-
JACC. Clinical Electrophysiology May 2022This study sought to examine QRS and intracardiac characteristics during selective (S) and nonselective (NS) left bundle branch pacing (LBBP) from direct left septal...
OBJECTIVES
This study sought to examine QRS and intracardiac characteristics during selective (S) and nonselective (NS) left bundle branch pacing (LBBP) from direct left septal recordings.
BACKGROUND
Criteria for S-LBBP and NS-LBBP have not been validated with intracardiac mapping.
METHODS
Pacing was performed from multielectrode Purkinje recordings below the left-sided His. S-LBBP and NS-LBBP were performed in patients with narrow QRS (n = 9), right bundle branch block (n = 3), intraventricular conduction delay (n = 5), and left bundle branch block (n = 10). QRS duration was measured from stimulus onset (QRS) and from the intrinsicoid deflection of the R-wave in V-V (QRS) to QRS end. Retrograde left bundle branch conduction was assessed by stimulus-to-retrograde His intervals.
RESULTS
Among 27 patients analyzed, 20 demonstrated both NS- and S-LBBP and were studied in paired comparisons. NS-LBBP resulted in narrower QRS compared to S-LBBP (QRS: 163 ms [interquartile range (IQR): 144-179 ms] vs 181 ms [IQR: 173-203 ms]; P < 0.001; QRS: 125 ms [IQR: 117-142 ms] vs 150 ms [IQR: 135-157 ms]; P < 0.001). Left ventricular activation time was also significantly shorter for NS-LBBP compared to S-LBBP (88 ms [IQR: 75-111 ms] vs 97 ms [IQR: 82-123 ms]; P = 0.019). Left intrahisian block was bidirectional in 10 patients with long retrograde stimulus-to-His intervals. QRS duration was significantly longer in patients with complete conduction block compared to those with intact Purkinje activation during NS-LBBP (181 ms [IQR: 162-195 ms] vs 157 ms [IQR: 139-168 ms]; P = 0.022).
CONCLUSIONS
In contrast to His-bundle pacing, S-LBBP predominantly yields a wide QRS as a result of delayed RBB synchronization, whereas NS-LBBP results in shorter QRS duration because of recruitment of the basal right ventricular septum. A wider-paced morphology of LBBP was noted in patients with complete conduction block caused by bidirectional left intrahisian block. Achievement of narrow QRS during LBBP is predicated upon capture nonselectivity or programmed atrioventricular fusion, rather than intrinsic physiologic synchrony from left bundle branch stimulation.
Topics: Atrioventricular Block; Bundle of His; Bundle-Branch Block; Cardiac Pacing, Artificial; Electrocardiography; Humans; Ventricular Septum
PubMed: 35589176
DOI: 10.1016/j.jacep.2022.01.012 -
Annals of Noninvasive Electrocardiology... Nov 2021To evaluate the efficacy and safety of left bundle branch area pacing (LBBaP) in patients with heart failure and left bundle branch block (LBBB), and to compare the...
OBJECTIVE
To evaluate the efficacy and safety of left bundle branch area pacing (LBBaP) in patients with heart failure and left bundle branch block (LBBB), and to compare the clinical effects with traditional cardiac resynchronization therapy (CRT).
METHODS
Thirty-two patients with dilated cardiomyopathy complicated by cardiac insufficiency and left bundle branch block were divided into CRT group and LBBaP group. Parameters including pacing threshold, R-wave amplitude, pacing impedance and operation time, and X-ray exposure time were recorded. The left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) were examined by echocardiography. The changes of QRS complex before and after operation were compared.
RESULTS
Compared with CRT group, the LBBaP group spent less time on total operation time and X-ray exposure time and had stable electrode parameters including pacing threshold, R-wave amplitude, and lead impedance after 12-month follow-up. In addition, LBBaP can achieve narrow QRS complex (117.15 ± 9.91) ms immediately than that in CRT group (130.32 ± 12.41) ms. The change of QRS between LBBaP is (50.30 ± 23.79) ms and CRT group is (33.15 ± 20.22) ms. After 6 months' follow-up in LBBaP group, EF was higher than that before operation. Followed up for 12 months after operation, EF and LVEDD in LBBaP group were significantly improved compared with those before operation.
CONCLUSION
Left bundle branch area pacing is a safe and effective resynchronization method for patients with cardiac insufficiency and asynchronization, which can achieve same clinical effects to CRT.
Topics: Bundle-Branch Block; Cardiac Resynchronization Therapy; Electrocardiography; Heart Failure; Humans; Stroke Volume; Treatment Outcome; Ventricular Function, Left
PubMed: 34550625
DOI: 10.1111/anec.12898 -
Annals of Noninvasive Electrocardiology... Mar 2016Episodic (transient/ intermittent) left bundle branch block (LBBB) has been associated with different conditions such as bradycardia, tachycardia, anesthesia, acute... (Review)
Review
Episodic (transient/ intermittent) left bundle branch block (LBBB) has been associated with different conditions such as bradycardia, tachycardia, anesthesia, acute pulmonary embolism, changes in intrathoracic pressure, chest trauma, cardiac interventional procedures, mad honey poisoning, and in other clinical settings. Of note, exclusion of an acute coronary syndrome in the setting of episodic LBBB is of great importance. Moreover, episodic LBBB is sometimes symptomatic and may be associated with left ventricular systolic and/or diastolic dysfunction or conduction disturbances leading to syncope. This review article provides a comprehensive overview of the conditions associated with episodic LBBB and discusses the clinical impact of this phenomenon.
Topics: Bundle-Branch Block; Humans
PubMed: 27296905
DOI: 10.1111/anec.12361 -
International Journal of Cardiology May 2005The Brugada syndrome is an autosomal dominant disease with incomplete penetrance that may cause syncope and sudden cardiac death in young individuals with a normal... (Review)
Review
The Brugada syndrome is an autosomal dominant disease with incomplete penetrance that may cause syncope and sudden cardiac death in young individuals with a normal heart. It is characterized by an electrocardiographic pattern of complete or incomplete right bundle branch block and ST segment elevation in leads V1-V3. One of the genes linked to this syndrome is SCN5A, the gene encoding for the cardiac sodium channel. Mutations in SCN5A cause a functional reduction in the availability of cardiac sodium current in Brugada syndrome. However, only 20-25% of patients affected by this syndrome have mutations on this gene. A novel gene locus on chromosome 3, distinct from SCN5A, has been identified recently. The relative male preponderance of the phenotype, despite equal inheritance of the gene in males and females, has led to the speculation of a role for testosterone in the phenotype. The disease could manifest at first time as cardiac arrest without any previous symptom, and the electrocardiographic pattern could be intermittent, requiring a pharmacological challenge with Class I antiarrhythmic drugs to unmask ST elevation. Several conditions producing Brugada-like electrocardiographic patterns should be borne in mind and excluded while making a diagnosis of the Brugada syndrome. The management is difficult as pharmacological agents are not universally effective. The mode of treatment recommended by the majority of cardiac electrophysiologists is the implantation of a cardioverter defibrillator. Symptomatic patients with inducible ventricular arrhythmias and a positive family history should be considered for prophylactic implantation of a cardioverter defibrillator.
Topics: Bundle-Branch Block; Electrocardiography; Exercise Test; Heart Arrest; Heart Rate; Humans; Syndrome; Tachycardia, Ventricular
PubMed: 15882659
DOI: 10.1016/j.ijcard.2004.03.068 -
BMC Cardiovascular Disorders Jul 2020Cardiac manifestations of neonatal lupus include an array of structural and conduction abnormalities due to placental transference of maternal anti-SSA/Ro and...
BACKGROUND
Cardiac manifestations of neonatal lupus include an array of structural and conduction abnormalities due to placental transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies. Late-onset neonatal lupus cardiomyopathies, occurring outside the neonatal period, is an infrequently reported manifestation with unknown pathophysiology and poorly defined treatment regimens. Due to the rarity of this condition, additional studies and case reports are required to better understand and manage late-onset neonatal lupus cardiomyopathies.
CASE PRESENTATION
A 4-week-old female, born to a mother with known anti-SSA/Ro and anti-SSB/La autoantibodies, presents with classic cutaneous manifestations for neonatal lupus and is found to have left bundle branch block, severely dilated cardiomyopathy with an ejection fraction of 25%, and a thin echogenic dyskinetic ventricular septum. Weekly second trimester and 30-week fetal echocardiograms showed no signs of structural or conduction abnormalities. There were no histologic signs of inflammation on cardiac tissue biopsy. After a complicated hospital course, she was successfully treated with biventricular pacemaker, intravenous immunoglobulin, and plasmapheresis.
CONCLUSIONS
We present a case of late-onset neonatal lupus with severe dilated cardiomyopathy, a dyskinetic ventricular septum, and left bundle branch block. To our knowledge, the dyskinetic ventricular septum has never been reported and left bundle branch block is rarely reported in NL. This case further validates the need for long term cardiac follow up for patients born with NL, even if lacking cardiac manifestations in the peripartum period. We characterize a unique presentation of a rare clinical entity, highlighting the diagnostic challenges, and describe a successful treatment course.
Topics: Bundle-Branch Block; Cardiac Resynchronization Therapy; Cardiac Resynchronization Therapy Devices; Cardiomyopathy, Dilated; Female; Humans; Immunoglobulins, Intravenous; Infant, Newborn; Lupus Erythematosus, Systemic; Plasmapheresis; Treatment Outcome
PubMed: 32727396
DOI: 10.1186/s12872-020-01637-4 -
Singapore Medical Journal Oct 2022
-
Journal of Cardiovascular Translational... Apr 2012Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right... (Review)
Review
Left bundle branch block (LBBB) is generally associated with a poorer prognosis in comparison to normal intraventricular conduction, but also in comparison to right bundle branch block which is generally considered to be benign in the absence of an underlying cardiac disorder like congenital heart disease. LBBB may be the first manifestation of a more diffuse myocardial disease. The typical surface ECG feature of LBBB is a prolongation of QRS above 0.11 s in combination with a delay of the intrinsic deflection in leads V5 and V6 of more than 60 ms and no septal q waves in leads I, V5, and V6 due to the abnormal septal activation from right to left. LBBB may induce abnormalities in left ventricular performance due to abnormal asynchronous contraction patterns which can be compensated by biventricular pacing (resynchronization therapy). Asynchronous electrical activation of the ventricles causes regional differences in workload which may lead to asymmetric hypertrophy and left ventricular dilatation, especially due to increased wall mass in late-activated regions, which may aggravate preexisting left ventricular pumping performance or even induce it. Of special interest are patients with LBBB and normal left ventricular dimensions and normal ejection fraction at rest but who may present with an abnormal increase in pulmonary artery pressure during exercise, production of lactate during high-rate pacing, signs of ischemia on myocardial scintigrams (but no coronary artery narrowing), and abnormal ultrastructural findings on myocardial biopsy. For this entity, the term latent cardiomyopathy had been suggested previously.
Topics: Bundle-Branch Block; Cardiac Pacing, Artificial; Electrocardiography; Heart Failure; Humans; Prognosis; Ventricular Function, Left
PubMed: 22258866
DOI: 10.1007/s12265-011-9344-5 -
JACC. Cardiovascular Imaging Nov 2021
Topics: Bundle-Branch Block; Cardiac Resynchronization Therapy; Humans; Predictive Value of Tests; Ventricular Dysfunction, Left
PubMed: 34274274
DOI: 10.1016/j.jcmg.2021.05.028 -
Emergencias : Revista de La Sociedad... Apr 2023
Topics: Humans; Flecainide; Bundle-Branch Block; Arrhythmias, Cardiac; Ventricular Dysfunction
PubMed: 37038953
DOI: No ID Found -
Arquivos Brasileiros de Cardiologia Jul 2011Exercise-induced left bundle branch block (EI-LBBB) is an infrequent finding. Its prevalence and prognostic significance are not clear.
BACKGROUND
Exercise-induced left bundle branch block (EI-LBBB) is an infrequent finding. Its prevalence and prognostic significance are not clear.
OBJECTIVE
To evaluate, in a longitudinal study, the prevalence and prognostic significance of EI-LBBB in American war veterans.
METHODS
We evaluated 9,623 patients submitted to an exercise test (ET) in treadmill between 1987 and 2007. The outcomes were compared between those with normal TE, the ones with EI-LBBB and the ones with down-sloping ST-segment. Mortality and causes of death were identified while blinded to the ET results.
RESULTS
In this prospective cohort, 6,922 individuals had normal ET results (57.2 ± 11.4 years), 1,739 had abnormal ST-segment depression (62.7 ± 9.8 years), and 38 had EI-LBBB (65.2 ± 11.9 years). The prevalence of EI-LBBB was 0.38%. After 8.8 years, there were 1,699 deaths due to all-cause mortality and 610 cardiovascular (CV) deaths; coronary artery disease and heart failure were more prevalent in patients with EI-LBBB. Patients with EI-BCRE had a hazard ratio of 2.37 (p = 0.002) for all-cause mortality, but it was not significant when adjusted for age or when the CV death was the assessed outcome.
CONCLUSION
EI-LBBB is a rare clinical finding. Individuals with BCRE-EI have higher all-cause mortality when compared to those with normal ET results. However, this fact is explained by the fact that these patients are significantly older and have more associated cardiovascular diseases.
Topics: Age Factors; Aged; Brazil; Bundle-Branch Block; Cardiovascular Diseases; Cause of Death; Epidemiologic Methods; Exercise Test; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prognosis; Prospective Studies; Sex Factors; United States; Veterans
PubMed: 21552647
DOI: 10.1590/s0066-782x2011005000054