± 6.6	11.7 ± 10.0	14.9 ± 14.5	0.003	0.80
Septal Scar, n (%)	11 (35)	11 (58)	9 (64)	0.12	0.71
Lateral Scar, n (%)	7 (23)	11 (58)	7 (50)	0.012	0.65
QRS duration (ms)	163 ± 21	129 ± 16	114 ± 3	<0.0001	<0.0001
Patients without detectable contraction in 1 of 2 septal segments, n (%)	15 (48)	3 (16)	2 (14)	0.020	0.90

LVEF=left ventricular ejection fraction, LVEDV=left ventricular end diastolic volume, LVESV= left ventricular end systolic volume