Relationship between electrocardiographic characteristics and subclinical left ventricular systolic dysfunction in isolated left bundle branch block patients

Table 5 LVSD reclassification of QRS duration, discordant LBBB and presence of QS

	Reclassification
Variables	NRI	95% CI	P-value	IDI	95% CI	P-value
QRS duration	-	-	-	-	-	-
Presence of QS	-0.19	-0.44-0.07	0.15	-0.07	-0.16-0.01	0.09
Discordant LBBB*	-0.09	-0.35-0.17	0.51	-0.03	-0.12-0.05	0.44
QRS duration + Presence of QS	0.50	0.15–0.86	0.006	0.07	0.02–0.12	0.004
QRS duration + Discordant LBBB	0.63	0.28–0.99	<0.001	0.08	0.03–0.13	0.001
QRS duration + Discordant LBBB + Presence of QS	0.55	0.21–0.89	0.001	0.15	0.09–0.22	<0.001

Abbreviations: LVSD left ventricle systolic dysfunction, IDI integrated discrimination index, NRI net reclassification improvement, CI confidence interval
* Discordant LBBB T-wave orientation discordant with QRS complex in leads I, V5, and V6

ISSN: 1476-7120