Presence Of Left Bundle Branch Block Research Articles

Short Registry of Terminal Forms of Chronic Heart Failure in the Samara Region.

To study the clinical characteristics and prognosis of patients with functional class (FC) III-IV chronic heart failure (CHF) who meet the criteria for inclusion in the palliative care program. A short registry of severe CHF forms was conducted at 60 outpatient and inpatient clinics in the Samara region for one month (16.05.2022-15.06.2022). The registry included patients with FC III-IV CHF who sought medical help during that period. Lethal outcomes were assessed at 90 days after the inclusion in the registry using the Mortality Information and Analytics system. 591 patients (median age, 71.0 [64.0; 80.0] years were enrolled, including 339 (57.4%) men, of which 149 (24.1%) were of working age (under 65 years). The main cause of CHF was ischemic heart disease (64.5%). 229 (38.7%) patients had left ventricular ejection fraction <40%. During the past year, 513 (86.8%) patients had at least one hospitalization for decompensated CHF. 45.7% of patients had hydrothorax, and 11.3% of patients had ascites. Low systolic blood pressure was observed in more than 25% of patients; 14.2% required in-hospital inotropic support; and 9.1% received it on the outpatient basis. 4.2% of patients received outpatient oxygen support and 0.8% required the administration of narcotic analgesics. 12 (1.9%) patients were on the waiting list for heart transplantation. In this study, there was an inconsistency in the number of patients with ventricular tachycardia and/or left bundle branch block (LBBB) who were implanted with cardiac resynchronization therapy devices (CRTD) or an implantable cardioverter defibrillator (ICD), a total of 19 patients (11 patients with CRTD and 8 patients with ICD), while 58 (9.8%) patients had indications for CRTD/ICD implantation. Within 90 days from inclusion in the registry, 59 (10.0%) patients died. According to binary logistic regression analysis, the presence of LBBB, hydrothorax, the requirement for outpatient oxygen support, and a history of cardiac surgery were associated with a high risk of death. Patients with severe forms of CHF require not only adequate drug therapy, but also dynamic clinical observation supplemented with palliative care aimed at improving the quality of life, including the ethical principles of shared decision-making and advance care planning to identify the priorities and goals of patients in relation to their care.

Association between left bundle branch block and ventricular septal mid-wall fibrosis in patients with preserved left ventricular ejection fraction

BackgroundThe left bundle branch block (LBBB) is associated with ventricular septal mid-wall fibrosis (SMF) in patients with dilated cardiomyopathy (DCM). However, whether LBBB is also associated with SMF in patients with preserved left ventricular ejection fraction (LVEF) remains unclear. MethodsWe performed a retrospective study of 210 patients with preserved LVEF (male, n = 116; female, n = 94; mean age, 44 ± 17 years). LBBB was defined as QRS duration ≥140 ms for men or ≥ 130 ms for women, QS or rS in V1-V2, mid-QRS notching or slurring in at least two leads (V1, V2, V5, V6, I, and aVL). SMF determined by late gadolinium-enhancement cardiovascular magnetic resonance was defined as stripe-like or patchy mid-myocardial hyper-enhancement in the interventricular septal segments. ResultsSMF was detected in 24.8% (52/210) of these patients. The proportion of patients with SMF with LBBB was higher than the proportion of patients with SMF without LBBB (58.3% vs. 20.4%; P < 0.001). In the forward multivariate logistic analysis, LBBB (OR, 4.399; 95% CI, 1.774–10.904; P = 0.001) and age (OR, 1.028; 95% CI, 1.006–1.051; P = 0.011) were independently associated with SMF. The presence of LBBB showed a sensitivity of 27%%, specificity of 94%, positive predictive value of 58%%, and negative predictive value of 80% for the detection of SMF. ConclusionLBBB was significantly associated with SMF in hospitalized patients with preserved LVEF. Screening with a resting 12‑lead ECG may help to identify patients who are at a high risk of the presence of SMF.

Electrocardiographic prediction of left ventricular hypertrophy in women and men with left bundle branch block - Comparison of QRS duration, amplitude and voltage-time-integral.

Standard ECG criteria for left ventricular (LV) hypertrophy rely on QRS amplitudes. However, in the setting of left bundle branch block (LBBB), ECG correlates of LV hypertrophy are not well established. We sought to evaluate quantitative ECG predictors of LV hypertrophy in the presence of LBBB. We included adult patients with typical LBBB having ECG and transthoracic echocardiogram performed within 3months of each other in 2010-2020. Orthogonal X, Y, Z leads were reconstructed from digital 12‑lead ECGs using Kors's matrix. In addition to QRS duration, we evaluated QRS amplitudes and voltage-time-integrals (VTIs) from all 12 leads, X, Y, Z leads and 3D (root-mean-squared) ECG. We used age, sex and BSA-adjusted linear regressions to predict echocardiographic LV calculations (mass, end-diastolic and end-systolic volumes, ejection fraction) from ECG, and separately generated ROC curves for predicting echocardiographic abnormalities. We included 413 patients (53% women, age 73±12years). All 4 echocardiographic LV calculations were most strongly correlated with QRS duration (all p<0.00001). In women, QRS duration ≥ 150ms had sensitivity/specificity 56.3%/64.4% for increased LV mass and 62.7%/67.8% for increased LV end-diastolic volume. In men, QRS duration ≥ 160ms had a sensitivity/specificity 63.1%/72.1% for increased LV mass and 58.3%/74.5% for increased LV end-diastolic volume. QRS duration was best able to discriminate eccentric hypertrophy (area under ROC curve 0.701) and increased LV end-diastolic volume (0.681). In patients with LBBB, QRS duration (≥ 150 in women and≥160 in men) is a superior predictor of LV remodeling esp. eccentric hypertrophy and dilation.

PO-02-021 DIRECTION OF REPOLARIZATION IN BASELINE ECG IS PREDICTIVE OF RESPONSE TO CARDIAC RESYNCHRONIZATION THERAPY

Cardiac resynchronization therapy (CRT) is a cornerstone of treatment for advanced heart failure, but not all patients derive equal benefit from this intervention. Current approaches of using electrocardiographic and echocardiographic parameters to identify likely CRT responders demonstrate poor predictive ability. We seek to identify electrocardiographic parameters that can improve prediction of benefit with CRT This was a retrospective analysis of patients who underwent CRT-D placement at University of Pittsburgh Medical Center from 2014-2020. Patients were excluded if pre-implantation EKG or pre- and post-implantation echocardiograms were not available. Each patient’s immediate pre-implantation ECG was processed using the CineECG software (EKG Excellence) to obtain the mean temporospatial isochrone of ventricular activation. 192 features quantifying the activation and recovery pathways were computed for each patient. Response to CRT was defined as an improvement in ejection fraction (EF) of 5% on follow-up transthoracic echocardiogram 3-12 months after CRT implantation. Forward sequential feature selection was used to identify the features of highest importance based on negative logistic loss. 276 patients were included in this analysis (36% female, mean age 69 years, mean pre-procedural EF 27%). The 10 most important CineECG features were identified. When these features were used in a multivariate logistic regression, three features were independently predictive of CRT response: left bundle branch block (LBBB); leftward direction of late repolarization potentials (i.e., Tpeak - Tend rotated toward LV in the horizontal plane); and location of center-of-mass of terminal cardiac activation. Compared to CRT responders (n=169, 62%), non-responders were more likely to have abnormal direction of late repolarization potentials in both LBBB group (-0.34±0.30 vs. -0.45±0.30 vs, p=0.027) and RBBB group (0.25±0.51 vs. 0.61±0.27, p=0.031). In the latter group, direction of later repolarization potentials correlated with magnitude of change in post-procedural EF (r=0.23, p=0.016). Our findings confirm that the presence of LBBB is predictive of response to CRT. In addition, our data suggests that in patients with RBBB, a more leftward direction of late repolarization potentials is independently predictive of CRT response. Further studies into repolarization dynamics as a predictor of CRT response in RBBB are warranted.

Electrocardiogram QRS Complex Duration as a Predictor of Hospital Prognosis in Patients With COVID-19

Aim To determine the effect of major electrocardiographic (ECG) parameters on the prognosis of patients with COVID-19.Material and methods One of systemic manifestations of COVID-19 is heart injury. ECG is the most simple and available method for diagnosing the heart injury, which influences the therapeutic approach. This study included 174 hospitalized patients with COVID-19. Major ECG parameters recorded on admission and their changes before the discharge from the hospital or death of the patient, were analyzed, and the effect of each parameter on the in-hospital prognosis was determined. Results were compared with the left ventricular ejection fraction (LV EF), laboratory data, and results of multispiral computed tomography (MSCT) of the lungs.Results ECG data differed on admission and their changes differed for deceased and discharged patients. Of special interest was the effect of the QRS complex duration at baseline and at the end of treatment on the in-hospital survival and mortality rate. The Cox regression analysis showed that the QRS complex duration (relative risk (RR) 2.07, 95% confidence interval (CI): 1.17-3.66; р=0.01), MSCT data (RR, 1.54; 95 % CI: 1.14-2.092; р=0.005), and glomerular filtration rate (GFR) (RR, 0.98; 95 % CI: 0.96-0.99; р=0.001) had the highest predictive significance. In further comparison of these three indexes, the QRS duration and GFR retained their predictive significance, and a ROC analysis showed that the cut-off QRS complex duration was 125 ms (р=0.001). Patients who developed left bundle branch block (LBBB) in the course of disease also had an unfavorable prognosis compared to other intraventricular conduction disorders (р=0.038). The presence of LBBB was associated with reduced LV EF (р=0.0078). The presence of atrial fibrillation (AF) significantly predetermines a worse outcome both at the start (р=0.011) and at the end of observation (р=0.034). A higher mortality was observed for the group of deceased patients with ST segment deviations, ST elevation (р=0.0059) and ST depression (р=0.028).Conclusion Thus, the QTc interval elongation, LBBB that developed during the treatment, AF, and increased QRS complex duration are the indicators that determine the in-hospital prognosis of patients with COVID-19. The strongest electrocardiographic predictor for an unfavorable prognosis was the QRS complex duration that allowed stratification of patients to groups of risk.

142 ADVANCED HEART FAILURE IN PATIENTS WITH ARRHYTHMOGENIC CARDIOMYOPATHY

Abstract Background Arrhythmogenic Cardiomyopathy (ACM) is a primary disease of the heart muscle, characterized by fibro-fatty myocardial replacement. Improvements in the clinical diagnosis and antiarrhythmic therapy, including the use of the defibrillator (ICD) and endo-epicardial catheter ablation, have increased the survival of these patients, who experience late complications such as advanced heart failure, which sometimes requires cardiac transplantation. Aim of the study To evaluate clinical, instrumental and genetic features of patients affected with ACM who developed heart failure (HF) and to sought for possible predictive factors of HF. Methods From the entire cohort of probands and family members followed at the Cardiomyopathy unit of our University (555 patients), 34 patients (29%), both probands (n= 26, 77%) and family members who experienced HF (6%) were selected (24 males, 71%). Their anamnestic, clinical, and instrumental data were compared with those without episodes of HF (n-HF). Results The mean age at diagnosis in HF cohort was 45.2 (±18) years. In 14 patients (41%) HF was the first symptom that led to diagnosis. According to 2010 TFC 30 patients (88%) had a definite diagnosis of ACM. The most frequently observed phenotype was the biventricular ACM (n=27, 79%). A disease-related genetic variant was found in 18 (53%) and DSP was the more common disease-gene, accounting for 24% of cases. The mean duration of follow-up was 12.6 (±11.0) years (min-max, 1-20 years). During this period a total of 14 subjects (41.2%) experienced life-threatening arrhythmias (LTA), while 13 patients (38.2%) died, of whom 11 (84.6%) because of refractory HF. Eighteen patients (53%) underwent cardiac transplantation (mean age 43±17 years), approximately 4 (±3.5) years after the onset of symptoms. Comparison with the n-HF cohort of ACM patients showed a significant difference on presence of T-wave inversion (TWI) in V1-V3 (p=0.001), TWI in V4-V6 (p=0.010), low QRS voltages both in precordial and limb leads (both p&amp;lt;0.001) and presence of left bundle-branch block and right bundle-branch block (both p&amp;lt;0.001). Regarding CMR, HF cohort was characterized by a significantly more dilated right and left ventricle EDV (both p&amp;lt;0.001), EF reduction (both p&amp;lt;0.001), presence of wall motion alterations (respectively, p=0.007 and p&amp;lt;0.001) and LGE (respectively, p=0.002 and p=0.005) compared to n-HF group. Regarding outcomes evaluation, the HF group showed more frequently LTA (HF=41.2% vs n-HF 21.5%, p=0.008). Finally, the presence of right bundle-branch block at ECG (OR=20.562, CI 1.884-224.413, p=0.013) and of impaired RV ejection fraction (OR=0.821, CI 0.719-0.937, p=0.004) were found to be independent predictors of HF. Conclusions Heart failure is a rare complication in patients affected with ACM, with a prevalence of 6% in our study. The mean age of onset of HF was 45.2 (±18) years. Furthermore, 18 patients (53%) had an unfavorable progression to heart transplantation. The presence of right bundle branch block at ECG and an impaired CMR RV-EF were found to be predictors of HF. Our results suggest the importance of scheduling a close follow-up in ACM patients who show initial signs and/or symptoms of HF, taking into consideration the fast rate of progression to refractory HF, once established.

CMR feature tracking in patients with dilated cardiomyopathy: patterns of myocardial strain and focal fibrosis

BackgroundThere is a paucity of data on cardiovascular magnetic resonance feature tracking (CMR-FT) in patients with dilated cardiomyopathy (DCM). We aimed at describing global and segmental myocardial strain patterns and...

Impact of left bundle branch block in patients with takotsubo cardiomyopathy

Abstract Background Takotsubo cardiomyopathy (TCM) is a syndrome characterized by reversible left-ventricular regional systolic dysfunction in the absence of obstructive coronary artery disease (CAD). The presence of left bundle branch block (LBBB) has been described as an independent predictor of mortality in patients with CAD. One study using the National Inpatient Sample (NIS) for 2016 found that the presence of LBBB was associated with worse outcomes in patients with TCM. Purpose To better clarify the association between LBBB and various in-hospital outcomes in patients with TCM. Methods The NIS database was queried from 2016–2019 to identify all admissions with a primary diagnosis of TCM that had a cardiac catheterization to improve the specificity of the diagnosis. International classification of diseases, tenth revision clinical modification (ICD-10-CM) codes were used to divide patients based on the presence or absence of LBBB. A 1:3 propensity score matching based on age, race, gender, and risk factor stratification was used to reduce selection bias. Multivariate linear and logistic regression analysis was performed to compare various outcomes among both groups. Results A total of 27,125 patients admitted with a primary diagnosis of TCM that also underwent diagnostic coronary angiography were identified. In the study sample, 955 (3.5%) were determined to have a LBBB. After calculating propensity scores, 955 patients with LBBB were paired to 2,865 patients without LBBB. LBBB was associated with higher rates of ventricular arrhythmias (AOR=3.098, 95% CI 1.483–6.471, p=0.003); however, it was not statistically associated with cardiogenic shock, sudden cardiac arrest (SCA), acute kidney injury, acute heart failure, and hospital length of stay. In addition, there was no statistical difference in intra-hospital mortality. Conclusions LBBB is associated with left ventricular dyssynchrony. It has been proposed that intraventricular dyssynchrony might be a predisposing factor for ventricular arrhythmias (VA) and SCA. Several trials have demonstrated that cardiac resynchronization therapy alone (i.e., without defibrillation) reduces the rate of VA and SCA. The mechanism for this improvement is unclear but may be related to hemodynamic improvement from ventricular synchrony in heart failure (HF). In fact, LBBB has been reported as an independent risk factor for all-cause mortality and SCA at one year in patients with HF. Our analysis did not find any significant association between LBBB and SCA but did find an association with VA. Moreover, there were not enough events of intra-hospital mortality to assess a possible association between LBBB and mortality. Therefore, a prospective study with a longer follow-up would be needed to clarify the role of LBBB in mortality and establish causality between LBBB and VA in patients with TCM. Funding Acknowledgement Type of funding sources: None.

Cardiac shear wave elastography can detect the presence of a septal scar in patients with LBBB

Abstract Background In patients with heart failure and a left bundle branch block (LBBB), cardiac resynchronization therapy (CRT) is an established treatment. However, the rate of non-response to this costly therapy remains high. So far, CRT has proven to be less effective in patients with a septal scar. Detection of a septal scar before CRT implantation could therefore help to improve response rate to CRT. The gold standard to detect septal scarring, LGE MRI, is quite costly and not suited or available for all patients. Cardiac shear wave elastography (SWE) may be an alternative. It allows for the non-invasive assessment of myocardial stiffness based on the detection of shear waves, after for example mitral valve closure (MVC). SWE has shown to be capable to detect myocardial scar, however this has never been demonstrated in the presence of LBBB. Purpose To determine whether SWE is able to detect the presence of a septal scar in patients with LBBB. Methods To investigate this, 39 CRT patients with a LBBB were included with ischemic (n=10; age: 73±6 y; 70% males) or non-ischemic (n=29; 68±14 y; 52% males) cardiomyopathy and 9 age-matched healthy volunteers (68±4 y; 55% males) served as controls. In order to obtain native ventricular conduction biventricular (BiV) pacing was turned off. All ischemic patients had septal scar only, proven by MRI or scintigraphy. For SWE, left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (frame rate: 932±32 fps). Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed (Figure 1A). Results Patients characteristics and echocardiographic parameters are shown in Table 1. Shear wave speed after MVC was significantly higher in LBBB patients with and without a septal scar compared to healthy controls (7.8±1.2 m/s vs 4.5±1.1 m/s; p&amp;lt;0.001; 5.6±1.1 m/s vs 4.5±1.1 m/s; p=0.041; Figure 1B), indicating that the presence of LBBB increases myocardial stiffness. However, more importantly, shear wave speed was significantly higher in LBBB patients with a septal scar compared to LBBB patients without a septal scar (7.8±1.2 m/s vs 5.6±1.1 m/s; p&amp;lt;0.001; Figure 1B). This implies that the presence of a septal scar increases shear wave speed even more than LBBB alone. A ROC-curve analysis further showed that SWE is capable of distinguishing scarred from non-scarred septum in LBBB patients (AUC: 0.92; p&amp;lt;0.001; Figure 1C). A cut-off of 7.1 m/s could identify LBBB patients with a septal scar with a sensitivity of 80% and specificity of 93%. Conclusion Septal scarring results in a significant increase in myocardial stiffness, so that it reaches a clear pathological range. SWE seems therefore capable of detecting the presence of a septal scar in LBBB patients and could potentially be used as a novel approach for the assessment of septal scarring in CRT candidates. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research foundation Flanders (FWO)

Vulnerable Phase of Acute Heart Failure and its Association with Hospital Readmissions Reduction Program.

To determine the prevalence, characteristics and association with prognosis of left bundle branch block (LBBB) in 3 different cohorts of patients with acute heart failure (AHF).We retrospectively analyzed 12,950 patients with AHF who were included in the EAHFE (Epidemiology Acute Heart Failure Emergency), RICA (National Heart Failure Registry of the Spanish Internal Medicine Society), and BASEL-V (Basics in Acute Shortness of Breath Evaluation of Switzerland) registries. We independently analyzed the relationship between baseline and clinical characteristics and the presence of LBBB and the potential association of LBBB with 1-year all-cause mortality and a 90-day postdischarge combined endpoint (Emergency Department reconsultation, hospitalization or death). The prevalence of LBBB was 13.5% (95% confidence interval: 12.9%–14.0%). In all registries, patients with LBBB more commonly had coronary artery disease and previous episodes of AHF, were taking chronic spironolactone treatment, had lower left ventricular ejection fraction and systolic blood pressure values and higher NT-proBNP levels. There were no differences in risk for patients with LBBB in any cohort, with adjusted hazard ratios (95% confidence interval) for 1-year mortality in EAHFE/RICA/BASEL-V cohorts of 1.02 (0.89–1.17), 1.15 (0.95–1.38) and 1.32 (0.94–1.86), respectively, and for 90-day postdischarge combined endpoint of 1.00 (0.88–1.14), 1.14 (0.92–1.40) and 1.26 (0.84–1.89). These results were consistent in sensitivity analyses.Less than 20% of patients with AHF present LBBB, which is consistently associated with cardiovascular comorbidities, reduced left ventricular ejection fraction and more severe decompensations. Nonetheless, after taking these factors into account, LBBB in patients with AHF is not associated with worse outcomes.

Population-Level Impact of the Guidelines Update on Patient Selection and Outcomes After Cardiac Resynchronization Therapy

This study sought to analyze the impact of the American College of Cardiology, American Heart Association, and Heart Rhythm Society (ACC/AHA/HRS) guidelines for cardiac resynchronization therapy with defibrillator (CRT-D) update on utilization and efficacy of CRT-D. In September 2012, the ACC/AHA/HRS guidelines for CRT-D were modified to include left bundle branch block (LBBB) as a Class I indication. The IBM Watson MarketScan Database was queried between January 1, 2003, and December 31, 2018, for CRT-D implants or upgrades. The primary outcome was heart failure (HF) hospitalization following left ventricular lead implant. Secondary outcomes included all-cause mortality and device-related lead revision. A total of 27,238 patients were analyzed: 18,384 pre-update and 8,854 post-update. Mean age was 69 ± 11 years, 73% men, and 98% with history of HF hospitalization. The proportion of patients with LBBB increased from 29% to 55% (P< 0.001) after the update. Patients receiving CRT-D post-update demonstrated a greater prevalence of comorbidities, including atrial fibrillation (47% vs 40%; P< 0.001), diabetes mellitus (45% vs 39%; P< 0.001), chronic kidney disease (24% vs 15%; P< 0.001), and HF hospitalization in the year before CRT-D (40% vs 37%; P< 0.001). Despite greater baseline comorbidities, HF hospitalization significantly declined post-update (HR: 0.89; P< 0.001). Multivariate predictors of reduced HF hospitalization included angiotensin receptor neprilysin inhibitor prescription (HR: 0.48; P< 0.001) and presence of LBBB (HR: 0.71; P< 0.001). All-cause mortality was not significantly different between the 2 groups, and fewer lead revisions were noted post-update (0.6% vs 1.7%; P< 0.001). The revised 2012 guidelines led to an increased proportion of LBBB patients receiving CRT-D at the population-level. This change was associated with reduced HF hospitalization, despite broadening therapy to patients with more comorbid conditions.

Can cardiac shear wave elastography detect the presence of septal scar in patients with left bundle branch block?

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWO: Fonds Wetenschappelijk Onderzoek (fund for scientific research Flanders) Background Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients with left bundle branch block (LBBB). Regardless, CRT has proven to be less effective in patients with ischemic cardiomyopathy, in particular when the septum is affected. The detection of septal scar prior to CRT implantation could therefore help to improve response rate. However, magnetic resonance imaging (MRI), the gold standard to assess myocardial scar, cannot be used in every patient due to already implanted devices or impaired renal function. Cardiac shear wave elastography (SWE) allows for the non-invasive assessment of myocardial stiffness via the detection of shear waves, for example induced by mitral valve closure (MVC), that travel through the myocardium. Shear wave speed is directly related to tissue stiffness. Recently, SWE has shown to be capable to detect myocardial scar, however this has never been demonstrated in the presence of LBBB. Purpose To evaluate whether SWE is able to detect the presence of septal scar in patients with LBBB. Methods We included 34 heart failure patients with LBBB (age: 69 ± 13 y; 56% males) and with ischemic (n = 9) or non-ischemic (n = 25) cardiomyopathy and 9 age-matched healthy volunteers (age: 68 ± 4 y; 66% males) as controls. In order to obtain native ventricular conduction biventricular (BiV) pacing was turned off. All ischemic patients had septal scar only, proven by MRI or scintigraphy. For SWE, left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (frame rate: 932 ± 32 fps). Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed (Figure A). Results Patient characteristics including echocardiographic parameters are shown in Table 1. Shear wave speed after MVC was significantly higher in patients with LBBB with or without septal scar compared to healthy controls (7.9 ± 1.2 m/s vs 4.5 ± 1.1 m/s; p = 0.044; 5.6 ± 1.2 m/s vs 4.5 ± 1.1 m/s: p &amp;lt; 0.001; figure B). This implies that the presence of LBBB alone increases myocardial stiffness. Most importantly, however, shear wave speed was significantly higher in LBBB patients with a septal scar compared to LBBB patients without a septal scar (7.9 ± 1.2 m/s vs 5.6 ± 1.2 m/s; p &amp;lt; 0.001; figure B), indicating that the presence of scar increases myocardial stiffness even more than LBBB alone. Conclusions LBBB causes a mild but significant increase in shear wave propagation speed in non-ischemic patients compared to controls. The presence of septal scarring leads to an additional and more significant increase. This indicates that SWE is capable of detecting stiffer scarred myocardium even in the presence of LBBB. Therefore, SWE could potentially be used as a novel method to detect septal scarring in LBBB patients before CRT implantation. Abstract Figure. Abstract Figure.

Cardiac deformation imaging in differentiation between patients with ischemic versus non-ischemic dilated cardiomyopathy presented with Left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: None. Background Differentiation between ischemic (IDCM) and non-ischemic(NIDCM) cardiomyopathy using non-invasive image modalities is a clinical dilemma. Left bundle branch block (LBBB) imparts additional challenges into the etiologic diagnosis of DCM. This study employed 2D-strain imaging to characterize myocardial deformation and extent of mechanical discoordination in IDCM and NIDCM in presence of LBBB and their possible value for etiologic diagnosis. Methods We examined myocardial longitudinal&amp; circumferential strain at segmental &amp; global levels and LV twist [derived from basal and apical rotation] and electromechanical dyssynchrony in 36 DCM patients with LBBB. Of these patients, 16 were diagnosed with IDCM and 20 with NIDCM using coronary angiography, they were compared to 30 healthy controls. Results NIDCM were younger in age (45.7 ± 14 versus 61.5 ± 7.5, P&amp;lt;.0001) had larger LV end systolic (P&amp;lt;.03), end diastolic (P&amp;lt;.02) dimensions, LAV (P&amp;lt;.003), more mitral regurgitation(P&amp;lt;.02) and lower EF (31% vs 39%, P&amp;lt;.04). Compared with IDCM, patients with NIDCM had lower longitudinal strain of septal, lateral, inferior walls and global longitudinal strain (GLS), P&amp;lt;.001 and lower LV twist (1.64 ± 1.4º vs. 3.25 ± 2.1º, p&amp;lt; 0.01). IDCM had prevalent typical contraction activation (38% versus 5%) and higher electromechanical delay compared with NIDCM (P&amp;lt;.01). However, there was no significant difference in circumferential strain between LBBB groups. Using ROC analysis value of GLS &amp;lt;3.4% predicted NIDCM with 87.5% sensitivity and 78.9% specificity, area under curve is 0.836 and p &amp;lt; 0.001. Conclusion In dilated cardiomyopathy with LBBB, deformation imaging is offering newer mechanistic insights and enables detailed characterization of ischemic and non-ischemic etiologies in heart failure patients.

Prevalence, Related Factors and Association of Left Bundle Branch Block With Prognosis in Patients With Acute Heart Failure: a Simultaneous Analysis in 3 Independent Cohorts

To determine the prevalence, characteristics and association with prognosis of left bundle branch block (LBBB) in 3 different cohorts of patients with acute heart failure (AHF). We retrospectively analyzed 12,950 patients with AHF who were included in the EAHFE (Epidemiology Acute Heart Failure Emergency), RICA (National Heart Failure Registry of the Spanish Internal Medicine Society), and BASEL-V (Basics in Acute Shortness of Breath Evaluation of Switzerland) registries. We independently analyzed the relationship between baseline and clinical characteristics and the presence of LBBB and the potential association of LBBB with 1-year all-cause mortality and a 90-day postdischarge combined endpoint (Emergency Department reconsultation, hospitalization or death). The prevalence of LBBB was 13.5% (95% confidence interval: 12.9%-14.0%). In all registries, patients with LBBB more commonly had coronary artery disease and previous episodes of AHF, were taking chronic spironolactone treatment, had lower left ventricular ejection fraction and systolic blood pressure values and higher NT-proBNP levels. There were no differences in risk for patients with LBBB in any cohort, with adjusted hazard ratios (95% confidence interval) for 1-year mortality in EAHFE/RICA/BASEL-V cohorts of 1.02 (0.89-1.17), 1.15 (0.95-1.38) and 1.32 (0.94-1.86), respectively, and for 90-day postdischarge combined endpoint of 1.00 (0.88-1.14), 1.14 (0.92-1.40) and 1.26 (0.84-1.89). These results were consistent in sensitivity analyses. Less than 20% of patients with AHF present LBBB, which is consistently associated with cardiovascular comorbidities, reduced left ventricular ejection fraction and more severe decompensations. Nonetheless, after taking these factors into account, LBBB in patients with AHF is not associated with worse outcomes.

How to Estimate QT Interval in Patients With Left or Right Bundle Branch Block: A Systematic Review.

Prolonged QT interval related to psychopharmacological treatment is a risk factor for potentially life-threatening arrhythmias. Electrocardiographic measurements are recommended in patients with cardiovascular risk factors before initiating treatment with potentially QT-prolonging medications, such as certain antidepressants or antipsychotics. In patients with left bundle branch block (LBBB) or right bundle branch block (RBBB), conventional QT-estimation methods will lead to overestimation of the QT interval, as the conduction defect, reflected by the QRS duration, will increase the QT interval without representing longer repolarization as in drug-induced QT prolongation. We conducted a systematic review of methods to estimate QT interval in the presence of LBBB or RBBB. We searched electronic databases Embase and Medline (last search, August 12, 2020). We found 8 different methods, including linear correction formulae with and without correction for heart rate, or simpler formula correcting QRS duration with empirically derived modifiers. Only 3 of 8 methods were applicable in the presence of RBBB, whereas all 8 methods could be applied in the presence of LBBB. The QT interval is overestimated in patients with LBBB or RBBB, when using conventional measurements. Several alternative correction formulae exist, which can be applied using standard measurements from ordinary electrocardiographic readings. However, it is currently unknown whether or not the QT prolongation observed in the presence of bundle branch block significantly increases the risk of arrhythmias, as these formulae have not been tested against patient-specific clinical outcomes.

Utility of echocardiography in patients with suspected acute myocardial infarction in the presence of left bundle-branch block

Abstract Background Rapid identification of acute myocardial infarction (AMI) as life-threatening disorder by clinical assessment, cardiac troponin and the electrocardiogram (ECG) is important for the early initiation of highly effective, evidence-based therapy. Patients presenting with suspected AMI and left bundle branch block (LBBB) to the emergency department (ED) represent a unique diagnostic and therapeutic challenge, as altered ventricular depolarization masks changes in ventricular repolarization associated with myocardial ischemia. Current guidelines suggest, based on expert opinion, early echocardiography as a helpful tool in patients with suspected AMI and LBBB to identify new wall motion abnormalities, which guides further diagnostics strategies in these patients. Purpose To evaluate the diagnostic accuracy of echocardiography among patients with suspected AMI and LBBB in the recorded ECG at ED presentation. Methods We prospectively evaluated the diagnostic accuracy of echocardiography in patients with LBBB presenting with chest discomfort to 26 ED's in three international, prospective, diagnostic studies. Two independent cardiologists centrally adjudicated the final diagnosis in each study according to the universal definition of myocardial infarction. All patients underwent a clinical assessment that included standardized and detailed medical history including assessment of chest pain characteristics, vital signs, physical examination, 12-lead ECG, continuous ECG rhythm monitoring, pulse oximetry, standard blood test, and chest radiography and echocardiography if indicated. We compared echocardiographic findings in patients with LBBB who were diagnosed with an AMI to those without an AMI. Results Among 283 patients presenting with chest pain and LBBB to the ED, AMI was the final diagnosis in 36% (102 of 283 patients) of patients. An echocardiography had been performed in 100/283 patients (35%) in the emergency department. AMI was the final diagnosis in 41/100 (41%) of patients. A wall motion abnormality in any region was seen in 77 (77%) of patients with no difference between patients diagnosed with AMI (33 patients, 81%) versus without AMI (44 patients, 75%, p=0.49). Additionally, we found no differences for each wall region (Table 1). Most patients with LBBB had moderately reduced left ventricular ejection fraction (LVEF, median 40%), a dilated left atrium (67%) or left ventricular hypertrophy (55%) without any differences between the two groups (Table 1). Conclusions Early echocardiography in patients with suspected AMI and LBBB provided only limited utility to identify patients, which may benefit from immediate coronary angiography. Our findings scrutinize current guidelines and downgrades the utility of echocardiography in this setting. Funding Acknowledgement Type of funding source: Other. Main funding source(s): Swiss National Science Foundation, the Swiss Heart Foundation, the European Union, the Cardiovascular Research Foundation Basel, the University Hospital Basel, Queensland Emergency Medicine Research Foundation, Christchurch Heart Institute and Health Research Council and Heart Foundation of New Zealand, Christchurch Emergency Care Foundation

Long-Term Outcomes in Patients With a Left Ejection Fraction≤15% Undergoing CardiacResynchronization Therapy.

This study aimed to determine the long-term outcomes and predictors of left ventricular (LV) ejection fraction (LVEF) improvement in patients with severe cardiomyopathies undergoing cardiac resynchronization therapy (CRT). Whether patients with severe LV dysfunction benefit from CRT or have reached a point in disease severity past the point at which CRT is beneficial is unknown. We collected clinical and echocardiographic data on 420 patients with an LVEF of≤15% and a QRS duration of≥120ms undergoing CRT at the Cleveland Clinic and 2 hospitals in the Johns Hopkins Health System between April 2003 and May 2014. Multivariate models were created to determine factors associated with response to CRT, defined as an absolute improvement in LVEF of >5% and survival free of LVAD and heart transplant. Procedure-related deaths were also collected. A total of 298 patients had pre- and appropriately timed post-CRT echocardiograms, of whom 145 (48.7%) met the criteria for response. In multivariate analysis, LV size and left bundle branch block (LBBB) were associated with response. Among the most dilated quintile (LV end-diastolic diameter [LVEDD] of >7.8cm), 30.4% met the criteria for response. In multivariate analysis, smaller LV end-diastolic dysfunction and presence of LBBB were associated with improved survival free of heart failure and LVAD over a mean follow-up period of 5.2 years. There were no procedure-related deaths. Patients with severe LV dysfunction respond to CRT, although at a lower rate compared to traditional CRT candidates. Smaller LV size and LBBB are important predictors of positive outcomes in this population. Even among the most dilated patients, 30.4% realized a meaningful improvement in LVEF with CRT. The CRT implant procedure itself appears well tolerated.

His-bundle and left bundle pacing with optimized atrioventricular delay achieve superior electrical synchrony over endocardial and epicardial pacing in left bundle branch block patients

His-bundle pacing (HBP) and left bundle pacing (LBP) are emerging as novel delivery methods for cardiac resynchronization therapy (CRT) in heart failure patients with left bundle branch block (LBBB). HBP and LBP have never been compared to biventricular endocardial (BiV-endo) pacing. Furthermore, there are indications of negative effects of LBP on right ventricular (RV) activation times (ATs), but these effects have not been quantified. The purpose of this study was to compare changes in ventricular activation induced by HBP, LBP, left ventricular (LV) septal pacing, BiV-endo, and biventricular epicardial (BiV-epi) pacing using computer simulations. We simulated ventricular activation on 24 four-chamber heart meshes inclusive of the His-Purkinje network in the presence of LBBB. We simulated BiV-epi pacing, BiV-endo pacing with left ventricular (LV) lead at the lateral wall, BiV-endo pacing with LV lead at the LV septum, HBP, and LBP. HBP was superior to BiV-endo and BiV-epi in terms of reduction in LV ATs and interventricular dyssynchrony (P <.05). LBP reduced LV ATs but not interventricular dyssynchrony compared to BiV-epi and BiV-endo pacing. RV latest AT was higher with LBP than with HBP (141.3 ± 10.0 ms vs 111.8±10.4 ms). Optimizing AV delay during LBP reduced RV latest AT (104.7 ± 8.7 ms) and led to comparable response to HBP. In case of complete AV block, BiV-endo septal pacing was equivalent to LBP. HBP is superior to BiV-epi and BiV-endo. To achieve comparable response to HBP, AV delay optimization during LBP is required in order to reduce RV ATs.

Angiographic pattern of patients with left bundle branch block: A comparative cross-sectional study

Objectives: We purposed to determine the relationship between left bundle branch block (LBBB) and coronary artery disease (CAD) site, severity, and CAD risk factors. Methods: Eighty patients with LBBB were sorted into two groups based on coronary angiography (CA) findings: Group 1: 56 patients with CAD (stenosis ≥70% in ≥1 epicardial vessel) and Group 2: 24 patients with normal coronaries. Results: Our observations confirm male preponderance of LBBB and affirm hypertension and diabetes as common risk factors for CAD within this subpopulation. Hence, these risk factors can be considered a strong predictor of CAD in LBBB. Cardiac echocardiography data suggest that LBBB and CAD are associated with regional hypokinesia and decreased ejection fraction. The most frequently diseased vessel was left anterior descending (LAD), followed by left circumflex then right coronary artery. Our study CA showed single-vessel disease (SVD) in 37 participants (46.3%), two-vessel disease in 16 subjects (20%), three-vessel disease in 3 subjects (3.8%), and normal vessels in 24 participants (30%). Hence, SVD frequency was high in our study. Conclusion: The risk for left ventricular dysfunction and SVD more commonly LAD artery involvement had increased in the presence of LBBB in electrocardiogram. CA present only in tertiary centers, which considered a major and invasive diagnostic tool for CAD, so selection criteria are required to predict patients with LBBB who are prone to be at risk of CAD and need this invasive procedure, on the other hand, avoid CAD overdiagnosis, unnecessary admissions to hospital, and antianginal drugs consumption.

P782 Septal flash is a prevalent and early dyssynchrony marker in transcatheter aortic valve replacement-induced left bundle branch block

Abstract BACKGROUND New-onset left bundle branch block (LBBB) is a frequent complication after transcutaneous aortic valve replacement (TAVR). LBBB is associated with echocardiographic dyssynchrony in heart failure patients, but this has not been thoroughly investigated in acute LBBB following TAVR. PURPOSE This study aims to assess the timing and incidence of echocardiographic dyssynchrony in acute TAVR-induced LBBB patients. METHODS The study enrolled all TAVR-induced LBBB patients at our Hospital between January 2013 and May 2019. Presence of LBBB was scored within 72 hours following TAVR. Dyssynchrony was assessed by: 1/ presence of septal flash (SF), 2/ interventricular mechanical delay (IVMD, the difference between left and right ventricular pre-ejection interval using pulsed wave Doppler; cut-off ≥40 ms) and 3/ presence of ‘classical dyssynchronous strain pattern’ assessed with speckle tracking (Figure 1). As a control, these three LBBB-related dyssynchrony markers were assessed and compared to LBBB patients without TAVR (non-TAVR patients) in normal ànd reduced EF, but all having SF. RESULTS Out of 134 consecutive TAVR procedures, 30 (22%) were complicated by acute LBBB. SF was present in 72% of TAVR-induced LBBB patients, with a median time from TAVR to SF diagnosis of 24 hours. However, only 1 (5%) of these TAVR patients exhibited a classical dyssynchronous contraction strain pattern (Figure 1), despite presence of SF. Finally, the IVMD values in these TAVR-LBBB patients did not meet the ‘dyssynchrony’ cut-off. As a control, we compared these dyssynchrony parameters in patients with non-TAVR related LBBB with normal and reduced EF, all exhibiting SF. A classical strain pattern was present in 33% of non-TAVR LBBB patients with preserved left ventricular ejection fraction (LV EF) (p = 0.17), and in 80% of non-TAVR LBBB patients with reduced LV EF ≤30% (p &amp;lt; 0.001). The IVMD in non-TAVR LBBB patients with SF and preserved LV EF was 52 ms (p = 0.002) and 57 ms in non-TAVR LBBB patients with SF and LV EF ≤30% (p = 0.009). CONCLUSION SF as dyssynchrony marker develops early after TAVR-induced LBBB and is much more prevalent than the classical strain-based dyssynchrony pattern and IVMD. Our findings from the control population suggest that progressive LBBB-induced LV remodeling (septal thinning and relative lateral thickening) may be required for a ‘classical dyssynchrony strain pattern’ or significant IVMD to occur in TAVR-LBBB patients, but longitudinal follow-up studies in TAVR-LBBB patients are required as proof-of-concept. Abstract P782 Figure 1