Septal Location Research Articles

Propensity score-matched analysis in isolated left ventricular dilation and non-ischaemic dilated cardiomyopathy

Abstract Introduction The presence and extent of late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance imaging (CMR) are strong prognosticators of death in patients with non-ischaemic dilated cardiomyopathy (DCM), defined as left ventricular (LV) dilation and left ventricular ejection fraction (LVEF)<50%. Although the current guidelines defined the concept of "isolated LV dilation" (ILVD) as LV dilation with preserved LVEF≥ 50%, the prognostic value of the "LGE granularity" is not established in this population. Purpose To assess the prognostic value of the concept of "LGE granularity" including its extent, location, and pattern for predicting all-cause death above traditional prognosticators in patients with DCM or ILVD, separately. Methods Between 2008 and 2021, all consecutive patients with DCM and ILVD without implantable cardioverter-defibrillator or history of sustained ventricular arrhythmia referred for CMR were included in two centres. The primary outcome was all-cause death using the French National Registry of Death. A propensity score matching was performed to balance characteristics in patients with DCM vs. those with ILVD. Cox regressions were performed to determine the prognostic value of each LGE findings. Results Of 2,752 patients analysed (age 52±8 years, 56% male), 15% patients died after a median (interquartile range) follow-up of 9 (7-12) years. A total of 737 (27%) patients had LGE. In the propensity-score matched population (N=1,084 in DCM subgroup and N=1,084 in isolated LV dilation), the LGE presence was associated with death (HR=2.98, 95%CI: 1.97-4.50, p<0.001). In ILVD patients with LGE (N=265), the LGE extent (HR=1.41, 95%CI:1.09-1.83, p=0.009), the presence of LGE in multiple areas (HR=3.86, 95%CI: 1.73-8.61, p<0.001) and the septal location (HR=2.97, 95%CI:1.37-6.46, p=0.006) were strong prognosticators of death after adjustment for traditional prognosticators. Similarly, in DCM patients with LGE (N=268), the LGE extent (HR=1.42, 95% CI:1.07-1.89, p=0.014), the presence of LGE in multiple areas (HR=8.41, 95%CI: 3.32-21.3, p<0.001) and the septal location (HR=6.65, 95% CI: 3.02-14.6, p<0.001) were strongly associated with death. Conclusion The concept of "LGE granularity" was independently associated with all-cause death after adjustment for all traditional prognosticators in both DCM and ILVD. These results suggest that CMR assessment could improve the risk stratification in this population. Survival curves Multivariable analysis

Prognostic impact of non-ischaemic late gadolinium enhancement in patients with ischaemic cardiomyopathy

Abstract Background Although the presence and extent of ischaemic late gadolinium enhancement (LGE) as assessed by cardiovascular magnetic resonance (CMR) have emerged as robust predictors of outcomes in patients with ischaemic cardiomyopathy (ICM), the prognostic significance of non-ischaemic LGE is not well established. Objective To assess the prognostic impact of the presence of non-ischaemic LGE in a large cohort of patients with ICM with reduced left ventricular ejection fraction (LVEF) undergoing CMR for myocardial viability. Methods Between 2008 and 2022, all consecutive patients referred for myocardial viability assessment using CMR with a history of ICM (≥70% stenosis in ≥1 epicardial coronary vessel on angiography and/or history of myocardial infarction and/or coronary revascularisation) and LVEF <50% were included. Non-ischaemic was defined as midwall-LGE corresponding to non-specific myocardial fibrosis. Patients with a history of acute myocarditis and/or sub-epicardial LGE were excluded. The primary outcome was all-cause mortality using the National Registry of Death. Nested Cox proportional hazard models were used to assess the additional prognostic value of the presence of non-ischaemic LGE, including its location (lateral and/or septal and other locations) and its extent (1 or ≥2 segments), beyond the presence of ischaemic-LGE and traditional prognostic factors. The incremental prognostic value of non-ischaemic LGE extent and location was assessed by the C-statistic increment. Results Among the 6,082 patients (average age 65±12 years, 73% male), 702 (12%) had additional midwall-LGE. Over a median follow-up of 9 years (IQR 7-12), 652 (11%) patients died. Non-ischaemic LGE alone was associated with a higher risk of mortality (HR: 2.9; 95% CI: 2.4-3.4, p<0.001). Figure 1 shows an increased all-cause mortality rate, regardless of ischaemic-LGE extent and transmurality. In patients with non-ischaemic LGE (N=702), survival curves indicated higher risk for lateral and/or septal locations, larger extent, and the presence of ischaemic-LGE (all p<0.001, Figure 2). After adjustment for traditional prognosticators and ischaemic-LGE extent, non-ischaemic LGE in septal and/or lateral locations (adjusted HR: 2.6; 95% CI: 1.8-3.6) and extent ≥2 segments (adjusted HR: 2.6; 95% CI: 1.8-3.7, both p<0.001) were independently associated with mortality. A comprehensive LGE model including all non-ischaemic LGE characteristics improved reclassification compared to traditional factors with and without ischaemic-LGE (C-statistic improvement: 0.13 and 0.05, all p<0.001). Conclusion In a large cohort of ICM patients, the presence of non-ischaemic LGE is an independent predictor of all-cause death, particularly for larger extent or in the septal and/or lateral segments. All-cause mortality rates Prognostic impact of non-ischaemic LGE

Clinical utility of ischaemic late gadolinium enhancement granularity in ischaemic cardiomyopathy patients with reduced left ventricular ejection fraction

Abstract Background Although the presence and extent of ischaemic late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance (CMR) are robust predictors of outcomes in patients with ischaemic cardiomyopathy (ICM), the prognostic significance of other ischaemic-LGE parameters is not well established, and no integrated score exists. Purpose This study aims to evaluate the additional prognostic value of a model that assesses the granularity of ischaemic-LGE over traditional factors in predicting mortality in ICM patients. The granularity includes ischaemic-LGE extent, transmurality, location, and associated midwall-LGE (Figure 1). A simplified score based on these parameters will be implemented to facilitate its use in clinical practice. Methods This study is a bi-centric retrospective analysis of a prospective observational cohort consisting of 6,082 patients with ICM and left ventricular ejection fraction (LVEF)<50% referred for viability assessment using CMR between 2008 and 2022. The primary outcome was all-cause mortality using the National French Registry of Death. Cox regression analysis was used to assess the incremental prognostic value of the LGE granularity model after adjustment for traditional prognosticators. Using a Cox model including all these LGE granularity parameters we built a new risk prediction score entitled "CMR-LGE score". Results Among the 6,082 patients (average age 65±12 years; 73% men), 3,591 (59%) exhibited ischaemic-LGE. Over a median follow-up period of 9 [7-12] years, 652 (11%) patients died. After adjustment, the presence of ischaemic-LGE was significantly associated with all-cause mortality (hazard ratio, HR=3.5, 99.5% CI: 2.6-4.7, p<0.001). In patients with ischaemic-LGE (N=3,591), the LGE extent (HR=1.4, 99.5% CI: 1.3-1.5), LGE transmurality (subendocardial ≤50%, subendocardial >50% HR=2.2, 99.5% CI: 1.5-3.2, and transmural HR=2.9, 99.5% CI: 1.9-4.4), and ischaemic LGE location (septal location HR=7.1, 99.5% CI: 4.9-10.4), and the presence of associated midwall-LGE were all independently associated with mortality (adjusted HR=1.9, 99.5% CI: 1.4-2.5, all p<0.001). The LGE granularity model, which included all these LGE features, showed the greatest improvement in model discrimination over traditional prognostic factors and ischaemic-LGE extent alone (ROC-AUC: 0.90 vs 0.84, p<0.001). The "CMR-LGE score" was highly effective ischaemic to predict mortality (ROC-AUC: 0.87, precision-recall-AUC: 0.61, Figure 2). Conclusions In a large cohort of ICM patients with reduced LVEF, a model incorporating the granularity of ischaemic-LGE—covering extent, transmurality, location, and associated midwall-LGE—provided additional prognostic value beyond traditional prognostic factors for predicting all-cause mortality. The “Ischaemic-LGE granularity" The “CMR-LGE Score”

Propensity score-matched analysis in isolated left ventricular dilation and non-ischaemic dilated cardiomyopathy

Abstract Background The presence and extent of late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance imaging (CMR) are strong prognosticators of death in patients with non-ischaemic dilated cardiomyopathy (DCM), defined by the current guidelines as left ventricular (LV) dilation and left ventricular ejection fraction (LVEF)<50%. Although the current guidelines defined the concept of "isolated LV dilation" as LV dilation with preserved LVEF≥50%, the prognostic value of the LGE granularity including its extent, location and pattern is not established in this population. Purpose To assess the prognostic value of the concept of "LGE granularity" including its extent, location, and pattern for predicting all-cause death above traditional prognosticators in patients with LV dilation and reduced LVEF (i.e. DCM) or preserved LVEF (i.e. isolated LV dilation), separately. Methods Between 2008 and 2021, all consecutive patients with DCM and isolated LV dilation without ICD or history of sustained ventricular arrhythmia referred for CMR were included in two centres. All patients with history of coronary artery disease or myocarditis were excluded. The primary outcome was all-cause death using the French National Registry of Death. A 1:1 propensity score matching was performed to balance baseline characteristics in patients with DCM vs. those with isolated LV dilation. Cox regressions were performed to determine the prognostic value of each LGE findings. Results Of 2,752 patients analysed (age 52±8 years, 56% male), 408 (15%) patients died after a median (interquartile range) follow-up of 9 (7-12) years. A total of 737 (27%) patients had LGE. Patients with DCM had a higher rate of death than patients with isolated LV dilation (16% versus 13%, p=0.02). In the propensity-score matched population (N=1,084 in DCM subgroup and N=1,084 in isolated LV dilation), the LGE presence was associated with death (HR=2.98, 95%CI: 1.97-4.50, p<0.001). In isolated LV dilation patients with LGE (N=265), the LGE extent (HR=1.41, 95%CI:1.09-1.83, p=0.009), the presence of LGE in multiple areas (HR=3.86, 95%CI: 1.73-8.61, p<0.001) and the septal location (HR=2.97, 95%CI:1.37-6.46, p=0.006) were strong prognosticators of death after adjustment for traditional prognosticators. Similarly, in DCM patients with LGE (N=268), the LGE extent (HR=1.42, 95% CI:1.07-1.89, p=0.014), the presence of LGE in multiple areas (HR=8.41, 95%CI: 3.32-21.3, p<0.001) and the septal location (HR=6.65, 95% CI: 3.02-14.6, p<0.001) were strongly associated with death after adjustment. Conclusion In a large cohort of DCM and isolated LV dilation patients, the concept of "LGE granularity" was independently associated with all-cause death after adjustment for all traditional prognosticators in both DCM and isolated LV dilation. These results suggest the existence of a continuum between isolated LV dilation and DCM, and that CMR assessment could improve the risk stratification in this population.

Prognostic impact of the concept of late gadolinium enhancement granularity in non-ischaemic dilated cardiomyopathy

Abstract Background The prognostic stratification of non-ischaemic dilated cardiomyopathy (DCM) to predict the risk of death is mainly driven by the left ventricular ejection fraction (LVEF). Indeed, LVEF<35% is currently the only indication for primary prevention with implantable cardioverter-defibrillator (ICD) in these patients. Beyond LVEF, several cardiac magnetic resonance imaging (MRI) studies have suggested the strong prgnostic impact of late gadolinium enhancement (LGE), and particularly its extent and location. Therefore, we assumed that a more granular approach combining detailed LGE findings including extent, location and pattern could improve risk stratification in this population. Purpose To assess the additional prognostic value of the concept of "Late Gadolinium Enhancement (LGE) Granularity" that includes extent, location, and pattern in non-ischaemic dilated cardiomyopathy (DCM) patients to predict all-cause death. Methods Between 2008-2021, all consecutive patients with DCM without ICD or history of sustained ventricular arrythmia referred for cardiac MRI were included in two French centres. In line with the current ESC and AHA guidelines, DCM was defined by the LV dilation and LVEF< 50% using cardiac MRI. All patients with history of coronary artery disease or clinical history of myocarditis were excluded. The primary outcome was all-cause death using the French National Registry of Death. Cox regressions were performed to determine the prognostic value of each LGE findings. The additional prognostic value of the LGE granularity was assessed by the C-statistic increment, the continuous net reclassification improvement (NRI), and the integrative discrimination index (IDI). Results Of 1,668 DCM patients (age 52±8 years, 54% males), 268 (16%) died after a median (interquartile range) follow-up of 9 (7-12) years. With a median LVEF value of 39% (30-46), 472 (28%) patients had non-ischemic LGE. Using survival curves, patients with LVEF>35% but the LGE septal location showed a higher risk of death compared to all patients with LVEF≤35% with or without LGE (except for the septal location, all p<0.001). In DCM patients with LGE (N=472), LGE extent (adjusted HR: 4.27, 95% CI: 2.22-8.22), septal location (HR: 5.74, 95% CI: 3.35-9.85) and multiple areas of LGE (HR: 4.38, 95% CI: 2.08-9.22; all p<0.001) were all independently associated with death after adjustment for prognosticators. The concept of "LGE granularity" combining all these LGE features showed the best improvement in model discrimination and reclassification over traditional prognosticators including LVEF (C-statistic improvement: 0.14; net reclassification improvement=64.3%; integrative discrimination index=29.0%; all p<0.05). Conclusion In a large cohort of DCM patients, the concept of "LGE granularity" combining LGE extent, location and the presence of multiple areas had an additional prognostic value above traditional prognosticators including LVEF to predict all-cause death.

Prognostic value of additional midwall late gadolinium enhancement in patients with ischemic cardiomyopathy

Abstract Background Although several studies have reported the additional presence of midwall late gadolinium enhancement (LGE) using cardiac magnetic resonance (CMR) in patients with ischemic cardiomyopathy (ICM), its prognostic value is not well established. Purpose To assess the prognostic value of the additional presence of midwall-LGE in a large cohort of patients with ICM and reduced left ventricular ejection fraction (LVEF). Methods Between 2008 and 2022, all consecutive patients referred for myocardial viability assessment using CMR with an history of ICM (≥70% stenosis in ≥1 epicardial coronary vessel on angiography and/or history of myocardial infarction and/or coronary revascularization) and LVEF <50% were included. Midwall-LGE was defined by non-ischemic LGE corresponding to non-specific myocardial fibrosis. All patients with a history of acute myocarditis and/or sub-epicardial LGE were excluded. The primary outcome was all-cause death. Nested Cox proportional hazard models were used to assess the prognostic value of additional midwall-LGE including its location (lateral and/or septal and other location) and extent (1 or ≥2 segments), above the presence of ischemic-LGE and traditional prognostic factors. The incremental prognostic value of midwall-LGE extent and location was assessed by the C-statistic increment, the continuous net reclassification improvement (NRI), the integrative discrimination index (IDI) and the global Chi-2. Results Among the 6,082 included patients (65±12 years, 73% males), 702 (11.5%) had an additional midwall-LGE. During a median follow-up of 9 (IQR, 7-12) years, 652 (11%) patients died. The presence of midwall-LGE alone was strongly associated with the risk of death compared to patients without midwall-LGE (p<0.001, Figure 1A). Among these patients with midwall-LGE (N=702), survival curves showed an increased risk for midwall-LGE in lateral and/or septal location (p<0.001), for larger extent (p<0.001) and the presence of ischemic-LGE (p<0.001, Figure 1B). In this population with midwall-LGE (N=702), after adjustment for risk factors and extent of ischemic-LGE, midwall-LGE with septal and/or lateral location (adjusted HR: 2.6; 95%CI: 1.8-3.6) and extent ≥2 segments (adjusted HR: 2.6; 95%CI: 1.8-3.7, both p<0.001) were independently associated with all-cause death. A comprehensive LGE model combining all the characteristics of midwall-LGE showed the best improvement in model discrimination and reclassification above traditional prognosticators (C-statistic improvement: 0.13; NRI=46%; IDI=19%, Chi-2 global=261, all p<0.05; LR-test p<0.001, Figure 2). Conclusion In a large cohort of ICM patients, the presence of an additional non-ischemic midwall-LGE is an independent prognosticator of all-cause death, particularly for larger extent or when present in the septal and/or lateral location.Prognostic value of midwall-LGEIncremental prognostic value

Real life experience with point by point pulsed field ablation for recurrent ventricular arrhythmias

Abstract Introduction The safety and effectiveness of electroporation/point by point pulsed field ablation (PP PFA) as emerging technoloy for catheter ablation (CA) of ventricular arrhythmias (VAs) has been described till now only in case reports. Purpose The aim of this observational retrospective study is to present real life data concerning the overall performance of PP PFA for CA of recurrent VA. Methods A total number of 13 consecutive patients (11 VTs and 2 PVCs), in whom recurrent VTs after RF ablation documented, were included. In all patients the substrate location was documented beforehand based on cardiac MRI or CT with myocardial thinning. For substrate mapping a high resolution multipoint mapping catheter was used. A complete success was defined as non inducibility of any arrhythmia at the end of procedure respectively lack of VA recurrence at follow – up. Results Excepting 2 patients, all other had a non ischemic cardiomyopathy as underlying heart disease (mean age 63 ± 8 y/o, mean LVEF 42 % ± 9 %). In every patient at least one conventional RF CA has been performed previously (mean 2 ± 1) and 38 % of patients had a previous epicardial RF VT ablation. The PP PFA VT ablation was performed endocardialy in 11 patients (84 %), respectively epicardialy in 2 patients. The ablation sites had a septal location in 53 % of patients and other localisation in 47 % of patients. The applied energy was 25 A. The overall acute complete success was achieved in 77 % patients. At medium 6 ± 3 months follow up a complete success was present in 46 % cases. Most frequently a VT recurrence after PP PFA ablation was encountered in patients with combined septal and nonseptal substrate distrubution. After PP PFA, the RF CA strategy due to recurrent VAs was endocardial in 2 patients, respectively epicardial 2 in cases and bipolar in 1 case. No PP PFA redos were undergone. Three major complications have been documented (1 tamponade, 1 AV block III° and 1 complete LBBB). Conclusion As bailout strategy in patients with failed conventional CA, PP PFA represents a safe strategy. Specific complications like temporary atrioventricular or intraventricular conduction disturbancies are extremely rare, reversible but not life threathening. The midterm success is satisfactory but still limited in patients with intramural substrate.

Machine learning using cardiovascular magnetic resonance to predict cardiovascular events in patients with acute myocarditis

Abstract Background In patients with acute myocarditis (AM), current prognostic risk assessment is based on a limited selection of clinical, biological, and imaging findings using cardiovascular magnetic resonance (CMR). While the potential value of a stratification risk score in these patients is not well established, machine learning (ML) methods could provide accurate score for prediction. Purpose To investigate the feasibility and accuracy of ML to predict major adverse cardiovascular events (MACE) in patients with AM, and compare its performance with traditional statistical methods. Methods Between 2008-2017, all consecutive patients with diagnosis of AM based on CMR and without hemodynamic compromise were recruited in two centres (Hospital 1, N=203 and Hospital 2, N=185) to constitute the derivation cohort. The external validation cohort of the ML score was performed in another centre (N=218, Hospital 3, APHP). The primary composite outcome was major adverse cardiac events (MACE) defined by: cardiac death, cardiac transplantation, ventricular arrythmia, hospitalization for heart failure, recurrence of AM, and unplanned hospitalization for cardiac reason. Least absolute shrinkage and selection operator (LASSO) regression was used to select variables and prevent model overfitting. Several ML models (Elastic Net, Random Forest, Multi-Layer Perceptron [MLP], Support Vector Machine [SVM], and XGBoost) were then trained on 70% of patients and evaluated on the other 30% as internal validation. Their performance was compared against standard logistic regression model, using receiver operating characteristics (ROC) and precision-recall (PR) curves and area-under-the curves (AUC). Results Of the 388 AM patients (mean age 39 years, 77% male) included in the derivation cohort, 71 experienced a MACE (18%) after a median follow-up of 7.5 [IQR 6.6–8.9] years. Among those, 30 patients (7.7%) had a recurrence of AM. CMR was performed 4 ± 2 days after index presentation. Out of 56 clinical, biological, and CMR variables, 7 variables were selected as being the most important in predicting MACE: age, initial presentation with syncope, LV ejection fraction, myocardial extent of LGE, mid-wall pattern of LGE, septal location of LGE, and number of segments with T2-hypersignal (T2-STIR). The Random Forest model showed the best performance compared with the other ML models (AUROC=0.74, PR-AUC=0.33). This ML model exhibited a higher AUC compared with a traditional model using logistic regression analysis (AUROC 0.74 vs 0.70; p<0.001). The ML score also exhibited a good performance for predicting MACE in the external validation cohort (AUROC 0.73). Conclusions A machine learning score using Random Forest including clinical and CMR data exhibited a better performance than traditional statistical methods to predict MACE in patients with acute myocarditis.Performance of Machine Learning models

Abstract 15352: Deep Learning Model-Enabled Electrocardiogram to Localize Premature Ventricular Contractions in Patients Referred for Catheter Ablation

Introduction: Accurate pre-procedure localization of the premature ventricular contractions (PVCs) is critical in preparing for the ablation. So far, no tools exist for artificial intelligence guided PVC-localization. Hypothesis: Trained deep learning model will be able to predict the site of origin (SOO) of PVCs using 12 lead electrocardiogram (ECG). Methods: We analyzed 707 ECG-ablation pairs from 2403 patients who had at least one ECG flagged for PVCs in the 6 months prior to their procedure. First, we used a cohort of 100,000 ECGs without PVCs and 10,000 ECGs with PVCs to train a convolutional neural network (CNN) to isolate the ECG segments with PVCs in them from a 12-lead ECG (Figure 1). We then trained two models, one utilizing a 10-second 12-lead ECG, and the other with just the isolated PVC beats as input. The models were trained using the Keras framework with TensorFlow (Google). Results: The mean age of the patients in the cohort was 61.2 ± 15.0 years. 66.3 percent of patients underwent left ventricle ablation, 54.6 percent had outflow ablation, and 55.3 percent had ablation of sites with leftward axis (septal location for midline and left ventricle PVCs). The model trained on 10-second ECGs yielded validation and test AUCs of 0.941 and 0.931 for outflow, 0.898 and 0.891 for ventricle, and 0.863 and 0.846 for leftward axis (Figure 1A). The model trained on isolated segments containing PVC beats yielded validation and test AUCs of 0.966 and 0.957 for outflow, 0.879 and 0.907 for ventricle, and 0.846 and 0.829 for SOO for leftward axis (Figure 1B). Conclusions: We have trained an accurate convolutional neural network that can predict SOO using the surface ECG. Further fine-tuning would be needed to refine the model and develop prediction of specific sites.

Amber-codon suppression for spatial localization and in vivo photoaffinity capture of the interactome of the Pseudomonas aeruginosa rare lipoprotein A lytic transglycosylase.

The 11 lytic transglycosylases of Pseudomonas aeruginosa have overlapping activities in the turnover of the cell-wall peptidoglycan. Rare lipoprotein A (RlpA) is distinct among the 11 by its use of only peptidoglycan lacking peptide stems. The spatial localization of RlpA and its interactome within P. aeruginosa are unknown. We employed suppression of introduced amber codons at sites in the rlpA gene for the introduction of the unnatural-amino-acids Νζ -[(2-azidoethoxy)carbonyl]-l-lysine (compound 1) and Nζ -[[[3-(3-methyl-3H-diazirin-3-yl)propyl]amino]carbonyl]-l-lysine (compound 2). In live P. aeruginosa, full-length RlpA incorporating compound 1 into its sequence was fluorescently tagged using strained-promoted alkyne-azide cycloaddition and examined by fluorescence microscopy. RlpA is present at low levels along the sidewall length of the bacterium, and at higher levels at the nascent septa of replicating bacteria. In intact P. aeruginosa, UV photolysis of full-length RlpA having compound 2 within its sequence generated a transient reactive carbene, which engaged in photoaffinity capture of neighboring proteins. Thirteen proteins were identified. Three of these proteins-PBP1a, PBP5, and MreB-are members of the bacterial divisome. The use of the complementary methodologies of non-canonical amino-acid incorporation, photoaffinity proximity analysis, and fluorescent microscopy confirm a dominant septal location for the RlpA enzyme of P. aeruginosa, as a divisome-associated activity. This accomplishment adds to the emerging recognition of the value of these methodologies for identification of the intracellular localization of bacterial proteins.

Diverse QRS morphology reflecting variations in lead placement for left bundle branch area pacing.

Left bundle branch area pacing (LBBAP) is a potential alternative to His bundle pacing. This study aimed to investigate the impact of different septal locations of pacing leads on the diversity of QRS morphology during non-selective LBBAP. Non-selective LBBAP and left ventricular septal pacing (LVSP) were achieved in 50 and 21 patients with atrioventricular block, respectively. The electrophysiological properties of LBBAP and their relationship with the lead location were investigated. QRS morphology and axis showed broad variations during LBBAP. Echocardiography demonstrated a widespread distribution of LBBAP leads in the septum. During non-selective LBBAP, the qR-wave in lead V1 indicated that the primary location for pacing lead was the inferior septum (93%). The non-selective LBBAP lead was deployed deeper than the LVSP lead in the inferior septum. The Qr-wave in lead V1 with the inferior axis in aVF suggested pacing lead placement in the anterior septum. The penetration depth of the non-selective LBBAP lead in the anterior septum was significantly shallower than that in the inferior septum (72 ± 11 and 87 ± 8%, respectively). In lead V6, the deep S-wave indicated the time lag between the R-wave peak and the latest ventricular activation in the coronary sinus trunk, with pacemaker leads deployed closer to the left ventricular apex. Different QRS morphologies and axes were linked to the location of the non-selective LBBAP lead in the septum. Various lead deployments are feasible for LBBAP, allowing diversity in the conduction system capture in patients with atrioventricular block.

Infarct-like versus Non-Infarct-like Clinical Presentation of Acute Myocarditis: Comparison of Cardiac Magnetic Resonance (CMR) Findings.

The clinical presentation of acute myocarditis (AM) is widely variable, ranging from a subclinical disease to an infarct-like syndrome. Cardiac magnetic resonance (CMR) has become the reference non-invasive diagnostic tool for suspected AM, allowing the identification of the various hallmarks of myocardial inflammation (edema, fibrosis, and hyperemia). The aim of the study was to investigate any differences in morphological, functional, and tissue characterization CMR parameters between infarct-like AM in patients with unobstructed coronary arteries and non-infarct-like AM, diagnosed according to the original Lake-Louise Criteria (LLC); Methods: We retrospectively selected 39 patients diagnosed with AM according to LLC, divided into 2 groups according to the clinical presentation: infarct-like in group 1 patients and non-infarct-like in group 2 patients. CMR morphologic, functional, and tissue characterization parameters were analyzed and compared. In group 1, CMR tissue characterization parameters were mainly altereda in septal location with mesocardial myocardial involvement; in group 2, CMR tissue characterization parameters were mainly altered in a lateral location with subepicardial myocardial involvement mainly at the mid-cavity. No significant differences in morphological or functional parameters were observed between the two study groups. Our results showed differences in the localization and distribution of myocardial tissue damage assessed by CMR among forms of AM accompanied by an infarct-like clinical presentation compared with non-infarct-like presentations of AM. The mechanisms underlying the different preferential sites of damage observed in our study are not known, and we do not exclude the possibility of their prognostic implications.

3830 lead extraction from two patients with left bundle branch area pacing.

3830 lead extraction from two patients with left bundle branch area pacing.

Is Computed Tomography Necessary Before Septoplasty? Correlation With Physical Examination and Patient Complaints.

Septoplasty is one of the most common surgeries performed by otorhinolaryngologists. The gold standard for the evaluation of septal deviation is anterior rhinoscopy and nasal endoscopy. Frequently, computed tomography (CT) is also performed, although the correlation between septal deviation on CT and physical examination is unclear. To study the relationship between symptoms and physical and radiological evaluation in patients who underwent septoplasty. A prospective study of patients with nasal obstruction and septal deviation who underwent septoplasty. Anterior rhinoscopy and nasal endoscopy were performed by the surgeon, and the CT was evaluated by a radiologist. The degree of obstruction was evaluated in three distinct septal locations. The Nasal Obstruction Symptom Evaluation (NOSE) score was used before the surgery and two months after the surgery. The study included 43 patients, of whom 60.5% were male, with an average age of 37.09 years (±12.56). The degree of septal deviation in the physical examination was significantly different from that observed in CT (p˂0.05).Cartilaginous or maxillary crest septal deviations >75% were more commonly recognized by physical examination, while osseous septum deviations of 25%-50% were more easily detected by CT.There was no difference between the degree of septal deviation and the preoperative NOSE. The median preoperative NOSE was 60, and the postoperative was 5, with significant improvement (p<0.05). CT doesn't appear to be useful in the evaluation of septal deviation since it is different from the findings of a physical examination and isn't associated with the NOSE score. Clinical decisions should be based on a physical examination and patient complaints.

PO-04-013 A CASE OF INTERMITTENT ANODAL CAPTURE AFTER LEFT BUNDLE AREA PACING

Left bundle area pacing (LBAP) is emerging as a reliable form of conduction system pacing (CSP) that can be beneficial in cardiac resynchronization therapy (CRT). We present a case of intermittent anodal capture noted after septal lead insertion in a patient undergoing LBAP. N/A An 80-year-old male with hypertension, COPD, and sick sinus syndrome who had undergone dual chamber pacemaker implantation in 2007, had known atrial lead fracture since 2020, now presented with heart failure syndrome (EF dropped from 60% to 15%). A coronary angiogram showed non-obstructive coronary artery disease. As such decision was made for fractured atrial lead extraction and implantation of new atrial lead to provide AV synchrony as well as upgrading the device to biventricular ICD, given the persistent low ejection fraction. During the procedure, coronary sinus anatomy was found unsuitable for lead insertion, and hence LBAP was opted for instead. LBAP lead was placed at an appropriate septal location with QRS morphology in lead V1 changing from an initial “W” pattern to notching as the lead was advanced with an appropriate rise in thresholds. QRS duration decreased to 144 milliseconds; however, intermittently variable QRS morphologies were noted. In LBAP, anodal capture can occur during bipolar configuration where the tip of the lead (cathode) is capturing the left bundle, and the ring (anode) starts capturing the right bundle area. This happens when the lead is penetrating the interventricular septum (IVS) enough for the ring portion to come into contact with the right septal area. In our patient, note the different QRS morphologies in lead V1 (Panel A). The right bundle morphology QRS (marked red) is the expected result of LB pacing, while the left bundle morphology QRS (marked green) is likely occurring from concurrent anodal capture of the right bundle. The QRS duration is noted to be somewhat narrower when the left bundle morphology is present, as would be expected when both bundles are simultaneously captured (LB by the tip and RB by the ring) (Panel B). It is unclear whether such a phenomenon as anodal capture of the RB along with concurrent LB pacing can be of any clinical significance and needs further research.

Apports diagnostique et pronostique de l'imagerie par résonance magnétique cardiaque dans la myocardite

Cardiac magnetic resonance imaging (CMR) became over the last 30 years an essential tool in the management of patients with myocarditis. Noninvasive diagnosis of acute myocarditis relies on a clinical picture compatible with myocarditis and fulfilling of the updated 2018 Lake Louise criteria. These criteria include highlights of myocardial edema by conventional T2-weighted sequences or by T2 mapping in one hand and evidence of myocardial injury using late gadolinium enhancement sequences, T1 mapping or extra-cellular volume measurement in the other hand. It is recommended to perform basal examination in the 2 or 3 weeks following acute episode and to repeat CMR during follow-up. The literature reports excellent diagnostic accuracy, between 80% and 90%, making CMR a robust and reliable noninvasive alternative to endomyocardial biopsy. Besides, beyond its diagnostic performance, CMR can also help to identify patients with unfavourable long-term outcome. For instance, medio-ventricular and septal location of late gadolinium enhancement, degree of late gadolinium enhancement extent or high T2 mapping values are independent predictive factors of major cardio-vascular events.

Characteristics of Maxillary Sinus Septa: A Cone-Beam Computed Tomography Evaluation.

Objective Our study aimed to determine the prevalence, location, and morphological differences of the septa using CBCT images. Methods This retrospective study was conducted on CBCT examinations. The sample included both mixed and permanent dentition and edentulous patients. The images were viewed in 3 planes (sagittal, coronal, and axial) and the left and right maxillary sinuses were evaluated for the septa's prevalence, location, and morphological differences. Results The measurements were statistically analyzed using SPSS software. Out of 200, 122 patients showed one or more bony septa in the maxillary sinus. The septal location and angulation were not limited to a specific area or a specific range. Significant differences between genders were found. Conclusions The increased surface area of the septa using plane 2-dimensional radiographs is impossible. CBCT has improved the planning of any sinus procedure and offers adequate information compared to conventional radiographs.

A cardiac magnetic resonance myocardial strain patterns analysis in left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Recently, a classification with four types of septal longitudinal strain patterns was described using a speckle tracking based strain analysis in echocardiography suggesting pathophysiological continuum of LBBB-induced LV remodeling. Little data exist on feature tracking cardiac magnetic resonance (FT-CMR) in LBBB patients, and whether such patterns could be reproduced in CMR is not established yet. Purpose In this study, we aimed to: 1) Assess and reproduce the new strain patterns classification by CMR and 2) Evaluate its association with LV remodeling and myocardial scar in a LBBB cohort. Methods Single center registry which included LBBB patients with septal flash (SF) referred to CMR to assess the structural cause of LV dysfunction. LBBB was defined according to Strauss criteria as strict LBBB, non-strict LBBB or nonspecific LV conduction delay. A semi-automated FT-CMR was used to quantify myocardial strain and detect the four septal longitudinal and radial strain patterns, according to the recent classification (LBBB-1 through LBBB-4) – Figure. Extent of SF was visually scored as mild, moderate, or prominent. Results A total of 115 patients were included (mean age 66±11 years; 57% men; 38% with ischemic heart disease). Median duration of QRS was 150± 26ms and majority of the patients (n=90, 78%) were classified as strict LBBB. In longitudinal strain analyses LBBB-1 was observed in 23 (20%), LBBB-2 in 37 (32.1%), LBBB-3 in 25 (21.7%), and LBBB-4 in 30 (26%) patients. Patients at higher LBBB stages (longitudinal or radial pattern) had more prominent septal flash, greater LV volumes, lower LV ejection fraction and lower absolute global longitudinal, circumferential and radial strain values compared with patients in less advanced stages (p &amp;lt; 0.05 for all) - table. There was no difference between patterns in clinical characteristics, ischemic etiology, QRS duration and time delay between septal and lateral LV wall. Late gadolinium enhancement (LGE) was found in 63 patients (54.8%), with a septal location in 34 (29.6%) patients, lateral in 4 (3.5%) patients, septal and lateral in 11 (9.6%) patients. Furthermore, no difference was found for LGE presence, distribution or location between the four strain patterns. Conclusions Among patients with LBBB, our study found a good association between longitudinal and radial strain patterns with the degree of LV remodeling and LV dysfunction by FT-CMR analysis. Additionally, myocardial fibrosis didn’t seem to interfere with the staged LBBB classification.

Computerized tomography image correlation of His bundle/deep septal pacing location and outcomes: an analysis from the Canberra HIs bundle/deep septal Pacing Study (CHIPS)

BackgroundLocalisation of the conduction system under fluoroscopy is not easy and the ideal location of the pacing leads in physiological pacing is still being debated.ObjectiveThe primary aim was to assess the lead locations using cardiac CT scan. Secondary aims were clinical outcomes including success and safety of the procedure and lead performance.MethodsOf the 100 consecutive patients who received physiological pacing, 34 patients underwent follow-up cardiac CT scan. The four different types of pacing were identified as His bundle (HBP), para-Hisian, left bundle branch (LBBP), and deep septal pacing.ResultsMost patients had successful HBP via the right atrium (RA) (87.5%) as compared to the right ventricle (RV) (12.5%). Lower thresholds were observed when leads were placed within 2 mm of the junction of the membranous and muscular ventricular septum. Unlike HBP, LBBP was possible at a wide region of the septum and selective capture of individual fascicles was feasible. LBBP showed deeper penetration of leads into the septum, as compared to deep septal pacing (70% vs. 45%). Approximately, 80% of patients did not have an intra-ventricular portion of the membranous septum.ConclusionsThe anterior part of the atrio-ventricular (AV) septum at the junction between the membranous and muscular septum via RA appeared to be the best target to successfully pace His bundle. LBBP was possible at a wide region of the septum and selective capture of individual fascicle was feasible. Adequate depth of penetration of lead was very important to capture the left bundle.

A New Electrocardiographic Criterium to Estimate a Septal or Lateral Location of a Right-Sided Accessory Pathway

Introduction: There are algorithms to estimate the location of an accessory pathway (AP). However, in right-sided APs, they tend to present low accuracy. This paper presents a new electrocardiographic criterium to estimate the location of a right-sided AP. Materials and methods: Rest ECGs from patients with manifest pre-excitation of right-sided APs were evaluated and the SV2/RV3 ratio was calculated, considering values &lt;1 for lateral (anterior or posterior) and ≥ 1 for septal (anterior or posterior) APs. We compared this ratio with other signs already described in literature. Results: In 175 consecutive patients, 60 met the inclusion criteria. For APs located in superior portions of tricuspid ring, the SV2/RV3 ratio &lt;1 was 80% accurate for anteroseptal location (specificity: 75%), where His electrograms were recorded. For APs located in inferior portions of tricuspid ring A SV2/RV3 &lt; 1 was 82,86% accurate for mid and posteroseptal location (specificity: 95.38%). Conclusion: We report a new and simple criterium that can accurately distinguish right-sided lateral and septal APs with good specificity: SV2/RV3 ratio.