Ventricular electrical delay as a predictor of arrhythmias in patients with cardiac resynchronization implantable cardioverter defibrillator

Figures & data

Table 1. Patient characteristics (n = 69).

Variable	Study Cohort (n = 69)
Age (yrs) (mean ± SD)	72 ± 10
Gender (Males) n (%)	46 (67%)
Ejection Fraction (%)	23 ± 8
QRS Duration (ms) (mean ± SD)	154 ± 26
cQLV (%)(mean ± SD)	52 ± 26
LBBB cQLV (%)(mean ± SD)	52 ± 25
RBBB cQLV (%)(mean ± SD)	48 ± 14
IVCD cQLV (%)(mean ± SD)	54 ± 29
Hypertension n (%)	40 (58%)
Diabetes Mellitus n (%)	29 (42%)
Dilated CMP n (%)	17(25%)
Obesity n (%)	11 (16%)
OSA n (%)	10 (14%)
Asthma/COPD n (%)	14 (20%)
On ACE(-) n (%)	50 (72%)
On ARB n (%)	14 (20%)
On BB n (%)	61 (88%)
On Digoxin n (%)	21 (31%)

LBBB: left bundle branch block; RBBB: right bundle branch block; IVCD: non-specific intraventricular conduction delay; cQLV: adjusted left ventricular lead electrical delay; CMP: cardiomyopathy; OSA: obstructive sleep apnea; COPD: chronic obstructive pulmonary disease; ACE(-): angiotensin converting enzyme inhibitor; ARB: angiotensin receptor blocker; BB: beta blocker.

Figure 1. Association of corrected LV lead electrical delay (cQLV) with arrhythmic events among CRT recipients. Figure 1A: cQLV in patients with atria tachycardia/supraventricular tachycardia (AT/SVT) events compared to patients without AT/SVT events (43.4 ± 22% vs. 60.3 ± 26.7%, p = .006.); Figure 1B: cQLV in patients with ventricular tachycardia/fibrillation (VT/VF) events compared to patients without VT/VF events (46.2 ± 25.4% vs. 56 ± 25.7%, p = .13).

Figure 2. Association of corrected LV lead electrical delay (cQLV) with new onset arrhythmic events among CRT recipients. Figure 2A: cQLV in patients with new onset atria tachycardia/supraventricular tachycardia (AT/SVT) events compared to patients without new onset AT/SVT events (38.3 ± 22.2% vs. 55.7 ± 25.7%, p = .028); Figure 2B: cQLV in patients with new onset ventricular tachycardia/fibrillation (VT/VF) events compared to patients without new onset VT/VF events (44.2 ± 25.2% vs. 56.3 ± 25.5%, p = .069).

Table 2. Comparison of demographic and clinical characteristics of patients with and without arrhythmic events.

	Yes	No	p-value	Yes	No	p-value
	AT/SVT			VT/VF
Age (yrs)	75 ± 9	69.4 ± 11	.022	77 ± 7	69 ± 11	.001
Men; n (%)	21 (66%)	25 (68%)	.864	16 (64%)	30 (68%)	.723
Ejection Fraction (%)	23 ± 9	23 ± 8	.730	20 ± 8	25 ± 8	.047
ICM/NICM; (n)	19/13	18/19	.373	11/14	26/18	.227
LBBB; n (%)	16 (50%)	23 (62 %)	.309	14 (56%)	25 (57%)	.947
	New onset AT/SVT			New onset VT/VF
Age (yrs)	76 ± 10	71 ± 10	.099	77 ± 7	70 ± 11	.011
Men; n (%)	5 (39%)	41 (73%)	.017	14 (64%)	32 (68%)	.715
Ejection Fraction (%)	21 ± 8	24 ± 8	.274	21 ± 8	24 ± 8	.203
ICM/NICM; (n)	6/7	31/25	.549	10/12	27/20	.352
LBBB; n (%)	10 (77%)	29 (52%)	.100	12 (55%)	27 (57%)	.821

AT/SVT: atrial arrhythmia/supraventricular tachycardia; VT/VF: ventricular tachycardia/ventricular fibrillation; ICM: ischemic cardiomyopathy; NICM: non-ischemic cardiomyopathy; LBBB: left bundle branch block.

Table 3. Odds ratios for arrhythmic events.

		Unadjusted		Adjusted
Outcome	Factor	Estimate (95% Confidence Interval)	p-value	Estimate (95% Confidence Interval)	p-value
AT/SVT	cQLV	0.972 (0.952–0.993)	.009	0.974 (0.953–0.996)	.019
	Age (yrs)	1.059 (1.005–1.115)	.030	1.042 (0.985–1.102)	.156
	Gender, Female	1.091 (0.400–2.975)	.864	1.168 (0.332–4.112)	.809
	Ejection fraction	0.989 (0.933–1.049)	.722	0.976 (0.913–1.043)	.470
	NICM	0.648 (0.249–1.686)	.374	0.710 (0.212–2.379)	.579
	LBBB	0.609 (0.233–1.590)	.311	0.602 (0.207–1.752)	.352
VT/VF	cQLV	0.984 (0.964–1.005)	.135	0.985 (0.962–1.008)	.208
	Age (yrs)	1.087 (1.021––1.157)	.009	1.098 (1.027–1.175)	.006
	Gender, Female	1.205 (0.429–3.390)	.723	0.521 (0.134–2.026)	.347
	Ejection fraction	0.935 (0.876–0.999)	.047	0.932 (0.867–1.002)	.056
	NICM	1.838 (0.681–4.959)	.229	3.296 (0.895–12.144)	.073
	LBBB	0.967 (0.360–2.602)	.947	0.966 (0.303–3.079)	.953
New onset AT/SVT	cQLV	0.967 (0.937–0.998)	.037	0.962 (0.928–0.998)	.040
	Age (yrs)	1.059 (0.986–1.138)	.113	1.032 (0.947–1.125)	.472
	Gender, Female	4.373 (2.235–15.483)	.022	6.280 (1.099–35.888)	.039
	Ejection fraction	0.956 (0.885–1.033)	.259	0.942 (0.859–1.034)	.211
	NICM	1.447 (0.431–4.856)	.550	0.644 (0.113–3.664)	.620
	LBBB	3.103 (0.771–12.492)	.111	3.594 (0.752–17.189)	.109
New onset VT/VF	cQLV	0.980 (0.958–1.002)	.074	0.981 (0.958–1.005)	.115
	Age (yrs)	1.081 (1.014–1.151)	.016	1.085 (1.014–1.161)	.017
	Gender, Female	1.219 (0.421–3.530)	.715	0.611 (0.158–2.363)	.475
	Ejection fraction	0.957 (0.897–1.022)	.189	0.956 (0.892–1.025)	.207
	NICM	1.620 (0.585–4.489)	.354	2.666 (0.731–9.720)	.137
	LBBB	0.889 (0.321–2.463)	.821	0.860 (0.272–2.716)	.797

AT/SVT: atrial arrhythmia/supraventricular tachycardia; VT/VF: ventricular tachycardia/ventricular fibrillation; cQLV: adjusted left ventricular lead electrical delay; ICM: ischemic cardiomyopathy; NICM: non-ischemic cardiomyopathy; LBBB: left bundle branch block.