Complete Bundle Branch Block Research Articles

Temporal evolution of His bundle pacing thresholds: a sub-study of the PACE-CONDUCT trial

Abstract Background His bundle pacing (HBP) has become a valuable alternative for cardiac resynchronization therapy, offering physiological pacing. This substudy of the PACE-CONDUCT trial aimed to explore the influence selective and non-selective HBP on threshold height. We assessed these parameters in patients with both normal conduction and bundle branch block conduction. Methods Our study included 61 consecutive patients with a median age of 73 years, who underwent a successful HBP implantation for indications such as sick sinus syndrome, AV Block 2 type 2, binodal disease, and ablate and pace therapy prior to AV-node ablation. Among these patients, 18 exhibited QRS durations exceeding 150 ms, indicating a complete and broad bundle branch block which made them candidates for cardiac resynchronization therapy (CRT). All patients received HBP implantation with the assistance of a 3D electroanatomical system. This system allowed for low-fluoroscopic, atraumatic evaluation of the His bundle (HB) area, presenting the His voltage as a color-coded map for precise electrode placement. Results The feasibility of bundle branch correction is generally accepted in selective HBP distal to the site of block, albeit associated with higher threshold values and potentially lower battery duration. Our analysis encompassed 61 patients who underwent HBP implantation, with 23 patients (37,7%) exhibiting selective HBP and 38 (62,3%) non-selective HBP. Remarkably, 10 out of the 23 patients with selective HBP demonstrated a complete bundle branch block correction after HBP implantation even with a basal QRS durations exceeding 150 ms. We evaluated HBP thresholds at implantation, one day post-implantation, and one month post-implantation, correlating these data with selective and non-selective HBP. Threshold values were converted to volts per millisecond (volts × milliseconds) for analysis. Statistical analysis conducted with IBM SPSS 29.0 revealed a significant difference at the day of implantation, indicating higher threshold capture in selective HBP compared to non-selective HBP (one-sided p-value: < 0.01, two sided p value 0.01). However, this difference could not be sustained at the one-day and one-month threshold follow-ups, suggesting normalization of the selective HBP threshold. Conclusion In our study, the initially higher threshold in selective HBP normalized within 24 hours compared to non-selective HBP. Additionally, our study demonstrated the feasibility of selective His pacing in patients with complete bundle branch block and broad QRS durations. These findings provide insights into HBP optimization and encourage further investigations with larger patient cohorts to validate our observations and enhance patient care in the realm of cardiac pacing.Threshold trend

Is electrophysiological study a novel predictor for permanent pacemaker implantation after transcatheter aortic valve implantation?

Despite advancements in valve technology and increased clinical experience, complications related to conduction defects after transcatheter aortic valve implantation (TAVR) have not improved as rapidly as expected. In this study, we aimed to predict the development of complete atrioventricular (AV) block and bundle branch block during and after the TAVR procedure and to investigate any changes in the cardiac conduction system before and after the procedure using electrophysiological study. A total of 30 patients who were scheduled for TAVR at our cardiovascular council were planned to be included in the study. TAVR was performed on patients at Erciyes University Medical Faculty Hospital as a single center between May 2019 and August 2020 Diagnostic electrophysiological study was performed before the TAVR procedure and after its completion. Changes in the cardiac conduction system during the preprocedure, intra-procedure, and postprocedure periods were recorded. Significant increases in baseline cycle length, atrial-His (AH) interval, his-ventricular (HV) interval and atrioventricular (AV) distance were observed before and after the TAVR procedure (p = 0.039, p < 0.001, p = 0.018, p < 0.001, respectively). During the TAVR procedure, the preprocedural HV interval was longer in patients who developed AV block and bundle branch block compared to those who did not and this difference was statistically significant (p = 0.024). ROC curve analysis revealed that a TAVR preprocedure HV value >59.5 ms had 86% specificity and 75% sensitivity in detecting AV block and bundle branch block (AUC = 0.83, 95% CI: 0.664-0.996, p = 0.013). The preprocedure HV distance was 98 ± 10.55ms in the group with permanent pacemaker implantation and the mean value in the group without permanent pacemaker implantation was 66.27 ± 15.55 ms, showing a borderline significant difference (p = 0.049). The prolongation of HV interval in patients with AV block and bundle branch block suggests that the block predominantly occurs at the infra-hisian level. Patients with longer preprocedural HV intervals should be closely monitored for the need for permanent pacemaker implantation after the TAVR procedure.

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

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. Patients with aortic stenosis undergoing AVR were included. The apical-to-basal strain ratio was calculated by dividing the average strain of the basal segments by the average strain of the apical 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. Two hundred seventy-four patients were included (74 years (IQR 65, 80), 46.4% male). During a median follow-up of 12.2 months (IQR 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 = 0.007). 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. 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.

Machine learning based electrocardiogram peaks analyzer for Wolff-Parkinson-White syndrome

The slurred upstroke named Delta in an Electrocardiogram (ECG) signal is known as the main indicator of the existence of the Wolff-Parkinson-White (WPW) pattern. Previous studies propose methods of detection based only on the position of the well-known peaks (P, Q, R, S, and T) where it might suffer from confusion with other pathologies patterns such as complete bundle branch block. This work introduces a new robust method for precisely detecting the actual location of Delta wave using signal peaks scan cooperating with machine learning algorithms that could be trained for any ECG lead. The method is sequenced in seven steps which include the detection of P, QRS, and T waves. Each step represents a machine learning model which considers the statistical parameters of the signal for either selecting an appropriate feature of the signal or manipulating a function for peaks scan or tangent deviation scan. The method is performed using Neural Networks, Naïve Bayes, and K-Nearest Neighbors (KNN) algorithms on 122 signals from the MIT-BIH Arrhythmia database. The performance is evaluated in different cross-validation configurations, where Neural Networks and KNN recorded the highest precision in holdout cross-validation with mean accuracy, sensitivity, specificity, and MASE of the seven steps of 99.25%, 97.16%, 74.37%, 2.33 respectively from Neural Networks performance, and of 99.11%, 94.64%, 74.37%, 1.26 respectively from KNN performance. Naïve Bayes obtained the same evaluation metrics results in 3-fold cross-validation with 81.23%, 46.91%, 57.84%, and 5.63 respectively.

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

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. 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. 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). 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.

Left bundle branch area pacing guided by electroanatomical mapping in patients with structural heart disease and advanced conduction abnormalities

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch area pacing (LBBAP) can be technically challenging and fluoroscopy-intense, particularly in patients with structural heart disease (SHD) and advanced conduction abnormalities. Three-dimensional electroanatomical mapping (EAM) facilitates high-resolution, real-time, and non-fluoroscopic lead navigation, electrogram and pace mapping. Purpose The purpose of the study was to prospectively evaluate the feasibility, safety, and outcomes of routine EAM-guided LBBAP in patients with SHD and advanced conduction abnormalities. Methods Consecutive patients with SHD and advanced conduction abnormalities (defined as second or third-degree atrioventricular (AV) block and/or complete bundle branch block) who underwent an attempt at EAM-guided LBBAP were included. EAM-guided lead implantation was performed in all patients following a standardized protocol irrespective of the pacing indication and type of conduction disturbance. The feasibility, safety, procedural and mid-term outcomes were evaluated. Electrical, echocardiographic, and clinical parameters were assessed at implantation and last follow-up. Results Thirty-two patients (68±18 years; 19% female) were included. The indication for pacing was cardiac resynchronization therapy in 50%, AV block in 44%, and pace-and-ablate in 6% of patients; 24 patients (75%) had an intrinsic QRS &amp;gt;150 ms, 17 (53%) had LBBB. Primary EAM-guided LBBAP was successful in 29 patients (91%). Procedural duration was 95 (70-110) min, total fluoroscopy time 0.93 (0.40-1.73) min, and total fluoroscopy dose 35.4 (20.5-77.2) cGycm2 (Figure 1A). The paced QRS duration during LBBAP was significantly shorter than the baseline intrinsic QRS duration (121.9±10.7 vs. 159.2±34.4 ms; p&amp;lt;0.001) (Figure 1B) and remained stable (120.3±11.1 ms; p=0.370) during a mean follow-up of 7.0±5.9 (median 5.4 [IQR 2.1-12.6]) months. LBBAP capture threshold was 0.57±0.23V/0.4ms at implantation and remained low during follow-up (0.58±0.18V/0.5±0.2ms; p=0.877). There was no increase in LBBAP capture threshold &amp;gt;1.0V/0.4 ms during follow-up. Overall LVEF improved significantly from 44.2±14.3% at baseline to 49.4±13.1% at last follow-up (p=0.009), NYHA functional class from 2.4±0.6 to 1.8±0.6 (p=0.002), respectively (Figure 1C+D). No complications occurred that required intervention. Conclusion Routine near-zero fluoroscopy EAM-guided LBBAP can safely be performed in patients with SHD and advanced conduction abnormalities with high success rates and favourable mid-term outcomes. Further studies are needed to investigate whether the use of EAM improves overall outcome of conduction system pacing, and to identify specific patient populations who benefit the most from EAM-guided lead implantation.

Riesgo arrítmico en episodios únicos o recurrentes de síncope inexplicado con bloqueo completo de rama

Introduction and objectivesPatients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. MethodsCohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. ResultsOf the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. ConclusionsPatients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.Full English text available from:www.revespcardiol.org/en

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

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

Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block

Introduction and objectivesPatients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. MethodsCohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. ResultsOf the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. ConclusionsPatients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.

A unique cardiac electrocardiographic 3D model. Toward interpretable AI diagnosis.

Mathematical models of cardiac electrical activity are one of the most important tools for elucidating information about heart diagnostics. In this paper, we present an efficient mathematical formulation for this modeling simple enough to be easily parameterized and rich enough to provide realistic signals. It relies on a five dipole representation of the cardiac electric source, each one associated with the well-known waves of the electrocardiogram signal. Beyond the physical basis of the model, the parameters are physiologically interpretable as they characterize the wave shape, similar to what a physician would look for in signals, thus making them very useful in diagnosis. The model accurately reproduces the electrocardiogram signals of any diseased or healthy heart. This new discovery represents a significant advance in electrocardiography research. It is especially useful for diagnosis, patient follow-up or decision-making on new therapies; is also a promising tool for well-performing, transparent and interpretable AI approaches.

PO49 Presentation Time: 10:00 AM: Prevalence of QTc Prolongation in Prostate Cancer Patients Undergoing Brachytherapy

<h3>Purpose</h3> QTc has been associated not only with a higher risk of Torsade de Pointes (TdP), sudden cardiac arrest but also with general cardiac mortality, including cardiovascular and coronary death. We examined the prevalence of prolonged QTc interval in prostate cancer patients undergoing brachytherapy in general and in patients with more aggressive cancers who may be exposed to ADT and compared them to patients who underwent prostatectomy. <h3>Materials and Methods</h3> We randomly selected 1094 patients treated with either low-dose rate (LDR) or high-dose rate (HDR) brachytherapy between August 2010 and February 2022 from our internal database. All patients had an ECG as part of the preoperative work-up. The QTc was automatically calculated using the Bazett formula. Excluded were patients with left or complete bundle branch block, ventricular extrasystoles, atrial fibrillation, presence of a pacemaker or a QRS ≥ 120 ms. .As primary outcome, a QTc ≥450ms was considered abnormal. Chi-square or Fisher's exact test, when appropriate was used to compare groups. Pearson correlation coefficient and binary multivariable regression analysis was used to evaluate correlations between QTc and clinical values. <h3>Results</h3> A total of 6.2% (n=68) had a QTc ≥450ms. Patients with a Cancer of the Prostate Risk Assessment (CAPRA) high risk disease (score 6-10) were significantly more likely to have a QTc ≥450ms than patients with low-or intermediate risk (9.7% vs. 5.5%, p=0.039). QTc as a continuous variable correlated weakly with the neutrophil count (r=0.13, p<0.001), age (r=0.08, p=0.009) and inversely with testosterone (r=-0.17, p=0.002). On binary multivariable regression analysis including neutrophils, testosterone and age, only testosterone [nmol/L] was predictive of a QTc ≥450ms, OR 0.9, 95% CI 0.82-0.98, p=0.02. We then compared the patients treated with brachytherapy to 178 patients who underwent prostatectomy. The latter had a non-significantly smaller portion of patient with a QTc ≥450ms: 4.5% vs. 6.2%, p=0.5. <h3>Conclusions</h3> Our data show that about 10% of patients with high-risk prostate cancer are at increased risk of TdP. Treating physicians should be aware of this and monitor the QTc during ADT to possible decrease cardiac mortality in these patients who require ADT. The correlation between increasing age, neutrophil count and low testosterone with QTc prolongation links inflammation and hypogonadism.

Compelling new electrocardiographic markers for automatic diagnosis

Background and Objective: The automatic diagnosis of heart diseases from the electrocardiogram (ECG) signal is crucial in clinical decision-making. However, the use of computer-based decision rules in clinical practice is still deficient, mainly due to their complexity and a lack of medical interpretation. The objetive of this research is to address these issues by providing valuable diagnostic rules that can be easily implemented in clinical practice. In this research, efficient diagnostic rules friendly in clinical practice are provided. Methods: In this paper, interesting parameters obtained from the ECG signals analysis are presented and two simple rules for automatic diagnosis of Bundle Branch Blocks are defined using new markers derived from the so-called FMMecg delineator. The main advantages of these markers are the good statistical properties and their clear interpretation in clinically meaningful terms. Results: High sensitivity and specificity values have been obtained using the proposed rules with data from more than 35,000 patients from well known benchmarking databases. In particular, to identify Complete Left Bundle Branch Blocks and differentiate this condition from subjects without heart diseases, sensitivity and specificity values ranging from 93% to 99% and from 96% to 99%, respectively. The new markers and the automatic diagnosis are easily available at https://fmmmodel.shinyapps.io/fmmEcg/, an app specifically developed for any given ECG signal. Conclusions: The proposal is different from others in the literature and it is compelling for three main reasons. On the one hand, the markers have a concise electrocardiographic interpretation. On the other hand, the diagnosis rules have a very high accuracy. Finally, the markers can be provided by any device that registers the ECG signal and the automatic diagnosis is made straightforwardly, in contrast to the black-box and deep learning algorithms.

Beyond the wrist: Using a smartwatch electrocardiogram to detect electrocardiographic abnormalities

When worn on the wrist, smartwatch electrocardiograms may provide important but incomplete information. We sought to evaluate the added benefit of placing the smartwatch on the ankle and on the chest to diagnose various electrocardiographic abnormalities compared with 12-lead electrocardiograms. Two hundred and sixty patients with (n=189) or without (n=71) known cardiac disorders underwent 12-lead electrocardiogram and smartwatch electrocardiogram recordings of lead I (AW-I) and of leads I and II and pseudo chest leads V1 and V6 (AW-4). AW-I and AW-4 diagnoses (three-cardiologist consensus) were compared with 12-lead electrocardiogram diagnoses (three-cardiologist consensus) to calculate sensitivity and specificity. AW-I showed high accuracy for the diagnoses of atrial fibrillation (96% sensitivity, 91% specificity) and complete bundle branch block (85% sensitivity, 98% specificity). Compared with AW-I, AW-4 improved detection of an abnormal 12-lead electrocardiogram (91% vs. 80% sensitivity; P<0.01), atrial flutter/tachycardia (69% vs. 25% sensitivity; P=0.04), T-wave abnormalities (77% vs. 34% sensitivity; P<0.01), pathological Q-waves (41% vs. 7% sensitivity; P<0.01) and left anterior hemiblock (70% vs. 0% sensitivity; P=0.02). AW-4 also enabled better differentiation between atrioventricular block and sinus bradycardia (from 81% to 95% correct; P=0.03) and between atrial fibrillation and atrial flutter/tachycardia (from 71% to 89% correct; P=0.02), but not between bundle branch blocks (from 82% to 87% correct; P=0.57). A smartwatch electrocardiogram on the wrist accurately diagnoses atrial fibrillation and bundle branch block. Recording additional leads significantly improves the accuracy of detecting an abnormal electrocardiogram and repolarization changes, and also allows for better differentiation of brady- and tachyarrhythmias.

No evidence of association between habitual physical activity and ECG traits: Insights from the electronic Framingham Heart Study

No evidence of association between habitual physical activity and ECG traits: Insights from the electronic Framingham Heart Study

Performance of a novel ECG criterion for improving detection of left ventricular hypertrophy: a cross-sectional study in a general Chinese population

ObjectivesThe sensitivity of ECG for detecting left ventricular hypertrophy (LVH) is low. The aim of this study was to explore a better ECG criterion for screening LVH in a large...

Isolated right ventricular noncompaction in an adult woman with severe pulmonary hypertension following at the intensive care unit

Pulmonary hypertension is defined by a mean pulmonary artery pressure ≥25 mmHg at rest, measured during right heart catheterization. Ventricular noncompaction is a genetic cardiomyopathy which mostly effects left ventricle. It is related with deterioration of myocardial embryogenesis and commonly together with other cardiac diseases (1). Isolated ventricular non-compaction is characterized by modified morphology of myocardial wall, increased trabeculation in ventricular cavity and deep intertrabecular recesses. A 43-year-old woman presented exercise induced dyspnea and atypical chest pain. She has not any medical history prior. On admission, her 12 lead ECG showed complete righ bundle branch block, her blood pressure was 120/80 and pulse rate 80 per minutes. Transthoracic 2D echocardiogram and magnetic resonance imaging showed dilated and hypertrophied right ventricle with non-compaction of the right ventricular apex. The systolic pulmonary arterial pressure was 80 mmHg on the Doppler echocardiography. The coronary angiography revealed normal coronary arteries. The catheterization was showed pulmonary hypertension, right ventricle non-compaction and negative pulmonary vasoreactivity testing. Ventricular noncompaction, especially right ventricular noncompaction, complicated by severe pulmonary hypertension is exceptional. Only a few isolated right ventricular noncompaction has been reported but inclusion of pulmonary hypertesion cases are rare subsets . Diagnosis of pulmonary hypertension may be a consequence of increased pulmonary venous pressures caused by systolic and diastolic ventricular dysfunction secondary to right ventricular noncompaction. Widespread usage of cardiac magnetic resonance imaging, may enhance visual quality and evaluation of ventricular morphology, probably this will provide prevalance increment and clinical outcome improvements. Early diagnosis would bring better results.

Anatomical localization and classification of bundle branch blocks using novel CineECG

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the Dutch Heart Foundation Background Ventricular conduction disorders can induce arrhythmias and impair cardiac function. Bundle branch blocks are diagnosed by 12-lead ECG, but discrimination between complete bundle branch blocks, incomplete bundle branch blocks and normal tracings can be challenging. CineECG computes the mean temporo-spatial isochrone (mTSI) trajectory of activation waveforms in a 3D-heart model from 12-lead ECGs. This trajectory represents the mean trajectory of the ventricular electrical activation at any time interval directly related to ventricular anatomy. In Brugada patients, CineECG has localized the terminal components of ventricular depolarization to right ventricle outflow tract (RVOT). Also, for the localization of bundle branch blocks, the region of latest activation contains the most information. Using CineECG, subject specific anatomically related information about the location of bundle branch blocks is obtained. Purpose This study aimed at exploring whether CineECG can improve the discrimination between complete left/right bundle branch blocks (LBBB/RBBB), and incomplete RBBB (iRBBB). Methods We utilized 400 12-lead ECGs from the online Physionet-XL-PTB-Diagnostic ECG Database with a certified ECG diagnosis. The mTSI trajectory was calculated and projected into the anatomical 3D-heart model. Five CineECG classes were established: "Normal", "iRBBB", "RBBB", "LBBB" and "Undetermined", to which each tracing was allocated. We determined the accuracy of CineECG classification with the gold standard diagnosis. Results A total of 391 ECGs were analyzed (9 ECGs were excluded for noise) and 240/266 were correctly classified as "normal", 14/17 as "iRBBB", 55/55 as "RBBB", 51/51 as "LBBB" and 31 as "undetermined". Average mTSI trajectories were calculated according to ECG diagnosis (Figure). The terminal mTSI contained most information about the BBB localization, as that part directs to the site of latest activation (Figure, red arrow). Conclusion CineECG provided the anatomical localization of different BBBs and accurately differentiated between normal, LBBB and RBBB, and iRBBB. CineECG may aid clinical diagnostic work-up, potentially also contributing to the difficult discrimination between normal, iRBBB and Brugada patients. Abstract Figure. Average CineECG trajectories

Impact of Baseline and Newly Acquired Conduction Disorders on Need for Permanent Pacemakers With 3 Consecutive Generations of Self-Expanding Transcatheter Aortic Heart Valves

IntroductionWe aimed to compare conduction dynamics and need for permanent pacemaker implantation (PPI) after CoreValve, Evolut R and PRO (transcatheter aortic valve replacement (TAVR)). MethodsPatients were stratified based on conduction at baseline; Cohort A had normal conduction, Cohort B had conduction abnormalities including atrioventricular (AV)-block, fascicular block or complete bundle branch block. Three different dynamic QRS-patterns were defined: stable QRS-duration, transient QRS-prolongation and persistent QRS-prolongation. We performed multivariable regression analysis to estimate the effect of the three separate transcatheter heart valves (THV's) on need for PPI at 30 days. ResultsTAVR was performed with CoreValve (N = 113), Evolut R (N = 157) or Evolut PRO (N = 92). Conduction dynamics were similar between the different THVs. Overall, Evolut R and PRO showed a tendency towards less PPI compared to CoreValve (17% vs. 19% vs. 27%, P = 0.08), which was driven by a lower PPI rate in Cohort A (6% vs. 11% vs. 25%, P = 0.002). Need for PPI was restricted to patients with persistent QRS-prolongation in Cohort A (26/106) but did not correlate with conduction dynamics in Cohort B. In multivariable logistic regression analysis the use of Evolut R (OR 0.38, 95% CI 0.19–0.78, P = 0.008) and PRO (OR 0.41, 95% CI 0.19–0.91, P-value = 0.028) were independently associated with less need for PPI. ConclusionThe newer generations Evolut R and PRO were associated with less PPI compared to CoreValve. Acquired persistent conduction abnormalities predicted PPI after TAVR only in patients with normal conduction at baseline. Our findings may help identify eligible patients for early discharge after Evolut R/PRO TAVR.

Incidence and predictors of arrhythmias in patients with systemic sclerosis and no overt cardiac disease

Abstract Background Cardiac involvement in SSc is frequent, mostly subclinical and represents a negative prognostic factor. Speckle tracking derived measurement global longitudinal strain (GLS) has been able to identify primary heart involvement in patients with SSc and no overt cardiac disease. SSc-related cardiomyopathy, defined as a condition affecting the heart primarily and globally, has been proven to progress over time and seems to be correlated to cardiac arrhythmias. Nonetheless, cardiac arrhythmias represent 6% of the overall causes of death in SSc patients. Purpose The aim of our study was to assess the incidence of cardiac arrhythmias in SSc patients with no overt cardiac disease and to identify potential predictors. Methods Prospective longitudinal study enrolling all consecutive patients with a diagnosis of SSc and no overt cardiac disease or pulmonary hypertension. Echocardiographic parameters and GLS were obtained at baseline and at each follow up. Presence of atrial fibrillation (AF), atrial tachycardia (AT), ventricular ectopic beats &amp;gt;1000/24 h (VEB), supraventricular ectopic beats (SVEB), bundle branch block (BBB) and atrioventricular block (AVB) was assessed through clinical history, ECG and 24-Holter monitoring over time. Results Among 67 consecutive patients with SSc, 11 (16.7%) had at least one episode of AF or AT. Moreover, respectively 12 (17.9%) and 16 (23.9%) had a significant amount of SVEB and VEB at Holter monitoring. Conduction defects were common, with 4 (4.6%) of all patients with grade I AVB, 1 (1.5%) with grade II AVB and 1 (1.5%) with complete heart block. Complete right BBB was seen in 6 (6.9%) of patients. Four patients (4.6%) experienced a sudden cardiac death during follow-up (median 20 months, 1st-3rd quartile 12–24 months). Years from SSc diagnosis (RR 1.10; 95% CI 1.02–1.23; p=0.047) and indexed right atrial volume (iRAV; RR 1.22; 95% CI 1.07–1.39; p=0.004), but not indexed left atrial volume were independently correlated with the diagnosis of AF/AT. The same two variables were independently correlated with any degree of AV block (years from SSc diagnosis: RR 1.11; 95% CI 1.01–1.23; p=0.004; iRAV: RR 1.14; 95% CI 1.02–1.27; p=0.019). Due to the low sample size, we were unable to detect any clinical predictors of sudden cardiac death in our population, however those who died experienced a larger worsening in left ventricle GLS values (4.0±1.6 vs. 0.9±0.4, p=0.056). Conclusions Supraventricular arrhythmias and conduction defects are common in patients with SSc. Time from diagnosis and right atrial volumes are able to predict the incidence of such conditions, supporting the hypothesis that a long-lasting disease and the anatomical remodelling of the right atrium could contribute to the developing of tachy- and bradyarrhythmias in this population. Funding Acknowledgement Type of funding source: None

A Case of Cardiac Arrest Soon after Receiving a Sting from a Wasp

While felling trees along a national roadside in a remote area, a 38-year-old man suddenly cried out that he had been stung by a wasp on his left hand. His colleague came over to him, and he fell unconscious, so his colleague called an ambulance. When emergency technicians found him, he was in cardiopulmonary arrest. His initial rhythm was asystole. He receive advanced cardiac life support but was unable to obtain return of spontaneous circulation, possibly due to his anaphylactic shock and complication with Kounis syndrome resulting in a low cardiac output, as he showed temporal complete bundle branch block with tachycardia PEA, repeated ventricular fibrillation, and elevated cardiac enzymes. The presence of a sting mark may also have been a sign of his severe state and complication of Kounis syndrome. The establishment of a new framework, such as permitting non-medical staff to inject adrenaline into patients with anaphylaxis, might be required.