Prognosis of new-onset left bundle branch block after transcatheter aortic valve replacement in patients with aortic stenosis: A systematic review and meta-analysis / 中国胸心血管外科临床杂志

@#Objective    To systematically review the clinical outcome of patients with new-onset left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR). Methods    Electronic search was performed in PubMed, EMbase, Cochrane Library, Web of Science, CNKI, Wanfang and CBM databases to identify studies about the new-onset LBBB after TAVR from inception to March 19, 2022. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 15.0 software. Results    A total of 17 cohort studies were included, covering 9 205 patients, including 2 202 patients with new-onset LBBB and 7 003 without new-onset LBBB after TAVR. The results of meta-analysis showed that patients with new-onset LBBB after TAVR at 30-day (RR=1.65, 95%CI 1.30 to 2.10, P<0.001) and 1-year (RR=1.30, 95%CI 1.16 to 1.45, P<0.001) all-cause mortality was higher than no new-onset LBBB group. One-year cardiovascular mortality was higher in the new-onset LBBB group (RR=1.47, 95%CI 1.21 to 1.79, P<0.001). In the occurrence of 30-day (RR=1.51, 95%CI 1.10 to 2.08, P=0.011) and 1-year (RR=1.34, 95%CI 1.14 to 1.58, P=0.001) rehospitalization rate, 30-day (RR=3.05, 95% CI 1.49 to   6.22, P=0.002) and 1-year (RR=2.15, 95%CI 1.52 to 3.03, P<0.001) pacemaker implantation, the incidence of patients with new-onset LBBB was higher than that of the no new-onset LBBB group. Conclusion    Compared with the patients without LBBB after TAVR, the clinical prognosis of patients with new-onset LBBB after TAVR is poor. In the future, the management and follow-up of the patients with LBBB after TAVR should be further strengthened to improve the prognosis of patients.

Arrhythmia-induced cardiomyopathy: a specific pediatric dilated cardiomyopathies / 中国小儿急救医学

Arrhythmia-induced cardiomyopathy(AIC) is an reversible dilated cardiomyopathy and appears to occur at any age.The morbidity of AIC is unclear and likely underestimated.The pathophysiology and mechanism of AIC is unknown.It is often difficult to determine whether arrhythmias are the cause or result of cardiac dysfunction.The diagnosis of AIC can be only confirmed after recovery or improvement of cardiac function after elimination of the tachyarrhythmia.Tachycardias, ventricular premature contraction, left bundle branch block and ventricular preexcitation are known to trigger AIC.Appropriate diagnosis and treatment of AIC can reverse cardiac function.However, arrhythmia recurrence can lead to rapid recurrence of AIC and symptoms of heart failure.

Short-term and medium-term changes of the left ventricular ejection fraction in children with dilated cardiomyopathy complicated with complete left bundle branch block and the predictive value of relevant electrocardiogram indexes / 中华实用儿科临床杂志

Objective:To investigate the short-term and medium-term changes of the left ventricular ejection fraction (LVEF) and the predictive value of relevant electrocardiogram (ECG) indexes in children with dilated cardiomyopathy (DCM) complicated with complete left bundle branch block (CLBBB).Methods:Children clinically diagnosed with DCM in the Department of Heart Center, Women and Children′s Hospital, Qingdao University and Beijing Anzhen Hospital, Capital Medical University between November 2011 and August 2020 were retrospectively recruited.According to the combination of CLBBB, they were divided into CLBBB group and non-CLBBB group.Echocardiogram and ECG were regularly performed.Short-term and medium-term changes of LVEF based on the 1-5-year follow-up data were compared between groups.COX proportional hazards model and Kaplan-Meier multiplicative limit method were used to analyze the predictive value of ECG indexes of LVEF changes in children with DCM combined with CLBBB.Results:Ninety-four children with DCM were enrolled, including 35 cases in CLBBB group and 59 cases in non-CLBBB group.There was no difference in baseline LVEF between groups.However, significant differences were found in QRS duration, corre-cted QT interval(QTc), R peak time in lead V 5 (T V5R) and QRS notching or slurring between groups ( P<0.05). LVEF of all children showed an upward trend within one year after onset, while the Z value of eft ventricular end diastolic diameter(LVEDd) showed a downward trend, and the two indexes tended to be stable within 1 - 5 years.The Z value of LVEDd in CLBBB group was significantly higher than that of non-CLBBB group, while LVEF was significantly lower (all P<0.05). The mean LVEF of CLBBB group slightly fluctuated around 50%, that of LVEF in non-CLBBB group was 60%.The multivariate COX regression analysis showed that QRS duration ( HR=0.979; 95% CI: 0.960-0.999, P<0.05) and QTc ( HR=0.988; 95% CI: 0.979-0.998, P<0.05) were independent predictors of LVEF recovery in children with DCM.Kaplan-Meier method showed a significant difference of LVEF normalization between DCM children with different QRS durations ( P<0.05), which was also detected in those with QTc interval ( P<0.05). Conclusions:LVEF of children with DCM combined with CLBBB increases in the short term after standard treatment, and then being stable.CLBBB can affect the recovery of left ventricular systolic function in children with DCM.Moreover, QRS duration and QTc interval are independent predictors of LVEF recovery in DCM children.

El fenómeno de la memoria eléctrica como simulador de isquemia miocárdica

RESUMEN Los trastornos de la repolarización ventricular son manifestaciones comunes de una amplia variedad de situaciones, entre las que se incluye la memoria cardíaca; un fenómeno no reconocido frecuentemente en la práctica diaria. La gravedad de cada una de estas causas es muy variable; sin embargo, el diagnóstico definitivo de cada una de ellas no siempre es evidente. Se presenta el caso de un paciente que acude al servicio de urgencias con dolor torácico y ondas T negativas profundas en el electrocardiograma, que simulan una isquemia miocárdica grave, y que fue definido como memoria eléctrica cardíaca.

ABSTRACT The abnormalities in ventricular repolarization are common manifestations of several conditions, among these, we can include cardiac memory, a frequently unrecognized phenomenon in medical practice. The severity of each of these causes is variable; nonetheless, a definitive diagnosis of each of them is not always evident. We present the case of a patient admitted at the emergency room with chest pain and deeply inverted T waves in the electrocardiogram, mimicking a severe myocardial ischemia, which was defined as cardiac electrical memory.

Bloqueo de rama izquierda como equivalente ST, ¿cuándo sí, cuándo no? / Left bundle branch block as equivalent of ST-segment elevation myocardial infarction: when yes, when not?

Resumen La presencia de un bloqueo de rama izquierda del haz de His nuevo o presumiblemente nuevo junto con síntomas isquémicos se ha considerado tradicionalmente un equivalente electrocardiográfico de infarto agudo de miocardio con elevación del segmento ST, el cual debe ser llevado a reperfusión emergente. Para su definición se han propuesto varios criterios, pero ninguno ha alcanzado un rendimiento diagnóstico óptimo. A continuación detallaremos dichos criterios, sus principales problemas y las ventajas que han demostrado.

Abstract A new or presumably new left bundle branch block along with ischemic symptoms has traditionally been considered an electrocardiographic equivalent of ST-segment elevation myocardial infarction, which should be brought to emergent reperfusion. However, several criteria have been proposed for its definition, but none has reached out an optimal diagnostic yield. Below we detail these criteria, their main problems and the advantages they have shown.

Cardiac conduction block after transcatheter aortic valve replacement / 第二军医大学学报

Objective To evaluate the effectiveness of transcatheter aortic valve replacement (TAVR) using domestic valves for treating aortic valve stenosis or regurgitation, and to explore the incidence of cardiac conduction block after surgery and its influence on the prognosis of the patients. Methods The patients with severe aortic valve stenosis or regurgitation receiving TAVR surgery in our department from Sep. 2017 to Jan. 2018 were enrolled in this study. The TAVR surgery was performed with domestic valves (J-Valve or Venus-A), and the outcomes and incidence of complications were assessed after surgery. The patients were observed for the incidence of new-onset cardiac conduction block during and after TAVR and the recovery of arrhythmia during hospitalization. According to the presence of cardiac conduction block at discharge, the patients were divided into normal rhythm group and conduction block group. The baseline and postoperative characteristics, and left ventricular structure and function were compared between the two groups. Results Sixteen patients were enrolled in this study, including 12 in the normal rhythm group and 4 in the conduction block group. Brain natriuretic peptide ([1 114.87±802.32] pg/mL vs [530.39±276.26] pg/mL, P=0.026), aortic transvalvular pressure difference ([83.06±37.76] mmHg vs [24.14±9.73] mmHg, P0.05). Conclusion TAVR with domestic valves can effectively reduce the aortic transvalvular pressure difference with fewer complications. It may cause complete left bundle branch block, which has no significant influence on the short-term adverse cardiac events and cardiac function after operation.

The New Diagnostic Algorithm for New or Presumably New Left Bundle Branch Block and Suspected Acute Myocardial Infarction

PURPOSE: Patients with a suspected acute myocardial infarction (AMI) in the setting of a new or presumably new left bundle branch block (LBBB) present an important diagnostic and therapeutic challenge to clinicians. This study was conducted to identify the frequency of ST-segment elevation myocardial infarction (STEMI)-equivalent in this population, determine the diagnostic value of electrocardiographic and echocardiographic features and propose a new diagnostic algorithm. METHODS: From 793 patients who underwent emergent coronary angiography between January 1, 2012 and July 31, 2015, we examined data pertaining to 21 patients with new or presumably new LBBB. These patients were classified into three groups: 1) STEMI-equivalent, defined as an acute coronary occlusion on coronary angiogram (six patients), 2) non-STEMI (NSTEMI) (six patients), and 3) diagnosis other than myocardial infarction (non-MI) (nine patients). RESULTS: Six patients who met the ST-segment concordance criteria (score≥3) were STEMI-equivalent. On the other hand, seven patients with a discordant ST-elevation of ≥5 mm (score=2) were NSTEMI or non-MI. Therefore ST-segment concordance was highly sensitive and specific for the diagnosis of STEMI-equivalent. Compared with NSTEMI patients, nine non-MI patients with a normal angiogram had a low ejection fraction (35.6±19.0 vs. 56.0±12.9, p=0.04) and increased left ventricle end-diastolic dimension (63.9±8.8 vs. 51.7±6.4, p=0.012). CONCLUSION: Only a minority of patients with LBBB and suspected AMI have a STEMI-equivalent. Low ejection fraction and increased end-diastolic dimension of left ventricle indicate normal coronary angiogram in patients without ST-segment concordance of Sgarbossa criteria. We propose a new modified diagnostic algorithm in this population.

Evaluation of left ventricular morphology and function related to complete left bundle branch block with cardiac magnetic resonance in patients with systolic heart failure / 中国介入心脏病学杂志

Objective To evaluate the left ventricular morphology and function related to complete left bundle branch block(CLBBB)in patients with systolic heart failure with cardiac magnetic resonance.Methods Thirteen consecutive patients with left ventricular ejection fraction(LVEF)＜50％evaluated by echocardiography and CLBBB were included as the study group,and patients with other reasons leading to heart failure were excluded.During At the same period,patients with primary dilated cardiomyopathy were selected as the control group(n=19)whose age,sex and LVEF were matched with the study group.All patients received contrast magnetic resonance imaging examination.Results Left ventricular end-diastolic volume(LVEDV)in patients with CLBBB was(173.8±23.1)ml and left ventricular end-systolic volume(LVESV)was(123.1±18.7)ml,while LVEDV in patients without CLBBB was(247.9±60.7)ml and LVESV was(188.2±57.1)ml respectively.All LV measurements/indexes were smaller in patient with CLBBB when compared to the control(all P＞0.05).Right atrium area was also smaller in CLBBB patients(P=0.037).The maximal wall thickness in the patients with CLBBB [(8.3±1.4)mm] was thicker than that in the patients without CLBBB[(7.2±1.1)mm](P=0.016).Conclusions CLBBB may play an important role in the progress of heart failure and LV dilation may not have similar significant contribution with relative thicker ventricular wall.

Intermittent left bundle branch block - reversal to normal conduction during general anesthesia / Bloqueio intermitente de ramo esquerdo - reversão para condução normal durante anestesia geral

Abstract Background and objectives: Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value). Case report: This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Conclusions: Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia.

Resumo Justificativa e objetivos: Alterações transitórias da condução cardíaca no intraoperatório são pouco frequentes. Foram reportados raros casos de desenvolvimento ou remissão de bloqueio completo de ramo esquerdo sob anestesia (geral e locorregional), associados a isquemia do miocárdio, hipertensão, taquicardia e fármacos. O bloqueio completo de ramo esquerdo é uma manifestação clínica importante em alguns hipertensos crônicos, pode também significar doença arterial coronária, doença valvular aórtica ou cardiomiopatia subjacentes. Embora habitualmente permanente, pode ocorrer na forma intermitente dependente da frequência cardíaca (quando a frequência cardíaca excede determinado valor crítico). Relato de caso: Este é um caso de bloqueio completo de ramo esquerdo registrado no pré-operatório de cirurgia urgente que reverteu para condução normal no intraoperatório sob anestesia geral após diminuição da frequência cardíaca. Ressurgiu, de forma intermitente e dependente da frequência cardíaca, no pós-operatório imediato, acabou por reverter novamente à condução normal de forma sustentada durante vigilância em unidade semi-intensiva. O estudo com marcadores de necrose muscular cardíacos foi negativo. A dor do quadro cirúrgico urgente e pós-operatório imediato pode ter estado na origem da subida da frequência cardíaca até ao valor crítico e causado bloqueio. Conclusões: Embora o desenvolvimento ou a remissão desse bloqueio sob anestesia sejam incomuns, o anestesiologista deverá estar alertado para a possibilidade da sua ocorrência. Pode ter caráter benigno, contudo o diagnóstico correto é muito importante. As manifestações eletrocardiográficas podem ser confundidas com ou encobrir isquemia miocárdica, fatos de especial importância num paciente sob anestesia geral incapaz de referir sintomatologia característica de isquemia.

Electrical approach to improve left ventricular activation during right ventricle stimulation

Coronary sinus mapping is commonly used to evaluate left atrial activation. Herein, we propose to use it to assess which right ventricular pacing modality produces the shortest left ventricular activation times (R-LVtime) and the narrowest QRS widths. Three study groups were defined: 54 controls without intraventricular conduction disturbances; 15 patients with left bundle branch block, and other 15 with right bundle branch block. Left ventricular activation times and QRS widths were evaluated among groups under sinus rhythm, right ventricular apex, right ventricular outflow tract and high output septal zone (SEPHO). Left ventricular activation time was measured as the time elapsed from the surface QRS onset to the most distal left ventricular deflection recorded at coronary sinus. During the above stimulation modalities, coronary sinus mapping reproduced electrical differences that followed mechanical differences measured by tissue doppler imaging. Surprisingly, 33% of the patients with left bundle branch block displayed an early left ventricular activation time, suggesting that these patients would not benefit from resynchronization therapy. SEPHO improved QRS widths and left ventricular activation times in all groups, especially in patients with left bundle branch block, in whom these variables became similar to controls. Left ventricular activation time could be useful to search the optimum pacing site and would also enable detection of non-responders to cardiac resynchronization therapy. Finally, SEPHO resulted the best pacing modality, because it narrowed QRS-complexes and shortened left ventricular activations of patients with left bundle branch block and preserved the physiological depolarization of controls.

El mapeo del seno coronario se utiliza comúnmente para evaluar la activación de la aurícula izquierda. Aquí, investigamos su utilidad para evaluar qué modalidad de estimulación ventricular derecha produce los menores tiempos de activación ventricular izquierda (R-LVtime). Se definieron tres grupos: 54 controles; 15 pacientes con bloqueo de rama izquierda y 15 con bloqueo de rama derecha. El ancho de QRS y los tiempos de activación fueron evaluados en cada grupo bajo las siguientes modalidades: ritmo sinusal, ápex del ventrículo derecho, tracto de salida del ventrículo derecho y alta salida en septum (SEPHO). El R-LVtime se midió como el tiempo transcurrido desde el inicio del QRS de superficie y la deflexión ventricular izquierda más distal del seno coronario. Durante las distintas modalidades de estimulación, el mapeo del seno coronario reprodujo diferencias eléctricas acompañadas por diferencias mecánicas que fueron evaluadas mediante Tissue Doppler Imaging. El 33% de los pacientes con bloqueo de rama izquierda mostró R-LVtime tempranos, lo que sugiere que estos pacientes no se beneficiarían con terapia de resincronización. SEPHO mejoró el ancho de QRS y el R-LVtime de todos los grupos, especialmente en los pacientes con bloqueo de rama izquierda. En conclusión, el R-LVtime serviría para identificar el sitio óptimo de estimulación y permitiría detectar ciertos no respondedores a la terapia de resincronización. Además, el SEPHO resultó la mejor modalidad de estimulación porque estrechó el QRS y acortó el R-LVtime de los pacientes con bloqueo de rama izquierda pero no alteró la despolarización fisiológica de los controles.

Preexcitation Syndrome with a Mahaim-type Accessory Pathway

Wide QRS complex tachycardia with a left bundle branch block pattern can be caused by supraventricular tachycardia with aberrant conduction, preexcitation syndrome mediated through a right-sided accessory pathway, and/or ventricular tachycardia. The use of atrial pacing maneuvers can be beneficial for unmasking minimal preexcitation to differentiate between these conditions. Here, we report a case of successful radiofrequency catheter ablation of a Mahaim fiber in a patient with wide QRS complex tachycardia.

Relationship Between Septal Myocardial Metabolism and Left Ventricular Mechanical Synchronization in Patients With Dilated Cardiomyopathy and Left Bundle Branch Block / 中国循环杂志

Objective: To explore the relationship between septal myocardial metabolism and left ventricular mechanical synchronization in patients with dilated cardiomyopathy (DCM) and left bundle branch block (LBBB) by gated 18F-FDG myocardial metabolic imaging. Methods: A total of 20 consecutive patients diagnosed for DCM with LBBB from 2010-10 to 2013-05 were enrolled, there were 11 male and 9 female at the mean age of (54±11) years. All patients received gated 18F-FDG myocardial metabolic PET imaging. TrueD software was used to determine the maximal standardized 18F-FDG uptake value (S-SUVmax) and the average standardized uptake value (S-SUVavg). QGS software was applied to conduct left ventricular phase analysis and to detect the cardiac function, left ventricular bandwidth (BW), standard deviation of bandwidth (SD), left ventricular end-diastolic volume (LVEDV), LVESV and LVEF. The relationship between 18F-FDG uptake in septal myocardium with the indexes of phase analysis and the indexes of cardiac function was analyzed. Results: S-SUVmax and S-SUVavg were respectively negatively related to BW (r=-0.44, P0.05. Conclusion: In patients of DCM with LBBB, reduced septal myocardial metabolism was closely related to left ventricular mechanical synchronization, gated 18F-FDG myocardial metabolic PET imaging may simultaneously detect both functions, which was important for prognostic evaluation and therapeutic monitoring in clinical practice;phase analysis.

Effect of Cardiac Resynchronization Therapy in Patients With Chronic Heart Failure Combining Left Bundle Branch Block Conformed to New Diagnostic Standard / 中国循环杂志

Objective: To analyze the effect of cardiac resynchronization therapy (CRT) in patients with chronic heart failure (CHF) combining left bundle branch block (LBBB) conformed to new diagnostic standard. Methods: A total of 19 CHF patients who received CRT in our hospital from 2005-06 to 2013-05 were studied. The patients were divided into 2 groups: True LBBB group,n=13 patients conformed to new diagnostic standard and False LBBB group, n=6 patients conformed to traditional diagnostic standard. Pre- and Post-operative LVEF, LVEDD, QRS duration (QRSd) and IVMD were compared in all patients; post-operative LVEF, LVEDD, QRSd, IVMD and Tmsv16-SD, Tmsv16-Dif were compared between 2 groups. Results: The post-operative LVEF, LVEDD, QRSd and IVMD were improved than pre-operative condition in both groups. Compared with False LBBB group, the improvements were more obvious in True LBBB group as LVEDD by mm (5.95±0.72 vs 7.13±0.78), IVMD by ms (22.45±8.00 vs 27.63±13.09), and QRSd by ms (140.38±5.80 vs 153.68±14.38), all P<0.01. The post-operative LVEF and Tmsv16-SD, Tmsv16-Dif were similar between 2 groups. Conclusion: CHF patients combining either true or false LBBB could be beneift from CRT, while the patients with true LBBB may receive better clinical outcomes from CRT.

Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block

OBJECTIVES: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. OBJECTIVE: We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. METHODS: Thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82Rb-positron emission tomography studies and without left bundle branch block (GII). RESULTS: Stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p<0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). CONCLUSION: The data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients with left bundle branch block.

Complete atrioventricular block during tunneled cuffed hemodialysis catheter insertion in a patient with pre-existing left bundle branch block / 영남의대학술지

Arrhythmias are complications of tunneled cuffed hemodialysis catheter insertion. Most complications associated with arrhythmias occur during guide-wire access, where the guide wire can cause traumatic damage to the conduction system of the heart. Conducting system injury in tunneled cuffed hemodialysis catheter insertion often involves the right bundle, causing right bundle branch block (RBBB). Transient RBBB with sinus rhythm is not usually accompanied by abnormal vital signs. However if patients already have left bundle branch block (LBBB), new onset RBBB can cause complete atrioventricular block (AVB), which can lead to fatal complications requiring invasive treatment. We report on a patient with LBBB who developed complete AVB during hemodialysis catheter insertion.

Clinical analysis of complete left bundle branch block after transcatheter closure of ventricular septal defect / 中华实用儿科临床杂志

Objective To evaluate the clinical features and prognosis of patients with complete left bundle branch block(CLBBB)following transcatheter device closure of ventricular septal defect(VSD)closure. Methods Clinical feathers of 11 patients with postoperative CLBBB in Department of Pediatric Cardiology,Guangdong General Hospital from January 2011 to December 2013 were collected and reviewed retrospectively. They were treated with dif-ferent protocol based on the appeared time of CLBBB occurrence and clinical symptoms. The patients were followed up, and the prognosis was recorded. Results The median age of 11 patients was 3. 9 years(3. 4 to 17. 5 years old). The median interval of intervention therapy to first attack of CLBBB was 2. 8 months(1 day to 25. 4 months). CLBBB oc-curred within 1 week to 1 month postoperatively in 4 patients,another 1 case suffered from CLBBB between 1 week to 1 month postoperatively,meanwhile 6 cases underwent CLBBB after 6 months postoperatively. The longest term of CLBBB attack postoperatively was 25. 4 months in 1 patient. The electrocardiograms on 5 patients returned to normal by only drug treatment. However,3 patients failed to recover with drug therapy,2 of them undertaken surgical procedure to re-move the occluder associated with VSD repair,1 patient recovered to normal and another converted to incomplete right bundle branch block. One of them refused to undertake surgical procedure and still bothered with persistent CLBBB. Another 3 cases did not receive special treatment due to the later attack of CLBBB(≥6 months)without clinical symp-toms. By the end of observation,the electrocardiogram(ECG)in 4 patients returned to normal,4 patients presented with persistent CLBBB. One patient's ECGs were presented with right bundle branch block. After ECG successfully returning to normal ECG by drug therapy,2 patients relapsed during follow - up,and 1 of them developed to an enlarging left ven-tricle and heart failure which led to death. Conclusions CLBBB may occur in short or long - term after VSD closure. ECG may become normal after early and appropriate treatment postoperatively. Systolic dyssynchrony and cardiac dys-function may be caused by persistent CLBBB. Therefore,patients with CLBBB after VSD closure should be treated ap-propriately without delay,and more frequent and longer follow - ups are required.

Effect of cardiac resynchronization therapy on heart failure patients with different morphologies of left bundle branch block in ECG / 天津医药

Objective To compare the efficacy of cardiac resynchronization therapy (CRT) on chronic heart failure (CHF) patients with different left bundle branch block (LBBB) morphologies. Methods Patients(n=45)who were treated with CRT were enrolled. According to the intrinsic ECG morphologies, patients were divided into 1)genuineLBBB group (n=32) who present negative dominant V1 and V2 lead wave (QS or rS);mid-QRS notching or slurring in at least 2 leads of Vl, V2, V5, V6, I and aVL as well as QRS duration≥140 ms in male or≥130 ms in female and 2)falseLBBB group (n=10) who meet traditional standards but fail to meet“genuine”LBBB diagnostic standard. The QRS duration, echocardiographic indi?ces and New York Heart Association (NYHA) Functional Classification were evaluated at the 12 months follow-up. CRT re?sponder was defined as patient with≥1 decrease in NYHA class and/or with≥15%reduction in left ventricular end-systolic volume (LVESV). CRT super-responder was defined as patient with≥30%reduction in LVESV. Results There was no dif?ference in basic characteristics of patients between groups. At the 12 months follow-up, 20 patients in genuine LBBB group and 6 patients infalseLBBB group were identified as responders (P>0.05). Compared with those infalseLBBB group, the responders ingenuineLBBB group showed better improvement in left ventricular ejection fraction and left ven?tricular end diastolic diameter (LVEDD) (both P<0.05). Conclusion Left bundle branch block morphology is less predic?tive for the efficacy of CRT. However, patients who show response to CRT withgenuineLBBB profile may get more bene?fits from CRT treatment than the patients withfalseLBBB profile.

Radiofrequency Catheter Ablation of Left Bundle Branch Guided by Left Bundle Potential, X-ray Image With EnSiteNavX System in Experimental Canine Model / 中国循环杂志

Objective:To explore the efifcacy and safety for radiofrequency catheter ablation (RFCA) of left bundle branch guided by left bundle potential (LBP), X-ray image with EnSiteNavX System in canine model. Methods:The RFCA of left bundle branch was conducted in 13 dogs. A mapping catheter was positioned in right atrium to record right-sided His-bundle (R-His) potential, and an ablation catheter via right femoral artery was retrograded to left ventriclefor LBP mapping and ablation. Meanwhile, EnSiteNavX System was used to identify R-His, L-His and LBP at the same time. The potential characteristics in dogs with successful ablation were observed, the PR interval, QRS shape and time limit, AH interval, HV interval, the A/V electro-gram ratio in ablationcatheter at before and after ablation were recorded. The procedural time and X-ray exposure time between LBP with X-ray image method and LBP, X-ray image with EnSiteNavX System method were compared. Results: There were 9/13 dogs received successful left bundle branch ablation, 3 dogs failed and 1 suffered from complete A-V block. At the successful ablation target site, the LBP-V was (17.8 ± 2.6) ms with the range of (13-21) ms, and the A/V electro-gram ratio Conclusion:Under the LBP, X-ray image with EnSiteNavX System guidance method, left bundle branch could be safely and effectively ablated to establish left bundle branch block (LBBB) model in experimental canine.

Transient left bundle branch block associated with hypoxia during monitored anesthesia care: A case report

Transient left bundle branch block (LBBB) is uncommon during anesthesia. It is mainly related to the changes in blood pressure or heart rate. Its occurrence can be confused with acute myocardial ischemia or ventricular tachycardia, therefore differential diagnosis is important. We report a case of transient LBBB which developed with hypoxia during monitored anesthesia care. LBBB is reversed to sinus rhythm after recovery from hypoxia.