Search Results (97)

Brugada syndrome (BrS) is a cardiac arrhythmic disorder associated with distinctive electrocardiographic (ECG) abnormalities and an increased risk of sudden cardiac death due to ventricular arrhythmias. While the classic BrS ECG pattern is a coved ST-segment elevation in the right precordial leads, a wide spectrum of atypical ECG presentations can mislead the diagnosis. This review discusses rare and under-recognized ECG findings associated with BrS, including its coexistence with right and left bundle branch block, alterations in peripheral leads and in the morphology of the QRS complex, as well as atrioventricular conduction abnormalities. Emphasis is placed on the clinical relevance of these findings, their underlying electrophysiological mechanisms, and their prognostic implications. Recognizing these atypical manifestations is critical to avoid misdiagnosing or failing to recognize the condition in patients with BrS. Full article

Background and Clinical Significance: Heart failure with reduced ejection fraction (HFrEF) and atrial fibrillation (AF) frequently coexist, creating a complex clinical interplay that exacerbates morbidity and mortality. AF can directly precipitate or worsen HFrEF through mechanisms such as tachycardia-induced cardiomyopathy, loss of atrial contribution to ventricular filling, and irregular ventricular response. The use of evidence-based therapies improves clinical outcomes in patients with HFrEF. Case Presentation: We present a clinical case of a 58-year-old man with left bundle branch block (LBBB), tachysystolic AF, and the aforementioned induced HFrEF. The patient’s medical treatment was optimized according to recent guidelines. Subsequent to the improvements in HF treatment, the patient’s echocardiographic data showed a higher left ventricle ejection fraction (LVEF); however, it remained below 35%. Moreover, tachysystolia persisted and was not sufficiently controlled with medications. Therefore, an upgrade of the pacemaker to cardiac resynchronization therapy (CRT) following the destruction of the AV node was performed to control tachysystolic AF and worsening of HF. After the treatment adjustments, the patient’s symptoms regressed, and echocardiography showed improved LVEF up to 41%. Conclusions: This case highlights the successful identification and timely application of intensive heart rate control management and heart failure induced by AF treatment. Full article

Background: Left bundle branch block (LBBB) following trans-catheter aortic valve implantation (TAVI) has been excluded from same-day discharge. Early identification of patients with stable LBBB can help facilitate same-day discharge. We aim to assess the role of 6-hour ECG to determine development of LBBB in patients undergoing TAVI. Methods: This is a prospective single-centre study of patients who have LBBB following elective TAVI procedures. All patients underwent ECGs pre-TAVI, as well as immediately, 6 h, and 24 h post-TAVI. Changes in ECG were compared at 6 and 24 h with the one immediately post TAVI. Results: The study included 115 patients with uncomplicated procedures. The mean age was 81 ± 7 years, with 54% male. A self-expanding valve was used in 67% of patients. Following TAVI, prolongations of PR interval and QRS duration were dynamic and reduced at 6 h. The change in PR interval at 6 and 24 h was comparable [−11 (−20 to 3) vs. −2 (−24 to 16) ms, p = 0.18]. Similarly, there was no statistical difference in the change of QRS duration at 6 and 24 h compared to the ECG immediately post-TAVI [−10 (−40 to −2) vs. −7 (−34 to 0) ms, p = 0.055]. Changes in ECG were also comparable in patients undergoing balloon-expandable and self-expanding valves. Conclusions: The current study supports that 6-hour ECG has the potential to reduce the need for prolonged continuous monitoring post-TAVI. ECG at 6 h can help optimise patient flow and facilitate early discharge. Future studies with larger sample sizes are required to confirm our findings. Full article

Left ventricular systolic dysfunction (LVSD) is associated with increased mortality and is sometimes reversible when found early. Artificial intelligence (AI)-enabled electrocardiogram (ECG) has emerged as an efficient screening tool for LVSD, but has not been validated in left bundle branch block (LBBB) patients. The clinical significance of developing an AI prediction model for LBBB patients lies in the fact that LBBB can be a cause, consequence, or both of LVSD. This pilot study was designed to develop an AI model for LVSD detection in the LBBB population using a limited dataset. ECG data from 508 patients with sinus rhythm and LBBB were labeled based on an LVSD threshold of 35%. To enhance the performance of a model derived from such a small and skewed dataset, we combined an autoencoder-based anomaly detection model with a convolutional neural network (CNN). We used a lead-wise ensemble technique for the final classification. Experimental results showed an accuracy of 0.81, precision of 0.87, recall of 0.56, and an area under the receiver operating characteristic curve of 0.75 in LVSD prediction among LBBB patients. Despite the limited dataset size, our study findings suggest the potential of deep learning techniques in detecting LVSD in patients with LBBB. Full article

Background/Objectives: Transcatheter aortic valve replacement (TAVR) has been introduced as an optimal treatment for patients with severe aortic stenosis, offering a minimally invasive alternative to surgical aortic valve replacement. Predicting these outcomes following TAVR is crucial. Artificial intelligence (AI) has emerged as a promising tool for improving post-TAVR outcome prediction. In this systematic review and meta-analysis, we aim to summarize the current evidence on utilizing AI in predicting post-TAVR outcomes. Methods: A comprehensive search was conducted to evaluate the studies focused on TAVR that applied AI methods for risk stratification. We assessed various ML algorithms, including random forests, neural networks, extreme gradient boosting, and support vector machines. Model performance metrics—recall, area under the curve (AUC), and accuracy—were collected with 95% confidence intervals (CIs). A random-effects meta-analysis was conducted to pool effect estimates. Results: We included 43 studies evaluating 366,269 patients (mean age 80 ± 8.25; 52.9% men) following TAVR. Meta-analyses for AI model performances demonstrated the following results: all-cause mortality (AUC = 0.78 (0.74–0.82), accuracy = 0.81 (0.69–0.89), and recall = 0.90 (0.70–0.97); permanent pacemaker implantation or new left bundle branch block (AUC = 0.75 (0.68–0.82), accuracy = 0.73 (0.59–0.84), and recall = 0.87 (0.50–0.98)); valve-related dysfunction (AUC = 0.73 (0.62–0.84), accuracy = 0.79 (0.57–0.91), and recall = 0.54 (0.26–0.80)); and major adverse cardiovascular events (AUC = 0.79 (0.67–0.92)). Subgroup analyses based on the model development approaches indicated that models incorporating baseline clinical data, imaging, and biomarker information enhanced predictive performance. Conclusions: AI-based risk prediction for TAVR complications has demonstrated promising performance. However, it is necessary to evaluate the efficiency of the aforementioned models in external validation datasets. Full article

Background and Objectives: The role of biventricular pacing (BVP) is less well-established in patients with heart failure with reduced ejection fraction (HFrEF) without left bundle branch block (LBBB). Conduction system pacing (CSP) has gained significant traction and may provide a safe and more physiological alternative to BVP in these patients. A few small studies studying this question have reported conflicting results. This meta-analysis aims to compare procedural and clinical outcomes between CSP and BVP in this group. Materials and Methods: An online literature search was systematically conducted to retrieve studies comparing CSP and BVP in HFrEF patients with non-LBBB. Four studies with 461 patients were included. Results: Implant-derived paced QRS duration was significantly shorter (mean difference [MD] −19.7 ms, 95% confidence interval [CI] −36.2 to −3.3, p = 0.0355) with CSP. Echocardiographic response with significantly greater improvement in left ventricular ejection fraction (MD 5.6%, 95% CI 3.1 to 8.0, p = 0.0106) was also observed with CSP. There were no statistically significant differences in clinical outcomes such as all-cause mortality (relative risk [RR] 0.53, 95% CI 0.18 to 1.60, p = 0.133) and heart failure hospitalization (RR 0.54, 95% CI 0.19 to 1.56, p = 0.129). Conclusions: This meta-analysis suggests that CSP may have better electrical synchrony and echocardiographic response compared to BVP in HFrEF patients with non-LBBB. Further randomized studies with longer follow-up may be required to elucidate potential benefits in clinical outcomes. Full article

Transcatheter aortic valve replacement (TAVR) is now established as a safe and effective treatment for severe aortic stenosis across all surgical risk categories. Nevertheless, periprocedural conduction disturbances—including new-onset left bundle branch block (LBBB), right bundle branch block (RBBB), and other intraventricular blocks—remain among the most frequent complications, often resulting in permanent pacemaker (PPM) implantation and impacting left ventricular remodeling. A review was conducted using the PubMed/MEDLINE database. Relevant clinical trials, observational studies, and meta-analyses addressing post-TAVR LBBB were included and analysed with a focus on frequency, risk factors, and association with adverse outcomes. We describe the incidence of post-TAVR conduction disturbances and identify key predictors: pre-existing RBBB, membranous septum length, valve oversizing, implantation depth, infra-annular leaflet extension, compression ratio, and valve type/generation. New-onset LBBB is a frequent complication after TAVR and may negatively affect patient outcomes. Accurate risk stratification and standardised post-procedural monitoring protocols are essential. Further prospective studies are needed to better define management strategies for patients developing LBBB after TAVR. Full article

Background/Objectives: Although cardiac resynchronization therapy (CRT) plays an established role in the management of heart failure, a significant proportion of patients do not respond despite appropriate candidate selection. The optimization of CRT pacing is one strategy to enhance response. Fusion pacing algorithms aim to synchronize intrinsic right ventricular (RV) conduction with paced left ventricular (LV) activation, resulting in a more physiological ventricular depolarization pattern. This approach may improve electrical synchrony and enhance left ventricular contraction compared to conventional simultaneous biventricular pacing. The aim of this study was to compare the acute, beat-to-beat effects of standard biventricular pacing versus fusion pacing on myocardial function, using both conventional and speckle-tracking echocardiography in heart failure patients with left bundle branch block (LBBB). Methods: In total, 27 heart failure patients (21 men and 6 women) with reduced ejection fraction (EF < 35%), left bundle branch block (QRS > 150 ms), and newly implanted CRT-D systems (Abbott) underwent echocardiographic assessment immediately after device implantation. Echocardiographic parameters—including left atrial strain, left ventricular strain, TAPSE, mitral and tricuspid valve function, and cardiac output—were measured at 5 min intervals under three different pacing conditions: pacing off, simultaneous biventricular pacing, and fusion pacing using Abbott’s SyncAV^® algorithm. Results: In our study, CRT led to a significant shortening of the QRS duration from 169 ± 19 ms at baseline to 131 ± 17 ms with standard biventricular pacing, and further to 118 ± 16 ms with fusion pacing (p < 0.05). Despite the electrical improvement, no significant changes were observed in global longitudinal strain (GLS: −9.15 vs. −9.39 vs. −9.13; p = NS), left ventricular stroke volume (67.5 mL vs. 68.4 mL vs. 68.5 mL; p = NS), or left atrial parameters including strain, area, and ejection fraction. However, fusion pacing was associated with more homogeneous segmental strain patterns, improved aortic valve closure time, and enhanced right ventricular function as reflected by tissue Doppler-derived S’. Conclusions: Immediate QRS narrowing observed in CRT patients—particularly with fusion pacing optimization—is associated with a more homogeneous pattern of left ventricular contractility and improvements in selected measures of mechanical synchrony. However, these acute electrical changes do not translate into immediate improvements in stroke volume, global LV strain, or left atrial function. Longer-term follow-up is needed to determine whether the electrical benefits of CRT, especially with fusion pacing, lead to meaningful hemodynamic improvements. Full article

Background: Transcatheter aortic valve replacement (TAVR) has become the preferred treatment for severe aortic stenosis in high- and intermediate-risk patients, with expanding indications for lower-risk populations. However, post-procedural complications, such as stroke, conduction disturbances, and heart failure readmissions, remain concerns. The aim of our study is to analyze the national trends in TAVR procedures, in-hospital outcomes, major readmission causes, and the association of risk factors for readmissions following TAVR. Methods: We analyzed NIS data (2018–2022) to assess TAVR utilization trends, patient demographics, and in-hospital outcomes. The NRD (2021–2022) was used to evaluate 60-day readmission rates for stroke, complete heart block, and heart failure. Multivariate regression models were employed to identify risk factors having significant association with major readmission causes. Results: TAVR utilization increased from 10,788 cases in 2018 to 17,784 in 2022, with a concurrent decrease in in-hospital mortality (1.33% to 0.90%) and length of stay (3.88 to 2.97 days). Of 123,376 TAVR index admissions in 2021, 28,654 patients had 66,100 readmission events (53.57%) in the 60 days following discharge. Heart failure (17,566 cases, 26.57% of readmissions) was the most common readmission cause, followed by complete heart block (1760 cases, 2.66% of readmissions) and stroke (284 cases, 0.42% of readmissions). Predictors of post-TAVR stroke included uncontrolled hypertension (OR 2.29, p < 0.001) and chronic heart failure (OR 2.73, p < 0.001). Left bundle branch block (LBBB) was strongly associated with complete heart block (OR 12.89, p < 0.001) and heart failure readmissions (OR 7.65, p < 0.001). Conclusions: TAVR utilization has increased with improving perioperative outcomes, but post-TAVR readmissions remain significant, particularly for heart failure, stroke, and conduction disturbances. Pre-procedural uncontrolled hypertension, hyperlipidemia, congestive heart failure, and atrial fibrillation were risk factors with significant association with stroke in the 60 days following TAVR. The presence of documented pre-procedural LBB, RBB, as well as BFB were risk factors with significant association with complete heart block following TAVR placements. Pre-procedural LBB, RBB, BFB, and atrial fibrillation were risk factors having significant association with heart failure readmissions in the 60 days following TAVR. Full article

Left bundle branch block (LBBB), initially described in the early 20th century, has become increasingly recognized as one of the leading causes of advanced heart failure (HF). In addition to rapidly growing data on guideline-directed medical therapy, cardiac resynchronization therapy (CRT) via transvenous coronary sinus lead has been the gold-standard therapy, but one-third of the indicated patients do not receive the expected benefits. Recently, cardiac conduction system pacing (CSP) was identified as an alternative to traditional CRT strategy, and multiple data have been published during the last few years. This review will discuss the diagnostic criteria of LBBB and its relation to the development of HF and review available data for traditional CRT as well as CSP in depth. Full article

Cardiac resynchronization therapy (CRT) using biventricular (BiV) pacing is the standard treatment for heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF) and electrical dyssynchrony. However, one in three patients remains a non-responder. Left bundle branch area pacing (LBBAP) could represent a more physiological alternative, but its effectiveness is limited in cases of atypical left bundle branch block (LBBB) or intraventricular conduction delay (IVCD). Left Bundle Branch Pacing Optimized cardiac resynchronization therapy (LOT-CRT) integrates LBBAP with coronary sinus (CS) lead pacing to improve electrical synchrony and clinical outcomes. This review evaluates the feasibility, advantages, disadvantages, and clinical outcomes of LOT-CRT. Additionally, we describe our center’s experience and propose an evidence-based implantation algorithm. A review of published studies investigating LOT-CRT was conducted, comparing its effectiveness with BiV-CRT and LBBAP alone using QRS narrowing, LVEF improvement, left ventricular remodeling, New York Heart Association (NYHA) class changes and NT-proBNP levels. It was found that LOT-CRT outperforms BiV-CRT or LBBAP alone in selected populations, at the cost of higher clinical skills, longer procedural times, and specific device setups. Randomized trials are underway to further define its role in clinical practice. Full article

Background: While left-bundle-branch-block-related contraction patterns as well as echocardiography-derived strain are variably associated with the volumetric response to cardiac resynchronization therapy (CRT), the role of CMR-derived strain parameters is unexplored. Methods: A total of 50 patients receiving CRT implantation were retrospectively analyzed, all of whom had undergone CMR imaging within one year before, and echocardiography within 6 months before and 6–12 months after CRT implantation. We assessed CMR-derived morphological and functional parameters with regard to the echocardiographic response, defined as a reduction in the left ventricular end-systolic volume of ≥15%. Results: Among the standard CMR parameters, the indexed right ventricular volumes in end-diastole (RVEDVi) (74.5 ± 19.5 vs. 94.8 ± 30.2 mL/m², p = 0.006) and end-systole (RVESVi) (43.2 ± 13.3 vs. 61.6 ± 28.8 mL/m², p = 0.003), as well as the left atrial (LA) area (24.8 ± 3.5 vs. 30.4 ± 9.5 cm², p = 0.020), differed significantly between CRT responders and non-responders. In strain analysis, CRT responders showed a significantly better LA global longitudinal strain (GLS) (25.1 ± 10.4 vs. 15.3 ± 10.5, p = 0.002), LA global circumferential strain (GCS) (27.9 ± 14.7 vs. 17.1 ± 13.1%, p = 0.012), RV GLS (−25.0 ± 6.5 vs. −18.9 ± 7.6%, p = 0.004) and RV free wall strain (−31.1 ± 7.9 vs. −24.9 ± 9.5, p = 0.017). Conclusions: CMR-derived peak septal circumferential strain and RVEDVi correlated with the echocardiographic volumetric response to CRT at 6–12 months. Full article

Electrical and mechanical dyssynchrony (MD) underlies left ventricular (LV) contractile dysfunction in patients with heart failure (HF) and left bundle branch block (LBBB). In some cases, cardiac resynchronization therapy (CRT) almost completely reverses LV contractile dysfunction. The LBBB electrocardiographic Strauss criteria and MD assessment were proposed to improve CRT response. However, using these techniques separately does not improve LV contraction in 20–40% of patients after CRT device implantation. We aimed to evaluate whether the combined use of electrocardiography (ECG), speckle-tracking echocardiography (STE) and cardiac scintigraphy could improve the prognosis of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. The study prospectively included patients with HF, classified as New York Heart Association (NYHA) functional class (FC) II–III in sinus rhythm with Strauss LBBB criteria and reduced left ventricular ejection fraction (LVEF). Before and 6 months after CRT device implantation, ECG, STE and cardiac scintigraphy were performed. The study’s primary endpoint was the NYHA class improvement ≥ 1 and left ventricle end systolic volume decrease > 30% or LVEF improvement > 15% after 6 months of CRT. Based on collected data, we developed a prognostic model regarding the CRT super-response. Out of 54 (100.0%) patients, 39 (72.2%) had a CRT super-response. Patients with CRT super-response were likelier to have a greater S wave amplitude in V₂ lead (p = 0.004), higher rates of global longitudinal strain (GLS) (p = 0.001) and interventricular delay (IVD) (p = 0.005). Only three indicators (S wave amplitude in V₂ lead, GLS and IVD) were independently associated with CRT super-response in univariable and multivariable logistic regression. We created a prognostic model based on the logistic equation and calculated a cut-off value (>0.73). The resulting ROC curve revealed a discriminative ability with an AUC of 0.957 (sensitivity 87.2%; specificity 100.0%). The electrical and mechanical dyssynchrony assessment using ECG, STE and cardiac scintigraphy is useful in the prediction of CRT super-response in patients with HF and Strauss LBBB criteria during a 6-month follow-up period. Our prognostic model can identify patients who are super-responders to CRT. Full article

Background/Objectives: COVID-19 is associated with multiple systemic effects, including cardiovascular complications. However, its interplay with cardiac conduction abnormalities remains underexplored. We compared the clinical profile of COVID-19 patients with pre-existing left bundle branch block (LBBB) or right bundle branch block (RBBB) at hospital admission. Methods: This study included 100 COVID-19 patients with antecedent BBB (50 LBBB, 50 RBBB). Critical cardiometabolic, renal, hematological, and inflammatory markers were measured. Logistic regression was used to identify key predictors differentiating COVID-19 patients with LBBB and RBBB. Spearman’s correlations were applied to assess intra-strata associations for these variables. Results: COVID-19 patients with LBBB patients were significantly more likely to display lower systolic blood pressure (p = 0.012) but greater left atrial size (p = 0.008), left ventricular diameter (p = 0.001), and interventricular septal thickness (p = 0.023). Hematological and inflammatory markers differed, with LBBB patients being prone to exhibit higher red cell distribution width (p = 0.005), lymphocyte count (p < 0.001), neutrophil count (p = 0.045), and C-reactive protein (p < 0.001). This group also tended to show lower erythrocyte sedimentation rate (p = 0.013) and glycated hemoglobin (p = 0.045) but higher random glucose (p = 0.014). Absolute lymphocyte count, C-reactive protein, and left ventricular diameter were the most robust predictors distinguishing LBBB from RBBB. Significant associations were found exclusively for LBBB, all of them being weak. These predominantly negative relationships indicated an inflammatory origin, and most of them occurred for lymphocyte count. Conclusions: COVID-19 patients with LBBB and RBBB present distinct clinical profiles at hospital admission. The former group demonstrates a more adverse baseline clinical profile, particularly in terms of cardiac and inflammatory markers. These findings suggest that pre-existing BBB type may influence disease progression, potentially helping in risk stratification for COVID-19 patients. Full article

Heart failure with reduced ejection fraction due to ischemic cardiomyopathy remains a significant clinical challenge. Electrical conduction delays exacerbate symptoms by causing uncoordinated contractions, reducing pumping efficiency, and increasing mortality. Right ventricular pacing further worsens dyssynchrony, while resynchronization therapy improves outcomes but has a high non-responder rate. Given these limitations, bundle branch pacing engages the heart’s conduction system, restoring synchronized contraction and enhancing cardiac function. This review examines the impact of left-bundle-branch-block-induced dyssynchrony, the role of advanced imaging in assessing ventricular function, and the clinical outcomes of bundle branch pacing in heart failure patients. Specifically, we explore the mechanical and hemodynamic effects of left bundle branch block, imaging techniques for dyssynchrony evaluation, and the comparative benefits of bundle branch pacing versus resynchronization therapy. Conduction delays impair function, increase myocardial stress, and worsen clinical outcomes. Advanced imaging plays a critical role in patient selection, identifying those most likely to benefit from conduction system pacing. By restoring electrical coordination, bundle branch pacing enhances ventricular function, reduces hospitalizations, and promotes reverse remodeling. It offers similar or superior benefits to conventional resynchronization therapy, regulates stress hormones, reduces oxidative damage, and improves calcium handling. Bundle branch pacing represents a significant advancement in heart failure management, but careful patient selection remains crucial. Future research should focus on optimizing implantation techniques and validating long-term benefits through large-scale clinical trials. Full article