Incidence and Outcomes of New-Onset Right Bundle Branch Block Following Transcatheter Aortic Valve Replacement.

BACKGROUND: The incidence and prognosis of right bundle branch block (RBBB) following transcatheter aortic valve replacement (TAVR) are unknown. Hence, we sought to characterize the incidence of post-TAVR RBBB and determine associated risks of permanent pacemaker (PPM) implantation and mortality. METHODS: All patients 18 years and above without preexisting RBBB or PPM who underwent TAVR at US Mayo Clinic sites and Mayo Clinic Health Systems from June 2010 to May 2021 were evaluated. Post-TAVR RBBB was defined as new-onset RBBB in the postimplantation period. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. RESULTS: Of 1992 patients, 15 (0.75%) experienced new RBBB post-TAVR. There was a higher degree of valve oversizing among patients with new RBBB post-TAVR versus those without (17.9% versus 10.0%; P=0.034). Ten patients (66.7%) with post-TAVR RBBB experienced high-grade atrioventricular block and underwent PPM implantation (median 1 day; Q1, 0.2 and Q3, 4), compared with 268/1977 (13.6%) without RBBB. Following propensity score adjustment for covariates (age, sex, balloon-expandable valve, annulus diameter, and valve oversizing), post-TAVR RBBB was significantly associated with PPM implantation (hazard ratio, 8.36 [95% CI, 4.19-16.7]; P<0.001). No statistically significant increase in mortality was seen with post-TAVR RBBB (hazard ratio, 0.83 [95% CI, 0.33-2.11]; P=0.69), adjusting for age and sex. CONCLUSIONS: Although infrequent, post-TAVR RBBB was associated with elevated PPM implantation risk. The mechanisms for its development and its clinical prognosis require further study.

Comparison of diagnostic accuracy of current left bundle branch block and ventricular pacing ECG criteria for detection of occlusion myocardial infarction.

BACKGROUND: Electrocardiographic detection of patients with occlusion myocardial infarction (OMI) can be difficult in patients with left bundle branch block (LBBB) or ventricular paced rhythm (VPR) and several ECG criteria for the detection of OMI in LBBB/VPR exist. Most recently, the Barcelona criteria, which includes concordant ST deviation and discordant ST deviation in leads with low R/S amplitudes, showed superior diagnostic accuracy but has not been validated externally. We aimed to describe the diagnostic accuracy of four available ECG criteria for OMI detection in patients with LBBB/VPR at the emergency department. METHODS: The unweighted Sgarbossa criteria, the modified Sgarbossa criteria (MSC), the Barcelona criteria and the Selvester criteria were applied to chest pain patients with LBBB or VPR in a prospectively acquired database from five emergency departments. RESULTS: In total, 623 patients were included, among which 441 (71%) had LBBB and 182 (29%) had VPR. Among these, 82 (13%) patients were diagnosed with AMI, and an OMI was identified in 15 (2.4%) cases. Sensitivity/specificity of the original unweighted Sgarbossa criteria were 26.7/86.2%, for MSC 60.0/86.0%, for Barcelona criteria 53.3/82.2%, and for Selvester criteria 46.7/88.3%. In this setting with low prevalence of OMI, positive predictive values were low (Sgarbossa: 4.6%; MSC: 9.4%; Barcelona criteria: 6.9%; Selvester criteria: 9.0%) and negative predictive values were high (all >98.0%). CONCLUSIONS: Our results suggests that ECG criteria alone are insufficient in predicting presence of OMI in an ED setting with low prevalence of OMI, and the search for better rapid diagnostic instruments in this setting should continue.

Risk Assessment of Permanent Pacemaker Implantation After Transcatheter Aortic Valve Implantation in Patients With Preexisting Right Bundle Branch Block.

Preexisting right bundle branch block (RBBB) is the strongest predictor for permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI). However, the risk assessment for new PPI and effective procedural strategy for preventing new PPI in patients with preexisting RBBB are still unclear. This study stratified the new PPI risk after TAVI and investigated the impact of implantation strategy in a preexisting RBBB cohort. We analyzed 237 patients with preexisting RBBB who underwent TAVI. The primary endpoint was the incidence of new PPI. Multivariate analyses investigating predictors for new PPI were performed. The overall PPI rate was 33.3%. Significant baseline predictors for new PPI were combination of RBBB, left anterior or posterior fascicular block, and first-degree atrioventricular block (odds ratio [OR] 2.55, 95% confidence interval [CI] 1.09 to 5.04), high calcium volume of noncoronary cusp (OR 2.08, 95% CI 1.05 to 4.10), and membranous septum (MS) length <2 mm (OR 2.02, 95% CI 1.09 to 3.75) in the univariate analysis and MS length <2 mm (OR 2.25, 95% CI 1.06 to 4.82) in the multivariate analysis. On the multivariate analysis including procedural variables, predilatation (OR 2.41, 95% CI 1.01 to 5.83), self-expanding valves (Corevalve, Evolut R, and Evolut Pro/Pro+; Medtronic Inc., Minneapolis, Minnesota) or mechanical expanding valves (Lotus/Lotus Edge; Boston Scientifics, Marlborough, Massachusetts) (OR 3.00, 95% CI 1.31 to 6.91), and implantation depth > MS length (OR 4.27, 95% CI 1.81 to 10.08) were significantly associated with new PPI. The incidence of new PPI increased according to the number of baseline predictors (0: 20.9%, 1: 34.3%, and ≥2: 52.0%) and procedural predictors (0: 3.7%, 1: 20.9%, 2: 40.5%, and 3: 60.0%). New PPI risk in a preexisting RBBB subset could be stratified by baseline factors. Device selection and implantation strategy considering MS length could prevent new PPI even in these high-risk population.

Ten years follow-up of the largest oral Chagas disease outbreak: Cardiological prospective cohort study.

BACKGROUND: Chagas disease (ChD) is the most important endemy in Latin America. Some patients, develop chronic Chagasic cardiopathy (CCC) years after the acute phase. It is unknown if patients infected by the oral route have higher risk of developing early CCC. METHODS AND FINDINGS: A prospective cohort study was conducted to assess morbidity and mortality during 10 years observation in 106 people simultaneously infected and treated in the largest known orally transmitted ChD outbreak in 2007. A preschooler died during the acute phase, but thereafter was no mortality associated to ChD. All acute phase findings improved in the first-year post-treatment. Each person was evaluated 8.7 times clinically, 6.4 by electrocardiogram (ECG)/Holter, and 1.7 by echocardiogram. Based on prevalence, the number of people who had any abnormalities (excluding repolarization abnormalities and atrial tachycardia which decreased) was higher than 2007, since they were found at least once between 2008-2017. However, when we evaluated incidence, except for clinical bradycardia and dizziness, it was observed that the number of new cases of all clinical and ECG findings decreased at the end of the follow-up. Between 2008-2017 there was not incidence of low voltage complex, 2nd degree AV block, long QT interval, left bundle branch block or left ventricular dysfunction that allowed the diagnosis of CCC. Total improvement prevailed over the persistence of all clinical and ECG/Holter findings, except for sinus bradycardia. Incomplete right bundle branch block, sinus bradycardia and/or T-wave inversion were diagnosed persistently in 9 children. The second treatment did not have significant influence on the incidence of clinical or ECG/Holter findings. CONCLUSIONS: At the end of the 10-year follow-up, there were not clinical or ECG/Holter criteria for classifying patients with CCC. The incidence of arrhythmias and repolarization abnormalities decreased. However, special attention should be paid on findings that not revert as sinus bradycardia, or those diagnosed persistently in all ECG as sinus bradycardia, incomplete right bundle branch block or T-wave inversion. Early diagnosis and treatment may have contributed to the rapid improvement of these patients. In ChD follow-up studies prevalence overestimates the real dimension of abnormalities, the incidence looks as a better indicator.

Consecutive Experience with Left Bundle Branch Area Pacing in a High-Volume Australian Centre.

INTRODUCTION: Left-bundle branch area pacing (LBBAP) is a relatively new technique for conduction system pacing. Australian safety and efficacy data is currently lacking. We aim to evaluate the learning curve, medium-term safety, and lead performance in a high-volume Australian setting. METHODS: We performed a retrospective cohort study of 200 consecutive LBBAP procedures performed by a single operator at two centres between January 2019 and May 2020. Left bundle branch area pacing was performed predominantly via left subclavian access using a 69 cm Medtronic SelectSecure 3830 pacing lead and a preformed non-steerable C315-His sheath. Procedural success was defined as evidence of left septal or left bundle branch area capture as evidenced by a right bundle branch block-like paced morphology. Procedural characteristics, and follow-up (including lead performance) data were collected. Procedural efficiency over time, as well as safety data, were collected. RESULTS: Median age was 78.26 years (interquartile range [IQR] 71-85), 37% were female. Atrial fibrillation was present in 22%. The left ventricular ejection fraction <50% in 24%, atrioventricular (AV) block was present in 43.5%, left bundle branch block in 22.5% and right bundle branch block in 24.5%. Acute procedural success was 91.5%. Implant threshold was 0.6V @ 0.5 ms, and 0.75V @ 0.5 ms at 11.9 months of follow-up. The QRS was significant reduced (baseline 134 ms vs implant 114 ms, p<0.001) There was a reduction in procedural time and X-ray dose over the course of the study. There were no complications specific to LBBAP. CONCLUSION: LBBAP appears to be a safe and effective pacing strategy. The QRS duration was significantly reduced compared to baseline. There appears to be an early learning curve with LBBAP.

Conduction Disorders And Their Clinical Impact After Sutureless/Rapid Deployment Aortic Bioprosthesis.

INTRODUCTION: Aortic stenosis remains the number one heart valve pathology. The drive to improve the surgical outcomes brought to focus rapid deployment valves (RDV), which reduce aortic cross-clamping and cardio-pulmonary bypass (CPB) times. However, some centers have reported a higher rate of conduction abnormalities and permanent pacemaker (PPM) implantation. The aim of this study was to investigate the incidence of conduction abnormalities after aortic valve replacement with RDV, as well as its impact on immediate postoperative outcomes. METHODS: Retrospective analysis of associated conductions disorders and PPM implantation rates, as well as post-operative outcomes of all patients undergoing isolated aortic valve replacement between April 2014 and December 2019 with an RDV. Comparative analysis between the group with PPM implantation and the one with no PPM implantation. Patients with previous PPM implantation, reoperations and patients with missing pre or postoperative ECG data were excluded. RESULTS: We studied 201 patients. The majority of conduction abnormalities were left bundle branch block (54,0%). Twenty-six PPM were implanted (12,6%). Pre-operative characteristic between the groups were similar and little differences were found in regard to most complications. However, the PPM group showed significantly higher rates of stroke (7.7% vs 0.0%, p=0.016) and hemodynamic support for longer than 24 hours (60.0% vs 36.1%, p=0.028). From the multivariable analysis, preoperative right bundle branch block was the only independent risk factor associated with PPM. CONCLUSIONS: PPM implantation rates with RDV are relatively high and are associated with prolonged hospital and ICU stays, postoperative stroke rates and requirement of aminergic support. Their use should be made on a case-by-case basis taking into consideration the existence of preoperative conduction disorders, especially right bundle branch block.

[Left bundle branch block - dilated cardiomyopathy - heart failure: common links in the closed pathogenetic chain].

This review summarizes the available information on the epidemiology and prognosis of patients with left bundle branch block (LBBB), morphological alterations of the myocardium both resulting in and ensuing LBBB, cardiac biomechanics in LBBB, and possibilities of its correction.

[Monocentric retrospective study on the prevalence and significance of incomplete right bundle branch block in young competitive athletes in Tunisia]. / Étude rétrospective monocentrique sur la prévalence et la signification du bloc de branche droit incomplet chez les jeunes sportifs de compétition en Tunisie.

AIMS: Few studies have assessed the prevalence and significance of right bundle branch block in athletes. Aims of this study were to evaluate the prevalence of incomplete right bundle branch block and its correlation with the nature of sports practice and to compare the athlete with right bundle branch block and the one with a normal electrocardiogram. METHODS: It was a retrospective study of the electrocardiogram and echocardiography of competitive athletes recruited in the medical-sports center of Sousse RESULTS: A total of 554 athletes were included. Mean age was 16.1 ± 2.9 years and 69 % were male. The mean training duration was 5.8 hours per week. The prevalence of incomplete right bundle branch block was 13.9 % (77 cases). Endurance sports were practiced in 71.4 % of cases among subjects with right bundle branch block versus 55.4 % in the rest of the population (p < 0.001). The basal diameter of the right ventricle was larger in athletes with right bundle branch block compared to athletes without right bundle branch block: 28 ± 3.6 mm versus 24 ± 2.4 mm (p < 0.001). CONCLUSIONS: The results of this study suggest that right bundle branch block is a marker of incomplete right ventricular remodeling. This remodeling represents a form of adaptation to sustained elevation of volumetric load observed mainly in endurance sports.

Incidence and management of atrioventricular conduction disorders in new-onset left bundle branch block after TAVI: A prospective multicenter study.

BACKGROUND: New-onset left bundle branch block (LBBB) is one of the most frequent complications after transcatheter aortic valve implantation (TAVI) and is associated with delayed high degree atrioventricular (AV) block. OBJECTIVES: The objectives of this study were to determine the incidence of AV block in such a population and to assess the performance and safety of a risk stratification algorithm on the basis of electrophysiology study (EPS) followed by implantation of a pacemaker or implantable loop recorder (ILR). METHODS: This was a prospective open-label study with 12-month follow-up. From June 8, 2015, to November 8, 2018, 183 TAVI recipients (mean age 82.3 ± 5.9 years) were included at 10 centers. New-onset LBBB after TAVI persisting for >24 hours was assessed by electrophysiology study during initial hospitalization. High-risk patients (His-ventricle interval ≥70 ms) were implanted with a dual-chamber pacemaker recording AV conduction disturbance episodes. Patients at lower risk were implanted with an ILR with automatic remote monitoring. RESULTS: A high-grade AV conduction disorder was identified in 56 patients (30.6%) at 12 months. Four subjects were symptomatic, all in the ILR group. No complications were associated with the stratification procedure. Patients with His-ventricle interval ≥70 ms displayed more high-grade AV conduction disorders (53.2% [25 of 47] vs 22.8% [31 of 136]; P < .001). In a multivariate analysis, His-ventricle interval ≥70 ms was independently associated with the occurrence of a high-grade conduction disorder (subdistribution hazard ratio 2.4; 95% confidence interval 1.2-4.8; P = .010). CONCLUSION: New-onset LBBB after TAVI was associated with high rates of high-grade AV conduction disturbances. The stratification algorithm provided safe and valuable aid to management decisions and reliable guidance on pacemaker implantation.

Lifestyle habits associated with cardiac conduction disease.

AIMS: Cardiac conduction disease can lead to syncope, heart failure, and death. The only available therapy is pacemaker implantation, with no established prevention strategies. Research to identify modifiable risk factors has been scant. METHODS AND RESULTS: Data from the Cardiovascular Health Study, a population-based cohort study of adults ≥ 65 years with annual 12-lead electrocardiograms obtained over 10 years, were utilized to examine relationships between baseline characteristics, including lifestyle habits, and conduction disease. Of 5050 participants (mean age 73 ± 6 years; 52% women), prevalent conduction disease included 257 with first-degree atrioventricular block, 99 with left anterior fascicular block, 9 with left posterior fascicular block, 193 with right bundle branch block (BBB), 76 with left BBB, and 102 with intraventricular block at baseline. After multivariable adjustment, older age, male sex, a larger body mass index, hypertension, and coronary heart disease were associated with a higher prevalence of conduction disease, whereas White race and more physical activity were associated with a lower prevalence. Over a median follow-up on 7 (interquartile range 1-9) years, 1036 developed incident conduction disease. Older age, male sex, a larger BMI, and diabetes were each associated with incident conduction disease. Of lifestyle habits, more physical activity (hazard ratio 0.91, 95% confidence interval 0.84-0.98, P = 0.017) was associated with a reduced risk, while smoking and alcohol did not exhibit a significant association. CONCLUSION: While some difficult to control comorbidities were associated with conduction disease as expected, a readily modifiable lifestyle factor, physical activity, was associated with a lower risk.

Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block.

INTRODUCTION AND OBJECTIVES: Patients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. METHODS: Cohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. RESULTS: Of the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. CONCLUSIONS: Patients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.

Incidence of Persistent Left Bundle Branch Block After Rapid-Deployment Aortic Valve Replacement.

BACKGROUND: We evaluated the incidence, prognosis, and predictive factors of new onset of persistent left bundle branch block (NOP-LBBB) after rapid-deployment aortic valve replacement (RD-AVR). METHODS: This was an observational, retrospective, single-center study of 274 consecutive patients with no baseline ventricular conduction disorder and no previous permanent pacemaker implantation (PPI) who underwent RD-AVR with an INTUITY valve (n = 55) or INTUITY Elite Valve (n = 219) (Edwards Lifesciences). Transthoracic echocardiography and 12-lead electrocardiography was performed preoperatively, at discharge, and at 1-month and 1-year intervals. The incidence, prognosis, and predictive factors of NOP-LBBB were evaluated. RESULTS: NOP-LBBB occurred in 58 patients (21.2%) after discharge. In multivariate analysis, age (P < .01), INTUITY valve diameter ≥23 mm (P = .02), and INTUITY Elite implantation (P = .01) were independent predictors of NOP-LBBB. By 1:1 propensity matching analysis between the NOP-LBBB group and the control group, there were no significant differences in 1-year overall mortality (P = .23), hospitalization for congestive heart failure (P = .99), or PPI (P = .99). NOP-LBBB exposed patients to a high rate of dysrhythmic events (12.1% vs 1.4%, P < .01) and was associated with a significant decrease in left ventricular ejection fraction (0.62 ± 0.095 vs 0.652 ± 0.0783, P = .02) without an impact on New York Heart Association functional status (1.25 ± 0.32 and 1.52 ± 0.70, P = .32). PPI was performed in 17 patients (6.2%) before discharge, including 14 NOP-LBBB patients. CONCLUSIONS: NOP-LBBB after RD-AVR is prevalent in patients with no prior conduction disorders. INTUITY Elite is associated with a significantly higher rate of NOP-LBBB. The persistence of NOP-LBBB predisposed patients to the occurrence of high-grade conduction disorders and might have led to PPI but did not increase death or hospitalization for congestive heart failure.

Right Bundle Branch and Bifascicular Blocks: Insensitive Prognostic Indicators for Acute Myocardial Infarction.

The clinical significance of right bundle branch block (RBBB) or bifascicular block (BFB) in the setting of acute myocardial infarction (AMI) is uncertain. RBBB was found in 211 of 7,626 patients (2.8%), presenting to the ED (emergency department) with chest pain, of which 18 (8.5%) also had acute coronary syndrome (ACS). Incidences of ACS were not significantly different between new or presumed new RBBB and prior known RBBB or new or presumed new BFB and prior known BFB. In 2 patients, baseline ST-segment depression in leads V1-3 masked anterior ST-elevation detected on electrocardiogram (ECG). In opposition to the guidelines, the presence of RBBB or BFB does not appear to offer any clinical utility when evaluating patients with suspected AMI. Patients with suspected AMI who present with RBBB and any ST-elevation in leads V1-3 should be considered for emergent coronary angiography rather than RBBB alone.

Post-transcatheter aortic valve implantation isolated PR prolongation: incidence and clinical significance.

AIMS: Conduction abnormalities post-transcatheter aortic valve implantation (TAVI) are common. Post-TAVI PR prolongation was mainly studied as an adjunct to new-onset bundle branch block. The net effect of isolated PR prolongation (IPRP) without post-TAVI QRS changes is not well known. The aim of this study was to define the incidence and clinical significance of post-TAVI IPRP. METHODS AND RESULTS: A total of 1108 consecutive TAVI patients were reviewed. Patients with IPRP were compared with patients without post-TAVI electrocardiogram (ECG) changes. Clinical outcomes included permanent pacemaker implantation (PPI) and overall mortality. A total of 146 patients with IPRP were compared with 290 patients without post-TAVI ECG changes. At 1 year follow-up, 4 (2.7%) and 7 (2.4%) patients underwent PPI (P = 0.838) and 10 (6.8%) and 25 (8.6%) died (P = 0.521), from the study and control groups, respectively. No patient with IPRP and narrow QRS underwent PPI during 1 year post-TAVI, and all death events were non-cardiac except one unknown cause. Permanent pacemaker implantation rates among patients with IPRP and wide QRS were higher (n = 4, 12.1%), compared with patients with wide QRS without post-TAVI ECG change (n = 3, 4%) however not reaching statistical significance (P = 0.126). Multivariate Cox proportional hazards model demonstrated that in patients with narrow QRS, neither PR prolongation nor baseline or maximal PR intervals was associated with the combined endpoint of PPI and mortality. However, in patients with wide QRS, baseline PR intervals and QRS width, but not PR prolongation were associated with the combined outcome. CONCLUSION: Post-TAVI IPRP in patients with narrow QRS is not associated with adverse outcome. This finding may translate clinically into a more permissive approach to these patients.

The Relationship of Conduction Disorder and Prognosis in Patients with Acute Coronary Syndrome.

Objective: Conduction disorders with a widened QRS are associated with poor prognosis in patients with acute coronary syndrome (ACS). Conduction disorders include left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (NICD). Previous studies did not have conflicting results regarding the type of bundle branch block (BBB) with the worst prognosis, and few studies have focused on the prognosis of patients with NICD. Methods: Patients with ACS were enrolled between January 2005 and December 2019, and their medical history (International Classification of Diseases codes) was obtained from the Chang Gung Research Database. Age, sex, comorbidities, left ventricular ejection fraction (LVEF), and drug use were compared between the patients with and without conduction disorders. The following clinical outcomes were compared between patients with and without conduction disorders: heart failure (HF) hospitalization, cardiovascular (CV) mortality, and all-cause mortality. After propensity score matching, the Kaplan-Meier curve analysis for HF hospitalization, CV mortality, and all-cause mortality were compared among patients with LBBB, RBBB, and NICD. Results: This study enrolled a total of 33970 participants and involved 3392 and 30578 patients with and without conduction disorders, respectively. Older age and a higher prevalence of comorbidities were noted in patients with conduction disorders. Lower mean LVEF was exhibited in the patients with conduction disorders (with vs. without; 44.64 ± 20.73% vs. 49.85 ± 20.63%; p < 0.001). During the 3-year follow-up period, higher incidences of HF hospitalization (21.55% vs. 17.51%; p < 0.001), CV mortality (17.98% vs. 12.14%; p < 0.001), and all-cause mortality (38.86% vs. 31.15%; p < 0.001) were noted in the patients with conduction disorder. After ACS events, 10.0% of patients presented with conduction disorders, with LBBB in 3.3%, RBBB in 6.0%, and NICD in 0.7%. The lowest mean of LVEF was presented in the patients with NICD (LBBB vs. RBBB vs. NICD; 41.00 ± 19.47% vs. 47.73 ± 20.82% vs. 34.57 ± 20.02%; p < 0.001). Among the three groups, the highest incidence of HF hospitalization was noted in patients with LBBB after propensity score matching. The lowest incidence of CV and all-cause mortality was observed in patients with RBBB. After adjustment of age, gender, comorbidities, medication, and mean LVEF, those with LBBB had the highest hazard ratio for major adverse cardiovascular events (MACEs) of 1.113 (p=0.029; 95% CI = 1.013-1.266). Conclusions: In the ACS population, patients with conduction delay had a poor prognosis due to a higher prevalence of comorbidities and lower mean LVEF. Among the patients with LBBB, RBBB, and NICD, those with LBBB and NICD had a higher incidence of HF hospitalization, CV mortality, and all-cause mortality. Patients with NICD had the lowest mean LVEF compared to those with LBBB and RBBB. Patients with LBBB had a significantly highest HR of MACE.

Incidence, predictors, and prognostic impact of temporary left bundle branch block after transcatheter aortic valve replacement.

BACKGROUND: Little is known about temporary Left Bundle Branch Block (LBBB) after transcatheter aortic valve replacement (TAVR). We aim to evaluate the incidence, prognostic impact and predictors of temporary LBBB in TAVR patients. METHODS: Electrocardiograms (ECGs) obtained before and after TAVR, at discharge and at 30-day follow-up were anonymously analyzed by 5 cardiologists. Temporary LBBB included transient LBBB or persistent LBBB. The primary endpoint was all-cause mortality at 1-year after TAVR. RESULTS: Out of 198 patients, 55 (27.7%) developed temporary LBBB. No differences between groups were observed in primary endpoint. Left ventricular ejection fraction (LVEF) was identified as predictive factor of transient LBBB. CONCLUSIONS: Temporary LBBB has no significant impact on survival at 1 year after the procedure.

Predictors of high-degree atrioventricular block in patients with new-onset left bundle branch block following transcatheter aortic valve replacement.

BACKGROUND: The development of new left bundle branch block (LBBB) is frequently seen post TAVR and is a known risk factor for progression to high degree AV block. The timing and likelihood of progression into complete heart block is variable and can develop after hospital discharge. We sought to determine predictors for the development of high degree AV block in patients who developed LBBB following TAVR. METHODS: All patients between 2014 and 2019 underwent electrophysiology study after developing LBBB post TAVR. Data on these patients including baseline characteristics, echo parameters, EKG variables, HV interval, and the need for subsequent pacemaker implantation were extracted. A prolonged HV interval was defined as ≥ 65 ms. Clinically significant conduction abnormality was defined as development of high-degree AV block or clinically significant complete heart block. RESULTS: Thirty-four patients were included in our study of which 10 (29.4%) developed clinically significant heart block, while 24 (70.6%) did not. The mean HV interval for patients with clinically significant heart block was 70.1 ms vs 57.8 ms for those who did not (p = 0.022). Pre-existing first-degree heart block prior to TAVR (p = 0.026), history of AFib (p = 0.05) in addition to STS score (p = 0.037) were predictors of development of high-degree AV block in our patient population. CONCLUSIONS: In patients who develop LBBB following TAVR, HV interval, pre-existing first-degree heart block, and STS score predict progression to high-degree AV block. Performance of a routine electrophysiology study should be considered for high-risk patients who develop LBBB following TAVR.

Electrical Dyssynchrony in Cardiac Amyloidosis: Prevalence, Predictors, Clinical Correlates, and Outcomes.

BACKGROUND: Conduction-system involvement in cardiac amyloidosis (CA) is common. The prevalence, clinical correlates and impact on outcome related to ventricular electrical dyssynchrony in CA remain insufficiently elucidated. METHODS: Data from a prospectively maintained registry of patients with CA diagnosed in the Cleveland Clinic's amyloidosis clinic was used to determine the frequency of electrical dyssynchrony (defined as a QRS > 130 msec). The relation with the clinical profile and clinical outcome was assessed. To determine the impact of hypertrophy on QRS prolongation, a QRS-matched cohort without CA was used for comparison of cardiac magnetic resonance imaging. RESULTS: A total of 1140 patients with CA (39% AL, 61% TTR) were evaluated, of whom 230 (20%) had electrical dyssynchrony. The type of conduction block was predominantly a right bundle branch block (BBB, 48%) followed by left BBB (35%) and intraventricular conduction delay (17%). Presence of transthyretin amyloidosis (ATTR-CA), older age, male gender, white race, and coronary artery disease were independently (P< 0.05 for all) associated with electrical dyssynchrony, and patients were more commonly prescribed a mineralocorticoid receptor antagonist. In ATTR-CA, specifically, every increase in ATTR-CA disease stage was associated with a 1.55-fold (1.23--1.95; P< 0.001) increased odds for electrical dyssynchrony. In a subset of patients with CA who underwent cardiac magnetic resonance imaging (n = 41), left ventricular mass index was unrelated to the QRS duration (r = 0.187; P = 0.283) in CA, in contrast to a non-CA QRS-matched cohort (r = 0.397; P< 0.001). Patients with electrical dyssynchrony were more symptomatic at initial presentation, as illustrated by a higher New York Heart Association class (P= 0.041). During a median follow-up of 462 days (IQR:138--996 days), a higher proportion of patients with electrical dyssynchrony died from all-cause death (P= 0.037) or developed a permanent pacing indication (3% vs 10.4%; P< 0.001) during follow-up. CONCLUSION: Electrical dyssynchrony is common in CA, especially in ATTR-CA, and is associated with worse functional status and clinical outcome. Given the high rate of permanent pacing indications at follow-up, additional studies are necessary to determine the best monitoring and pacing strategies in CA.

New-onset persistent left bundle branch block following sutureless aortic valve replacement.

OBJECTIVE: To evaluate the incidence, predictive factors and prognostic value of new-onset persistent left bundle branch block (NOP-LBBB) in patients undergoing sutureless surgical aortic valve replacement (SU-SAVR). METHODS: A total of 329 consecutive patients without baseline conduction disturbances or previous permanent pacemaker implantation (PPI) who underwent SU-SAVR with the Perceval valve (LivaNova Group, Saluggia, Italy) in two centres from 2013 to 2019 were included. Patients were on continuous ECG monitoring during hospitalisation and 12-lead ECG was performed after the procedure and at hospital discharge. NOP-LBBB was defined as a new postprocedural LBBB that persisted at hospital discharge. Baseline, procedural and follow-up clinical and echocardiography data were collected in a dedicated database. RESULTS: New-onset LBBB was observed in 115 (34.9%) patients, and in 76 (23.1%) persisted at hospital discharge. There were no differences in baseline and procedural characteristics between patients with (n=76) and without (n=253) NOP-LBBB. After a median follow-up of 3.3 years (2.3-4.4 years), patients with NOP-LBBB had a higher incidence of PPI (14.5% vs 6.3%, p=0.016), but exhibited similar rates of all-cause mortality (19.4% vs 19.2%, p=0.428), cardiac mortality (8.1% vs 9.4%, p=0.805) and heart failure readmission (21.0% vs 23.2%, p=0.648), compared with the no/transient LBBB group. NOP-LBBB was associated with a decrease in left ventricular ejection fraction (LVEF) at 1-year follow-up (delta: -5.7 vs +0.2, p<0.001). CONCLUSIONS: NOP-LBBB occurred in approximately a quarter of patients without prior conduction disturbances who underwent SU-SAVR and was associated with a threefold increased risk of PPI along with a negative impact on LVEF at follow-up.