Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

Left bundle branch pacing in a ventricular pacing dependent patient with heart failure:A case report

BACKGROUND Left bundle branch pacing(LBBP)is a physiological pacing method that has emerged in recent years.It is an ideal choice for patients with complete left bundle branch block who are in need of cardiac resynchronization therapy(CRT).Moreover,LBBP is superior in maintaining physiological ventricular activation and can effectively improve heart function and quality of life in patients with pacemaker-induced cardiomyopathy.However,LBBP in pacing-dependent patients who already have cardiac dysfunction has not been well assessed.CASE SUMMARY A 69-year-old male patient presented with symptoms of chest tightness,palpitation and systolic heart failure with New York Heart Association class III for 1 mo.The 12-lead electrocardiogram showed atrial fibrillation with third-degree atrioventricular block and ventricular premature beat.Holter revealed a right bundle branch block,atrial fibrillation with third-degree atrioventricular block,frequent multifocal ventricular premature beats,Ron-T and ventricular tachycardia.The echocardiogram documented an enlarged left atrium and left ventricle and a low left ventricular ejection fraction.Coronary angiography indicated a stenosis of 30%in the middle left anterior descending artery.Apparently,a CRT-D pacemaker was the best choice for this patient according to previous findings.However,the patient was worried about the financial burden.A single-chamber pacemaker with LBBP was selected,with the plan to take amiodarone and upgrade with dual-chamber implantable cardioverter-defibrillator or CRT-D at an appropriate time.During the follow-up at 3 mo after LBBP,the patient showed an improvement in cardiac function with slight improvement in echocardiography parameters,and the New York Heart Association functional class was maintained at I.Moreover,the patient no longer suffered from chest tightness and palpitation.Holter showed decreased ventricular arrhythmia of less than 5%.CONCLUSION LBBP might be used in patients with heart failure and a high-degree atrioventricular block as an alternative to conventional CRT.

Application of permanent left bundle branch pacing in patients with bradycardia after cardiac surgery

Background The study was to access the feasibility and effectiveness of permanent left bundle branch pacing(LBBP)in patients with bradycardia after cardiac surgery,in comparison with conventional right ventricular outflow tract septal pacing(RVOSP).Methods A total of 50 patients with cardiac surgery who underwent permanent pacemaker implantation(PPI)were enrolled,21 patients underwent LBBP(LBBP group)and 29 patients underwent RVOSP(RVOSP group).Pacing electrical parameters,QRS duration(QRSd),echocardiographic measurements,lead and device related complications were obtained at procedure and during follow-ups.Results There were no statistically significant differences between the LBBP group and the RVOSP group at procedure and at the twelfth month’s follow-up in pacing thresholds(0.64±0.16 V vs.0.63±0.22 V)and(0.91±0.28 V vs.0.85±0.20 V),R-wave amplitude(16.68±4.52 mV vs.15.09±4.53 mV)and(14.41±8.65 mV vs.12.65±6.17 mV),pacing impedances(719.24±152.65Ωvs.639.13±177.04Ω)and(534.01±96.92Ωvs.499.18±77.87Ω).But the average ventricular pacing percentage(VP%)at the first month’s follow-up(81.96±32.06%vs.58.37±42.96%)and at the twelfth month’s follow-up(84.65±35.84%vs.53.57±38.47%)showed significant difference between two groups(P<0.05);The LBBP group produced narrower QRSd(121.13±23.91 ms)than the RVOSP group(158.00±9.69 ms)(P=0.011).There were no significant differences between the LBBP group and the RVOSP group at pre-procedure and at the twelfth month’s follow-up in echocardiographic parameters,which included left ventricular end-diastolic dimension(LVEDD)(48.76±7.08 mm vs.47.34±6.91 mm)and(50.58±10.33 mm vs.45.97±7.11 mm),left ventricular ejection fraction(LVEF)(58.33±12.64%vs.61.50±8.40%)and(55.85±16.35%vs.61.50±10.52%),and area of tricuspid regurgitation(TR)(2.79±3.65 cm2 vs.2.85±2.26 cm2)and(3.09±2.34 cm2 vs.2.95±1.92 cm2).No lead and device related complication was observed during follow-ups.Conclusions LBBP is feasible and effective in patients with bradycardia after cardiac surgery.LBBP produces narrow QRSd,which may be a preferred pacing strategy for patients after cardiac surgery.[S Chin J Cardiol 2021;22(1):13-20]

Lead helix winding tricuspid chordae tendineae: A case report

BACKGROUND As left bundle branch pacing(LBBP)is more like physiological pacing,LBBP has emerged as a novel pacing strategy that uses the native conduction system to improve ventricular synchronization with stable pacing parameters.LBBP has been revealed associated with a significantly reduced risk of new-onset atrial fibrillation and heart failure compared with conventional permanent pacemaker implantation.CASE SUMMARY A 64-year-old man was admitted with a 24-h history of chest distress and shortness of breath,which continued unabated.The patient had no symptoms of chest pain,dizziness,syncope,nausea nor vomiting.There were no abnormalities found in routine examinations after admission.Twelve-lead electrocardiogram presented a result of 2:1 atrioventricular block.Coronary angiography was performed the next day and no abnormality was found.Finally,the patient agreed to received LBBP and signed the informed consent.During the process of withdrawing the Medtronic Model 3830 lead into sheath,we found the lead helix was wrapped around the chordae tendineae of the septal valve of tricuspid.Attempts to rotate the 3830 lead failed to release the lead helix from the chordae tendineae,and ultimately we used radiofrequency ablation to ablate the wrapped chordae tendineae.CONCLUSION Radiofrequency ablation effectively solved this problem without complications.It is an effective and reliable method to resolve lead winding chordae.