Right Bundle Branch Block Research Articles

Left bundle branch area pacing in patients with heart failure and right bundle branch block: Results from International LBBAP Collaborative-Study Group.

BackgroundCardiac resynchronization therapy (CRT) using biventricular pacing has limited efficacy in patients with heart failure (HF) and right bundle branch block (RBBB). Left bundle branch area pacing (LBBAP) is a novel physiologic pacing option.ObjectiveThe aim of the study was to assess the feasibility and outcomes of LBBAP in HF patients with RBBB and reduced left ventricular systolic function, and indication for CRT or ventricular pacing.MethodsLBBAP was attempted in patients with left ventricular ejection fraction (LVEF) <50%, RBBB, HF, and indications for CRT or ventricular pacing. Procedural, pacing, and electrocardiographic parameters; clinical response (no HF hospitalization and improvement in NYHA class); and echocardiographic response (≥5% increase in ejection fraction) to LBBAP were assessed.ResultsLBBAP was attempted in 121 patients and successful in 107 (88%). Patient characteristics included age 74 ± 12 years, female 25%, ischemic cardiomyopathy 49%, and ejection fraction 35% ± 9%. QRS axis at baseline was normal in 24%, left axis 63%, right axis 13%. LBBAP threshold and R-wave amplitudes were 0.8 ± 0.3 V @ 0.5 ms and 10 ± 9 mV at implant and remained stable during mean follow-up of 13 ± 8 months. LBBAP resulted in narrowing of QRS duration (156 ± 20 ms to 150 ± 24 ms (P = .01) with R-wave peak times in V6 of 85 ± 16 ms. LVEF improved from 35% ± 9% to 43% ± 12% (P < .01). Clinical and echocardiographic response was observed in 60% and 61% of patients, respectively. Female sex and reduction in QRS duration with LBBAP were predictive of echocardiographic response and super-response.ConclusionLBBAP is a feasible alternative to deliver CRT or physiologic ventricular pacing in patients with RBBB, HF, and LV dysfunction.

Long-term study on electrophysiological characteristics and catheter ablation of idiopathic ventricular arrhythmias originating from the left ventricular posterior papillary muscles guided by intracardiac ultrasound.

BackgroundThis study aimed to investigate the electrophysiological characteristics of idiopathic ventricular arrhythmias (VAs) originating from the left ventricular posterior papillary muscles (LPPM) and explore the efficiency of catheter ablation using three‐dimensional intracardiac ultrasound technology.MethodsTwenty‐seven cases of premature ventricular contraction/ventricular tachycardia (PVC/VT) originating from the left ventricular posterior papillary muscles were recorded from July 2015 to June 2019 in the Central Hospital of Shengli Oil Field and the First Affiliated Hospital of Zhengzhou University. Electrophysiological mapping and radiofrequency catheter ablation (RFCA) were performed using three‐dimensional intracardiac ultrasound technology. The characteristics of the body surface and intracavity electrocardiogram were analyzed. All cases were followed up for 24 months after the operation.ResultsThe VAs of all 27 cases were successfully eliminated by catheter ablation. QRS complexes were observed with a right bundle branch block (RBBB) pattern and a steep slope in the initial segment. Lead I appeared with an Rs pattern, and inferior leads (lead II, III, and aVF) were usually with an S wave. The lead aVR appeared with a qR pattern, while the R wave was commonly found in aVL. The main wave in leads V1‐V3 was positive but negative in V5 and V6.ConclusionVentricular arrhythmias originating from the left ventricular posterior papillary muscles have similar electrophysiological characteristics. The origin site was accurately located using three‐dimensional intracardiac ultrasound technology. Catheter ablation effectively eliminated VAs.

Predicting permanent pacemaker implantation following transcatheter aortic valve replacement: A contemporary meta-analysis of 981,168 patients.

BackgroundHeart block requiring permanent pacemaker (PPM) implantation is a relatively frequent complication of transcatheter aortic valve replacement (TAVR).ObjectiveThe purpose of this study was to perform a contemporary meta-analysis to provide an updated assessment of clinically useful predictors of PPM implantation post-TAVR.MethodsMedline and EMBASE searches were performed to include all studies reporting PPM post-TAVR between 2015 and 2020. Pertinent data were extracted from the studies for further analysis. RevMan was used to create forest plots and calculate risk ratios (RRs).ResultsWe evaluated 41 variables from 239 studies with a total of 981,168 patients. From this cohort, 17.4% received a PPM following TAVR. Strong predictors for PPM implant were right bundle branch block (RBBB) (RR 3.12; P <.001) and bifascicular block (RR 2.40; P = .002). Intermediate factors were chronic kidney disease (CKD) (RR 1.53; P <.0001) and first-degree atrioventricular block (FDAVB) (RR 1.44; P <.001). Weak factors (RR 1–1.50; P <.05) were male gender, age ≥80 years, body mass index ≥25, diabetes mellitus (DM), atrial fibrillation (AF), and left anterior fascicular block (LAFB). These factors along with increased left ventricular outflow tract (LVOT) area (>435 mm2) and/or aortic annulus diameter (>24.4 mm) were incorporated to propose a new scoring system to stratify patients into high- and low-risk groups.ConclusionMale gender, age ≥80 years, FDAVB, RBBB, AF, DM, CKD, Medtronic CoreValve, transfemoral TAVR, increased LVOT, and aortic annulus diameter were significant predictors of post-TAVR PPM implantation. Preprocedural assessment should consider these factors to guide clinical decision-making before TAVR. Validation of our scoring system is warranted.

The role of electrocardiographic findings in pulmonary embolism risk assessment

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The electrocardiogram (ECG) is helpful in patients (P) with pulmonary embolism (PE), but it is not present in the existing risk prediction tools, such as the Pulmonary Embolism Severity Index (PESI). Intermediate risk PE encompasses a heterogeneous group of P, with different prognoses, some of whom will need fibrinolytic treatment. This study aims to determine the prognostic impact of ECG in intermediate-risk PE. Methods All P admitted for intermediate-risk PE in an Intensive Cardiac Care Unit between 2007 and 2016 were included. P were followed up for two years for all-cause mortality. Clinical and analytical variables, ECG, echocardiographic, and computed tomography (CT), were collected. Statistical analysis used chi-square and Mann-Whitney U tests, binary logistic regressions, Kaplan-Meier curves, and Cox regression. Results This study included 209 P: mean age 63±18years; 38.5% male. T-wave inversion in leads V1-V3 was present in 81 (38.8%), S1Q3T3 pattern in 51 (24.4%), incomplete right bundle branch block (RBBB) in 27 (12.9%), and complete RBBB in 22 (10.5%). T-wave inversion in leads V1-V3 was associated with syncope at presentation (p=0.032); presence of echocardiographic right ventricle dilation (p=0.003) and abnormal interventricular septal (IVS) motion (p=0.001). S1Q3T3 pattern was associated with syncope (p=0.028); higher heart rate at admission (p=0.001); higher troponin (p=0.013) and BNP (p=0.010) levels; abnormal IVS motion (p=0.004); and increased CT-derived right-to-left ventricle diameter (RV/LV) ratio (p=0.014). RBBB were associated with syncope (p=0.020); higher troponin and BNP levels (p=0.001); and increased RV/LV ratio (p=0.029). For each increase in the number of these ECG findings, there was an increase in the odds of fibrinolytic treatment (OR 1.573, 95%CI 1.150-2.151, p=0.005), and the number of ECG findings was a predictor of fibrinolysis independently from PESI (OR 1.535, p=0.008). In survival analysis, T-wave inversion in leads V1-V3 was associated with decreased survival during follow-up (x2=4.398; p=0.036), even after adjustment for PESI (OR 0.322, p=0.041). Conclusions ECG findings of PE were associated with clinical, analytical and imagiological risk features. They were also predictors of fibrinolysis, and T-wave inversion in leads V1-V3 was associated with decreased survival after adjustment for PESI. Therefore, in the future, incorporation of ECG findings in risk scores might allow better risk assessment in intermediate-risk PE.

Evaluation of electrophysiological characteristics and ventricular synchrony: An intrapatient-controlled study during His-Purkinje conduction system pacingversus right ventricular pacing.

Objectives to BackgroundTo compare electromechanical ventricular synchrony when pacing from different sites, including right ventricular apex pacing (RVAP), right ventricular septum pacing (RVSP), His bundle pacing (HBP), left bundle branch pacing (LBBP), and RVSP during unipolar pacing from the ring electrode of LBBP lead (RVSPring) in each patient and evaluate the correlations between electrophysiological characteristics and ventricular synchrony.MethodsTwenty patients with complete atrioventricular block indicated for dual‐chamber pacemaker implantation were included in the study. Unipolar pacing at different sites, including RVAP, RVSP, HBP, LBBP, and RVSPring, was successively performed in each patient. The pacing characteristics and echocardiogram parameters were collected and compared among intrinsic rhythm and pacing at different sites.ResultsSimilar to HBP (114.84 ± 18.67 ms), narrower paced QRSd was found in LBBP (116.15 ± 11.60 ms) as compared to RVSPring (135.11 ± 13.68 ms), RVSP (141.65 ± 14.26 ms), and RVAP (160.15 ± 19.35 ms) (p < .001). LBBP showed comparable pacing parameters to RVAP or RVSP and was significantly better than HBP, with maintained cardiac function. TS‐12‐SD was significantly improved in LBBP (41.80 ± 20.97 ms) than RVAP (69.70 ± 32.42 ms, p = .003) and RVSP (63.30.56 ± 32.53 ms, p = .018) but similar to HBP (51.50 ± 25.67 ms, p = .283) or RVSPring (57.80 ± 25.65 ms, p = .198). Among these pacing strategies, negative values of interventricular mechanical delay (IVMD) were only identified in LBBP (−19.25 ± 18.43 ms), significantly different from RVAP (35.00 ± 30.72 ms), RVSP (22.85 ± 22.05 ms), HBP (5.20 ± 18.64 ms), and RVSPring (16.00 ± 26.76 ms (all p < .05). Using Pearson's analysis, Sti‐LVAT was positively correlated with QRS duration, IVMD, TS‐12‐SD, LVEDV, and LVESV, while a negative relationship could be observed for left ventricular ejection fraction.ConclusionsHis‐Purkinje conduction system pacing (HPCSP) achieved better electrical and mechanical synchrony than conventional RV pacing. For interventricular synchrony, only LBBP initiated earlier LV activation than RV, in accordance with the right bundle branch block (RBBB) pattern of paced QRS during LBBP. Sti‐LVAT might be a good parameter correlating with LV systolic function and mechanical synchrony.

Abstract 60: Mortality Following Heart Failure Hospitalization By QRS Duration In Patients With Preserved Ejection Fraction

Background: Heart failure with preserved ejection fraction (HFpEF) comprises almost half of all heart failure (HF) diagnoses. Similar to HF with reduced ejection fraction (HFrEF), HFpEF carries up to a 75% 5-year mortality following HF hospitalization. However, unlike its corollary, HFpEF has exceedingly limited therapeutic options to alter its natural history. While QRS prolongation (QRS &gt; 120 msec) carries prognostic significance in HFrEF, less is known about the implications of this conduction abnormality in HFpEF. Objective: To determine the association of QRS prolongation with survival among patients with HFpEF following HF hospitalization. Methods: A retrospective review of 1,454 patients with left ventricular EF ≥ 45% discharged from the Minneapolis VA Medical Center between 2015 and 2019 from a HF hospitalization. All patients’ electrocardiograms (ECG) were classified by QRS duration as either prolonged (QRS &gt;120 msec) or narrow complex (QRS ≤120 msec). Those with prolonged QRS were further subtyped as: left bundle branch block (LBBB), right bundle branch block (RBBB), intraventricular conduction delay (IVCD), or ventricular paced (VP) rhythm. Results: Of the 1,454 patients (mean age 75.1 ± 10.8 years, 97.7% male, and mean EF 58.5% ± 10.2%), 545 (37.5%) had QRS prolongation. Specifically, 61 (4.2%) had LBBB, 266 (18.3%) had RBBB, 77 (5.3%) had IVCD and 141 (9.7%) had VP. Over 4.09 ± 1.00 years of follow up, 769 (52.9%) of the patients died (Table). Patients with a narrow QRS had a similar survival relative to those with a QRS &gt;120 msec with an age and sex adjusted hazard ratio of 1.01 (95% CI: 0.87-1.17, p = 0.16) (Figure). Conclusions: The mortality rate is exceedingly high in patients with HFpEF discharged after a HF hospitalization. While the QRS interval was not significantly associated with near-term survival in this analysis, these data suggest that studies with greater statistical power and follow-up duration are warranted.

PO-644-05 CONCURRENT LEADLESS PACEMAKER INSERTION DURING TRANSCATHETER AORTIC VALVE REPLACEMENT: A CASE SERIES

Complete heart block requiring permanent pacemaker implantation occurs in approximately 10% of patients (pts) undergoing transcatheter aortic valve replacement (TAVR), and in approximately 40% of TAVR pts who have preexisting right bundle branch block (RBBB). It is unknown whether it would be safe and efficacious to perform concomitant leadless pacemaker implantation for TAVR pts with preexisting conduction system disease and TAVR-related complete heart block.

Bradycardia-dependent complete AV block after TAVR.

The patient was a 79-year-old man with a history of coronary artery disease and right coronary artery percutaneous intervention in the remote past. The patient was diagnosed with severe aortic stenosis for which he underwent a transcatheter aortic valve replacement (TAVR) procedure. This was complicated by the development of right bundle branch block (RBBB) postoperatively. Three leads of the electrocardiogram before and after TAVR are shown in Figure 1.

Short-coupled ventricular ectopics leading to cardiac arrest in a young woman

BackgroundThis case report highlights the importance of recognizing that ventricular ectopy may be a cause for syncope and sudden cardiac death, through triggered disorganized arrhythmia. In the context of syncope, ventricular ectopy should be carefully assessed for coupling interval and morphology.Case presentationA 39-year-old woman, who had presented with recurrent syncope, had a cardiac arrest shortly after admission that required emergency defibrillation. Review of her cardiac monitoring revealed an episode of polymorphic ventricular tachycardia which had degenerated into ventricular fibrillation. The dysrhythmia had been initiated by a short-coupled (R-on-T) ventricular ectopic (VE) beat. Anti-arrhythmic therapy was initiated in the form of hydroquinidine, but the patient continued to have frequent VEs of right bundle branch block (RBBB) morphology with a relatively narrow QRS complex and a variation in frontal axis. A cardiac MRI revealed late gadolinium enhancement of the posterior papillary muscle (indicative of focal scarring). The patient underwent electrophysiological mapping and catheter ablation of her ectopy. The patient made a good recovery and was discharged from hospital with a secondary prevention implantable cardioverter-defibrillator (ICD) in situ.ConclusionsShort-couped VEs that are superimposed onto the preceding T wave (R-on-T) are indicative of electrical instability of the heart and should prompt urgent investigation. By studying the morphologies and axes of the QRS complexes produced by VEs, we can identify their likely origins and ascertain their clinical significance.

P047 The triple M threat of check-point inhibitors - an emerging overlap syndrome

Abstract Background/Aims The objective of this abstract is to raise awareness on an emerging overlap syndrome of life-threatening immune-related adverse events, manifesting as a triad of myositis, myocarditis and myasthenia gravis in immune check-point inhibitor (ICI) treated patients. It highlights the success of combination, aggressive and prompt immunosuppression with high dose intravenous steroid, cyclophosphamide, rituximab and intravenous immunoglobulin therapy, in two patients presenting at Guy’s and St Thomas’s Hospital, London with this overlap syndrome following pembrolizumab therapy. Methods Case presentation. Case 1: 75-year-old Caucasian gentleman receives one dose of pembrolizumab for metastatic melanoma. Two weeks later, he presents with myalgia, weakness, elevated CK 10,000. Troponin T is raised 459, ECG shows right bundle branch block (RBBB) and on day 3, he rapidly descends into complete heart block then cardiac arrest. Return of spontaneous circulation is obtained and a permanent pacemaker (PPM) inserted. On day 6, myocardial biopsy confirms acute myocarditis. He develops progressive muscle weakness, dysphagia and Type 2 respiratory failure. He receives 3 doses of IV methylprednisolone, in addition to intravenous immunoglobulins (IVIG) and intravenous cyclophosphamide. EMG shows mild myopathic features, positive AChR antibody, SSA/Ro60 and myositis-specific SRP antibodies and he becomes dependent on non-invasive ventilation. He commences pyridostigmine for myasthenia gravis. On day 19 two doses 1g Rituximab two weeks apart is administered. Monthly IVIG continues for three months and he completes 6 cycles of 500mg cyclophosphamide. A year following discharge, he is maintained on prednisolone 5mg OD with no additional immunosuppression and significantly improved muscle strength. Case 2: 77-year-old Caucasian gentleman receives one dose of pembrolizumab for metastatic melanoma. Four weeks later, he presents with myalgia, bilateral ptosis, muscle weakness and breathlessness. Bloods show CK 6467, troponin T 1058. He promptly receives 3 doses of IV methylprednisolone in addition to IVIG. A PPM is inserted electively as ECGs show RBBB and intermittent bradyarrhythmias. His anti-Ro/SSA-52 antibody is positive and AChR and myositis-specific antibodies are negative. He trials neostigmine due to persistent ptosis. On Day 6, muscle biopsy confirms immune-mediated necrotising myositis and he commences intravenous cyclophosphamide 500mg followed by 5 further cycles. On day 7, 1g intravenous rituximab is administered and repeated two weeks later, additional to monthly IVIG for five months. 6 months later, his CK has normalised and he has no residual muscle weakness. Results n/a Conclusion Although a rare complication of ICIs, this triad of myositis, myocarditis and myasthenia gravis can be potentially severe and fatal. With ICI reshaping the prognosis of several cancers and pembrolizumab gaining recent further approvals, we will increasingly encounter this therapeutic challenge. Therefore, raising awareness of this overlap syndrome amongst rheumatologists is even more critical to allow for prompt recognition and treatment with immunosuppression. Disclosure A. Mootoo: None. A. Masood: None. P. Maghsoudlou: None. D. D'Cruz: None.

Unexpected paced wide QRS complex rhythm after successful implantation of cardiac resynchronization therapy; what is the mechanism?

The adaptive CRT (aCRT) is an innovative algorithm that was developed to avoid unnecessary right ventricular (RV) pacing through continuous intracardiac delay evaluation. We present a case of unexpected wide QRS paced rhythm after successful implantation of CRT in patients with right bundle branch block (RBBB) and describe the reasons and the programming changes required to resolve it.

Electrocardiography Adverse Effects Systemic Glucantime in a Child With Cutaneous Leishmaniosis: A Case Report and Brief Review

Background: Antimonial compounds are the most common choice for the treatment of cutaneous Leishmaniosis (CL). Antimonial toxicities are common and cardiac toxicity is one of them, which leads to the electrocardiogram (ECG) changes. In this study, ECG changes in a patient with CL, who received systemic glucantime, were evaluated. Objectives: A 7-year-old girl was admitted to Amir-Kabir Hospital with the complaint of skin lesions (CL) on her left leg from ten months ago. The patient had received glucantime (10-20mg/kg/day) as a treatment for two 15-day periods and unfortunately, she had not responded to the treatment. Due to the cardiac side effects of glucantime, cardiology consultation was requested and an ECG was performed for the patients during the administration of treatment for the third time. Several ECG changes were detected, including first-degree block, right bundle branch block (RBBB), and QTc prolongation. The cardiologist stopped the treatment with glucantime to improve the ECG changes, and an ECG was taken every week. Even though prolonged QT interval and RBBB improved after a month, the first-degree block was present for ten months. Conclusions: ECG monitoring is necessary prior to and during the treatment with this drug. Moreover, RBBB has not been commonly reported in other studies. Thus, it should be considered as one of the cardiac side effects of glucantime and needs more attention.

Premature Ventricular Contractions From the Left Anterior Fascicle: Electrocardiographic and Electrophysiological Characteristics, Mapping Strategy, and Immediate and Long-Term Catheter Ablation Results

BackgroundLeft anterior fascicle (LAF) premature ventricular contractions (PVC) are rarely reported. We described the electrocardiographic and electrophysiological characteristics of PVCs originating from LAF and evaluated the results of catheter ablation.MethodsThe baseline AH and HV intervals were recorded during normal sinus rhythm (NSR), and the HV interval of LAF-PVC was measured during the procedure. During the index procedure, the conduction interval from the earliest Purkinje potential (PP) site to the His was labeled as time A, the conduction interval from the earliest site to the onset of the QRS as time B, then the HV interval during NSR (HVNSR) is A + B, and the HV interval during PVC (HVPVC) is B-A; a predicted PP time was calculated using HVNSR and HVPVC. The calculated formula is as follows: Predicted target PP = (HVNSR + HVPVC)/2. During the repeat procedure, the mapping strategy only focuses on the earliest retrograde PP due to the injury or block of LAF sustained at the index procedure.ResultsNotably, 24 patients with LAF-PVC were included. The ECG characteristics of PVC exhibited right bundle branch block (RBBB) morphology with right-axis deviation (RAD) in 18 patients and only RAD in 6 patients. The QRS durations of NSR and PVC were 78.8 ± 7.9 and 106.8 ± 12.3 ms, respectively. There was no significant difference between the predicted and mapped PP site (31.5 ± 8.1 vs. 30.6 ± 7.8 ms; P = 0.17). There was a significant difference between the mean axis deviation before and after ablation (46.3 ± 25.4° vs. 18.3 ± 44.1°; P = 0.001); however, only 10 patients had a complete LAF block. Eight patients had a recurrence, the QRS morphology of LAF-PVC became narrower (95.9 ± 17.2 vs. 105.3 ± 16.9 ms, P = 0.003), and 4 patients’s PVC QRS morphology was similar to NSR. During the repeat procedure, the earliest retrograde PP interval was longer than the index procedure in four patients (12.0 ± 1.9 vs. 37.8 ± 1.1 ms; P < 0.001).ConclusionThe target PP site for ablation of the LAF region can be calculated using the HV interval during NSR and PVC at the index procedure. The mapping strategy at repeat procedures focused on the earliest retrograde PP interval.

Optimizing Care of Patients With Right Bundle Branch Block Undergoing Transcatheter Aortic Valve Replacement

ObjectivesTo evaluate the use of temporary-permanent pacemaker (TPP) in patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve replacement (TAVR). We also sought to identify key predictors of permanent pacemaker (PPM) within 30 days of TAVR in this population. BackgroundRBBB is a well-recognized risk factor for PPM post TAVR. TPP provides stable transient pacing and reduces the need for critical care beds. MethodsThis is a retrospective chart review of 371 patients who underwent TAVR at our institution. All patients with pre-existing RBBB had TPP placed prior to TAVR (n = 37). The primary outcome was the need for critical care beds. Multivariate logistic regression analysis was performed to identify predictors of PPM within 30 days of TAVR. Results67 patients required PPM within 30 days of TAVR, and 56 implanted before discharge. 51% (19 out of 37) of TPP group required PPM before discharge compared to 11% (37 out of 334) of No TPP (p < 0.001), yet TPP group spent significantly fewer hours in a critical care bed (19 vs 28 h, p = 0.01). Length of membranous septum (LMS) <8.49 mm was the strongest independent predictor of PPM within 30 days of TAVR (RAUC of 0.80, Sensitivity 0.7 and Specificity 0.8) and 98% of patients with LMS < 7 mm required PPM within 30 days. ConclusionTPP-TAVR is a well-defined multidisciplinary protocol that reduces the need for critical care beds in patients with pre-existing RBBB referred for TAVR. Additionally, LMS is the strongest predictor of PPM implantation in this population. Condensed abstract (100 words)This study evaluated the use of temporary-permanent pacemakers (TPP) in patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve replacement (TAVR). TPP-TAVR provided stable pacing allowing for early mobilization and reduced the need for critical care beds. Multivariate logistic regression analysis identified length of membranous septum (LMS) <8.49 mm in patients with RBBB as the strongest independent predictor of PPM need within 30 days of TAVR. 98% of patients with RBBB and LMS < 7 mm required PPM at 30 days regardless of other characteristics including valve type and size.

Risk Stratification and Management of Advanced Conduction Disturbances Following TAVI in Patients With Pre-Existing RBBB

BackgroundPre-existing right bundle branch block (RBBB) is a strong predictor of increased need for a permanent pacemaker (PPM) following transcatheter aortic valve implantation (TAVI). Yet, further risk stratification and management remain challenging in patients with pre-existing RBBB owing to limited data. Therefore, we sought to investigate the incidence, predictors, and management of advanced conduction disturbances after TAVI in patients with pre-existing RBBB. MethodsWe retrospectively reviewed 261 consecutive patients with pre-existing RBBB (median age 81 years; 28.0% female; 95.0% received a balloon-expandable valve) without a pre-existing PPM who underwent TAVI at our institution in 2015-2019. Outcomes were high-degree atrioventricular block/complete heart block (HAVB/CHB) and PPM requirement. ResultsOverall, the 30-day HAVB/CHB rate was 28.0%, of which 76.7% occurred during the TAVI procedure. The delayed HAVB/CHB rate was 8.3%. Implantation depth below aortic annulus (per 1-mm increase) was significantly associated with increased risk of procedural HAVB/CHB (adjusted odds ratio = 1.25, 95% confidence interval = 1.07-1.46), delayed HAVB/CHB (1.34 [1.01-1.79]), and 30-day PPM (1.32 [1.11-1.55]). Predilation was associated with delayed HAVB/CHB (4.02 [1.22-13.23]). The combination of no predilation and implantation depth of ≤2.0 mm had lower rates of procedural HAVB/CHB (11.2% vs. 26.7%-30.4%, p = 0.011), delayed HAVB/CHB (2.1% vs. 7.6%-28.1%, p < 0.001), and 30-day PPM (10.3% vs. 20.0%-43.5%, p < 0.001) than the other strategies of valve deployment. Complete HAVB/CHB recovery after PPM implantation was uncommon at 7.1%. ConclusionsIn patients with pre-existing RBBB, the majority of HAVB/CHB events occurred during the TAVI procedure. Avoidance of predilation coupled with high valve deployment may result in relatively low rates of procedural and delayed HAVB/CHB, along with 30-day PPM rates.

Automatic detection of arrhythmias from an ECG signal using an auto-encoder and SVM classifier.

Millions of people around the world are affected by arrhythmias, which are abnormal activities of the functioning of the heart. Most arrhythmias are harmful to the heart and can suddenly become life-threatening. The electrocardiogram (ECG) is an important non-invasive tool in cardiology for the diagnosis of arrhythmias. This work proposes a computer-aided diagnosis (CAD) system to automatically classify different types of arrhythmias from ECG signals. First, the auto-encoder convolutional network (ACN) model is used, which is based on a one-dimensional convolutional neural network (1D-CNN)that automatically learns the best features from the raw ECG signals. After that, the support vector machine (SVM) classifier is applied to the features learned by the ACN model to improve the detection of arrhythmic beats. This classifier detects four different types of arrhythmias, namely the left bundle branch block (LBBB), right bundle branch block (RBBB), paced beat (PB), and premature ventricular contractions (PVC), along with the normal sinus rhythms (NSR). Among these arrhythmias, PVC is particularly a dangerous type of heartbeat in ECG signals. The performance of the model is measured in terms of accuracy, sensitivity, and precision using a tenfold cross-validation strategy on the MIT-BIH arrhythmia database. The obtained overall accuracy of the SVM classifier was 98.84%. The result of this model is portrayed as a better performance than in other literary works. Thus, this approach may also help in further clinical studies of cardiac cases.

Clinical Outcomes of Permanent Left Bundle Branch Area Pacing in Patients With Left Bundle Branch Block and Left Ventricular Ejection Fraction >35 vs. ≤35.

AimsThe present study aimed to compare the effects of left bundle branch area pacing (LBBAP) on cardiac function and clinical outcomes in patients with left bundle branch block (LBBB) and left ventricular ejection fraction (LVEF) >35 vs. ≤35%.Methods and ResultsThirty-six consecutive patients with LBBB and LVEF <50% were enrolled. All patients were followed up for a mean of 6 months. The successful LBBAP was defined as a paced QRS complex presented as right bundle branch block (RBBB) morphology and QRSd < 130 ms. Echocardiography parameters, pacing parameters and clinical outcomes were collected. The successful LBBAP was achieved in 77.8% of all cases (28/36). In LVEF > 35% group (70 ± 8 years, 9 male), the success rate was 81.0% (17/21). QRSd significantly decreased from 174 ± 23 ms to 108 ± 13 ms (P < 0.001). The pacing threshold and R-wave amplitude were 0.6 ± 0.2 V @ 0.5 ms and 12 ± 7 mV, respectively. In LVEF ≤ 35% group (69 ± 5 years, 9 male), the success rate was 73.3% (11/15) with QRSd decreasing from 188 ± 25 ms to 107 ± 11 ms (P < 0.001). The hyperresponders to LBBAP (functional recovery and LVEF ≥ 50%) in LVEF > 35% group was 52.9%, which were almost twice of that in LVEF ≤ 35% group (33.3%). Whether patients had LBBAP or left ventricular septal pacing (LVSP), patients in the LVEF > 35% group showed significantly lower incidence of heart failure hospitalizations or death from any cause (hazard ratio in LVEF > 35% group, 0.22; 95%CI, 0.06 to 0.75, P = 0.011).ConclusionsLBBAP can significantly shorten the QRSd and improve cardiac function in LBBB patients with either LVEF > 35 or ≤ 35%. LBBAP should be considered as an effective therapy for preventing the deterioration of cardiac function in early-stage heart failure patients with LBBB and LVEF > 35%.

Evaluation of the 2021 European Society of Cardiology guidelines in pre-existing right bundle branch block patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

AimsThe 2021 European Society of Cardiology guidelines recommend early pacemaker implantation in pre-existing right bundle branch block (RBBB) patients who develop PR prolongation or QRS axis change after transcatheter aortic valve implantation (TAVI). We aimed to evaluate this recommendation in TAVI recipients with a balloon-expandable valve (BEV).Methods and resultsWe retrospectively reviewed 188 pre-existing RBBB patients without pre-existing permanent pacemaker (PPM) who underwent TAVI with a BEV at our institution in 2015–19. Patients who developed high-degree atrioventricular block (HAVB) during TAVI or within 24 h post-TAVI were excluded. Eligible patients were divided according to the guideline-directed criteria (ΔPR interval ≥20 ms and/or QRS axis change). Patients who met the criteria (n = 102, 54.3%), compared with those who did not (n = 86), had a higher prevalence of baseline right axis deviation and were more likely to have received a larger valve with greater oversizing. The 30-day delayed HAVB rate did not differ significantly between the groups (3.9% vs. 4.7%, P = 1.00; odds ratio = 0.84, 95% confidence interval = 0.20–3.45). There was also no significant difference in terms of death (5.0% vs. 8.4% at 1 year; overall log-rank P = 0.94) or a composite of death or PPM implantation (14.8% vs. 16.6% at 1 year; overall log-rank P = 0.94) during follow-up post-TAVI. The majority of PR prolongations (79.4%) and QRS axis changes (52.0%) regressed within the following 24 h.ConclusionThe present data did not demonstrate an association of significant changes in PR interval or QRS axis with heightened delayed HAVB risk in BEV recipients with pre-existing RBBB. Prospective studies are warranted to confirm these findings.

The Physiologic Mechanisms of Paced QRS Narrowing During Left Bundle Branch Pacing in Right Bundle Branch Block Patients.

Left bundle branch pacing (LBBP) is a physiological pacing technique that captures the left bundle branch (LBB) directly, causing the left ventricle (LV) to be excited earlier than the right ventricle (RV), resulting in a “iatrogenic” right bundle branch block (RBBB) pacing pattern. Several studies have recently shown that permanent LBBP can completely or partially narrow the wide QRS duration of the intrinsic RBBB in most patients with bradycardia, although the mechanisms by which this occurs has not been thoroughly investigated. This article presents a review of the LBBP in patients with intrinsic RBBB mentioned in current case reports and clinical studies, discussing the technique, possible mechanisms, future clinical explorations, and the feasibility of eliminating the interventricular dyssynchronization accompanied with LBBP.

Prevalence and impact on prognosis of right-bundle branch block in patients with acute heart failure: Findings from the RICA registry

ObjectivesThis work aims to determine the prevalence, characteristics, and impact on prognosis of right bundle branch block (RBBB) in a cohort of acute heart failure (AHF) patients. MethodsWe prospectively analyzed 3,638 AHF patients included in the RICA registry (National Heart Failure Registry of the Spanish Internal Medicine Society). We independently analyzed the relationship between baseline and clinical characteristics and the presence of RBBB as well as the potential impact of RBBB on 1-year all-cause mortality and a composite endpoint of 90-day post-discharge hospitalization or death. ResultsThe prevalence of RBBB was 10.9%. Patients with RBBB were older, a higher proportion were male, had more pulmonary comorbidities, had higher left ventricular ejection fraction values, and had worse functional status. There were no differences in risk for patients with RBBB, with an adjusted hazard ratio (95% confidence interval) for 1-year mortality of 1.05 (0.83–1.32), and for the composite endpoint of 90-day post-discharge hospitalization or death of 0.97 (0.74–1.25). These results were consistent on the sensitivity analyses. ConclusionsFew patients with AHF present with RBBB, which is consistently associated with advanced age, male sex, pulmonary comorbidities, preserved left ventricular ejection fraction, and worse functional status. Nonetheless, after considering these factors, RBBB in AHF patients is not associated with worse outcomes.