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Current Cardiology Reviews 2021RBBB, a pattern seen on the 12-lead ECG, results when normal electrical activity in the His-Purkinje system is interrupted for some reason. The normal sequence of... (Review)
Review
RBBB, a pattern seen on the 12-lead ECG, results when normal electrical activity in the His-Purkinje system is interrupted for some reason. The normal sequence of activation is altered in RBBB, with a resultant characteristic appearance on the ECG manifest by a widened QRS complex and changes in the directional vectors of the R and S waves. This ECG pattern is often seen in clinical practice and generally regarded as benign. The anatomy, epidemiology, causes, symptoms, ECG findings and diagnosis, differential diagnosis in ECG, treatment, complications, prognosis, with respect to RBBB are outlined here, demonstrating some typical ECGs of RBBB.
Topics: Bundle-Branch Block; Electrocardiography; Female; Humans; Male
PubMed: 32640959
DOI: 10.2174/1573403X16666200708111553 -
Journal of the American College of... Mar 2023Nonischemic cardiomyopathies are a frequent occurrence. The understanding of the mechanism(s) and triggers of these cardiomyopathies have led to improvement and even... (Review)
Review
Nonischemic cardiomyopathies are a frequent occurrence. The understanding of the mechanism(s) and triggers of these cardiomyopathies have led to improvement and even recovery of left ventricular function. Although chronic right ventricular pacing-induced cardiomyopathy has been recognized for many years, left bundle branch block and pre-excitation have been recently identified as potential reversible causes of cardiomyopathy. These cardiomyopathies share a similar abnormal ventricular propagation that can be recognized by a wide QRS duration with left bundle branch block pattern; thus, we coined the term abnormal conduction-induced cardiomyopathies. Such abnormal propagation results in an abnormal contractility that can only be recognized by cardiac imaging as ventricular dyssynchrony. Appropriate diagnosis and treatment will not only lead to improved left ventricular ejection fraction and functional class, but may also reduce morbidity and mortality. This review presents an update of the mechanisms, prevalence, incidence, and risk factors, as well as their diagnosis and management, while highlighting current gaps of knowledge.
Topics: Humans; Bundle-Branch Block; Stroke Volume; Ventricular Function, Left; Cardiac Conduction System Disease; Cardiomyopathies; Arrhythmias, Cardiac; Treatment Outcome
PubMed: 36948737
DOI: 10.1016/j.jacc.2023.01.040 -
European Heart Journal Oct 2022Permanent transseptal left bundle branch area pacing (LBBAP) is a promising new pacing method for both bradyarrhythmia and heart failure indications. However, data... (Observational Study)
Observational Study
AIMS
Permanent transseptal left bundle branch area pacing (LBBAP) is a promising new pacing method for both bradyarrhythmia and heart failure indications. However, data regarding safety, feasibility and capture type are limited to relatively small, usually single centre studies. In this large multicentre international collaboration, outcomes of LBBAP were evaluated.
METHODS AND RESULTS
This is a registry-based observational study that included patients in whom LBBAP device implantation was attempted at 14 European centres, for any indication. The study comprised 2533 patients (mean age 73.9 years, female 57.6%, heart failure 27.5%). LBBAP lead implantation success rate for bradyarrhythmia and heart failure indications was 92.4% and 82.2%, respectively. The learning curve was steepest for the initial 110 cases and plateaued after 250 cases. Independent predictors of LBBAP lead implantation failure were heart failure, broad baseline QRS and left ventricular end-diastolic diameter. The predominant LBBAP capture type was left bundle fascicular capture (69.5%), followed by left ventricular septal capture (21.5%) and proximal left bundle branch capture (9%). Capture threshold (0.77 V) and sensing (10.6 mV) were stable during mean follow-up of 6.4 months. The complication rate was 11.7%. Complications specific to the ventricular transseptal route of the pacing lead occurred in 209 patients (8.3%).
CONCLUSIONS
LBBAP is feasible as a primary pacing technique for both bradyarrhythmia and heart failure indications. Success rate in heart failure patients and safety need to be improved. For wider use of LBBAP, randomized trials are necessary to assess clinical outcomes.
Topics: Humans; Female; Aged; Bundle of His; Cardiac Pacing, Artificial; Bundle-Branch Block; Bradycardia; Electrocardiography; Heart Failure; Treatment Outcome
PubMed: 35979843
DOI: 10.1093/eurheartj/ehac445 -
Journal of the American College of... Aug 2018Traditional right ventricular (RV) pacing for the management of bradyarrhythmias has been pursued successfully for decades, although there remains debate regarding... (Review)
Review
Traditional right ventricular (RV) pacing for the management of bradyarrhythmias has been pursued successfully for decades, although there remains debate regarding optimal pacing site with respect to both hemodynamic and clinical outcomes. The deleterious effects of long-term RV apical pacing have been well recognized. This has generated interest in approaches providing more physiological stimulation, namely, His bundle pacing (HBP). This paper reviews the anatomy of the His bundle, early clinical observations, and current approaches to permanent HBP. By stimulating the His-Purkinje network, HBP engages electrical activation of both ventricles and may avoid marked dyssynchrony. Recent studies have also demonstrated the potential of HBP in patients with underlying left bundle branch block and cardiomyopathy. HBP holds promise as an attractive mode to achieve physiological pacing. Widespread adaptation of this technique is dependent on enhancements in technology, as well as further validation of efficacy in large randomized clinical trials.
Topics: Arrhythmias, Cardiac; Bundle of His; Bundle-Branch Block; Cardiac Pacing, Artificial; Cardiac Resynchronization Therapy; Cardiac Resynchronization Therapy Devices; Electrocardiography; Humans
PubMed: 30115232
DOI: 10.1016/j.jacc.2018.06.017 -
JACC. Clinical Electrophysiology Sep 2021This study sought to assess the predictive value of the proposed electrocardiogram and intracardiac electrogram characteristics for confirmation of left bundle branch...
OBJECTIVES
This study sought to assess the predictive value of the proposed electrocardiogram and intracardiac electrogram characteristics for confirmation of left bundle branch (LBB) capture.
BACKGROUND
Previously proposed criteria to distinguish left bundle branch pacing (LBBP) and left ventricular septum (LVS) pacing (LVSP) have not been fully validated.
METHODS
A His bundle pacing lead, an LBBP lead, and a multielectrode catheter at the LVS were placed. Direct LBB capture was defined as demonstration of retrograde His potential on the His bundle pacing lead and/or anterograde left conduction system potentials on the multielectrode catheter during LBBP. The routinely used parameters-His, LBB potential, time from stimulus to peak ventricular activation (Stim-LVAT), and paced QRS morphology during LVSP and LBBP at various depths and outputs were analyzed.
RESULTS
Thirty patients (21 non-left bundle branch block [LBBB], 9 LBBB) who demonstrated direct LBB capture using the defined criteria were included. The proportion of paced right bundle branch block was 100% during LBB capture in all patients compared to 23.4% in non-LBBB and 44.4% in LBBB during LVSP. LBB potential was recorded in all patients during intrinsic rhythm (non-LBBB group) or His corrective pacing in LBBB. Paced QRS duration was longer during selective LBBP compared to nonselective LBBP or LVSP only. All patients with characteristics of selective LBBP or abrupt decrease in Stim-LVAT of ≥10 ms demonstrated LBB capture.
CONCLUSIONS
Direct LBB capture can be confirmed by recording retrograde His potential and anterograde left conduction system potentials. Abrupt decrease in Stim-LVAT of ≥10 ms and demonstration of selective LBBP could be used as simple criteria to confirm LBB capture.
Topics: Bundle of His; Bundle-Branch Block; Cardiac Pacing, Artificial; Heart Rate; Humans; Ventricular Septum
PubMed: 33933414
DOI: 10.1016/j.jacep.2021.02.018 -
Europace : European Pacing,... May 2022The purpose of our study was to evaluate the feasibility and efficacy of cardiac resynchronization therapy (CRT) via left bundle branch pacing (LBBP-CRT) compared with... (Observational Study)
Observational Study
Cardiac resynchronization therapy via left bundle branch pacing vs. optimized biventricular pacing with adaptive algorithm in heart failure with left bundle branch block: a prospective, multi-centre, observational study.
AIMS
The purpose of our study was to evaluate the feasibility and efficacy of cardiac resynchronization therapy (CRT) via left bundle branch pacing (LBBP-CRT) compared with optimized biventricular pacing (BVP) with adaptive algorithm (BVP-aCRT) in heart failure with reduced left ventricular ejection fraction ≤35% (HFrEF) and left bundle branch block (LBBB).
METHODS AND RESULTS
One hundred patients with HFrEF and LBBB undergoing CRT were prospectively enrolled in a non-randomized fashion and divided into two groups (LBBP-CRT, n = 49; BVP-aCRT, n = 51) in four centres. Implant characteristics and echocardiographic parameters were accessed at baseline and during 6-month and 1-year follow-up. The success rate for LBBP-CRT and BVP-aCRT was 98.00% and 91.07%. Fused LBBP had the greatest reduced QRS duration compared to BVP-aCRT (126.54 ± 11.67 vs. 102.61 ± 9.66 ms, P < 0.001). Higher absolute left ventricular ejection fraction (LVEF) and △LVEF was also achieved in LBBP-CRT than BVP-aCRT at 6-month (47.58 ± 12.02% vs. 41.24 ± 10.56%, P = 0.008; 18.52 ± 13.19% vs. 12.89 ± 9.73%, P = 0.020) and 1-year follow-up (49.10 ± 10.43% vs. 43.62 ± 11.33%, P = 0.021; 20.90 ± 11.80% vs. 15.20 ± 9.98%, P = 0.015, P = 0.015). There was no significant difference in response rate between two groups while higher super-response rate was observed in LBBP-CRT as compared to BVP-aCRT at 6 months (53.06% vs. 36.59%, P = 0.016) and 12 months (61.22% vs. 39.22%, P = 0.028) during follow-up. The pacing threshold was lower in LBBP-CRT at implant and during 1-year follow-up (both P < 0.001). Procedure-related complications and adverse clinical outcomes including heart failure hospitalization and mortality were not significantly different in two groups.
CONCLUSIONS
The feasibility and efficacy of LBBP-CRT demonstrated better electromechanical resynchronization and higher clinical and echocardiographic response, especially higher super-response than BVP-aCRT in HFrEF with LBBB.
Topics: Algorithms; Bundle of His; Bundle-Branch Block; Cardiac Resynchronization Therapy; Electrocardiography; Heart Failure; Humans; Prospective Studies; Stroke Volume; Treatment Outcome; Ventricular Function, Left
PubMed: 34718539
DOI: 10.1093/europace/euab249 -
Journal of the American College of... Aug 2019Despite major improvements in transcatheter aortic valve replacement (TAVR) periprocedural complications in recent years, the occurrence of conduction disturbances has... (Review)
Review
Despite major improvements in transcatheter aortic valve replacement (TAVR) periprocedural complications in recent years, the occurrence of conduction disturbances has not decreased over time and remains the most frequent complication of the procedure. Additionally, there has been an important lack of consensus on the management of these complications, which has indeed translated into a high degree of uncertainty regarding the most appropriate treatment of a large proportion of such patients along with major differences between centers and studies in pacemaker rates post-TAVR. There is therefore an urgent need for a uniform strategy regarding the management of conduction disturbances after TAVR. The present expert consensus scientific panel document has been formulated by a multidisciplinary group of interventional cardiologists, electrophysiologists, and cardiac surgeons as an initial attempt to provide a guide for the management of conduction disturbances after TAVR based on the best available data and group expertise.
Topics: Aortic Valve Stenosis; Atrioventricular Block; Bundle-Branch Block; Cardiac Conduction System Disease; Cardiology; Consensus; Disease Management; Expert Testimony; Humans; Transcatheter Aortic Valve Replacement; Treatment Outcome; United States
PubMed: 31439219
DOI: 10.1016/j.jacc.2019.07.014 -
Turk Kardiyoloji Dernegi Arsivi : Turk... Jun 2023Left bundle branch block-induced cardiomyopathy is an increasingly recognized type of dilated cardiomyopathy identified in a minority but not negligible proportion of... (Review)
Review
Left bundle branch block-induced cardiomyopathy is an increasingly recognized type of dilated cardiomyopathy identified in a minority but not negligible proportion of patients with newly diagnosed heart failure. However, it has not yet been included among the possible etiologies of dilated cardiomyopathies or among the unclassified cardiomyopathies. Although a few sets of diagnostic criteria have been proposed, currently there is a lack of universal consensus regarding diagnostic criteria. Some specific clinical features and electrocardiography, echocardiography, and cardiac magnetic resonance imaging findings are recommended to help physicians in the diagnosis of left bundle branch block-induced cardiomyopathy. In this review, prevalence, pathophysiological mechanisms, diagnostic criteria, diagnostic modalities, and specific features of left bundle branch block-induced cardiomyopathy have been addressed with attention to the differential diagnosis of other dilated cardiomyopathies.
Topics: Humans; Bundle-Branch Block; Cardiomyopathy, Dilated; Cardiomyopathies; Electrocardiography; Echocardiography; Arrhythmias, Cardiac
PubMed: 37272151
DOI: 10.5543/tkda.2023.06737 -
International Heart Journal 2021
Topics: Bundle of His; Bundle-Branch Block; Humans; Ventricular Septum
PubMed: 33518650
DOI: 10.1536/ihj.20-771 -
Current Cardiology Reviews 2021Many advances in the knowledge of medical science are due to the observation of an unknown phenomenon that remains an open question. A plausible hypothesis must be... (Review)
Review
Many advances in the knowledge of medical science are due to the observation of an unknown phenomenon that remains an open question. A plausible hypothesis must be demonstrated and proved through a scientific method in order to be accepted by the scientific community and the same results must be reached by following either the same or different techniques. The original case described by Rosenbaum MB et al., in this review triggered a series of anatomic and physiologic investigations with clinical and experimental observations that supported the trifascicular nature of the intraventricular conduction system of the heart and the concept of hemiblocks. The recognition and description of the left fascicular blocks made by the Argentinian School of Electrocardiology bridged an important gap in electrocardiography and many electrocardiograms that could not be explained until that moment could finally be understood. This review intends to redefine reliable criteria for the electrocardiographic and vectorcardiographic diagnosis of left fascicular blocks [hemiblocks]. The anatomy of the left bundle branch is also discussed to better understand the incidence, prevalence, clinical significance and main causes of left anterior and left posterior hemiblock either isolated or associated with right bundle branch block. This review offers the reader a reappraisal of the trifascicular nature of the intraventricular conduction system regarding the anatomy of the left bundle branch system and its pathophysiological and clinical significance.
Topics: Bundle-Branch Block; Electrocardiography; Heart Conduction System; Humans
PubMed: 32640960
DOI: 10.2174/1573403X16666200708111928