AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Managing the Intricacies of Coronary Revascularization: A Close Look at the Complete Versus Culprit-Only Approach and its Implications in Elderly Patients

Coronary heart disease is the leading cause of mortality in the United States, and data indicates that 805,000 Americans will face a new or recurrent myocardial infarction (MI) attack every year. Frailty, a conceptual syndrome categorized by a functional decline that occurs with aging, has been linked to adverse health outcomes in cardiovascular disease and all cardiac-related procedures in general. It is therefore reasonable to deliberate that more conservative medical therapy or medical management should be considered in the frail population when managing acute coronary syndrome. This course of action has, in fact, been documented in clinical practice. However, the recent Functional Assessment in Elderly MI Patients with Multivessel Disease trial, in which all subjects were 75 years of age or above, indicated that the more invasive complete revascularization approach may be favorable over incomplete or culprit-only revascularization in patients with acute MI. In this review, we will discuss coronary heart disease and review guidelines and procedures for culprit lesion identification, including electrocardiogram procedures, coronary angiography, intravascular ultrasound, fractional flow reserve, and instantaneous fractional flow reserve. We then discuss the concept of complete vs culprit-only/incomplete coronary revascularization and staging. Following this, we will delve into recent trials discussing complete vs culprit-only revascularization, emphasizing the insights gleaned from this latest trial within this special frailty cohort which warrants special consideration.

ST-segment depression and left ventricular systolic function recovery post-atrial fibrillation ablation in heart failure

AIMS

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF). The impact of ST-segment depression before CA on LVEF recovery and clinical outcomes remains unknown. In the present study, we aimed to investigate the relationship between ST-segment depression during AF rhythm before CA and improvement in the LVEF and clinical outcomes in persistent atrial fibrillation (PerAF) patients with HFrEF.

METHODS AND RESULTS

The present study included 122 PerAF patients (male; 98 patients, 80%, mean age: 69 [56, 76] years) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry who had LVEF < 50% and underwent an initial ablation. The patients who underwent percutaneous coronary intervention or coronary artery bypass grafting within the past 1 month were not included in the enrolled patients. We assigned the patients based on the presence of ST-segment depression before CA during AF rhythm and evaluated improvement in the LVEF (LVEF ≥ 15%) 1 year after CA and the relationship between ST-segment depression and heart failure (HF) hospitalization/major adverse cardiovascular events (MACE), which are defined as a composite of HF hospitalization, cardiovascular death, hospitalization due to coronary artery disease, ventricular arrhythmia requiring hospitalization and stroke. The percentage of patients with improvement in the LVEF 1 year after CA was significantly lower in the patients with ST-segment depression than those without (58.6% vs. 79.7%, P = 0.012). Multiple regression analysis showed ST-segment depression was independently and significantly associated with improvement in the LVEF 1 year after CA (HR: 0.35; 95% CI: 0.129-0.928, P = 0.035). Kaplan-Meier analysis showed that the patients with ST-segment depression significantly had higher risk of HF hospitalization and MACE than those without (log rank P = 0.022 and log rank P = 0.002, respectively). Multivariable Cox proportional hazards analysis showed that ST-segment depression was independently and significantly associated with a higher risk of MACE (HR: 2.82; 95% CI: 1.210-6.584, P = 0.016).

CONCLUSIONS

ST-segment depression before CA during AF rhythm was useful prognostic predictor of improvement in the LVEF and clinical outcomes including HF hospitalization and MACE in PerAF patients with HFrEF.

Clinical significance and prognostic value of right bundle branch block in permanent pacemaker patients

AIMS

In patients undergoing pacemaker implantation with no prior history of heart failure (HF), the presence of left bundle branch block (LBBB) has been identified as an independent predictor of HF-related death or hospitalization, while the prognostic significance of right bundle branch block (RBBB) remains uncertain. We aimed to assess the long-term risk of all-cause mortality in patients with a standard indication for permanent pacing and normal or moderately depressed left ventricular function when RBBB is detected at the time of implantation.

METHODS

We retrospectively enrolled 1348 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center, from January 1990 to December 2022. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded.

RESULTS

The baseline 12-lead electrocardiogram revealed an RBBB in 241 (18%) and an LBBB in 98 (7%) patients. During a median follow-up of 65 [25th-75th percentile: 32-117] months, 704 (52%) patients died. The combined endpoint of cardiovascular death or HF hospitalization was reached by 173 (13%) patients. On multivariate analysis, RBBB was confirmed as an independent predictor of death [hazard ratio, 1.33; 95% confidence interval (CI), 1.09-1.63; P  = 0.005]. However, when considering the combined endpoint of cardiovascular death and HF hospitalization, this endpoint was independently associated with LBBB (hazard ratio, 2.13; 95% CI, 1.38-3.29; P  < 0.001), but not with RBBB.

CONCLUSION

In patients with standard pacemaker indications and normal or moderately depressed left ventricular function, the presence of basal RBBB was an independent predictor of mortality. However, it was not associated with the combined endpoint of cardiovascular death and HF hospitalization.

Determinants/Predictors of QT Abnormalities in Patients on Psychotropic Medications in a Nigerian Tertiary Hospital

Cardiovascular disease is a major global burden and a leading cause of premature death among patients with severe mental illness. Over time, research and clinical practice have paid increased attention to the impact of psychiatric medications on cardiac repolarization. In a resource-limited setting, it is common for psychotropic medications to be initiated and maintained in an outpatient setting without baseline or follow up ECG. This study evaluated the determinants and predictors of QT abnormalities among patient taking psychotropic drugs. We conducted a cross-sectional study in a population of 150 psychiatric patients on psychotropics and 75 controls. We studied the effects of various psychotropic drugs on QT dispersion (QTd) and corrected QT interval (QTc) as well as correlation with the types and dosages of psychotropic drugs used. All the subjects had detailed clinical examination and resting electrocardiogram (ECG) at 25 mm/sec done. QTc was determined using Bazett formula and QTd was determined by subtracting shortest from longest QT in 12-lead ECG. The prevalence of prolonged QTc and QTd as well as the mean QTc and QTd were significantly higher in patients than the control group. The mean QTc was significantly higher in patient on typical antipsychotics compared to those on atypical antipsychotics. Age, heart rate and antipsychotic dose in chlorpromazine equivalent were predictors of QTc with the heart rate being the most powerful predictor among them. Psychotropic drugs use is associated with QTc and QTd prolongation with age, heart rate and antipsychotic dose as predictors of QTc.

Electrocardiographic abnormalities and NT-proBNP levels at long-term follow-up of patients with dyspnea after pulmonary embolism

OBJECTIVES

Electrocardiogram (ECG) and measurement of plasma brain natriuretic peptides (BNP) are established markers of right ventricular dysfunction (RVD) in the setting of acute pulmonary embolism (PE) but their value at long-term follow-up is largely unknown. The purpose of this prospective study was to determine the prevalence of ECG abnormalities, describe levels of N-terminal proBNP (NT-proBNP), and establish their association with dyspnea at long-term follow-up after PE.

DESIGN

All Swedish patients diagnosed with acute PE in 2005 (n = 5793) were identified through the Swedish National Patient Registry. Surviving patients in 2007 (n = 3510) were invited to participate. Of these, 2105 subjects responded to a questionnaire about dyspnea and comorbidities. Subjects with dyspnea or risk factors for development of chronic thromboembolic pulmonary hypertension were included in the study in a secondary step, which involved collection of blood samples and ECG registration.

RESULTS

Altogether 49.3% had a completely normal ECG. The remaining participants had a variety of abnormalities, 7.2% had atrial fibrillation/flutter (AF). ECG with any sign of RVD was found in 7.2% of subjects. Right bundle branch block was the most common RVD sign with a prevalence of 6.4%. An abnormal ECG was associated with dyspnea. AF was associated with dyspnea, whereas ECG signs of RVD were not. 61.2% of subjects had NT-proBNP levels above clinical cut-off (>125 ng/L). The degree of dyspnea did not associate independently with NT-proBNP levels.

CONCLUSIONS

We conclude that the value of ECG and NT-proBNP in long term follow-up after PE lies mostly in differential diagnostics.

Explaining deep learning for ECG analysis: Building blocks for auditing and knowledge discovery

Deep neural networks have become increasingly popular for analyzing ECG data because of their ability to accurately identify cardiac conditions and hidden clinical factors. However, the lack of transparency due to the black box nature of these models is a common concern. To address this issue, explainable AI (XAI) methods can be employed. In this study, we present a comprehensive analysis of post-hoc XAI methods, investigating the glocal (aggregated local attributions over multiple samples) and global (concept based XAI) perspectives. We have established a set of sanity checks to identify saliency as the most sensible attribution method. We provide a dataset-wide analysis across entire patient subgroups, which goes beyond anecdotal evidence, to establish the first quantitative evidence for the alignment of model behavior with cardiologists' decision rules. Furthermore, we demonstrate how these XAI techniques can be utilized for knowledge discovery, such as identifying subtypes of myocardial infarction. We believe that these proposed methods can serve as building blocks for a complementary assessment of the internal validity during a certification process, as well as for knowledge discovery in the field of ECG analysis.

Paced QRS morphology mimicking complete left bundle branch block induced by right ventricular pacing is associated with pacing-induced cardiomyopathy

INTRODUCTION

Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing-induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development.

METHODS

We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB-like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%.

RESULTS

Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB-like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89-0.98, p = 0.006) and CLBBB-like paced QRS (OR: 2.69, 95% CI: 1.25-5.76, p = 0.011) were significantly associated with PICM development.

CONCLUSION

CLBBB-like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB-like QRS morphology, may need to be avoided, and patients with CLBBB-like paced QRS should be followed-up carefully.

A Revised Definition of Left Bundle Branch Block Using Time to Notch in Lead I

Importance

Current left bundle branch block (LBBB) criteria are based on animal experiments or mathematical models of cardiac tissue conduction and may misclassify patients. Improved criteria would impact referral decisions and device type for cardiac resynchronization therapy.

Objective

To develop a simple new criterion for LBBB based on electrophysiological studies of human patients, and then to validate this criterion in an independent population.

Design, Setting, and Participants

In this diagnostic study, the derivation cohort was from a single-center, prospective study of patients undergoing electrophysiological study from March 2016 through November 2019. The validation cohort was assembled by retrospectively reviewing medical records for patients from the same center who underwent transcatheter aortic valve replacement (TAVR) from October 2015 through May 2022.

Exposures

Patients were classified as having LBBB or intraventricular conduction delay (IVCD) as assessed by intracardiac recording.

Main Outcomes and Measures

Sensitivity and specificity of the electrocardiography (ECG) criteria assessed in patients with LBBB or IVCD.

Results

A total of 75 patients (median [IQR] age, 63 [53-70.5] years; 21 [28.0%] female) with baseline LBBB on 12-lead ECG underwent intracardiac recording of the left ventricular septum: 48 demonstrated complete conduction block (CCB) and 27 demonstrated intact Purkinje activation (IPA). Analysis of surface ECGs revealed that late notches in the QRS complexes of lateral leads were associated with CCB (40 of 48 patients [83.3%] with CCB vs 13 of 27 patients [48.1%] with IPA had a notch or slur in lead I; P = .003). Receiver operating characteristic curves for all septal and lateral leads were constructed, and lead I displayed the best performance with a time to notch longer than 75 milliseconds. Used in conjunction with the criteria for LBBB from the American College of Cardiology/American Heart Association/Heart Rhythm Society, this criterion had a sensitivity of 71% (95% CI, 56%-83%) and specificity of 74% (95% CI, 54%-89%) in the derivation population, contrasting with a sensitivity of 96% (95% CI, 86%-99%) and specificity of 33% (95% CI, 17%-54%) for the Strauss criteria. In an independent validation cohort of 46 patients (median [IQR] age, 78.5 [70-84] years; 21 [45.7%] female) undergoing TAVR with interval development of new LBBB, the time-to-notch criterion demonstrated a sensitivity of 87% (95% CI, 74%-95%). In the subset of 10 patients with preprocedural IVCD, the criterion correctly distinguished IVCD from LBBB in all cases. Application of the Strauss criteria performed similarly in the validation cohort.

Conclusions and Relevance

The findings suggest that time to notch longer than 75 milliseconds in lead I is a simple ECG criterion that, when used in conjunction with standard LBBB criteria, may improve specificity for identifying patients with LBBB from conduction block. This may help inform patient selection for cardiac resynchronization or conduction system pacing.

Electrocardiogram-based prediction of conduction disturbances after transcatheter aortic valve replacement with convolutional neural network

Aims

Permanent pacemaker implantation and left bundle branch block are common complications after transcatheter aortic valve replacement (TAVR) and are associated with impaired prognosis. This study aimed to develop an artificial intelligence (AI) model for predicting conduction disturbances after TAVR using pre-procedural 12-lead electrocardiogram (ECG) images.

Methods and results

We collected pre-procedural 12-lead ECGs of patients who underwent TAVR at West China Hospital between March 2016 and March 2022. A hold-out testing set comprising 20% of the sample was randomly selected. We developed an AI model using a convolutional neural network, trained it using five-fold cross-validation and tested it on the hold-out testing cohort. We also developed and validated an enhanced model that included additional clinical features. After applying exclusion criteria, we included 1354 ECGs of 718 patients in the study. The AI model predicted conduction disturbances in the hold-out testing cohort with an area under the curve (AUC) of 0.764, accuracy of 0.743, F1 score of 0.752, sensitivity of 0.876, and specificity of 0.624, based solely on pre-procedural ECG images. The performance was better than the Emory score (AUC = 0.704), as well as the logistic (AUC = 0.574) and XGBoost (AUC = 0.520) models built with previously identified high-risk ECG patterns. After adding clinical features, there was an increase in the overall performance with an AUC of 0.779, accuracy of 0.774, F1 score of 0.776, sensitivity of 0.794, and specificity of 0.752.

Conclusion

Artificial intelligence-enhanced ECGs may offer better predictive value than traditionally defined high-risk ECG patterns.

Prevalence and Clinical Significance of Intraventricular Conduction Disturbances in Hospitalized Children

Introduction: Data on the prevalence and clinical significance of interventricular conduction disturbances (IVCDs) in children are scarce. While incomplete right bundle branch blocks (IRBBBs) seem to be the most frequent and benign findings, complete bundle blocks and fascicular blocks are often seen in children with congenital/acquired cardiac conditions. This study aims to delineate the prevalence and the diagnostic accuracy of IVCD in children admitted to a paediatric cardiology unit. Methods: Children admitted to the paediatric cardiology unit between January 2010 and December 2020 who had an ECG were included in the study. IVCDs were diagnosed according to standard criteria adjusted for age. Results: Three thousand nine hundred and ninety-three patients were enrolled. The median age was 3.1 years (IQR: 0.0-9.2 years), and 52.7% were males. IVCDs were present in 22.5% of the population: 17.4% of the population presented with IRBBBs, 4.8% with a complete right bundle branch block (CRBBB), 0.1% with a complete left bundle branch block (CLBBB), 0.2% with a left anterior fascicular block (LAFB) and 0.2% with a combination of CRBBB and LAFB. Also, 26% of children with congenital heart disease had an IVCD, and 18% of children with an IVCD had previous cardiac surgery. The overall sensitivity of IVCD in detecting a cardiac abnormality was 22.2%, with a specificity of 75.5%, a PPV of 83.1% and an NPV of 15.1%, but the values were higher for CLBBB and LAFB. Conclusions: IVCDs were present in one-fifth of children admitted to the cardiology unit. IRBBB was the most frequent disturbance, while CRBBB, CLBBB and fascicular blocks were much rarer, though they had a higher predictive value for cardiac abnormalities.

Left bundle branch block-induced dilated cardiomyopathy: Definitions, pathophysiology, and therapy

Left bundle branch block (LBBB) is a frequent finding in patients with heart failure (HF), particularly in those with dilated cardiomyopathy (DCM). LBBB has been commonly described as a consequence of DCM development. However, a total recovery of left ventricular (LV) function after cardiac resynchronization therapy (CRT), observed in patients with LBBB and DCM, has led to increasing acknowledgement of LBBB-induced dilated cardiomyopathy (LBBB-iDCM) as a specific pathological entity. Its recognition has important clinical implications, as LBBB-iDCM patients may benefit from an early CRT strategy rather than medical HF therapy only. At present, there are no definitive diagnostic criteria enabling the universal identification of LBBB-iDCM, and no defined therapeutic approach in this subgroup of patients. This review compiles the main findings about LBBB-iDCM pathophysiology and the current proposed diagnostic criteria and therapeutic approach.

Outcomes with T-wave discordance of left bundle branch block and preserved or mildly reduced ejection fraction

AIMS

Left bundle branch block (LBBB) is associated with an increased risk of adverse outcomes for patients with heart failure. The prognosis of LBBB in patients with a preserved ejection fraction (EF) remains controversial. This study investigated the predictive value of T-wave discordance for the prognosis of patients with LBBB and preserved or mildly reduced EF.

METHODS AND RESULTS

We enrolled 707 patients with complete LBBB and left ventricular (LV) EF ≥ 40% observed using electrocardiograms (ECGs) and echocardiograms between January 2010 and December 2018. Their serial ECGs were reviewed during the follow-up period. The T-wave pattern was classified as discordant LBBB (dLBBB) or concordant LBBB (cLBBB) according to the 12-lead ECG T-wave morphology. The primary outcome was the composite of cardiovascular death or hospitalization for heart failure during a median follow-up period of 3.1 years. A multivariable Cox regression analysis was used to evaluate the independent predictors of the primary outcome. Patients with dLBBB had more comorbidities, a higher heart rate, a longer QRS and QTc duration, a larger LV end-systolic volume and left atrial dimension, a lower LVEF, and a higher mitral E/A ratio and E/e', compared with those with cLBBB. Older age [hazard ratio (HR) = 1.023, 95% confidence interval (CI) = 1.001-1.046, P = 0.023], history of heart failure (HR = 2.440, 95% CI = 1.524-3.905, P = 0.001), chronic kidney disease (HR = 1.917, 95% CI = 1.182-3.110, P = 0.008), larger LV end-systolic volume (HR = 1.046, 95% CI = 1.017-1.075, P = 0.002), lower LVEF (HR = 0.916, 95% CI = 0.885-0.948, P = 0.001), and presence of dLBBB (HR = 1.63, 95% CI = 1.011-2.628, P = 0.032) were independent predictors of the primary outcome in patients with LBBB and LVEF ≥ 40%. The discordant or concordant T-wave morphology of LBBB could transform from one subtype to the other in up to 23% of the study population during the follow-up period, and individuals with persistent or transformed dLBBB faced an increased risk of cardiovascular death or non-fatal heart failure hospitalization.

CONCLUSIONS

In patients with LBBB and EF ≥ 40%, dLBBB serves as an independent predictor of a higher risk of cardiovascular death or non-fatal heart failure hospitalization.

Association of abnormalities in electrocardiography and ultrasonic echocardiography with the occurrence of cardiovascular disease in patients with advanced chronic kidney disease

BACKGROUND

In patients with chronic kidney disease (CKD), the incidence of cardiovascular disease (CVD) increases with disease progression. CVD screening tests in those with CKD were researched to determine whether abnormalities observed in electrocardiography (ECG) and ultrasonic echocardiography (UCG) were risk factors associated with the development of CVD.

METHODS

This study included 604 patients with CKD G4 and G5, for whom both ECG and UCG were performed. They were divided into four groups: those without ECG- and UCG-indicated abnormalities (group A, n = 333), with only ECG abnormalities (group B, n = 106), with only UCG abnormalities (group C, n = 75), and with both ECG and UCG abnormalities (group D, n = 90). Multivariate analysis using Cox regression analysis of the occurrence of CVD was performed during a follow-up period.

RESULTS

During the observation period, 124 patients had clinical events. Among them, 45 patients (13.5%) were in Group A, 25 patients (23.6%) in Group B, 19 patients (25.3%) in Group C, and 35 patients (38.9%) in Group D, respectively. CVD event occurrence was highest in Group D. The results of the multivariate analysis also showed that the CVD event rates were significantly higher in Group C (HR: 2.96, P = < .001) and D (HR: 4.22, P < .001) than in Group A.

CONCLUSION

In patients with advanced CKD, there was a significant correlation of ECG and UCG abnormalities with CVD events. Additionally, those having both types of abnormalities may have a higher risk of coronary artery disease than other groups.

Pre-Existing Left Bundle Branch Block and Clinical Outcomes After Transcatheter Aortic Valve Replacement

Background

Few reports on pre-existing left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve replacement (TAVR) are currently available. Further, no present studies compare patients with new onset LBBB with those with pre-existing LBBB.

Objectives

This study aimed to investigate the association between pre-existing or new onset LBBB and clinical outcomes after TAVR.

Methods

Using data from the Japanese multicenter registry, 5,996 patients who underwent TAVR between October 2013 and December 2019 were included. Patients were classified into 3 groups: no LBBB, pre-existing LBBB, and new onset LBBB. The 2-year clinical outcomes were compared between 3 groups using Cox proportional hazards models and propensity score analysis to adjust the differences in baseline characteristics.

Results

Of 5,996 patients who underwent TAVR, 280 (4.6%) had pre-existing LBBB, while 1,658 (27.6%) experienced new onset LBBB. Compared with the no LBBB group, multivariable Cox regression analysis showed that pre-existing LBBB was associated not only with a higher 2-year all-cause (adjusted HR: 1.39; 95% CI: 1.06-1.82; P = 0.015) and cardiovascular (adjusted HR: 1.60; 95% CI: 1.04-2.48; P = 0.031) mortality, but also with higher all-cause (adjusted HR: 1.43, 95% CI: 1.07-1.91; P = 0.016) and cardiovascular (adjusted HR: 1.81, 95% CI:1.12-2.93; P = 0.014) mortality than the new onset LBBB group. Heart failure was the most common cause of cardiovascular death, with more heart failure deaths in the pre-existing LBBB group.

Conclusions

Pre-existing LBBB was independently associated with poor clinical outcomes, reflecting an increased risk of cardiovascular mortality after TAVR. Patients with pre-existing LBBB should be carefully monitored.

R-R' interval in the left bundle branch block predicts long-term outcomes after cardiac resynchronization therapy by estimating greater mechanical dyssynchrony and viable myocardium

BACKGROUND

Typical left bundle branch block (LBBB) shows 2 peaks of the R wave, which reflect activation reaching the interventricular septum (R) and posterolateral wall (R') sequentially.

OBJECTIVE

The purpose of this study was to investigate the relationship among R-R' interval (RR'), mechanical dyssynchrony, extent of viable myocardium, and long-term outcomes in cardiac resynchronization therapy (CRT) candidates.

METHODS

The study enrolled 49 patients (34 men; mean age: 69 ± 11 years) with LBBB who received CRT. The LBBB definition used requires the presence of mid-QRS notching in leads V1, V2, V5, V6, I, and aVL. Baseline evaluations were QRS duration (QRSd) and RR' measured from the 12-lead electrocardiogram; eyeball dyssynchrony (apical rocking and septal flash) and opposing-wall delay by speckle tracking from echocardiography, and extent of viable myocardium assessed by thallium-201 single-photon emission computed tomography. Primary outcomes included the combination of all-cause death and heart failure-related hospitalization.

RESULTS

RR' predicted volumetric response better than QRSd (area under the curve 0.73 vs 0.67, respectively). The long RR' group (≥48 ms) revealed more frequent eyeball dyssynchrony and significantly greater radial (SL) and circumferential dyssynchrony (AP and SL) and %viable segment than the short RR' group. In multivariate regression analysis, only RR' ≥48 ms was independently associated with higher event-free survival rates following CRT (hazard ratio 0.21; P = .014).

CONCLUSION

These findings suggest that RR' in complete LBBB was associated with mechanical dyssynchrony, extent of viable myocardium, and long-term outcomes following CRT.

Unlocking the potential of sacubitril/valsartan therapy in improving ECG and echocardiographic parameters in heart failure patients with reduced ejection fraction (HErEF)

BACKGROUND

Sacubitril/valsartan therapy has been found to reduce hospitalizations, improve echocardiogram parameters, and improve mortality in HFrEF. The objective is to assess S/V therapy effect on electrocardiogram indices and how those parameters related to echocardiographic parameters.

RESULTS

From June 2022 until June 2023, this prospective study enrolled 100 patients (mean age 56.1, 8.2, 78% male) with non-ischemic dilated cardiomyopathy (NIDCM) used PARADIGM-HF criteria: NYHA Class II, III, or IV HF; ejection fraction EF ≤ 40%; and hospitalization for HF within previous 12 months. Before starting S/V therapy, an echo and ECG were performed, as well as 6 months following the optimal dose and if LVEF was improved by more than 5%, they were termed notable S/V treatment responders. Aside from improving echo parameters, ECG parameters improved significantly. The QRS width was reduced from 123.7 ± 20.3 to 117.1 ± 18.8 ms (p 0.00), and QTc interval was reduced from 425.4 ± 32.8 to 421.4 ± 32.3 ms (p = 0.012). QRS width was significantly reduced in patients with LBBB, RBBB, and IVCD based on QRS morphology. QRS width (r = - 0.243, p = 0.016) and QTc (r = - 0.252, p = 0.012) had a negative connection with LVEF.

CONCLUSION

S/V therapy, in addition to improving echo parameters and NYHA class, improves QRS width and corrected QTc interval on ECG in HFrEF patients. This is an indication of reverse electrical LV remodeling and can be used as an auxiliary prediction for tracking therapy outcomes.

Left ventricular mechanical dispersion as a predictor of the need for pacemaker implantation after transcatheter aortic valve implantation: MeDiPace TAVI study

AIMS

Permanent pacemaker (PM) implantation is common after transcatheter aortic valve implantation (TAVI). Left ventricular mechanical dispersion (MeDi) by speckle tracking echocardiography is a marker of fibrosis that causes alterations in the conduction system. We hypothesized that MeDi can be a predictor of the need for PM implantation after TAVI.

METHODS AND RESULTS

Consecutively, 200 TAVI patients were enrolled. Transthoracic echocardiography and electrocardiography examinations were recorded before TAVI to evaluate global longitudinal strain (GLS), MeDi, and conduction disturbances. PM implantation information was obtained 3 months after TAVI. Patients were stratified into PM or no PM group. Mean age was 80 + 7 years (44% women). Twenty-nine patients (16%) received PM. MeDi, QRS duration, existence of right bundle branch abnormality (RBBB), and first-degree atrioventricular (AV) block were significantly different between groups. MeDi was 57 ± 15 ms and 48 ± 12 ms in PM and no PM groups, respectively (P < 0.001). In multivariate analysis, MeDi predicted the need for PM after TAVI independently of GLS, QRS duration, RBBB, and first-degree AV block [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.22-2.45] with an area under the curve (AUC) of 0.68 in receiver operating characteristic (ROC) curves. Moreover, RBBB was an independent predictor of PM need after TAVI (OR: 8.98, 95% CI: 1.78-45.03). When added to RBBB, MeDi had an incremental predictive value with an AUC of 0.73 in ROC curves (P = 0.01).

CONCLUSION

MeDi may be used as an echocardiographic functional predictor of the need for PM after TAVI.

[Clinical differences between transthyretin cardiac amyloidosis and hypertensive heart disease]

INTRODUCTION

A significant percentage of patients eventually diagnosed with cardiac transthyretin amyloidosis (TTRA) was previously diagnosed with hypertensive heart disease (HHD), since both conditions usually present with heart failure (HF) with preserved ejection fraction (HFpEF) and ventricular hypertrophy. Our objectives were to evaluate the clinical, electrocardiographic and echocardiographic differences, and to analyse whether there exists a differential prognosis between these two nosological entities.

MATERIALS AND METHODS

We retrospectively included all patients with HHD for whom a cardiac scintigraphy with 99mTc-diphosphonate (GDPD) and a free light chains test in blood and urine were ordered for ATTR screening in our centre, in the period between 2016 and 2021. Those diagnosed with other types of amyloidosis were excluded from the analysis.

RESULTS

A total of 72 patients were analyzed: 33 were finally diagnosed with TTRA and 39 with CHTA. Patients with TTRA had higher levels of ultrasensitive troponin I (TnI-US) and N-terminal brain natriuretic propeptide (NT-ProBNP); in electrocardiography (ECG) they presented a pseudo-infarction pattern more frequently as well as conduction disturbances; in echocardiography (TTE) they presented a higher degree of ventricular hypertrophy, left ventricular dysfunction and worse diastolic function parameters, with elevated filling pressures. In the 4-year follow-up, the ATTR group showed greater need for pacemaker (PCM), with no evidence regarding mortality, development of atrial fibrillation (AF), or more admissions for heart failure (HF).

CONCLUSIONS

In our series, patients with TTRA showed clinical, electrocardiographic and echocardiographic differences compared to patients with HHD, with increased risk of need for PCM.

Bradycardia risk stratification with implantable loop recorder after unexplained syncope

BACKGROUND

An implantable loop recorder is an effective tool for diagnosing unexplained syncope. However, after a first episode in non-high-risk patients, the usefulness of implantable loop recorder implantation remains unclear.

AIMS

To analyse relevant risk factors for significant bradycardia in order to identify patients who do or do not benefit from implantable loop recorder implantation. Also, to study whether implantable loop recorder implantation with remote monitoring is associated with less recurrence of traumatic syncope.

METHODS

This was a retrospective monocentric study including patients with implantable loop recorder implantation after unexplained syncope, using remote monitoring and iterative consultations.

RESULTS

Two hundred and thirty-seven patients were implanted for unexplained syncope. Significant bradycardia occurred in 53 patients (22.4%): 23 (43.4%) caused by paroxysmal atrioventricular block and 30 (56.6%) caused by sinus node dysfunction, leading to permanent pacemaker implantation in 48 patients. Compared with younger patients, there was a 3.46-fold increase (95% confidence interval 1.92-6.23; P<0.0001) in the risk of significant bradycardia in patients aged≥60 years. Based on multivariable analysis, only "typical syncope" was associated with significant bradycardia occurrence (hazard ratio 3.14, 95% confidence interval 1.75-5.65; P=0.0001). There was no recurrence of significant bradycardia with traumatic complications among patients implanted for traumatic syncope.

CONCLUSIONS

This study shows that: (1) implantable loop recorders identify more significant bradycardia in patients aged≥60 presenting with a first non-high-risk typical syncope, suggesting that an implantable loop recorder should be implanted after a first episode of unexplained syncope in such conditions; and (2) after traumatic syncope, implantable loop recorder implantation is safe, and is associated with little or no recurrence of traumatic syncope.

Comprehensive analysis of right fascicular and right bundle branch blocks: A multi-center study

Electrocardiographic patterns of right bundle branch and fascicular blocks were comprehensively analyzed in a two-phase study. The research aimed to address the scarcity of literature and the absence of standardized diagnostic criteria for these conditions. It revealed a weak correlation between the cardiac axis and age and highlighted the high misdiagnosis rate of these blocks. Furthermore, it discussed the challenges in fulfilling existing diagnostic criteria. The study emphasizes the need for a more precise understanding of right ventricular conduction disorders and the importance of developing robust diagnostic criteria.

Feasibility of Conduction System Pacing in Patients with Baseline Bundle Branch Block-A Single-Center Mid-Term Follow-Up Study

BACKGROUND

The primary prerequisite for a successful conduction system pacing (CSP) procedure is the integrity of the conduction system, which may be impaired if a baseline bundle branch block (BBB) is present. This study aimed to evaluate the feasibility and mid-term performance of permanent CSP in patients with baseline BBB and to compare the results between left bundle branch block (LBBB) and right bundle branch block (RBBB) patterns.

MATERIAL AND METHODS

A total of 101 patients with typical BBB and an attempt at CSP were retrospectively reviewed. Procedural characteristics, pacing, sensing parameters, and complications at baseline and after a mid-term follow-up were analyzed.

RESULTS

The global procedural success for CSP was 93%. His bundle pacing (HBP) had a significantly lower success rate than left bundle branch area pacing (LBBAP) (50.5% vs. 86%). The paced QRS duration was significantly narrower with HBP. The pacing and sensing thresholds were significantly better with LBBAP. Procedural complications occurred only in the LBBAP group (two acute perforations in the LV cavity and one acute chest pain during lead fixation) without long-term sequelae. The HBP and the LBBAP procedural success rates were higher in the RBBB versus the LBBB group (62.5% vs. 44.9% and 100% vs. 81.5%, respectively). Baseline QRS duration, atrial volumes, and right ventricular diameters were significantly associated with HBP procedural failure. The follow-up pacing and sensing thresholds were similar to the baseline values for all pacing methods and BBB morphology. Only one device-related complication leading to pacing interruption was recorded.

CONCLUSION

In patients with bundle branch blocks, CSP is a feasible procedure associated with a high success rate, stable pacing and sensing parameters, and low complication rates over a mid-term follow-up.

Impact of left ventricular inflow-outflow angle on heart failure readmission post-transcatheter aortic valve implantation

Heart failure (HF) readmission post-transcatheter aortic valve implantation (TAVI) is common; however, its anatomical predictors remain unclear. This study identified a small systolic left ventricular inflow-outflow (LVIO) angle, evaluated using computed tomography, as a potential anatomical predictor associated with HF readmission post-TAVI. Patients with a small systolic LVIO angle may require close follow-up post-TAVI.

Clinical outcomes and predictors of delayed echocardiographic response to cardiac resynchronization therapy

INTRODUCTION

The clinical outcomes and mechanisms of delayed responses to cardiac resynchronization therapy (CRT) remain unclear. We aimed to investigate the differences in outcomes and gain insight into the mechanisms of early and delayed responses to CRT.

METHODS

This retrospective study included 110 patients who underwent CRT implantation. Positive response to CRT was defined as ≥15% reduction of left ventricular (LV) end-systolic volume on echocardiography at 1 year (early phase) and 3 years (delayed phase) after implantation. The latest mechanical activation site (LMAS) of the LV was identified using two-dimensional speckle-tracking radial strain analysis.

RESULTS

Seventy-eight (71%) patients exhibited an early response 1 year after CRT implantation. Of 32 non-responders in the early phase, 12 (38%) demonstrated a delayed response, and 20 (62%) were classified as non-responders after 3 years. During the follow-up time of 10.3 ± 0.5 years, the delayed and early responders had a similar prognosis of mortality and heart failure (HF) hospitalization. In contrast, non-responders had a worse prognosis. Multivariate analysis revealed that a longer duration (months) between initial HF hospitalization and CRT (odds ratio [OR]: 1.126; 95% confidence interval [CI]: 1.036-1.222; p = .005), non-exact concordance of LV lead location with LMAS (OR: 32.744; 95% CI: 1.101-973.518; p = .044), and pre-QRS duration (OR: 0.901; 95% CI: 0.827-0.981; p = .016) were independent predictors of delayed response to CRT compared with early response.

CONCLUSION

The prognoses were similar regardless of the response time after CRT. A longer history of HF, suboptimal LV lead position, and shorter pre-QRS duration were related to delayed response than early response.

Association Between Left Ventricular Apical-to-Basal Strain Ratio and Conduction Disorders after Aortic Valve Replacement

BACKGROUND

The aim of the study was to evaluate whether left ventricular apical-to-basal longitudinal strain differences, representing advanced basal interstitial fibrosis, are associated with conduction disorders after aortic valve replacement (AVR) in patients with severe aortic stenosis.

METHODS

Patients with aortic stenosis undergoing AVR were included. The apical-to-basal strain ratio was calculated by dividing the average strain of the apical segments by the average strain of the basal segments. Values >1.9 were considered abnormal, as previously described. All patients were followed up for the occurrence of complete left or right bundle branch block or permanent pacemaker implantation within 2 years after AVR. Subgroup analysis was performed in patients undergoing transcatheter AVR.

RESULTS

Two hundred seventy-four patients were included (median age of 74 years [interquartile range, 65, 80], 46.4% male). During a median follow-up of 12.2 months (interquartile range, 0.2, 24.3), 74 patients (27%) developed complete bundle branch block or were implanted with a permanent pacemaker. These patients more often had an abnormal apical-to-basal strain ratio. Cumulative event-free survival analysis showed worse outcome in patients with an abnormal apical-to-basal strain ratio (log rank χ2 = 7.258, P = .007). In multivariable Cox regression analysis, an abnormal apical-to-basal strain ratio was the only independent factor associated with the occurrence of complete bundle branch block or permanent pacemaker implantation after adjusting for other factors previously shown to be associated with conduction disorders after AVR. Subgroup analysis confirmed the independent association of an abnormal apical-to-basal strain ratio with conduction disorders after transcatheter AVR.

CONCLUSION

The apical-to-basal strain ratio is independently associated with conduction disorders after AVR and could guide risk stratification in patients potentially at risk for pacemaker implantation.

Complete atrioventricular block following internal electrical cardioversion during atrial fibrillation ablation

BACKGROUND

Complete atrioventricular block (C-AVB) following internal electrical cardioversion (IEC) during atrial fibrillation (AF) ablation has not been fully investigated. We aimed to determine the prevalence and predictors of C-AVB following IEC during AF ablation.

METHODS

C-AVB (non-conducted sinus impulse after IEC) and ventricular pause (VP) (the interval between IEC and the QRS complex) following the first attempt of IEC, and baseline electrocardiographic parameters were investigated in patients who underwent first-time AF ablation.

RESULTS

We investigated the first attempt of IEC in 124 patients (mean age:70 ± 11 years, 81 men, 99 non-paroxysmal AF). AF was terminated in 109/124 (88%) patients, with a VP of 1590 [1014-2208] (maximum, 8780) ms. Transient C-AVB following IEC occurred in 14/109 (13%) patients. The VP was longer in patients with transient C-AVB than in those without transient C-AVB (2418 [1693-4425] vs. 1530 [876-2083] ms, p = 0.002). In multivariate analysis, the left atrial diameter (Odds ratio [OR]:1.21; 95% confidence interval (95%CI):1.06-1.39; p = 0.005) and preexisting intraventricular conduction abnormality (OR:9.22; 95%CI:1.60-53.3; p = 0.013) were predictors of transient C-AVB following IEC.

CONCLUSION

Left atrial diameter and preexisting intraventricular conduction abnormalities were predictors of transient C-AVB following IEC during AF ablation.

Electrocardiographic and genetic characteristics in first degree relatives of hypertrophic cardiomyopathy probands: A descriptive cross-sectional study from Vietnam

Objectives

In order to study the phenotype-genotype relationship and to better understand the early consequences of the mutation, we would report the spectrum of electrocardiographic and genetic features in the relatives of hypertrophic cardiomyopathy (HCM) patients.

Methods

Participants underwent a comprehensive clinical assessment, electrocardiography, standardized and echocardiography and genetic testing. In probands, next-generation sequencing was performed using the gene panel associated with HCM, while in relatives, Sanger sequencing was used to screen for mutations identified in their individual probands.

Results

A total of 84 participants were included in this study. The interventricular septal and posterior wall thickness was highest in the G+/LVH+ group, followed by the G+/LVH- group, and was lowest in G-/LVH- group. Compared to the normal control group, the pathologic Q wave was statistically more prevalent in the G+/LVH- group. The prevalence of repolarization abnormalities and major abnormalities was highest in the G+/LVH+ group, followed by the G+/LVH- group, and lowest in G-/LVH- group.

Conclusion

Our results suggested that sarcomere mutations have early consequences on myocardial biology. These findings suggest the possibility of implementing a mutation carrier detection model within families affected by HCM, where ECG could play a central role when combined with other relevant clinical factors. Longitudinal studies on a cohort of G+/LVH- patients are required.

Association of vectorcardiographic T-wave area with clinical and echocardiographic outcomes in cardiac resynchronization therapy

AIMS

Data on repolarization parameters in cardiac resynchronization therapy (CRT) are scarce. We investigated the association of baseline T-wave area, with both clinical and echocardiographic outcomes of CRT in a large, multi-centre cohort of CRT recipients. Also, we evaluated the association between the baseline T-wave area and QRS area.

METHODS AND RESULTS

In this retrospective study, 1355 consecutive CRT recipients were evaluated. Pre-implantation T-wave and QRS area were calculated from vectorcardiograms. Echocardiographic response was defined as a reduction of ≥15% in left ventricular end-systolic volume between 3 and 12 months after implantation. The clinical outcome was a combination of all-cause mortality, heart transplantation, and left ventricular assist device implantation. Left ventricular end-systolic volume reduction was largest in patients with QRS area ≥ 109 μVs and T-wave area ≥ 66 μVs compared with QRS area ≥ 109 μVs and T-wave area < 66 μVs (P = 0.004), QRS area < 109 μVs and T-wave area ≥ 66 μVs (P < 0.001) and QRS area < 109 μVs and T-wave area < 66 μVs (P < 0.001). Event-free survival rate was higher in the subgroup of patients with QRS area ≥ 109 μVs and T-wave area ≥ 66 μVs (n = 616, P < 0.001) and QRS area ≥ 109 μVs and T-wave area < 66 μVs (n = 100, P < 0.001) than the other subgroups. In the multivariate analysis, T-wave area remained associated with echocardiographic response (P = 0.008), but not with the clinical outcome (P = 0.143), when QRS area was included in the model.

CONCLUSION

Baseline T-wave area has a significant association with both clinical and echocardiographic outcomes after CRT. The association of T-wave area with echocardiographic response is independent from QRS area; the association with clinical outcome, however, is not.

ECG lead misplacement in the frontal and horizontal plane mimicking A myocardial infarction

BACKGROUND/AIMS

Electrocardiogram (ECG) is an inexpensive, fundamental screening tool used in daily clinical practice. It is essential in the diagnosis of life-threatening conditions, such as acute myocardial infarctions, ventricular arrhythmias etc. However, ECG lead misplacement is a common technical error, which may translate into wrong interpretations, unnecessary investigations, and improper treatments.

METHODS/RESULTS

We report a case of a multiple ECG lead misplacement made across two different planes of the heart, resulting in a bizarre series of ECG, mimicking an acute high lateral myocardial infarction. Multiple ECGs were done as there were abrupt changes compared to previous ECGS. Patient was pain free and administration of potentially harmful procedures and treatments were prevented.

CONCLUSION

Our case demonstrated the importance of high clinical suspicion in diagnosing ECG lead misplacement. It is the responsibility of both the healthcare workers who are performing and interpreting the ECG to be alert of a possible lead malposition, to prevent untoward consequences to the patient.

ECG characteristics of "true" left bundle branch block: Insights from transcatheter aortic valve-related LBBB and His-Purkinje conduction system pacing-correctable LBBB

BACKGROUND

Left bundle branch block (LBBB) pattern on the electrocardiogram includes patients with both complete conduction block in the His-Purkinje system as well as nonspecific left ventricular conduction delay without discrete block.

OBJECTIVE

The purpose of this study was to characterize electrocardiographic morphological features of LBBB patterns in patients with (1) LBBB after transcatheter aortic valve replacement (TAVR) and (2) LBBB correctable by conduction system pacing (CSP).

METHODS

Consecutive patients with post-TAVR (n = 123) or CSP-correctable LBBB (n = 58) from 2 centers were included in this retrospective evaluation. QRS durations as well as detailed morphological features, including notching and slurring, of QRS complexes in leads I, aVL, V1, V2, V5, and V6 and in all 3 inferior leads were recorded.

RESULTS

The mean age of the entire cohort was 78.3 ± 10.1 years, with 48% of the cohort being male (87/181). In the CSP-correctable group (n = 58), 14 (24.1%) underwent His-bundle pacing and 44 (75.9%) left bundle branch area pacing. A total of 17 of 181 (9.4%) of the combined cohort failed to completely meet the Strauss criteria. QRS morphology in lead V1/V2 was always either rS or QS, and there were no q/Q waves noted in lead V5/V6. Although dominant R waves were seen in leads I and aVL of 176 of 181 (97.2%), q/Q waves were present in only 21 of 181 (11.6%). Importantly, notched or slurred QRS complexes were identified in at least 1 lead of 4 leads I, aVL, V5, and V6 in 181 of 181 (100%).

CONCLUSION

Strauss criteria and QRS notching are highly prevalent in LBBB after TAVR and in LBBB correctable by CSP.

Comparison of strategies for catheter ablation of left posterior fascicular ventricular tachycardia

AIMS

Traditional ablation strategies including targeting the earliest Purkinje potential (PP) during left posterior fascicular (LPF) ventricular tachycardia (VT) or linear ablation at the middle segment of LPF during sinus rhythm are commonly used for the treatment of LPF-VT. Catheter ablation for LPF-VT targeting fragmented antegrade Purkinje (FAP) potential during sinus rhythm is a novel approach. We aimed to compare safety and efficacy of different ablation strategies (FAP ablation vs. traditional ablation) for the treatment of LPF-VT.

METHODS AND RESULTS

Consecutive patients with electrocardiographically documented LPF-VT referred for catheter ablation received either FAP ablation approach or traditional ablation approach. Electrophysiological characteristics, procedural complications, and long-term clinical outcome were assessed. A total of 189 consecutive patients who underwent catheter ablation for LPF-VT were included. Fragmented antegrade Purkinje ablation was attempted in 95 patients, and traditional ablation was attempted in 94 patients. Acute ablation success with elimination of LPF-VT was achieved in all patients. Left posterior fascicular block occurred in 11 of 95 (11.6%) patients in the FAP group compared with 75 of 94 (79.8%) patients in the traditional group (P < 0.001). Fragmented antegrade Purkinje ablation was associated with significant shorter procedure time (94 ± 26 vs. 117 ± 23 min, P = 0.03) and fewer radiofrequency energy applications (4.1 ± 2.4 vs. 6.3 ± 3.5, P = 0.003) compared with the traditional group. One complete atrioventricular block and one left bundle branch block were seen in the traditional group. Over mean follow-up of 65 months, 89 (93.7%) patients in the FAP group and 81 (86.2%) patients in the traditional group remained free of recurrent VT off antiarrhythmic drugs (P = 0.157).

CONCLUSION

Left posterior fascicular-ventricular tachycardia ablation utilizing FAP and traditional ablation approaches resulted in similar acute and long-term procedural outcomes. Serious His-Purkinje injury did occur infrequently during traditional ablation. The use of FAP ablation approach was associated with shorter procedure time and fewer radiofrequency energy applications, especially for non-inducible patients.

Left septal fascicular block: Evidence, causes, and diagnostic criteria

The existence of a tetrafascicular intraventricular conduction system is widely accepted by researchers. In this review, we have updated the criteria for left septal fascicular block (LSFB) and the differential diagnosis of prominent anterior QRS forces. More and more evidence points to the fact that the main cause of LSFB is critical proximal stenosis of the left anterior descending coronary artery before its first septal perforator branch. The most important characteristic of LSFB that has been incorporated in the corresponding diagnostic electrocardiographic criteria is its transient/intermittent nature mostly observed in clinical scenarios of acute (ie, acute coronary syndrome including vasospastic angina) or chronic (ie, exercise-induced ischemia) ischemic coronary artery disease. In addition, the phenomenon proved to be phase 4 bradycardia rate dependent and induced by early atrial extrastimulus. Finally, we believe that intermittent LSFB has the same clinical significance as "Wellens syndrome" and the "de Winter pattern" in the acute coronary syndrome scenario.

The degree of permanent pacemaker dependence and clinical outcomes following transcatheter aortic valve implantation: implications for procedural technique

Aims

Conduction abnormalities necessitating permanent pacemaker (PPM) implantation remain the most frequent complication post-transcatheter aortic valve implantation (TAVI), yet reliance on PPM function varies. We evaluated the association of right-ventricular (RV)-stimulation rate post-TAVI with 1-year major adverse cardiovascular events (MACE) (all-cause mortality and heart failure hospitalization).

Methods and results

This retrospective cohort study of patients undergoing TAVI in two high-volume centers included patients with existing PPM pre-TAVI or new PPM post-TAVI. There was a bimodal distribution of RV-stimulation rates stratifying patients into two groups of either low [≤10%: 1.0 (0.0, 3.6)] or high [>10%: 96.0 (54.0, 99.9)] RV-stimulation rate post-TAVI. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated comparing MACE in patients with high vs. low RV-stimulation rates post-TAVI. Of 4659 patients, 408 patients (8.6%) had an existing PPM pre-TAVI and 361 patients (7.7%) underwent PPM implantation post-TAVI. Mean age was 82.3 ± 8.1 years, 39% were women. A high RV-stimulation rate (>10%) development post-TAVI is associated with a two-fold increased risk for MACE [1.97 (1.20, 3.25), P = 0.008]. Valve implantation depth was an independent predictor of high RV-stimulation rate [odds ratio (95% CI): 1.58 (1.21, 2.06), P=<0.001] and itself associated with MACE [1.27 (1.00, 1.59), P = 0.047].

Conclusion

Greater RV-stimulation rates post-TAVI correlate with increased 1-year MACE in patients with new PPM post-TAVI or in those with existing PPM but low RV-stimulation rates pre-TAVI. A shallower valve implantation depth reduces the risk of greater RV-stimulation rates post-TAVI, correlating with improved patient outcomes. These data highlight the importance of a meticulous implant technique even in TAVI recipients with pre-existing PPMs.

Association of right bundle branch block or intraventricular conduction delay with recurrence of atrial fibrillation after catheter ablation

BACKGROUND

The association between bundle branch block (BBB) and recurrence of atrial fibrillation (AF) after catheter ablation is unclear. The aim of this study was to determine whether AF combined with BBB is associated with AF recurrence after catheter ablation.

METHODS

A total of 477 consecutive AF patients who underwent catheter ablation were included. The AF patients were divided into three groups according to BBB: AF without BBB (n = 427), AF with right bundle branch block (AF with RBBB) (n = 16), and AF with intraventricular conduction delay (AF with IVCD) (n = 34).

RESULTS

Of the 477 AF patients (mean age 57 years, 81% men, median CHA2 DS2 -VASc score of 1), 16 (3.4%) patients had RBBB, and 34 (7.1%) patients had IVCD. During a mean follow-up of 15.2 ± 6.7 months, 119 patients (24.9%) had recurrence of AF. Of these, 111 (26%) patients were in the AF without BBB group, with 2 (12.5%) and 6 (17.6%) patients in the RBBB and IVCD groups, respectively. The Kaplan-Meier estimate of the rate of recurrent AF was not significantly different among the three groups (p = .39). Multivariable analysis showed that persistent AF (HR 1.7, 95% CI 1.15-2.50, p = .007), chronic kidney disease (HR 2.94, 95% CI 1.20-7.17, p = .01), and left atrial diameter (HR 1.04, 95% CI 1.009-1.082, p = .01) were significantly associated with AF recurrence.

CONCLUSION

AF with BBB was not significantly associated with the recurrence of AF after catheter ablation in middle-aged patients with low-risk cardiovascular profile.

Longitudinal ECG changes among adults with HIV in Tanzania: A prospective cohort study

The prevalence of cardiovascular disease (CVD) is rising among people with HIV (PWH) in sub-Saharan Africa (SSA). Despite the utility of the electrocardiogram (ECG) in screening for CVD, there is limited data regarding longitudinal ECG changes among PWH in SSA. In this study, we aimed to describe ECG changes over a 6-month period in a cohort of PWH in northern Tanzania. Between September 2020 and March 2021, adult PWH were recruited from Majengo HIV Care and Treatment Clinic (MCTC) in Moshi, Tanzania. Trained research assistants surveyed participants and obtained a baseline ECG. Participants then returned to MCTC for a 6-month follow-up, where another ECG was obtained. Two independent physician adjudicators interpreted baseline and follow-up ECGs for rhythm, left ventricular hypertrophy (LVH), bundle branch blocks, ST-segment changes, and T-wave inversion, using standardized criteria. New ECG abnormalities were defined as those that were absent in a patient's baseline ECG but present in their 6-month follow-up ECG. Of 500 enrolled participants, 476 (95.2%) completed follow-up. The mean (± SD) age of participants was 45.7 (± 11.0) years, 351 (73.7%) were female, and 495 (99.8%) were taking antiretroviral therapy. At baseline, 248 (52.1%) participants had one or more ECG abnormalities, the most common of which were LVH (n = 108, 22.7%) and T-wave inversion (n = 89, 18.7%). At six months, 112 (23.5%) participants developed new ECG abnormalities, including 40 (8.0%) cases of new T-wave inversion, 22 (4.6%) cases of new LVH, 12 (2.5%) cases of new ST elevation, and 11 (2.3%) cases of new prolonged QTc. Therefore, new ECG changes were common over a relatively short 6-month period, which suggests that subclinical CVD may develop rapidly in PWH in Tanzania. These data highlight the need for additional studies on CVD in PWH in SSA and the importance of routine CVD screening in this high-risk population.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

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

BACKGROUND

Chagas disease (ChD) is the most important endemy in Latin America. Some patients, develop chronic Chagasic cardiopathy (CCC) years after the acute phase. It is unknown if patients infected by the oral route have higher risk of developing early CCC.

METHODS AND FINDINGS

A prospective cohort study was conducted to assess morbidity and mortality during 10 years observation in 106 people simultaneously infected and treated in the largest known orally transmitted ChD outbreak in 2007. A preschooler died during the acute phase, but thereafter was no mortality associated to ChD. All acute phase findings improved in the first-year post-treatment. Each person was evaluated 8.7 times clinically, 6.4 by electrocardiogram (ECG)/Holter, and 1.7 by echocardiogram. Based on prevalence, the number of people who had any abnormalities (excluding repolarization abnormalities and atrial tachycardia which decreased) was higher than 2007, since they were found at least once between 2008-2017. However, when we evaluated incidence, except for clinical bradycardia and dizziness, it was observed that the number of new cases of all clinical and ECG findings decreased at the end of the follow-up. Between 2008-2017 there was not incidence of low voltage complex, 2nd degree AV block, long QT interval, left bundle branch block or left ventricular dysfunction that allowed the diagnosis of CCC. Total improvement prevailed over the persistence of all clinical and ECG/Holter findings, except for sinus bradycardia. Incomplete right bundle branch block, sinus bradycardia and/or T-wave inversion were diagnosed persistently in 9 children. The second treatment did not have significant influence on the incidence of clinical or ECG/Holter findings.

CONCLUSIONS

At the end of the 10-year follow-up, there were not clinical or ECG/Holter criteria for classifying patients with CCC. The incidence of arrhythmias and repolarization abnormalities decreased. However, special attention should be paid on findings that not revert as sinus bradycardia, or those diagnosed persistently in all ECG as sinus bradycardia, incomplete right bundle branch block or T-wave inversion. Early diagnosis and treatment may have contributed to the rapid improvement of these patients. In ChD follow-up studies prevalence overestimates the real dimension of abnormalities, the incidence looks as a better indicator.

Elevated high-sensitivity C-reactive protein levels increase the risk of new-onset cardiac conduction disorders

BACKGROUND

Previous studies have reported that inflammatory responses can promote the onset of cardiovascular diseases; however, its association with cardiac conduction disorders remains unclear. The present community-based cohort study aimed to elucidate the effects of inflammatory responses on the risk of developing cardiac conduction disorders.

METHODS

After the exclusion of participants failing to meet the inclusion criteria, 86,234 eligible participants (mean age: 50.57 ± 11.88 years) were included. The participants were divided into high-sensitivity C-reactive protein (hsCRP)  ≤  3 mg/L, and hsCRP > 3 mg/L groups based on hsCRP values. Multivariate Cox proportional hazard model was used to analyze the relationship between inflammatory responses and various cardiac conduction disorders.

RESULTS

After adjusting for confounding factors, we observed that compared with the hsCRP ≤ 3 mg/L group, the hsCRP > 3 mg/L group exhibited increased risks of atrioventricular block (hazard ratio [HR]:1.64, 95%confidence interval [CI] 1.44-1.87) and left (HR:1.25, 95% CI 1.07-1.45) and right bundle branch block (HR:1.31, 95% CI 1.17-1.47). Moreover, the risk of various cardiac conduction disorders increased for every 1 standard deviation increase in log (hsCRP). The restricted cubic spline function confirmed a linear relationship between log (hsCRP) and the risk of developing cardiac conduction disorders (All nonlinearity P > 0.05).

CONCLUSIONS

High hsCRP levels are an independent risk factor for cardiac conduction disorders, and hsCRP levels are dose-dependently associated with the risk of conduction disorders. Our study results may provide new strategies for preventing cardiac conduction disorders.

Cardiac Death After Transcatheter Aortic Valve Replacement With Contemporary Devices

BACKGROUND

The burden of cardiac death after transcatheter aortic valve replacement (TAVR), particularly from advanced heart failure (HF) and sudden cardiac death (SCD), remains largely unknown.

OBJECTIVES

This study sought to evaluate the incidence and predictors of SCD and HF-related death in TAVR recipients treated with newer-generation devices.

METHODS

This study included a total of 5,421 consecutive patients who underwent TAVR with newer-generation devices using balloon (75.7%) or self-expandable (24.3%) valves.

RESULTS

After a median follow-up of 2 (IQR: 1-3) years, 976 (18.0%) patients had died, 50.8% from cardiovascular causes. Advanced HF and SCD accounted for 11.6% and 7.5% of deaths, respectively. Independent predictors of HF-related death were atrial fibrillation (HR: 2.17; 95% CI: 1.47-3.22; P < 0.001), prior pacemaker (HR: 1.79; 95% CI: 1.10-2.92; P = 0.01), reduced left ventricular ejection fraction (HR: 1.08 per 5% decrease; 95% CI: 1.01-1.14; P = 0.02), transthoracic approach (HR: 2.50; 95% CI: 1.37-4.55; P = 0.003), and new-onset persistent left bundle branch block (HR: 1.85; 95% CI: 1.14-3.02; P = 0.01). Two baseline characteristics (diabetes, HR: 1.81; 95% CI: 1.13-2.89; P = 0.01; and chronic kidney disease, HR: 1.72; 95% CI: 1.02-2.90; P = 0.04) and 3 procedural findings (valve in valve, HR: 2.17; 95% CI: 1.01-4.64; P = 0.04; transarterial nontransfemoral approach, HR: 2.23; 95% CI: 1.23-4.48; P = 0.01; and periprocedural ventricular arrhythmia, HR: 7.19; 95% CI: 2.61-19.76; P < 0.001) were associated with an increased risk of SCD after TAVR.

CONCLUSIONS

Advanced HF and SCD accounted for a fifth of deaths after TAVR in contemporary practice. Potentially treatable factors leading to increased risk of HF deaths and SCD were identified, such as arrhythmia/dyssynchrony factors for HF and valve-in-valve TAVR or periprocedural ventricular arrhythmias for SCD.

Conduction Disturbance After Transcatheter Aortic Valve Implantation With Self- or Balloon-Expandable Valve According to the Implantation Depth

Membranous septum (MS) length, in conjunction with implantation depth (ID), is known as a determinant of conduction disturbance (CD) after transcatheter aortic valve implantation (TAVI). However, its impact might be dissimilar among valve types because each valve has a different platform. This study sought to investigate the different impacts of ID and MS length on the new-onset CD between ACURATE neo and SAPIEN 3. This study included patients without a previous permanent pacemaker implantation who underwent TAVI with ACURATE neo and SAPIEN 3 and divided them into 2 groups based on the ID according to MS length (deep and shallow implantation group). Deep implantation was defined as transcatheter heart valve implantation deeper than MS length. The primary endpoint was new-onset CD (new permanent pacemaker implantation or new-onset complete left bundle branch block). A total of 688 patients (deep implantation: n = 373, shallow implantation: n = 315) were identified as a study cohort. New-onset CD developed more frequently in the deep implantation group (16.6% vs 7.0%; p = 0.0001). Deep implantation was revealed as a predictor of new-onset CD. Moreover, deep implantation was significantly associated with new-onset CD after SAPIEN 3 implantation but not after ACURATE neo. Among patients with MS shorter than 2 mm, ACURATE neo was superior in terms of avoiding new-onset CD. In conclusion, the deep implantation was associated with new-onset CD after TAVI with SAPIEN 3 but not with ACURATE neo. These results may impact device selection in patients with a preexisting high risk of CD.

Terminal T-wave concordance is associated with SYNTAX score among left bundle branch block patients suspected of acute coronary syndrome without modified Sgarbossa criteria

BACKGROUND

Timely and precise diagnosis of ischemic cardiac events based on electrocardiogram is challengeable among patients with Left Bundle Branch Block (LBBB). The present study aimed to assess the correlation between SYNTAX score and terminal T-wave morphologies among LBBB patients suspected of Acute Coronary Syndrome (ACS) without modified Sgarbossa criteria.

METHOD

This cross-sectional study was conducted on the LBBB patients suspected of ACS without modified Sgarbossa criteria. Binary logistic regression was used to assess the correlation of ischemic heart disease (IHD, SYNTAX score > 0) and SYNTAX score categories with terminal T-wave morphologies including T-wave direction in lead V6 and terminal T-wave concordance in leads I, V5, and V6.

RESULT

This study was done on 93 patients with the mean age of 62.4 ± 9.6 years. More than half of the patients were female (58.1%, 95% CI: 47.4% to 68.2%). Among the participants with IHD, the SYNTAX score categories were correlated to discordant terminal T-wave in leads I, V5, and V6 (OR = 5.71, 95% CI: 1.04 to 31.28, p = 0.04).

CONCLUSION

Among the LBBB patients with acute ischemic cardiac events without modified Sgarbossa criteria, those with discordant terminal T-waves in leads I, V5, or V6 had higher SYNTAX scores and might require more invasive coronary revascularization techniques such as Coronary Artery Bypass Graft (CABG) surgery.

A wobble tachycardia… supraventricular, ventricular or both?

We present the case of a 77-year-old man with ischemic heart disease and baseline right bundle branch block having a well-tolerated and regular wide complex tachycardia with right bundle branch block morphology. A wide complex tachycardia (WCT) could be of supraventricular or ventricular origin. In this setting, we discuss the differential diagnosis of WCT, the usefulness and limitations of the diagnostic criteria for ventricular tachycardia.

Natural history of chronic thromboembolic pulmonary disease with no or mild pulmonary hypertension

BACKGROUND

We describe baseline characteristics, disease progression and mortality in chronic thromboembolic pulmonary disease patients as a function of mean pulmonary artery pressure (mPAP) according to new and previous definitions of pulmonary hypertension.

METHODS

All patients diagnosed with chronic thromboembolic pulmonary disease between January, 2015 and December, 2019 were dichotomized according to initial mPAP: ≤ 20 mmHg ('normal') vs 21-24 mmHg ('mildly-elevated'). Baseline features were compared between the groups, and pairwise analysis performed to determine changes in clinical endpoints at 1-year, excluding those who underwent pulmonary endarterectomy or did not attend follow-up. Mortality was assessed for the whole cohort over the entire study period.

RESULTS

One hundred thirteen patients were included; 57 had mPAP ≤ 20 mmHg and 56 had mPAP 21-24 mmHg. Normal mPAP patients had lower pulmonary vascular resistance (1.6 vs 2.5WU, p < 0.01) and right ventricular end-diastolic pressure (5.9 vs 7.8 mmHg, p < 0.01) at presentation. At 3 years, no major deterioration was seen in either group. No patients were treated with pulmonary artery vasodilators. Eight had undergone pulmonary endarterectomy. Over 37 months median follow-up, mortality was 7.0% in the normal mPAP group and 8.9% in the mildly-elevated mPAP group. Cause of death was malignancy in 62.5% of cases.

CONCLUSIONS

Chronic thromboembolic pulmonary disease patients with mild pulmonary hypertension have statistically higher right ventricular end-diastolic pressure and pulmonary vascular resistance than those with mPAP ≤ 20 mmHg. Baseline characteristics were otherwise similar. Neither group displayed disease progression on non-invasive tests up to 3 years. Mortality over 37 months follow-up is 8%, and mainly attributable to malignancy. Further prospective study is required to validate these findings.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Nonspecific intraventricular conduction delay predicts the prognosis of dilated cardiomyopathy

PURPOSE

Left bundle branch block (LBBB) has been confirmed to be independently associated with adverse outcomes in dilated cardiomyopathy (DCM). However, prognostic data on nonspecific intraventricular conduction delay (NSIVCD) are still limited and conflicting. We aimed to evaluate the prognosis of DCM with NSIVCD.

METHODS

A total of 548 DCM patients who underwent cardiovascular magnetic resonance imaging (CMR) from January 2016 to December 2017 were consecutively enrolled. The cohort was divided into four groups: 87 with LBBB, 27 with RBBB, 61 with NSIVCD, and 373 without intraventricular conduction delay (IVCD). After a median follow-up of 58 months (interquartile range: 47-65), 123 patients reached the composite endpoints, which included cardiovascular death, heart transplantation, and malignant arrhythmias. The associations between different patterns of IVCD and the outcomes of DCM were analysed by Kaplan‒Meier analysis and Cox proportional hazards regression analysis.

RESULTS

Of 548 DCM patients, there were 398 males (72.6%), and the average age was 46 ± 15 years, ranging from 18 to 76 years. In Kaplan‒Meier analysis, patients with NSIVCD and LBBB showed higher event rates than patients without IVCD, while RBBB patients did not. By multivariate Cox regression analysis, LBBB, NSIVCD, NYHA class, left ventricular ejection fraction (LVEF), indexed left ventricular end-diastolic diameter (LVEDDI), percentage of late gadolinium enhancement mass (LGE%), and global longitudinal strain (GLS) were found to be independently associated with the outcomes of DCM.

CONCLUSIONS

In addition to LBBB, NSIVCD was an unfavourable prognostic marker in patients with DCM, independent of LVEDDI, NYHA class, LVEF, LGE%, and GLS.

Electrocardiographic characteristics of cirrhotic patients and their association with Child-Pugh score

BACKGROUND

Cardiac dysfunction is a serious complication of cirrhosis which is usually asymptomatic. We investigated the clinical and electrocardiographic (ECG)-related factors among patients with cirrhosis and our aim was to find any associations between ECG changes and the etiology of cirrhosis, as well as Child-Pugh score.

HYPOTHESIS

We hypothesized that some ECG-related factors, particularly prolonged QT interval, are more common in patients with cirrhosis. Also, these factors are associated with the severity of cirrhosis, measured by the Child-Pugh score.

METHODS

From April 2019 to December 2022, we reviewed admitted patients to Namazi and Abu-Ali Sina hospitals, Shiraz, Iran. Patients with confirmed diagnosis of cirrhosis and without concurrent disorders affecting the cardiovascular system were selected. Clinical and ECG-related data were then extracted for participants, and Child-Pugh score was calculated.

RESULTS

A total of 425 patients were included; the median age was 36 years, and 245 patients (57.6%) were men. Cryptogenic and primary sclerosing cholangitis were the most common etiologies. Prolonged QT followed by early transitional zone were the most common ECG changes (24.7% and 19.8%, respectively), which were significantly associated with the etiology of cirrhosis and Child-Pugh class.

CONCLUSIONS

Prolonged QT interval and presence of early transitional zone in patients with cirrhosis may indicate cardiac dysfunction, necessitating further evaluations.

Incidence and predictors of pacemaker implantation at follow-up after reversible high-degree sinus node dysfunction or atrioventricular block

BACKGROUND

A pacemaker implantation is not indicated in cases of reversible high-degree symptomatic sinus node dysfunction (SND) and atrioventricular block (AVB). However, it remains uncertain whether these reversible automaticity/conduction disorders may recur in some patients at follow-up, in the absence of reversible cause. This retrospective study aimed to determine the incidence and predictive factors of permanent pacemaker (PPM) implantation at follow-up and after reversible high-degree SND/AVB.

METHODS

Based on medical electronic files codes, we identified patients who were hospitalized in our cardiac intensive care unit between January 2003 and December 2020 due to reversible high-degree SND/AVB and who were discharged from the hospital alive and without PPM implantation. Acute myocardial infarction and post-cardiac surgery patients were excluded. We categorized the patients according to the need for PPM at follow-up due to non-reversible high-degree SND/AVB.

RESULTS

Of the 93 patients included, 26 patients (28%) were readmitted for PPM implantation at follow-up after hospital discharge. Among baseline characteristics, compared with patients who did not have high-degree SND/AVB recurrence, those who had subsequent PPM implantation had less frequent previous hypertension (70% vs. 46%, p = .031). Regarding the initial causes of reversible SND/AVB, isolated hyperkalemia was found more often in the patients readmitted for PPM (19% vs. 3% vs. p = .017). Moreover, recurrence of high-degree SND/AVB was significantly associated with the presence of intraventricular conduction disorders (either bundle branch block or left bundle branch hemiblock) on ECG at discharge (36% in patients without PPM vs. 68% in PPM patients, p = .012).

CONCLUSION

Almost one third of the patients discharged alive from the hospital after a reversible high-degree SND/AVB needed a pacemaker implantation at follow-up. Complete bundle branch block or left bundle branch hemiblock on discharge ECG after recovery of atrioventricular conduction and/or sinus automaticity was associated with a greater risk of recurrence leading to pacemaker implantation.

Predictors of Conduction Disturbances Requiring New Permanent Pacemaker Implantation following Transcatheter Aortic Valve Implantation Using the Evolut Series

(1) Background: Conduction disturbance requiring a new permanent pacemaker (PPM) after transcatheter aortic valve implantation (TAVI) has traditionally been a common complication. New implantation techniques with self-expanding platforms have reportedly reduced the incidence of PPM. We sought to investigate the predictors of PPM at 30 days after TAVI using Evolut R/PRO/PRO+; (2) Methods: Consecutive patients who underwent TAVI with the Evolut platform between October 2019 and August 2022 at University Hospital Galway, Ireland, were included. Patients who had a prior PPM (n = 10), valve-in-valve procedures (n = 8) or received >1 valve during the index procedure (n = 3) were excluded. Baseline clinical, electrocardiographic (ECG), echocardiographic and multislice computed tomography (MSCT) parameters were analyzed. Pre-TAVI MSCT analysis included membranous septum (MS) length, a semi-quantitative calcification analysis of the aortic valve leaflets, left ventricular outflow tract, and mitral annulus. Furthermore, the implantation depth (ID) was measured from the final aortography. Multivariate binary logistic analysis and receiver operating characteristic (ROC) curve analysis were used to identify independent predictors and the optimal MS and ID cutoff values to predict new PPM requirements, respectively; (3) Results: A total of 129 TAVI patients were included (age = 81.3 ± 5.3 years; 36% female; median EuroSCORE II 3.2 [2.0, 5.4]). Fifteen patients (11.6%) required PPM after 30 days. The patients requiring new PPM at 30 days were more likely to have a lower European System for Cardiac Operative Risk Evaluation II, increased prevalence of right bundle branch block (RBBB) at baseline ECG, have a higher mitral annular calcification severity and have a shorter MS on preprocedural MSCT analysis, and have a ID, as shown on the final aortogram. From the multivariate analysis, pre-TAVI RBBB, MS length, and ID were shown to be predictors of new PPM. An MS length of <2.85 mm (AUC = 0.85, 95%CI: (0.77, 0.93)) and ID of >3.99 mm (area under the curve (AUC) = 0.79, (95% confidence interval (CI): (0.68, 0.90)) were found to be the optimal cut-offs for predicting new PPM requirements; (4) Conclusions: Membranous septum length and implantation depth were found to be independent predictors of new PPM post-TAVI with the Evolut platform. Patient-specific implantation depth could be used to mitigate the requirement for new PPM.

Electrocardiographic Predictors of Complete Heart Block During Right Ventricular Lead Implantation in Patients Who Underwent Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) device procedures have their own complications in addition to the complications associated with standard pacemaker implantations. This study aimed to analyze the predictors of the right bundle branch injury resulting in complete heart block (CHB) during right ventricular (RV) lead implantation in patients who underwent CRT with defibrillator. We conducted an observational study of consecutive 790 patients who underwent CRT with defibrillator device implantation at our institution from 2010 to 2022. Relevant clinical information and complete data regarding the echocardiographic data, implantation procedure, and clinical follow-up were collected into a computerized database. A total of 29 patients (3.7%) had CHB during RV lead implantation. In multivariate analysis, left axis deviation (odds ratio [OR] 2.408, 95% confidence interval [CI] 1.025 to 5.658, p = 0.044), QRS width (OR 1.022, 95% CI 1.001 to 1.043, p = 0.035) and QRS alternans (OR 4.214, 95% CI 1.788 to 9.930, p = 0.001) were found independently related to right bundle branch injury resulting in CHB development during RV lead implantation. In conclusion, left axis deviation, QRS width, and QRS alternans were associated with a higher rate of CHB, and these findings provide insight into optimal and safe CRT device implantation strategies based on preprocedural characteristics.

The pivotal role of ECG in cardiomyopathies

Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Recent technological advances in cardiovascular imaging offer an opportunity for deep phenotypic and etiological definition. Electrocardiogram (ECG) is the first-line diagnostic tool in the evaluation of both asymptomatic and symptomatic individuals. Some electrocardiographic signs are pathognomonic or fall within validated diagnostic criteria of individual cardiomyopathy such as the inverted T waves in right precordial leads (V1-V3) or beyond in individuals with complete pubertal development in the absence of complete right bundle branch block for the diagnosis of arrhythmogenic cardiomyopathy of the right ventricle (ARVC) or the presence of low voltages typically seen in more than 60% of patients with amyloidosis. Most other electrocardiographic findings such as the presence of depolarization changes including QRS fragmentation, the presence of epsilon wave, the presence of reduced or increased voltages as well as alterations in the repolarization phase including the negative T waves in the lateral leads, or the profound inversion of the T waves or downsloping of the ST tract are more non-specific signs which can however raise the clinical suspicion of cardiomyopathy in order to initiate a diagnostic procedure especially using imaging techniques for diagnostic confirmation. Such electrocardiographic alterations not only have a counterpart in imaging investigations such as evidence of late gadolinium enhancement on magnetic resonance imaging, but may also have an important prognostic value once a definite diagnosis has been made. In addition, the presence of electrical stimulus conduction disturbances or advanced atrioventricular blocks that can be seen especially in conditions such as cardiac amyloidosis or sarcoidosis, or the presence of left bundle branch block or posterior fascicular block in dilated or arrhythmogenic left ventricular cardiomyopathies are recognized as a possible expression of advanced pathology. Similarly, the presence of ventricular arrhythmias with typical patterns such as non-sustained or sustained ventricular tachycardia of LBBB morphology in ARVC or non-sustained or sustained ventricular tachycardia with an RBBB morphology (excluding the "fascicular pattern") in arrhythmogenic left ventricle cardiomyopathy could have a significant impact on the course of each disease. It is therefore clear that a learned and careful interpretation of ECG features can raise suspicion of the presence of a cardiomyopathy, identify diagnostic "red flags" useful for orienting the diagnosis toward specific forms, and provide useful tools for risk stratification. The purpose of this review is to emphasize the important role of the ECG in the diagnostic workup, describing the main ECG findings of different cardiomyopathies.