Conduction Abnormalities after Transcatheter Aortic Valve Implantation: Incidence, Impact and Management Using CT Data Interpretation.

The demonstrated safety and effectiveness of transcatheter aortic valve implantation (TAVI) among low surgical risk patients opened the road to its application in younger low-risk patients. However, the occurrence of conduction abnormalities and need for permanent pacemaker implantation remains a frequent problem associated with adverse outcomes. The clinical implications may become greater when TAVI shifts towards younger populations, highlighting the need for comprehensive strategies to address this issue. Beyond currently available clinical and electrocardiographic predictors, patient-specific anatomical assessment of the aortic root using multi-sliced CT (MSCT) imaging can refine risk stratification. Moreover, leveraging MSCT data for computational 3D simulations to predict device-anatomy interactions may help guide procedural strategy to mitigate conduction abnormalities. The aims of this review are to summarise the incidence and clinical impact of new left bundle branch block and permanent pacemaker implantation post-TAVI using contemporary transcatheter heart valves; and highlight the value of MSCT data interpretation to improve the management of this complication.

Can the QRS morphology of outflow tract ventricular arrhythmia change when right bundle branch block emerges during sinus rhythm?

BACKGROUND: QRS morphology can change during ventricular arrhythmias (VAs) with the appearance of bundle branch block (BBB). METHODS: We retrospectively investigated 195 consecutive patients who underwent an initial ablation of VA. The study inclusion criteria were VAs that were successfully ablated in the outflow tract (OT) and in whom right bundle branch block (RBBB) was induced by catheter manipulation close to the His bundle area during sinus rhythm, before any radiofrequency application. We analyzed the QRS morphology of the VAs with and without RBBB during sinus beats. RESULTS: Twenty-four patients (age 59 ± 17 years, female 14) developed RBBB at some point during their procedure. The successful ablation sites of the VAs were the right ventricular outflow tract (RVOT) in 12 patients, pulmonary artery in one, left coronary cusp in five, right coronary cusp in three, right-left cusp junction in two, and great cardiac vein in two. QRS-morphology change was observed in five (20%) cases. The successful ablation sites in that group were the left coronary cusp in three cases, right coronary cusp in one, and RVOT septum in one. The QRS duration of the VAs increased during RBBB. CONCLUSIONS: There are some cases of OT-VAs in which the QRS waveform changes with the appearance of catheter induced RBBB. We need to be aware that when QRS morphology changes during an OT-VA ablation, it does not necessarily mean that the origin or exit of the VA has changed.

Ventricular dysfunction consequences of mechanical dyssynchrony in isolated complete right bundle branch block versus left bundle branch block.

Background: Complete bundle branch block in individuals without structural heart disease is known as isolated complete bundle branch block. Isolated complete left bundle branch block (CLBBB) is correlated with ventricular dysfunction secondary to dyssynchrony; however, few studies have investigated isolated complete right bundle branch block (CRBBB), which was previously considered benign but was recently found to be associated with adverse cardiovascular outcomes. This study aimed to evaluate cardiac mechanical synchrony, and systolic and diastolic function in patients with isolated CRBBB and compare cardiac synchrony and function to patients with isolated CLBBB. Methods: This cross-sectional study was conducted at The First Hospital of China Medical University in Shenyang, China, from 2020 to 2021. A total of 44 isolated CRBBB patients, 44 isolated CLBBB patients, and 42 healthy subjects were enrolled in the study. Transthoracic echocardiography was performed in all subjects. Synchrony parameters, including the mechanical dispersion of the right ventricle [the standard deviation of time to the peak longitudinal strain of six right ventricular (RV) segments] and atrioventricular dyssynchrony parameter [the ratio of left ventricular (LV) diastolic filling time to the time interval between two adjacent R waves (RR interval) measured by tissue Doppler imaging]. RV and LV function were assessed by the global longitudinal strain (GLS) of six RV segments and 18 LV segments, and the ratio of the peak early diastolic flow velocity to annular velocity (E/e') of the tricuspid valve and mitral valve. Statistical analyses were performed, including an analysis of variance, Pearson correlation analysis, and linear regression analysis. Results: Compared with the healthy subjects, the mechanical dispersion of the right ventricle was significantly increased, and ventricular function was impaired as evidenced by the decreased RV GLS and LV GLS, and the increased E/e' of the tricuspid valve and mitral valve in the isolated CRBBB patients (all P<0.001). Moreover, compared with the isolated CLBBB patients, the mechanical dispersion of the right ventricle and E/e' of the tricuspid valve were increased, and RV GLS was significantly reduced in the isolated CRBBB patients (all P<0.001). Mechanical dispersion of the right ventricle was independently associated with RV GLS [coefficient, 0.13; 95% confidence interval (CI): 0.004-0.26; P=0.04] in the isolated CRBBB patients. RV GLS (coefficient, 0.10; 95% CI: 0.01-0.20; P=0.03) and the ratio of the LV diastolic filling time to the RR interval measured (coefficient, -0.30; 95% CI: -0.53 to -0.07; P=0.01) were independent factors of LV GLS. Conclusions: The isolated CRBBB patients had impaired cardiac mechanical synchrony and ventricular function, and more decreased RV synchrony and function than the isolated CLBBB patients. Right intraventricular synchrony was independently associated with RV systolic dysfunction in patients with isolated CRBBB. Atrioventricular synchrony and RV systolic function were independently associated with the LV systolic function. Therefore, comprehensive evaluations of echocardiography results and close monitoring is required for isolated CRBBB patients.

Predictors of functional mitral regurgitation improvement in patients with left bundle branch block treated with left bundle branch area pacing.

BACKGROUND: Functional mitral regurgitation (FMR) and its severity are associated with adverse outcomes in heart failure patients. This study aims to analyze the predictors of FMR improvement after successful left bundle branch area pacing (LBBAP) in patients with LVEF < 50% and complete left bundle branch block (CLBBB). METHODS: Consecutive patients with LVEF < 50% and CLBBB who underwent successful LBBAP from July 2018 to July 2023 were retrospectively identified. Significant MR was defined as regurgitation of moderate severity or greater. Patients with significant FMR were included in the analysis. FMR improvement (FMRI) was defined as a reduction of at least one grade in regurgitation severity compared to baseline at 3 months or longer follow-up. RESULTS: Among the 81 identified patients, 42 patients with significant FMR preoperatively were included. After LBBAP, QRS duration significantly shortened from 170.6 ± 18.8 ms to 114.5 ± 20.2 ms (p < .001). Significant FMR improves in approximately 76.2%, and the patients were divided into an FMRI group (n = 32) and a non-FMRI group (n = 10). Univariate analysis showed that absence of persistent atrial fibrillation, typical CLBBB, and left atrium diameter at baseline were associated with improvement of FMR after LBBAP. Of these variables, only absence of persistent atrial fibrillation remains an independent predictor in the multivariate model (OR 12.436, p = .009). CONCLUSION: LBBAP is able to improve FMR in heart failure patients who had CLBBB with LVEF < 50%. Meanwhile, the absence of persistent atrial fibrillation is an independent predictor of FMR improvement.

Left ventricular diastolic dysfunction in non-myocardial disorders.

This article reviews and discusses non-myocardial disorders which represent diagnostic challenges when evaluating patients for suspected heart failure with preserved left ventricular ejection fraction. This includes pre-capillary pulmonary hypertension, which is important to differentiate from post-capillary hypertension caused by left sided heart disease. The impact of electrical disorders on LV diastolic function is also reviewed, and includes a discussion of left bundle branch, which has both a direct effect on LV diastolic function, as well as a long-term effect due to remodeling. Furthermore, evaluation of diastolic function in patients with atrial fibrillation is discussed. Pericardial diseases are reviewed as well as effects of a normal pericardium on diastolic function in failing hearts. Finally, the article reviews how valvular diseases impact LV diastolic function.

Takotsubo cardiomyopathy associated with free wall rupture and ventricular septal defect: a case report.

Takotsubo cardiomyopathy is a rare cardiac presentation. It can be associated with severe complications such as hemodynamically significant ventricular septal defect and cardiac free wall rupture. In cases of mechanical complications, surgical repair is often indicated. Despite best medical and surgical efforts, patients with Takotsubo cardiomyopathy and mechanical complications carry significant mortality risk. Herein, we present an unusual presentation of Takotsubo cardiomyopathy that was associated with a mechanical complication. Although the patient underwent a successful surgical repair, she passed away from multiorgan failure during the postoperative period.

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Predictors and clinical outcomes of permanent pacemaker implantation after transcatheter aortic valve implantation.

OBJECTIVE: This study aimed to identify the incidence, risk factors, and outcomes of permanent pacemaker (PPM) implantation after transcatheter aortic valve implantation (TAVI) procedures. METHODS: A retrospective analysis was conducted on 70 patients who underwent TAVI at the Department of Cardiology, Fujian Provincial Hospital, from January 2018 to March 2022. Based on whether a new PPM was implanted after TAVI, all patients were divided into two groups: NEW PPM and NO PPM. Baseline characteristics and clinical data were compared between the two groups. Univariate analysis was used to analyze different variables between the two groups. A binary logistic regression analysis was used to evaluate independent correlates for PPM implantation after TAVI. RESULTS: The mean age of the 70 patients was 73.1 ± 8.8 years. The incidence of PPM implantation was 17.1%. Patients with diabetes and chronic kidney disease were more likely to require PPM (50% vs. 20.7%, p = 0.042, 25% vs. 5.2%, p = 0.042). Our study did not identify any significant differences in the incidence of electrocardiographic conduction disturbances except for the previous right bundle branch block (RBBB) (NO PPM 6.9% vs. NEW PPM 33.3%, p < 0.05). We found that prosthesis size, implantation depth, procedural duration, and length of hospital and intensive care unit (ICU) stays were comparable between the two groups. The leading independent predictors of PPM implantation were previous RBBB (odds ratio 10.129, p = 0.034). CONCLUSION: The previous RBBB was the leading independent predictor of PPM implantation. New PPM was not associated with significantly new-onset left BBB, extended post-procedure hospitalization, ICU stay, or procedural duration.

Abnormal QRS-T angles in 5796 women and men aged 50-64: an electrocardiographic analysis providing mechanistic insights.

INTRODUCTION: Abnormal QRS-T angles are prognostic markers for cardiovascular deaths including sudden cardiac death. They occur in ∼5-6% of population-based cohorts but in ∼20% of patients with diabetes. The mechanistic background, electrical activation and/or recovery disturbances, is not known and the topic of this study. METHODS: Applying Frank vectorcardiography (VCG) and simultaneously recorded scalar 12­lead ECG, electrical activation and recovery of abnormal QRS-T angles were studied in 311 participants (5.4%) from a population-based cohort of 5796 women and men in the main Swedish CArdio-Pulmonary bio-Imaging Study (SCAPIS) in Gothenburg. Cut-off values for the peak and mean QRS-T angles were > 124° and > 119°, based on the >95th percentile among all 1080 participants in the pilot SCAPIS and reference values for normal directions (Q1-Q3) from 319 apparently healthy (30%) of them. RESULTS: Of 311 cases 17% had known cardiac disease. Deviations of QRS and QRSarea-vectors from reference limits (90%) were significantly more common than deviations of T- and Tarea-vectors (65%). Standard ECG signs suggested pathophysiology in 20%; left bundle branch block (LBBB) and voltage criteria for left ventricular hypertrophy being most frequent (9-10%) each. Sub-group analysis of the 30 with LBBB showed very large variability in vector directions. CONCLUSIONS: Our observations provide mechanistic insights about abnormal QRS-T angles of potential value for future prognostic and interventional studies. The results also have potential implications for LBB area pacing and the approach to left ventricular hypertrophy.

Sex differences outcomes in conduction system pacing for patients with typical left bundle branch block.

BACKGROUND: Biventricular pacing (BVP) appears to confer more pronounced advantages in women, yet the impact of conduction system pacing (CSP) remains insufficiently characterized. This investigation seeks to elucidate sex-specific disparities in clinical outcomes among patients with typical left bundle branch block (LBBB) undergoing CSP, with a particular focus on assessing contributory factors. METHODS: Consecutive patients diagnosed with nonischemic cardiomyopathy, exhibiting left ventricular ejection fraction (LVEF) ≤ 40%, and manifesting typical LBBB as Strauss criteria, underwent CSP. Subsequent longitudinal monitoring assessed improvements in LVEF and the composite endpoint of mortality or heart failure hospitalization (HFH). RESULTS: Among the included 176 patients, women (n = 84, mean age: 69.5 ±â€¯8.8 years) displayed smaller heart size (LVEDd, 62.0 ±â€¯8.3 mm vs. 64.8 ±â€¯7.9 mm, P = 0.023) and shorter baseline QRSd (163.5 ±â€¯17.7 ms vs. 169.7 ±â€¯15.1 ms; P = 0.013) than men. Of the 171 patients who completed the follow-up, super-response was observed in 120 (70%), with a higher occurrence in women than men (78.3% vs. 62.5%, P = 0.024). The incidence of death or HFH was numerically lower in women (7.1% Vs 13%, Log-rank P = 0.216). Notably, the super-response showed a significant difference in women compared to men at the same electrocardiography and/or echocardiographic parameters value. Mediation analysis between sex and super-response revealed that LVEDd and pQRSd play an intermediary role, with the mediation proportion of 26.07% and 27.98%, respectively. CONCLUSIONS: Women may derive more benefits from CSP, and pQRSd and LVEDd partly drive this difference.

Systemic Sclerosis With Cardiac Manifestations: A Case Report.

Systemic sclerosis (SSc), or scleroderma, is a multisystem disease process that can result in significant end-organ damage if left undiagnosed or untreated. While some manifestations are well-known and widely researched, other presentations of SSc, including the presentation of our patient, require further investigation. Though many non-pulmonary and non-dermatologic manifestations lack widespread recognition, such presentations are important to recognize clinically in order to adequately investigate and appropriately treat. Fibrotic changes affect not only the skin but also the myocardial conduction system which can result in chronic systolic heart failure and significant conduction delays. This report is a case of newly diagnosed scleroderma that presented with worsening dyspnea and activity intolerance who was discovered to have new onset prolonged PR interval, right bundle branch block, and left anterior fascicular block. After a comprehensive workup, the patient was diagnosed with scleroderma and underwent treatment by a multidisciplinary team.

Management of Postprocedural Conduction Disturbances Using a Prespecified Algorithm in the Optimize PRO Study.

Background: Lack of standardization in posttranscatheter aortic valve replacement (TAVR) conduction disturbance (CD) identification and treatment may affect permanent pacemaker implantation (PPI) rates and clinical outcomes. The safety and efficacy of a standardized TAVR CD algorithm has not been analyzed. This study analyzes the Optimize PRO post-TAVR CD management algorithm with Evolut PRO/PRO+ valves. Methods: Optimize PRO is a prospective, postmarket study implementing 2 strategies to reduce pacemaker rates: TAVR with cusp overlap technique and a post-TAVR CD algorithm. The 2-hour postprocedural electrocardiogram (ECG) stratified patients to early discharge in the absence of new ECG changes or to CD algorithms for (1) ECG changes with preexisting right or left bundle branch block (LBBB), interventricular conduction delay or first-degree atrioventricular block, (2) new LBBB, or (3) high-degree atrioventricular block (HAVB). Results: The interim analysis of the CD cohort consisted of 125/400 TAVR recipients. In the CD cohort, the 30-day new PPI rate was higher (28.1% vs 1.5%; P <.001), and 60 (48%) patients were discharged with a 30-day continuous ECG monitor. At 30 days, 90% of patients discharged with a monitor did not require PPI. Clinical outcomes, including mortality, stroke, bleeding, and reintervention, were similar in patients with and without CDs. No patient experienced sudden cardiac death. Conclusions: Effective management of CDs using a standard algorithm following Evolut TAVR provides similar 30-day safety outcomes to patients without CDs who undergo routine next day discharge. The CD algorithm may provide an effective strategy to recognize arrhythmias early, improve PPI utilization, and facilitate safe monitoring of patients after discharge.

Impact of left bundle branch block or permanent pacemaker after transcatheter aortic valve replacement on mid-term left ventricular ejection fraction.

BACKGROUND: Conduction disturbances have uncertain implications for long-term left ventricular ejection fraction (LVEF) after transcatheter aortic valve replacement (TAVR). We aimed to examine LVEF changes in patients up to two years post-TAVR. METHODS: We examined patients who underwent TAVR between 2012 and 2020 and underwent echocardiography follow-up. Patients were categorized into four groups: 1) Those without a permanent pacemaker (PPM) or left bundle branch block (LBBB) pre- or post-TAVR; 2) Patients with pre- and post-TAVR LBBB; 3) Individuals with preexisting PPM; and 4) Patients requiring new PPM after TAVR. LVEF was assessed at the outset of TAVR, at 30 days, 1-year, and 2-years post-TAVR. RESULTS: The study included 730 patients: 421 (57.6 %) without conduction abnormalities, 151 (20.7 %) with post-TAVR LBBB (48 pre-existing, 103 new-onset), 63 (8.6 %) with pre-existing PPM, and 95 (13.1 %) requiring new PPM. At discharge, patients without conduction abnormalities exhibited the highest LVEF (57.4 ± 11.5 %), whereas those with pre-existing PPM had the lowest (48.1 ± 15.5 %). Over two years, LVEF remained constant in patients without conduction issues and in those with pre-existing PPM. However, patients with new LBBB experienced a 6.3 % decrease in LVEF, and those requiring new PPM showed a 4.1 % reduction. CONCLUSION: New conduction abnormalities, such as LBBB or the need for PPM, induce a decline in LVEF post-TAVR. It is imperative to focus on the long-term monitoring of left ventricular function in patients experiencing new conduction disturbances post-TAVR.

Association Between Right Bundle Branch Block and Ventricular Arrhythmia in Patients With Cardiac Sarcoidosis.

Background: Ventricular arrhythmia (VA) is a life-threatening condition associated with cardiac sarcoidosis (CS). Right bundle branch block (RBBB) is a common conduction disorder in CS; however, its association with VA remains unknown. Objectives: This study aimed to investigate the relationship between RBBB and VA in patients with CS. Methods: This was a post hoc analysis of ILLUMINATE-CS (Illustration of the Management and Prognosis of Japanese Patients with Cardiac Sarcoidosis), a multicenter, retrospective, and observational study that evaluated the clinical characteristics and prognosis of CS. Eligible patients were divided into two groups based on the presence or absence of RBBB at the time of diagnosis. The primary outcome was serious ventricular arrhythmia events (SVAEs), defined as a combination of sudden cardiac death and documented ventricular fibrillation, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator therapy. Results: Overall, 312 patients were studied, with 155 (49.7%) patients presenting with RBBB (RBBB group). Patients in the RBBB group had a higher prevalence of basal interventricular septum (IVS) thinning and prominent late gadolinium enhancement in the basal IVS on cardiac magnetic resonance imaging than those in the non-RBBB group. During a median follow-up of 3.0 years (IQR: 1.6-6.0 years), 66 patients experienced SVAE. In multivariable Cox regression analysis, the RBBB group was independently associated with a higher incidence of SVAEs (HR: 1.93 [95% CI: 1.14-3.28]; P = 0.015). Conclusions: In patients with CS, RBBB was an independent predictor of SVAEs, which might reflect the specific scar distribution that is predominant in the IVS.

Risk of mortality associated to chronic kidney disease in patients with complete left bundle branch block.

Chronic kidney disease (CKD) is associated with cardiac conduction defects and is a strong risk factor for heart failure. Complete left bundle branch block (cLBBB), a cardiac conduction abnormality, may have an unfavorable effect on ventricular mechanical synchrony and lead to the progression of heart failure. Once heart failure develops, it seems to act together with underlying CKD in a vicious circle. Therefore, this study aimed to explore the influence of CKD in patients with cLBBB by assessing the estimated glomerular filtration rate (eGFR). We examined a hospital-based sample of 416 adult patients with cLBBB from 2010 to 2013. The eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Cox proportional hazard models were used to estimate the hazard ratio for all-cause mortality and cardiovascular mortality. A total of 416 adult patients with a mean age of 71 ± 13 years were enrolled. The median follow-up period was 3.6 years. After adjusting for clinical, electrocardiographic parameters, and medication use, cox regression analysis showed that total mortality was significantly associated with older age (Hazard Ratio (HR) = 1.03, 95% CI = 1.01-1.05, p = 0.002), presence of congestive heart failure (HR = 2.39, 95% CI = 1.63-3.49, p < 0.001), advanced CKD (HR = 2.48, 95% CI = 1.71-3.59, p < 0.001), higher HR (HR = 1.02, 95% CI = 1.01-1.03, p < 0.001) and without use of ACEI/ARB (HR = 0.59, 95% CI = 0.41-0.85, p = 0.005) were independent predictors of the total mortality. Multivariate Cox hazard regression analysis demonstrated that, in comparison to patients lacking cLBBB, the coexistence of CKD (eGFR < 60 mL/min/1.73 m2) among those with LBBB significantly heightened the risks of both total mortality (HR ratio of 5.01 vs. 2.40) and CV death (HR ratio of 61.78 vs. 14.41) even following adjustment for clinical covariates and ECG parameters. In summary, within patients exhibiting cLBBB, the presence of CKD serves as a significant risk factor for all-cause mortality.

Left bundle branch block cardiomyopathy (LBBB-CMP): from the not-so-benign finding of idiopathic LBBB to LBBB-CMP diagnosis and treatment.

Introduction Idiopathic left bundle branch block (iLBBB) is an uncommon finding. Its benignity has been increasingly questioned, though its natural history remains poorly clarified. Similarly, LBBB-cardiomyopathy (LBBB-CM) has been also increasingly recognized as a distinct entity, where electromechanical dyssynchrony seems to play a central role in left ventricular dysfunction (LVD) development. Still, it remains a scarcely studied topic. There is an urgent need for investigation and evidence reinforcement in these areas. OBJECTIVES: two main objectives: (1) to explore the natural history of "asymptomatic" iLBBB carriers; (2) to characterize the outcomes and therapeutic approach used in a "real-world" cohort of possible LBBB-CMP patients (pts). METHODS: tertiary care centre retrospective study of pts with iLBBB and possible LBBB-CMP, screened from a large hospital electrocardiographic database from 2011 to 2017 (LBBB = 347). To assign the 1st objective, only pts with left ventricular ejection fraction (LVEF) ≥ 50% and available follow-up (FU) data were included (n = 152). Regarding the 2nd objective, possible LBBB-CMP pts were selected and defined as iLBBB pts with LVD (LVEF < 50%) and no secondary causes for LVD (n = 53). Data were based on pts' careful review of medical records. RESULTS: focusing our 1st objective, 152 iLBBB carriers were identified. Median FU time were 8 years, and 61% were female. During FU, approximately 25% developed LVD, 20% needed ≥ 1 cardiovascular (CV) hospitalization, and 15% needed a cardiac device implantation. The majority (2/3) of pts with LVD on FU (n = 35) had no secondary causes for LVD, being classified as possible LBBB-CMP pts. Time-to-LVD analysis showed no differences between pts with a known cause for LVD vs LBBB-CMP pts (Log-rank = 0.713). Concerning the 2nd objective, 53 possible LBBB-CMP pts were identified. Median FU time were 10 years, and 51% were female. During the FU, 77% presented heart failure (HF) symptoms, and 42% needed ≥ 1 CV hospitalization, mainly due to HF. Half presented severe LVD at some point in time, and 55% needed a cardiac device, most of them a cardiac resynchronization therapy (CRT) device. Comparing CRT with non-CRT pts, no differences were found in terms of medical therapy, but better outcomes were observed in CRT group: LVEF improvement was higher (median LVEF improvement of 11% in non-CRT vs 27% in CRT; p < 0.001), and fully recovery from LVD was more frequent (50% of CRT vs 14% non-CRT; p = 0.028). CONCLUSION: our data strengthen current evidence on natural history of iLBBB, showing significant CV morbidity associated with the presence of iLBBB, and reinforces the need for a serial and proper FU of these carriers. Our data on "real-world" possible LBBB-CMP pts shows high rates of CV events, namely HF-related events, and supports the growing evidence pointing out CRT as this subgroup of pts' cornerstone of treatment. In conclusion, our work sheds additional light on these largely unknown topics and underlines the urgent need for larger and prospective studies addressing the identification of LVD development predictors in iLBBB carriers, as well as the establishment of diagnostic criteria and therapeutic approach for LBBB-CMP.

Evaluating Long-Term Outcomes in STEMI Patients with New Left Bundle Branch Block: The Impact of Modifiable Risk Factors.

Background/Objectives: Coronary artery disease, a leading global cause of death, highlights the essential need for early detection and management of modifiable cardiovascular risk factors to prevent further coronary events. Methods: This study, conducted at a major tertiary academic PCI-capable hospital in Romania from 1 January 2011 to 31 December 2013, prospectively analyzed 387 myocardial infarction with ST-segment elevation (STEMI) patients to assess the long-term management of modifiable risk factors. This study particularly focused on patients with new-onset left bundle branch block (LBBB) and compared them with a matched control group without LBBB. Results: During median follow-up periods of 9.6 years for LBBB patients and 9.2 years for those without LBBB, it was found that smoking, obesity, and dyslipidemia were prevalent in 73.80%, 71.42%, and 71.42% of the LBBB group, respectively, at baseline. Significant reductions in smoking were observed in both groups, with the LBBB group's smoking rates decreasing significantly to 61.90% (p = 0.034). Patients with LBBB more frequently achieved low-density lipoprotein cholesterol (LDLc) target levels during the follow-up period (from 71.42% to 59.52%; p = 0.026) compared to the control group (from 66.67% to 71.42%; p = 0.046). Prescription rates for dual antiplatelet therapy (DAPT), angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs), beta-blockers, and statins were initially high but then decreased by the follow-up. Statin use was reduced from 97.62% to 69.04% (p = 0.036) in the LBBB group and from 100% to 61.90% (p = 0.028) in the non-LBBB group. This study also highlighted moderate correlations between obesity (r = 0.627, p = 0.040) and subsequent coronary reperfusion in the LBBB group, while dyslipidemia and smoking showed very strong positive correlations across both groups (dyslipidemia: r = 0.903, p = 0.019 for LBBB; r = 0.503, p = 0.048 for non-LBBB; smoking: r = 0.888, p = 0.035 for LBBB; r = 0.517, p = 0.010 for non-LBBB). Conclusions: These findings underscore the crucial need for targeted management of modifiable risk factors, particularly focusing on dyslipidemia and smoking cessation, to improve subsequent coronary reperfusion outcomes post-STEMI, especially in patients with complicating factors like LBBB.

Retrograde Conduction in Left Bundle Branch Block: Insights From Left Bundle Branch Pacing.

BACKGROUND: Biventricular pacing is a well-established therapy for patients with heart failure (HF), left bundle branch block (LBBB) and left ventricular (LV) dysfunction. Left bundle branch pacing (LBBP) has emerged as an alternative to biventricular pacing. OBJECTIVES: The aim of this study was to assess the retrograde conduction properties of the left bundle branch in patients with nonischemic cardiomyopathy and LBBB during LBBP and its clinical implications. METHODS: Patients undergoing successful LBBP for nonischemic cardiomyopathy with LV ejection fraction (LVEF) ≤35% and LBBB were included. Continuous recording of His potential was performed using a quadripolar catheter. Unidirectional block was defined as retrograde His bundle activation during LBBP with stimulus to His potential (SH) duration less than or equal to antegrade HV interval and bidirectional block as VH dissociation or SH duration greater than HV interval. HF hospitalization, ventricular arrhythmias, and mortality were documented. RESULTS: A total of 165 patients were included. The mean follow-up duration was 21.8 ± 13.1 months. Bidirectional block (group I) was observed in 82% (n = 136), and these patients were noted to have advanced HF stage and prolonged baseline QRS duration. Unidirectional block (group II) with intact retrograde conduction was observed in 18% (n = 29) and was associated with narrow paced QRS duration and higher LVEF during follow-up. Super-response (LVEF ≥50%) was observed in 54.4% (n = 74) in group I compared with 73.3% (n = 22) in group II (P = 0.03). The OR for LVEF normalization was 4.1 (95% CI: 1.26-13.97; P = 0.02), with unidirectional block compared with bidirectional block in patients with LBBB and LV dysfunction. Adverse clinical outcomes as measured by a composite of HF hospitalization, ventricular arrhythmias, and mortality were significantly higher in group I compared with group II (12.5% vs 0%; P = 0.04). CONCLUSIONS: Bidirectional block in LBBB was characterized by advanced HF symptoms, while unidirectional block was associated with better clinical outcomes after cardiac resynchronization therapy by LBBP.

Association between anti-SSA autoantibodies and conduction disturbances in heart failure.

BACKGROUND: Conduction disturbances play an important role in the occurrence and development of heart failure (HF). Studies suggest autoantibodies may attack the conduction system. However, whether autoantibodies are associated with conduction disturbances in patients with HF is unclear. OBJECTIVE: The purpose of this study was to assess whether anti-SSA, anti-Ro/Sjögren syndrome-related antigen A antibodies known for congenital atrioventricular block (AVB), is associated with conduction disturbances in patients with HF. METHODS: This retrospective observational study used data from patients with HF who were admitted to Beijing Anzhen Hospital between January 2018 and June 2022. Patients who were tested for anti-SSA and had undergone electrocardiographic examination during hospitalization were included. Conduction disturbances, including AVB, bundle branch block (BBB), and intraventricular conduction delay, were confirmed by a cardiologist blinded to anti-SSA status. Univariate and multivariable logistic regression analyses were performed to assess the association between anti-SSA and conduction disturbances. RESULTS: A total of 766 patients were included in this study, of whom 70 (9.1%) were anti-SSA positive. Subjects who were anti-SSA positive showed a higher prevalence of AVB (20% vs 10.6%) and BBB (27.3 % vs 10.9 %), including both left BBB and right BBB (all P <.05). After adjusting for known risk factors, anti-SSA was independently associated with AVB (odds ratio [OR] 2.42; 95% confidence interval [CI] 1.18-5.43; P = .03) and BBB (OR 3.15; 95% CI 1.68-5.89; P <.001). CONCLUSION: Anti-SSA is independently associated with AVB and BBB in patients with HF. Further study of the role of autoantibodies in the development of conduction abnormalities in patients with HF to generate possible targeted treatments is required.

Effects of left bundle branch block on echocardiographic coronary flow assessment: A systematic review.

This systematic review investigates the diagnostic and prognostic utility of coronary flow reserve (CFR) assessment through echocardiography in patients with left bundle branch block (LBBB), a condition known to complicate the clinical evaluation of coronary artery disease (CAD). The literature search was performed on PubMed, EMBASE, Web of Science, Scopus, and Google Scholar, was guided by PRISMA standards up to March 2024, and yielded six observational studies that met inclusion criteria. These studies involved a diverse population of patients with LBBB, employing echocardiographic protocols to clarify the impact of LBBB on coronary flow dynamics. The findings emphasize the importance of CFR in stratifying cardiovascular risk and guiding clinical decision-making in patients with LBBB. Pooled results reveal that patients with LBBB and significant left anterior descending (LAD) artery stenosis exhibited a marked decrease in stress-peak diastolic velocity (MD = -19.03 [-23.58; -14.48] cm/s; p < .0001) and CFR (MD = -.60 [-.71; -.50]; p < .0001), compared to those without significant LAD lesions, suggesting the efficacy of stress echocardiography CFR assessment in the identification of clinically significant CAD among the LBBB population. This review highlights the clinical relevance of echocardiography CFR assessment as a noninvasive tool for evaluating CAD and stratifying risk in the presence of LBBB and underscores the need for standardized protocols in CFR measurement.