TABLE 1.
Studies comparing LBBP with BVP.
| References | Design | N | Success rate of LBBP |
Rescue LBBP (n) | Cross-over from CSP to BVP (n) | Criteria of inclusion/ exclusion |
Patients with AVB | Follow-up (m) | Pacing parameter | Electrical or mechanical changes | Echocardiographic changes | Clinical changes |
| Li et al. (34) | Prospective, multicenter, observational | 27 vs. 54 | 73.0% (27/37) | 9 | 4 | Inclusion: HF symptoms, LVEF ≤35% with LBBB | Not mentioned | 6 | Threshold: 0.81 vs. 1.22 V Impedance: 644.9 vs. 817.5 Ω |
Baseline QRSd: 178.2 ± 18.8 vs. 180.9 ± 29.7 ms Paced QRSd: 121.8 ± 10.8 vs. 158.2 ± 21.5 ms ΔQRSd: 58.0 vs. 12.5 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 28.8 ± 4.5 vs. 27.2 ± 4.9% Follow-up LVEF: 44.3 ± 8.7 vs. 35.0 ± 10.5% ΔLVEF: 15.6 vs. 7.0% ΔLVEDD: 8.0 vs. 0.5 mm Echocardiographic response: 88.9 vs. 66.7% Super response: 44.4 vs. 16.7% |
Baseline NYHA: 3.1 ± 0.7 vs. 3.0 ± 0.7 Follow-up NYHA: 1.5 ± 0.5 vs. 2.3 ± 0.7 clinical response: 96.3 vs. 75.9% |
| Wu et al. (35) | Prospective, non-randomized, single-center | 32 vs. 54 | 100% (32/32) | 32 | 15 | Inclusion: LVEF ≤40% and typical LBBB | 3.1 vs. 3.7% | 12 | Threshold: 0.49 (LBBP) vs. 0.61 (RV lead)/0.93 V (CS lead) Sensing: 11.2 vs. 14.1 mV |
Baseline QRSd: 166.2 ± 16.2 vs. 161.1 ± 18.2 ms Paced QRSd: 110.8 ± 11.1 vs. 135.4 ± 20.2 ms ΔQRSd: 56.0 vs. 26.0 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 30.4 ± 7.1 vs. 29.7 ± 5.1% Follow-up LVEF: 54.4 ± 9.8 vs. 46.5 ± 16.9% ΔLVEF: 24.0 vs. 16.7% LVESV: 54.6 vs. 84.8 ml |
Baseline NYHA: 2.8 ± 0.5 vs. 2.8 ± 0.6 Follow-up NYHA: 1.3 ± 0.5 vs. 1.9 ± 0.9 |
| Wang et al. (36) | Matched case–control study | 10 vs. 30 | 100% (10/10) | 0 | 0 | Inclusion: HF, LBBB with QRSd >140 ms in men and >130 ms in women, LVEF ≤35%, and NYHA II to IV | Not mentioned | 6 | Threshold: 0.54 vs. 1.00 V | Baseline QRSd: 183.60 ± 19.27 vs. 174.60 ± 19.48 ms Paced QRSd: 122.80 ± 17.24 vs. 141.60 ± 15.38 ms ΔQRSd: 60.8 vs. 33.0 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 26.80 ± 3.85 vs. 26.38 ± 5.27% Follow-up LVEF: 45.66 ± 9.22 vs. 39.35 ± 12.29% ΔLVEF: 18.86 vs. 12.97% Response rate: 100.00 vs. 63.33% |
Baseline NYHA: 2.90 ± 0.74 vs. 3.07 ± 0.74 Follow-up NYHA: 1.50 ± 0.55 vs. 1.97 ± 0.61 |
| Guo et al. (37) | Prospective, observational | 21 vs. 21 | 87.5% (21/24) | 0 | 3 | Inclusion: HF, LBBB morphology, with LVEF ≤35%, NYHA II to IV | Not mentioned | 6 | Threshold: 0.48 (LBBP) vs. 0.57 (RV lead)/1.12 V (CS lead) | Baseline QRSd: 167.7 ± 14.9 vs. 163.6 ± 13.8 ms Paced QRSd: 111.7 ± 12.3 vs. 130.1 ± 14.0 ms ΔQRSd: 56.0 vs. 32.3 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 30.0 ± 5.0 vs. 29.8 ± 4.1% Follow-up LVEF: 50.9 ± 10.7 vs. 44.4 ± 13.3% LVEF: 50.9 vs. 44.4% Super response: 80.9 vs. 57.1% |
Baseline NYHA: 3.0 ± 0.7 vs. 3.0 ± 0.7 Follow-up NYHA: 1.3 ± 0.9 vs. 1.5 ± 0.7 |
| Zu et al. (38) | Observational | 13 vs. 19 | 100% (13/13) | 3 | 0 | Inclusion: DCM complicated with HF and LBBB, ischemic cardiomyopathy was excluded | 30.8 vs. 10.5% | 12 | Comparison not mentioned | Baseline QRSd: 167.46 ± 28.11 vs. 163.47 ± 21.66 ms Paced QRSd: 117.15 ± 9.91 vs. 130.32 ± 12.41 ms ΔQRSd: 50.30 vs. 33.15 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 30.62 ± 6.983 vs. 29.11 ± 4.818% Follow-up LVEF: 48.92 ± 8.06 vs. 42.53 ± 4.89% |
Not mentioned |
| Chen et al. (39) | Prospective, multi-center, observational | 49 vs. 51 | 98.0% (49/50) | 5 | 1 | Inclusion: HF, NYHA II–IV, LVEF ≤35%, QRSd >150 ms, typical LBBB Exclusion: PR interval >200 ms, persistent AF and IVCD |
Not mentioned | 12 | Threshold: 0.92 vs. 1.45 V | Baseline QRSd: 180.12 ± 15.79 vs. 175.70 ± 11.29 ms Paced QRSd: 102.61 ± 9.66 vs. 126.54 ± 11.67 ms ΔQRSd: 59.16 vs. 31.00 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 29.05 ± 5.09 vs. 28.36 ± 5.30% Follow-up LVEF: 49.10 ± 10.43 vs. 43.62 ± 11.33% ΔLVEF: 20.9 vs. 15.2% LVEDD: 54.50 vs. 60.99 mm LVESD: 41.78 vs. 48.33 mm Super response: 61.22 vs. 39.22% |
Baseline NYHA (percentage of III–IV): 91.48 vs. 88.24% Follow-up NYHA (percentage of III–IV): 4.08 vs. 19.61% |
| Liu et al. (40) | Prospective, multicenter, cohort study | 27 vs. 35 | 79.4% (27/34) | 0 | 7 | Inclusion: HF, LVEF ≤35%, LBBB morphology and QRSd ≥130 ms Exclusion: narrow QRS or non-LBBB morphology |
Not mentioned | 3–6 | Not mentioned | Baseline QRSd: 177.1 ± 16.7 vs. 168.8 ± 16.8 ms Paced QRSd: 113.0 ± 18.4 vs. 136.3 ± 20.1 ms ΔQRSd: 64.1 vs. 32.5 ms Baseline QRS morphology: LBBB Better mechanical synchrony reflected by IVMD, PSD, GWE, GWI, GCW, MWE |
Baseline LVEF: 29.9 ± 4.8 vs. 29.5 ± 4.9% Follow-up LVEF: 47.1 ± 8.3 vs. 43.1 ± 11.0% ΔLVEF: 17.2 ± 9.3 vs. 13.7 ± 11.5% Echocardiographic response: 88.9 vs. 68.6% |
Baseline NYHA: 3.0 ± 0.5 vs. 2.8 ± 0.6 Follow-up NYHA: 1.6 ± 0.6 vs. 2.2 ± 0.8 ΔNYHA: 1.6 ± 0.6 vs. 0.9 ± 0.8 |
| Ivanovski et al. (41) | Retrospective, single-center, observational | 10 vs. 13 | 100% (10/10) | 0 | 0 | Inclusion: severely symptom AF with rapid ventricular rate, tachycardia-induced cardiomyopathy, LVEF <50%, NYHA II–IV, narrow QRSd ≤120 ms | Not mentioned | 6 | Threshold: 0.80 vs. 1.40 V Impedance: 749.0 vs. 760.0 Ω |
Baseline QRSd: 105 ± 15 vs. 98 ± 7 ms Paced QRSd: 127 ± 13 vs. 172 ± 13 ms ΔQRSd: −29.0 vs. −74.0 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 28.0 vs. 38.0% Follow-up LVEF: 40.0 vs. 37.0% ΔLVEF: 12.0% vs. −1.0% |
Baseline median NYHA: 3.0 vs. 3.0 Follow-up median NYHA: 2.0 vs. 3.0 ΔNT-proBNP: 1,057.0 vs. 52.0 pg/ml |
| Wang et al. (42) | Prospective, randomized trial | 22 vs. 18 | 91.7% (22/24) | 4 | 2 | Inclusion: age 18–80 years, sinus rhythm, complete LBBB meeting Strauss’s standard definition (QRSd >140 ms for men or >130 ms for women), LVEF ≤40%, and NYHA class II to IV Exclusion: (1) ischemic cardiomyopathy; (2) non-LBBB QRS morphology including RBBB or IVCD; (3) persistent AF; or (4) pregnancy |
Not mentioned | 6 | Threshold: 0.82 vs. 1.12 V Impedance: 476.0 vs. 592.0 Ω |
Baseline QRSd: 174.6 ± 14.3 vs. 174.7 ± 14.1 ms Paced QRSd: 131.5 ± 12.5 vs. 136.6 ± 12.9 ms Baseline QRS morphology: LBBB |
Baseline LVEF: 28.3 ± 5.3 vs. 31.1 ± 5.6% Follow-up LVEF: 49.4 ± 13.2 vs. 46.5 ± 9.4% ΔLVEF: 21.08 ± 1.91 vs. 15.62 ± 1.94% Super response: 65.0 vs. 42.1% |
Baseline NYHA: 2.40 ± 0.50 vs. 2.45 ± 0.51 ΔNYHA: 1.22 ± 0.11 vs. 1.10 ± 0.11 Δ6-min walk distance: 100.69 ± 14.14 vs. 80.56 ± 15.92 m ΔNT-proBNP: 1,768.36 ± 217.91 vs. 1,181.05 ± 216.75 pg/ml |
LBBB, left bundle branch block; LBBP, left bundle branch pacing; BVP, biventricular pacing; CSP, conduction system pacing; AVB, atrioventricular block; IVCD, intraventricular conduction defect; AF, atrial fibrillation; LV, left ventricle; RV, right ventricle; CS, coronary sinus; Δ, change of parameters; QRSd, QRS duration; LVEF, left ventricular ejection fraction; LVEDD, left ventricular end-diastolic diameter; LVESD, left ventricular end-systolic diameter; LVESV, left ventricular end-systolic volume; IVMD, interventricular mechanical delay; PSD, peak strain dispersion; GWE, global work efficiency; GWI, global work index; GCW, global constructive work; MWE, myocardial work efficiency; NYHA, New York Heart Association. NT-proBNP, N-terminal pro-brain natriuretic peptide. All the numerical values ahead of “vs.” represents the LBBP group while numerical values that comes after “vs.” represents the BVP group. The symbol “−” in the “Electrical or mechanical” column represents an increase in QRSd.