bluuebunny/crossref_metadata_2025 huggingface dataset:
Permanent epicardial pacing : a first line strategy in children
Authors: Zeriouh S , Koutbi L , Mancini J , Maille B , Hourdain J , Franceschi F , Deharo J C
Published: May 2024

Background

Permanent cardiac pacing in paediatric patients remains a challenge. According to the European Paediatric and Congenital Society (AEPC) recommendations, below 20 kg epicardial implantation is preferred, while above 20 kg endocardial implantation is given priority unless specific contraindication. In the literature, a weight at 15 kg is also found to be the minimal weight above which an endovascular implantation is considered. However, endovascular systems have been reported to be associated with a high risk of complications. Recent improvements in epicardial leads technology have significantly improved pacing thresholds (1-3), battery life and reduced the risk of re-intervention for epicardial lead dysfunction (4,5).

Purpose

The aim of the study is to evaluate the long-term results and efficacy of epicardial pacing in children and to investigate risk factors for epicardial lead dysfunction.

Method

We performed a retrospective, single-centre analysis of consecutive patients aged ˂18 years implanted with an epicardial PM between 2004 and 2020. The data collection included initial pacing parameters, at 1 month, 1 year, 2 years, and at last follow-up, as well as occurrence of early and late complications.

Results

A total of 101 patients (93 atrial and 131 ventricular epicardial) were analysed. The mean follow-up time was 6.2 years (range 2 days to 16.9 years). Median age at implantation was 4.2 years (IQ 0.3-8.8 years), median weight was 15.2 kg (IQ 5.2-28.0 kg). Congenital heart disease (CHD) was recorded in 59,4% of patients. Reasons for implantation were postoperative complete atrioventricular block (AVB) (40.6%), congenital AVB (37.6%), sinus dysfunction (7.9%), complete AVB with heart disease without surgery (7.9%), others (4%). Four patients had a system infection resulting in device extraction and reimplantation. The mortality rate was 15.8%, but no deaths was directly related to PM implantation or dysfunction. Detection values, impedances were stable over time, and the and average pacing thresholds remained ˂0,98±0,81 volt in the atrium and ˂ 1.57±0,89 volt in the ventricle. Lead survival was 96,7%, 90,7%, 82,3%, 74,5% at 1, 5, 8 and 10 years. The presence of CHD, weight ˂15kg, dual chamber implantation, implantation for postoperative BAV were not significant risk factors for lead dysfunction. In the group of patients implanted above 15kg the presence of a CHD significantly increased the risk of lead dysfunction (p=0.037) and all-cause reimplantation (p=0.010). In the group implanted above 15kg without any cardiopathy, the survival rate without lead dysfunction at 5 and 10 years was 100% and 90.9% respectively.

Conclusion

Epicardial pacing in children with steroid-eluting leads shows good long-term results with stable pacing parameters and good survival from lead dysfunction. For children implanted at a weight above 15 kg and without cardiopathy results with epicardial stimulation were excellent.Epicardial lead survival
Recording of chest leads via mobile ECG and quantitative correlation with Wilson leads in a patient with monomorphic PVCs
Authors: Mueller-Leisse J , Hillmann H A K , Eiringhaus J , Hohmann S , Karfoul N , Duncker D
Published: May 2024

Introduction

Mobile ECGs using handy smartphone-based devices such as the KardiaMobile (AliveCor) are increasingly used as diagnostic tool for arrhythmias. They can be especially useful in cases of non-permanent arrhythmia. However, they were designed to record limb leads and few experience exists with the recording of modified chest leads. However chest leads provide important diagnostic information in many forms of arrhythmias including premature ventricular contractions (PVCs). We hypothesized that chest lead recordings using the 6-lead enabled KardiaMobile 6L device in a novel way would closely resemble the Wilson chest leads.

Methods

A patient with monomorphic idiopathic PVCs was identified. A standard 12- lead ECG was then taken in a supine position, and the exact same electrode positions were then used to record a mobile ECG in the supine position in the following manner: right finger and left finger positioned at the right and left sensor of the KardiaMobile 6L device respectively; back sensor positioned on the chest wall at the former positions of the chest electrodes, in a sequential manner (figure 1). The QRS morphologies of the 12-lead ECG Wilson leads and the reconstructed chest-leads with the mobile device were then overlied using Adobe illustrator and photoshop. The 12-lead ECG was also compared to a second 12-lead ECG of the patient that had been taken on the day before.

Results

QRS-morphologies of the chest leads derived from the 12-lead ECG and mobile ECG device resembled closely considering both regularly conducted beats and PVCs (figure 2 left and middle ECGs). Transition scores (TZ) of the sinus beats (3,5) and the PVCs (4) were identical. Overlaying two representative QRS-complexes of leads V1-6 of the Wilson leads and the mobile tracings showed a mean correlation of 73% for sinus beats and 78% for PVCs. In comparison, correlation of the QRS-complexes between the two 12-lead ECGs taken on consecutive days was 60% and 68% respectively (figure 2 left and right ECGs).

Conclusion

QRS-morphologies of the chest-leads taken with the KardiaMobile closely resembled the Wilson leads of the 12-lead ECG, and correlated better than did another 12-lead ECG that was taken the day before. The techniques could be useful for self-recording of arrhythmias including PVCs by patients to guide clinical decision-making in cases where no 12-lead ECG can be achieved due to intermittent arrhythmia occurrence.
Electrocardiographic features in the early differential diagnosis of cardiac amyloidosis from cardiac sarcoidosis
Authors: Hachisuka M , Murata H , Yodogawa K , Toida Y , Okajima S , Ito N , Arai T , Kobayashi S , Fujimoto Y , Hagiwara K , Aizawa Y , Shimizu W , Asai K , Iwasaki Y
Published: May 2024

Introduction

Amyloidosis and sarcoidosis are both systemic infiltrative diseases which can cause cardiac involvement. Differentiating early-stage cardiac amyloidosis (CA) from cardiac sarcoidosis (CS) is still challenging, although hypertrophy for CA and septal thinning for CS are characteristic echocardiographic findings in each late-stage. The diagnosis is a time-sensitive issue, given the therapies for CA and CS likely to be effective at early disease stages.

Purpose

We aimed to evaluate the utility of electrocardiography (ECG) for distinguishing CA from CS before or early in the course of cardiomyopathy.

Methods

This study enrolled 36 consecutive patients (20 male, 75±13 years) diagnosed with transthyretin-CA in 25 (CA group) and isolated CS in 11 patients (CS group) according to accepted criteria at our institute from July 2014 to July 2023. We retrospectively reviewed electrocardiographic characteristics and clinical outcomes of early-stage CA and CS.

Results

The CS group were younger than the CA group at the time of diagnosis (59±9 vs 83±7 years, P<0.01) and had a shorter period between the date of their first ECG recording at our institute and the date of diagnosis (18±3 vs 62±67 months, P=0.012). Furthermore, the CA group showed specific P-waves with longer duration (142±19 vs 126±8 ms, P=0.003) and more notches and/or fragmentation (91% vs 33%, P=0.003) in the limb leads on the initial ECG than the CS group, although prolonged PR-interval is common in both CA and CS (191±44 vs. 208±43 ms, P=0.359). Unexpectedly, the CA group had a shorter QRS duration (103±25 vs 123±31 ms, P=0.047) and a higher R-wave in V5 (2.0±0.9 vs 1.3±1.1 mV, P=0.039) than the CS group. In addition, the low voltage in all limb leads, pseudoinfarct pattern and bundle branch block morphology characteristic of CA patients did not differ between diagnosis and initial examination. There were also no differences in atrial and ventricular arrhythmias. During the follow-up period, 5 patients (20%) in the CA group, but no patients in the CS group died.

Conclusion

CA and CS shares several electrocardiographic features. Prolonged P-wave with notches and fragmentation, suggesting atrial conduction disturbance, may be associated with amyloid deposition in CA. This finding might be useful in the early differential diagnosis for CA from CS.
Association of spontaneous coronary artery dissection with bradycardia - a novel observational study
Authors: Raj K , Jyotheeswara Pillai K E E R T H , Rangadham N A G A R A
Published: May 2024

Introduction

Spontaneous coronary artery dissection (SCAD) is a common cause of Myocardial infarction (MI) in women less than 50 years of age (1). SCAD has a high recurrent rate, and beta blockers are the only drug shown to reduce the recurrence of SCAD. However, in our clinical practice, we could not use beta-blockers in some of our patients due to sinus bradycardia of unclear cause. Therefore, we planned to study if SCAD could cause Bradycardia.

Purpose

To determine if Bradycardia is associated with SCAD.

Methodology

Utilising the National Inpatient Sample (NIS) from 2016 to 2020, we performed a multivariable logistic regression analysis to determine if SCAD was independently associated with Bradycardia (ICD-10 code R0.01) among adults. SCAD was defined as coronary artery dissection (ICD-10 code I25.42) after excluding patients who had PCI.

Results

A- A total of 2,561,434 (95% CI 2,526,646-2,596,222) weighted hospitalisations with Bradycardia and 18,049 (95% CI 17,288-18,811) with SCAD was included. Bradycardia was present in 5.2% (95% CI 4.6-6) of patients with SCAD and 1.7% (95% 1.7-1.7) in patients without SCAD. After adjusting for relevant causes of Bradycardia, SCAD was highly associated with Bradycardia (OR 3.04, 95% CI 2.61-3.55). Among all the risk factors studied, SCAD showed the 2nd highest strength of association (Table 1).

Discussion

We report the first described association of SCAD with Bradycardia in literature. Although the prevalence of Bradycardia with SCAD in our study is only 5.2%, Bradycardia is frequently not coded, and we suspect the true frequency of Bradycardia in SCAD is much higher. The exact mechanism for this association is unclear. Although the frequency of beta-blocker use is not available in our study, several other conditions, such as ischemic heart disease and cardiomyopathy, which involve more frequent beta-blocker use, did not show a degree of association as strong as SCAD with bradycardia. Therefore, we hypothesize Bradycardia could be from SCAD itself, and the current ongoing BA-SCAD (Beta-blockers and Antiplatelet agents in patients with Spontaneous Coronary Artery Dissection) trial could shed light on this association (2).
Electrophysiological assessment of atrial tachycardia substrates in patients with repaired tetralogy of Fallot
Authors: Mirizzi G , Tamborrino P , Rossi A , Startari U , Panchetti L , Garibaldi S , Nesti M , Festa P , Ait-Ali L , Marrone C , Ridolfi L , Santoro G , Assanta N , Piacenti M
Published: May 2024

Introduction

Adults with repaired tetralogy of Fallot (rToF) are most often referred to Adult Congenital Heart Disease centers for atrial tachycardia (AT) and radiofrequency catheter ablation (RFCA) is often required. A systematic evaluation of the mechanisms and recurrences of arrhythmias in these patients is lacking.

Methods

28 patients with rToF referred for catheter ablation to the Interventional Electrophysiology Unit of our center between January 2013 and January 2023 were evaluated. Pts underwent electrophysiologic study (EPS) with 3D electroanatomic high density mapping. Evaluation of right atrial bipolar voltage and activation mapping of the AT was performed. Intra-atrial re-entrant tachycardias (IART), focal AT (FAT), other. Activation mapping was performed to identify the critical isthmus for IART. FATs were localized according to the earliest unipolar signal. Whenever possible, all the induced tachycardias were treated besides the arrhythmia which represented the clinical indication to EPS. RFCA was aimed at the earliest activation point for FAT and at the critical isthmus for IART, anchoring lesion to fixed obstacles (valve annuli or atriotomy scar). All patients provided written informed consent for participating in the study.

Results

Among 28 adult (age 47±13 years) patients (females n=14, 50%), 53 AT were documented: 34 (64%) IART, 11 (21%) FAT and 8 (15%) atrial fibrillation (AF). Mean tachycardia cycle length (excluding AF) was 307±95 ms. At least 2 ATs were induced in 12 pts during index EPS. Among IARTs, incisional IART (IARTinc, atriotomy and superior and inferior vena cava orifices, SVC and IVC, respectively) was the prevalent critical part of the circuit (n=22, 52%), while CTI was the second mechanism (n=20, 48%). In three pts, due to non-inducibility, a pre-emptive lesion set comprising in one case CTI and in two cases CTI+SVC-atriotomy-IVC line was performed. 2 patient underwent scheduled pulmonary veins isolation and CTI ablation. Among FAT, in 3 cases the AT was mapped in the coronary sinus, in two at the tricuspid annulus, in the remaining at the crista terminalis, at the right appendage base, at the posterolateral incision scar or between atriotomy and SVC. In 6 patients AF was induced but not ablated. During a median follow up of 23 months (interquartile range, 6-37) recurrence occurred in 8 pts (18% of pts, 15% of tachycardias). Patients with recurrences were younger (43±7 vs. 48±17 y, p=0.04); no differences were found according to critical isthmus location (4 CTI and 4 IARTinc, 50%, p=ns).

Conclusions

Among rToF pts with AT, IART is the prevalent mechanism and atriotomy scar is the prevalent critical isthmus. FAT location is much more variable. Atrial fibrillation burden is not negligible. Long-term freedom from AT in this clinical setting is encouraging.
Coexistence of cardiac sarcoidosis and genetic cardiomyopathies: a conundrum
Authors: Rossi V A , Palazzini M , Gasperetti A , Brunckhorst C B , Manka R , Giannopoulos A A , Tanner F C , Medeiros-Domingo A , Gentile P , Gruebler M R , Ammirati E , Flammer A J , Ruschitzka F , Duru F , Saguner A M
Published: May 2024

Introduction

Cardiac sarcoidosis (CS) is a chronic inflammatory disease characterized histologically by the formation of non-caseating granuloma in the myocardium, however, causes remain largely unknown. Genetic arrhythmogenic cardiomyopathy (ACM) is an important differential diagnosis of CS. Until now, few data are available about the coexistence of CS in a patient with genetic ACM harboring a desmoglein-2 (DSG2) variant.

Purpose

We report a case series of patients who demonstrate coexistence of histologically proven CS and genetic ACM.

Methods

This is a multicentric study, which included patients from four high-volume cardiology referral centres for heart failure and ACM in Switzerland, Italy, and Austria. Patients with both a biopsy-proven diagnosis of sarcoidosis with cardiac involvement (according to the 2014 HRS criteria) also harboring a pathogenic/likely pathogenic (P/LP) variant for cardiomyopathy-associated genes were 1:1 matched for age, gender and genetic variant with patients with genetic ACM without CS (Gen-only). Clinical and imaging data (echocardiography (TTE), cardiac magnetic resonance (CMR) and positron-emission tomography (18FFDG-PET/CT) were collected.

Results

Each group included 5 patients (Gen+CS: age 48 ± 11 years, Gen only: age 52 ± 13.7 years, n=3 (60%) female in both groups). For each group, the following genes with P/LP variants were found: PKP2: n=2 (40%), DSG2: n=1 (20%), DSP: n=1 (20%), TTN: n=1 (20%). In patients with Gen+CS, atrio-ventricular block (AVB) I° (80% vs 20%, p=0.05) and paroxysmal atrial fibrillation (80% vs 0%, p=0.004) were more frequent, and median NT-proBNP levels (1346ng/l, IQR:103-4276 vs. 214ng/l, IQR:131-326, p=0.046), as well as high-sensitive C-reactive protein levels were higher (3.1g/dl, IQR:1.1-24.2 vs. 0.7g/dl, IQR:0.3-0.95, p=0.016). On imaging, Gen+CS patients were more likely to have septal involvement (60% vs 0%, p=0.021), as highlighted by positive late-gadolinium enhancement on CMR, metabolic activity on PET, or focal wall motion anomalies on TTE.

Conclusions

CS and genetic ACM can coexist. Hence, detection of a P/LP genetic variant associated with ACM should not lead to exclusion of CS, which more frequently presents with AVB, septal involvement, heart failure, and metabolic activity on imaging. On the contrary, CS can be associated with genetic variants in cardiomyopathy-associated genes.FDG-PET/CT
Use of 18F-fluorodeoxyglucose positron emission tomography in the differential diagnosis of arrhythmogenic right ventricular cardiomyopathy and cardiac sarcoidosis
Authors: Costa S , Haug S M , Gasperetti A , Buechel R M , Kovacs B , Akdis D , Rossi V , Cimen T , Tanner F , Manka R , Ruschitzka F , Brunckhorst C , Duru F , Saguner A M
Published: May 2024

Introduction

Arrhythmogenic Cardiomyopathy (ACM) is defined as an arrhythmogenic heart muscle disorder not explained by ischemic, hypertensive, or valvular heart disease, which ranges from a systemic immunologic disorder such as cardiac sarcoidosis (CS), to a genetically determined one (arrhythmogenic right ventricular cardiomyopathy=ARVC). The aim of this study was to assess the utility of 18F-fluordeoxyglucose positron emission tomography /computer tomography (18F-FDG-PET/CT) in the differential diagnosis of ACM.

Methods

This study included 45 patients with a definite diagnosis of ARVC, in whom 18F-FDG-PET/CT was performed to screen for CS. Following a positive PET, diagnosis of CS was pursued according to the 2014 HRS consensus document. The patients were divided into two cohorts: the ARVC Cohort (ARVC-C) and the Cardiac Sarcoidosis Cohort (CS-C).

Results

All 45 patients received an 18F-FDG-PET/CT, of these 5 had a positive PET showing myocardial hypermetabolism. All 5 patients with a positive PET had a final diagnosis of histologically confirmed CS, as such the 18F-FDG-PET/CT had a negative predictive value (NPV) of 100%. All 45 patients also received genetic testing (cardiomyopathy panel). In the ARVC-C, 23 (58%) patients harbored a pathogenic (P)/likely pathogenic (LP) variant (40% in PKP2). In the CS-C, 1 (20%) patient with histologically confirmed CS harbored a LP DSG2 variant. Nine (23%) subjects in the ARVC-C presented with atrioventricular block (AVB) (grade I) and 7 (18%) with QRS fragmentation, whereas 5 (100%) patients in the CS-C presented with AVB (grade I and higher) and 4 (80%) with QRS fragmentation. On TTE, left ventricular (LV) involvement was less frequent in the ARVC-C (LVEF 52.2 +/- 8.7%; wall motion abnormalities in 19 patients (48%)), while LV-involvement in the CS-C was more frequent (LVEF 44.0 +/- 16.2%; wall motion abnormalities in 3 (60%). On cardiac magnetic resonance imaging (cMRI), late gadolinium enhancement was present in the ARVC-C in 14 (35%) in the RV and 15 (38%) in the LV, while it was present in 3 (60%) patients in the RV and 3 (60%) in the LV in the CS-C.

Conclusions

CS is an underdiagnosed clinical entity, which can be challenging to differentiate from ARVC. 18F-FDG-PET/CT has a high NPV to exclude CS in patients fulfilling definite ARVC criteria. Hence, we recommend to offer 18F-FDG-PET/CT to patients fulfilling definite ARVC criteria who present with AVB, QRS fragmentation, or biventricular involvement to screen for CS, especially to those who do not have an LP/P variant in the PKP2 gene.
Long-term risk assessment in athletes with ventricular arrhythmias: the key roles of arrhythmia morphology, complexity, and substrate
Authors: Compagnucci P , Casella M , Narducci M L , Conte E , Cammarano M , Pelargonio G , Andreini D , Palmieri V , Lo Russo G , Pontone G , Natale A , Tondo C , Crea F , Zeppilli P , Dello Russo A
Published: May 2024

Background

Ventricular arrhythmias (VAs) are an important source of concern among athletes.

Purpose

To determine the prognostic role of non-invasive and invasive diagnostic assessments among athletes with complex VAs.

Methods

We included 215 athletes (83% male; 28 [19-43] years) with complex VAs in a prospective, multi-center cohort study. At baseline, each athlete underwent a prespecified comprehensive diagnostic workup, which included cardiac magnetic resonance (CMR) in 202 subjects, and electrophysiology study (EPS)/electroanatomical mapping (EAM) in 190. The primary study endpoint was the occurrence of sudden death or sustained VAs during long-term follow-up.

Results

During a median follow-up of 6.2 (4.4-8.1) years, 16 (7%) athletes had a primary outcome event, including one sudden cardiac death. In univariable Cox models, sustained VAs at presentation (p<0.001), uncommon VA morphology(p=0.004), syncope(p=0.005), abnormal ECG (p=0.003), VAs induction/persistence at exercise testing(p=0.021), late gadolinium enhancement (LGE;p=0.006), low-voltage areas (p=0.003) and late potentials (p<0.001) at EAM, and sustained VA induction by EPS (p<0.001) were all associated with increased risk of primary outcome events. The association of late potentials and EPS inducibility with primary outcome events was confirmed after controlling for all non-invasive predictors at univariable analysis, and the incorporation of findings of invasive tests allowed improved prediction of primary outcome events over clinical/non-invasive findings in isolation (log-likelihood ratio for nested models, p=0.043). Younger age (p=0.032), being a professional athlete (p=0.006), and absence of LGE (p=0.029) were independently associated with higher odds of uninterrupted competitive sports practice until last follow-up.

Conclusions

A comprehensive diagnostic assessment integrating clinical/ECG findings with CMR and EPS/EAM in selected cases may provide important prognostic information among athletes with complex VAs.
Twelve-lead electrocardiography-based artificial intelligence predicts the upcoming future of patients with heart failure with mildly reduced ejection fraction
Authors: Baek Y , Kim D Y , Lee S W , Lee D H , Lee S C , Jang J H , Shin S H , Choi W I , Kim D H
Published: May 2024

Background

Heart failure with mildly reduced ejection fraction (HFmrEF) has emerged as the predominant subtype of heart failure (HF), but there is a paucity of data for identifying it using artificial intelligence (AI) based electrocardiogram (ECG).

Purpose

This study aimed to develop artificial intelligence (AI)-ECG to identify and predict the prognosis of patients with HFmrEF.

Methods

We collected 104,336 12-lead electrocardiography (ECG) datasets from April 2009 to December 2021 in a tertiary center. The AI-ECG encompasses a novel model that combines an automatic labelling preprocessing method with a transformer architecture incorporating a triplet loss for HFmrEF analysis.

Results

The receiver operating characteristic analyses revealed that the area under the curve of AI-ECG for identifying all types of HF were acceptable (0.87, 95% confidence interval [CI]: 0.86-0.89), but that for identifying those with HFmrEF was relatively lower (0.83, 95% CI: 0.78-0.86) than those with HF with reduced ejection fraction (HFrEF) (0.89, 95% CI: 0.85-0.82) and those with normal ejection fraction (EF) (0.87, 95% CI: 0.85-0.89). The analysis of ECG features showed significant increases in QRS duration (p=0.001), QT interval (p=0.045), and corrected QT interval (p=0.041) with increasing ‘Severity by Euclidean distance’. Following the predictability analysis with another group of 1,134 patients for improvements of follow-up EF in HFmrEF, the patients were grouped into three clusters based on the AI- Euclidean distance; Cluster 1 had the most severe cases and poorer outcomes than Clusters 2 (p<0.001) and 3 (p<0.001).

Conclusion

AI-ECG presents an innovative approach for the prognostic stratification of cardiac contractility in patients with HFmrEF. By using AI-ECG, patients with HFmrEF will be able to predict upcoming disease progression.
Artificial Intelligence-based Electrocardiogram prediction for duration of Atrial Fibrillation
Authors: Park Y , Kim G K , Joo S , Chang M , Lee Y
Published: May 2024

Introduction

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with poor clinical outcomes, including stroke, acute coronary events, and heart failure. Recent studies have shown that early rhythm treatment of new-onset atrial fibrillation improves the patient's prognosis. However, atrial fibrillation is often asymptomatic, and it is difficult to determine its duration accurately. Recently, AI-bsed ECG has been studied for various cardiovascular diseases.

Hypothesis

We sought to develop and validate a predictive model of the ECG for the duration of atrial fibrillation.

Methods

All patients aged 18 years older with at least one ECG were included in the study. Only patients with sinus rhythm with ECG prior to atrial fibrillation with ECG were selected. An ECG within 1 year from AF was first documented in ECG was defined as new onset AF. After dividing our datasets into training (and test sets, we developed an end-to-end deep neural network to predict for the duration of AF. Performance evaluation was conducted using various metrics, including AUROC, AUPRC, sensitivity, specificity, F1 score.

Results

The dataset consisted of 83,525 ECGs from 16,193 patients from two hospitals. The AUROC for discriminating old AF and new-onset AF is 0.8186 (0.8181 - 0.8190) on internal validation set and 0.7967 (0.7966 - 0.7969) on external validation set. Sensitivity, Specificity, and F1 score are 0.7126((0.7118-0.7134), 0.7697 (0.7693-0.7701) and 0.5751 (0.5745-0.5757) on internal validation set and 0.7309 (0.7307-0.7311), 0.7225 (0.7224-0.7227) and 0.6354 (0.6352-0.6356)on external validation set.

Conclusion

Our deep learning model can be used to predict atrial fibrillation's duration. Additional studies are ongoing to understand the relative importance of ECG features.
Clinical validation of an artificial intelligence algorithm offering automated corrected QT-interval measurements from a single lead electrocardiogram
Authors: Mannhart D , Kennedy A , Weidlich S , Hennings E , Doggart P , Mc Connell E , Isenegger C , Serban T , Du Fay De Lavallaz J , Knecht S , Osswald S , Kuehne M , Sticherling C , Badertscher P
Published: May 2024

Introduction

A novel smartwatch (Withings Scanwatch, SW) offers automated analysis of the QTc based on single-lead ECG recordings. Prior clinical validation studies showed insufficient accuracy when compared to manual measurements based on a 12-lead ECG.

Purpose

We hypothesized that a novel AI-based algorithm (PulseAI) is capable of measuring QTc-interval based on PDF-exports from a single-lead ECG with improved accuracy compared to the manufacturer’s automated QTc measurements.

Methods

In this prospective, observational study, consecutive patients underwent a nearly simultaneously 12-lead ECG and a single-lead ECG. Two blinded, independent cardiologists manually interpreted the QT-interval in leads I and II of the 12-lead ECG using the tangent-method, which served as the gold standard. QTc was calculated using Bazett’s formula. QTc measurements were compared using the Bland-Altman method.

Results

A total of 317 patients (48% female, mean age 63 ± 17 years) were enrolled. QTc-intervals could be automatically calculated by the SW and by the novel AI algorithm in 175 patients (55%). Diagnostic accuracy of SW-ECG for detection of QTc-intervals ≥ 450 ms as quantified by the area under the curve was 0.85 for the manufacturer and 0.9 for novel AI algorithm. In 21 patients (12%) QTc was ≥450ms. The Bland-Altman analysis resulted in a bias of 21 ms [95% limit of agreement (LoA) -48 to 89 ms] for the manufacturer algorithm and 2 ms [95% LoA -35 to 39 ms] for the novel AI algorithm, respectively, when compared with manual QTc-measurement based on the 12-lead ECG.

Conclusion

A novel AI algorithm outperformed the manufacturer algorithm for automated QTc-measurements based on PDF-exported single-lead ECGs.Central Illustration
Polygenic risk score for Atrial Fibrillation as a predictor for the incidence of Sick Sinus Syndrome: A comprehensive analysis from the UK biobank
Authors: Kim H J , Yang P S , Kim D H , Sung J H , Jang E S , Yu H T , Kim T H , Pak H N , Lee M H , Jung B Y
Published: May 2024

Background

Sick sinus syndrome (SSS) and atrial fibrillation (AF) often coexist, demonstrating a bidirectional relationship. The polygenic risk score (PRS) represents the cumulative risk of disease onset based on variations at multiple genetic loci and is known as a predictor for disease incidence. However, the PRS for SSS remains under-investigated. This study aims to evaluate whether the PRS for AF can predict the incidence of SSS in the general population.

Methods

The UK biobank, comprising of about 500,000 participants aged 40 to 70, was established across 22 centres in the UK between 2006 and 2010. After excluding missing values, prior AF history, and valvular heart disease, a total of 101,654 participants without AF (median age, 56.0 [interquartile range (IQR), 49.0–63.0] years; 44,851 [44.1%] male) were analyzed. Participants were divided into quartiles according to a validated PRS for AF. Throughout the observation period, the incidence of SSS event was documented.

Results

During a follow-up period of 11.7 (IQR 11.0-12.5) years, a total of 157 cases of Sick sinus syndrome were identified. In the new-onset SSS group, age, PRS for AF, BMI, and waist measurements were significantly higher. Additionally, there was a statistically significant increase in the proportions of male sex, hypertension, previous MI, hypothyroidism, dyslipidemia, and ESRD/CKD. The Kaplan-Meier analysis demonstrated an association between the highest quartile and an increased incidence of SSS compared to the other quartiles. (Log-rank P < 0.001) The Cox regression model revealed that a PRS for AF was associated with an increased risk of incidence of sick sinus syndrome (aHR 1.29, 95% CI 1.10-1.51, p-value 0.002). Notably, the discriminative power of our model was substantial, yielding a C-index of 0.746.

Conclusion

In our study, the PRS for AF effectively predicted the incidence of SSS. In the absence of a dedicated PRS for SSS, the AF PRS may offer insights into developing one for SSS.
The right atrium affects in silico arrhythmia vulnerability in both atria
Authors: Martinez Diaz P , Sanchez J , Fitzen N A , Ravens U , Doessel O , Loewe A
Published: May 2024

Introduction

The role of the right atrium (RA) in atrial fibrillation (AF) has long been overlooked. Computer models of the atria can aid in assessing how the RA influences arrhythmia vulnerability and in studying the role of RA drivers in the induction of AF, both aspects challenging to assess in living patients. It remains unclear if incorporating the RA influences the reentry inducibility of the model. As personalized ablation strategies rely on non-inducibility criteria, the adequacy of left atrium (LA)-only models for developing such ablation tools is uncertain.

Aim

To evaluate the effect of incorporating the RA in 3D patient-specific computer models on arrhythmia vulnerability.

Methods

Imaging data from 8 subjects were obtained to generate patient-specific computer models. We created 2 models for each subject: a monoatrial with only the LA and a biatrial with both the RA and LA. We considered 3 different states of substrate remodeling: healthy (H), mild (M), and severe (S). The Courtemanche cellular model was modified from control conditions to a setup representing AF-induced remodeling [1] with 0%, 50%, and 100% changes for H, M, and S, respectively. Conduction velocity was set to 1.2, 1.0, and 0.8m/s for each remodeling state. Fibrosis extent corresponded to Utah 2 (5-20%) and Utah 4 (>35%) stages [2] for M and S, while the H state was modeled without fibrosis. Arrhythmia vulnerability was assessed by virtual S1S2 pacing from different points separated by 2cm using openCARP [3]. A point was classified as inducing arrhythmia if reentry was maintained for at least 1s. The vulnerability ratio was defined as the number of inducing points divided by the number of stimulation points. The mean tachycardia cycle length (TCL) was assessed at the stimulation site. We compared LA vulnerability ratios in monoatrial and biatrial models.

Results

Incorporating the RA increased the mean LA vulnerability ratio by 115.8% (0.19±0.13 to 0.41±0.22, p=0.033) in state M and 29.0% in state S (0.31±0.14 to 0.40±0.15, p=0.219) as illustrated in Figure 1. No arrhythmia was induced in the H models. RA inclusion increased the TCL of LA reentries by 5.5% (186.9±13.3ms to 197.2±18.3ms, p=0.006) in scenario M and decreased it by 7.2% (224.3±27.6ms to 208.2±34.8ms, p=0.010) in scenario S. RA inclusion increased LA inducibility revealing 5.5±3.0 new points per patient in the LA for the biatrial model, which did not induce reentry in the monoatrial model.

Conclusions

LA arrhythmia vulnerability in a biatrial model differs from that in a monoatrial model. Incorporating the RA in patient-specific computational models unmasked potential inducing points in the LA. The RA had a substrate-dependent effect on reentry dynamics, altering the TCL of LA-induced reentries. Our results provide evidence for an important role of the RA in the maintenance and induction of arrhythmia in patient-specific computational models, thus suggesting the use of biatrial models.
Practical use case of natural language processing for comprehensive atrial fibrillation cohort characterization from electronic health records in Poland
Authors: Maciejewski C , Ozieranski K O , Basza M B , Barwiolek A B , Ciurla M C , Bozym A B , Krajsman M J K , Lodzinski P L , Opolski G O , Grabowski M G , Cacko A C , Balsam P B
Published: May 2024

Background

Electronic health records (EHR) contain data valuable for clinical research but mostly in textual format. Natural language processing (NLP) is a computational technique that allows text analysis.

Purpose

To demonstrate a practical use case of NLP in Polish EHR for a large retrospective study cohort characterization and compare it to a standard, manual retrieval by a human.

Material and methods

The dataset consisting of anonymized discharge documentation of 10314 patients from the cardiology tertiary care department in Poland was analyzed for inclusion in the registry of patients with oral anticoagulation for atrial fibrillation (AF). Extensive clinical characteristics regarding: 73 concomitant diseases, medications from 21 classes, and 15 numeric echocardiography parameters were collected manually and through NLP.

Results

There were 2624 and 2601 patients fulfilling study inclusion criteria according to human and NLP-based approaches, respectively, reflecting 99.5% accuracy of NLP in identifying correct study participants. The calculated CHA2DS2VASc and HASBLED scores based on both methods did not differ (human vs NLP; median, IQR, p-value): 3 (2-4) vs 3 (2-4) p=0.74 and 1 (0-1) vs 1(0-1) p=0.98. Despite numeric differences, no statistically significant differences in any of the analyzed clinical characteristics entities were found. Therefore, similar conclusions on cohort characteristics would be made in a shorter time.

Conclusions

NLP utilization in Polish EHR may accelerate acquisition and provide accurate data for a retrospective study.Patient flow.
Electronic 1 year follow up after ablation
Authors: Torsvik E
Published: May 2024

Background

Several studies have shown that phone calls are an effective but resource intensive Follow-up (FU) method to collect patient reported data (PROM) after discharge from hospital. Regarding patient preference for FU, who has been ablated for atrial fibrillation (AF), most of the AF patients favoured a questionnaire with a stamped return envelope. In 2019 the National registry for ablation and electrophysiology in Norway (AblaNor) was established. All patients who have been in an EP lab receive an electronic FU questionnaire (ePROM) 1 year after the date of ablation. In Norway, it has been developed a technical solution which allows data submitted from the patient to be registered in the Health Network,"ePROM engine". Little is known about the functionality and response rate of electronic solutions.

Purpose

The aim of our study was to investigate an electronic FU approach in general and in different patient subgroups from AblaNor.

Method

We used data from the National register of ablation and electrophysiologi in Norway, Ablanor. The data are FU questionnaire who all patients received 1 year after ablation. All questionares are the same, independent diagnosis group. The patients received the FU questionnaires electronically via Helse Norge.no. The data is based on registrations from 2020-21.

Results

The data shows that amongst the 7169 selected procedures in 2020 and 2021, 5235 completed the ePROM form . There is a difference in response rates for both age and sex alone. Younger women have a higher response rate than men of same age, whereas in older age groups,men have higher response rates than women . Patients who have been ablated for AF have a higher respons rate than other procedures. Patients who have only undergone an electrophysiological examination (EP) have the lowest response rate.

Conclusion

Mandatory follow-up 1 year after completion of the procedure takes place in electronic form and contains simple registration of PROMS. The response rate among patients is 78% over the two years. This indicates an extremely high level of digital competence and motivation among patients to provide feedback for completed treatment. This shows that there is a discrepancy for FU regarding patient who has been ablated for atrial fibrillation (AF) .

Abbreviations

RFA: Radiofrequency Ablation; FU: Follow-up; AF: Atrial fibrillation; PROM: Patient reported outcome Measurement
Revealing functional-molecular parasympathetic dysfunction in PVC-induced cardiomyopathy via dual stressor PVC and exercise
Authors: Shoureshi P , Ahmad Z , Wang L , Myadam R , Rose B , Das A , Uzelac I , Kaszala K , Ellenbogen K A , Huizar J F , Tan A
Published: May 2024

Background

Exercise intolerance is a common presentation of premature ventricular contractions-induced cardiomyopathy (PVC-CM). In a canine PVC-CM model, previous studies have shown cardiac autonomic nervous system remodeling, resulting in persistent sympathetic excess. Nevertheless, the molecular mechanisms and functional implications of this neural remodeling, as well as parasympathetic alterations, remain unclear.

Purpose

We aim to evaluate the functional-molecular mechanisms of parasympathetic remodeling and its potential contribution to exercise intolerance in an animal model of PVC-CM.

Methods

We studied 15 canines (8 experimental vs 7 sham controls) chronically instrumented with pacemakers and telemetry devices to deliver 12-weeks of bigeminal PVCs (200ms coupling) to induce PVC-CM and to record sympathetic (SNA), vagal nerve activity (VNA) and heart rate (HR) over this period. Exercise challenge was conducted in sinus rhythm (SR) and in the presence of bigeminal PVCs ("dual stressor") at baseline and after development of PVC-CM. Sympatho-vagal neural and HR responses were assessed during and after exercise at baseline and after PVC-CM development, with and without PVCs, thus comparing baseline SR, baseline with PVCs, CM SR and CM with PVCs. Western Blot was performed on intrinsic and extrinsic cardiac neural tissues to evaluate molecular mechanisms of neural remodeling.

Results

Compared to baseline, SNA was significantly higher in PVC-CM in all phases of exercise (rest, exercise, recovery, p=0.03). In contrast, VNA was significantly lower in PVC-CM than baseline during exercise recovery (P=0.014). After exercise, HR recovery (HRR) was impaired (p=0.001), VNA lower (p=0.014) and SNA (p=0.03) higher in PVC-CM compared with baseline. Tyrosine hydroxylase (TH) immunoreactivity in the left ventricle (LV, p=0.001) and stellate ganglia (SG, p=0.03) and trans-cardiac plasma NE levels (p=0.03) were higher in PVC-CM compared with sham. Choline Acetyltransferase (CHAT) was not significantly different in either vagus (p=0.33) or LV (p=0.8) between PVC-CM vs sham. Cardiac (LV) Nerve Growth Factor (NGF), Growth Associated Protein (GAP-43) and beta 1-adrenoreceptor levels were lower (p=0.042, p=0.003, p=0.002 respectively) whereas beta 2-adreno- and muscarinic M2-cholinergic receptors were higher (p=0.02, p<0.01 respectively) in PVC-CM compared with sham.

Conclusion

Neural remodeling in PVC-CM results in an imbalanced sympathetic excess and sympathetic-parasympathetic dysfunction characterized by a loss of sympathetic functional reserve during exercise and impaired parasympathetic activity and HRR after exercise. Adaptive downregulation of NGF might explain this imbalance and dysfunction. These data open the intriguing possibility of neural-targeted therapies to reverse remodeling and restore autonomic function disrupted by chronic PVCs.GraphsMolecular
Linking ablation curves with transmural lesions using a thoracoscopic bipolar biparietal irrigated radiofrequent clamp
Authors: Aerts L , Norup Hertel J , Hermans B J M , Lans R , Saljic A , Maessen J G , Jespersen T , Linz D , Maesen B
Published: May 2024

Background

The cornerstone of atrial fibrillation (AF) ablation is the achievement of long-lasting transmural lesions. However, it is currently unknown when transmurality is reached during ablation using the thoracoscopic bipolar biparietal irrigated radiofrequent (RF) clamp.

Purpose

To study the relation between transmural lesions and their corresponding ablation curves using a thoracoscopic bipolar biparietal irrigated RF clamp in pigs.

Methods

In 4 ventilated pigs, endo-epicardial beating-heart ablation was conducted via sternotomy. In the first 3 pigs, 1 up to 4 ablations were performed at multiple sites on right and left ventricular tissue. Objective indicators of transmurality in the ablation curves were retrospectively identified by visual inspection. After the ablation procedure, the pigs were sacrificed and subsequent macroscopic evaluation was performed. The ablated tissue was excised and immersed in 2,3,5-triphenyltetrazolium chloride-staining at 36 °C. After 90 minutes the lesions were sectioned longitudinally and photographed. The ablated nonviable muscle appears white, and the viable muscle appears red (see Figure 1). In the 4th pig, ablations (up to 5) were applied to the ventricles at multiple sites until one or more of the potential identified indicators were observed in the ablation curve. Subsequent histology was performed as described in the first three pigs.

Results

Three indicators of transmurality were identified in the ablation curves: type I, a sharp impedance rise (blue peak); type II, three power drops with more than one energy level decline in one curve and type III, a first power drop before 11 seconds with subsequent hovering of power levels between 15 and 25 Wattage (Figure 1). In the first 3 pigs, a total of 20 ablations were performed, with 50% (n = 10) of the ablations considered transmural. In 80% of the transmural lesions one of the three types was observed. Among the transmural lesions, 50%, 10%, and 20% corresponds to type I, II, and III indicators of transmurality, respectively, with 20% remaining inconclusive. In the lesions classified not transmural (n = 10, 50%), no type I, II, or III indicators of transmurality was observed. In the fourth pig, all lesions (n=7) were considered transmural based on macroscopic evaluation, comprising 86% of type I and 14% of type III indicators of transmurality.

Conclusion

Three promising ablation curve types of transmurality have been identified that are associated with transmural lesions using the bipolar biparietal irrigated RF clamp. Transmurality of the lesion was confirmed by macroscopic histological evaluation. In the next step, these ablation curve types will be tested and validated in the clinical setting.Figure 1
Proteomic and phosphoproteomic remodeling in a rabbit model of electrical storm
Authors: Tsuji Y , Yamauchi R , Shimojo M , Yamagisawa S , Inden Y , Murohara T
Published: May 2024

Background

Electrical storm (ES), characterized by repetitive ventricular tachycardia/fibrillation (VT/VF) over a short time-interval, is a major problem with substantial mortality in patients with implantable cardioverter-defibrillators (ICDs) and structural heart diseases, but therapeutic strategy in the survivors has not been established, likely due to incomplete understanding of the pathophysiology.

Objective

To explore molecular mechanisms of ICD-shocked VT/VF-related death in experimental ES.

Methods

The model was created by inducing chronic complete atrioventricular-block in ICD-implanted rabbits, causing cardiac hypertrophy, QT-prolongation, and VT/VF-episodes. Relative protein/phosphoprotein abundances in hearts from 5 rabbits with ES (defined as ≥3 VF-episodes/24-hr period) experiencing 81±28 VF-episodes and 5 controls (CTL) were assessed by iTRAQ LC-MS/MS and key regulatory pathways were examined by Ingenuity-Pathway-Analysis.

Results

Proteomic analysis identified 1938 proteins, 302 of which were differentially expressed between ES and CTL (P<0.05). ES was profoundly associated with mitochondrial dysfunction and oxidative phosphorylation inactivation along with decreased measurement and predicted inhibition of electron transport chain-proteins. Reductions in mitochondrial matrix-enzymes inferred downregulation of fatty acid β-oxidation and TCA-cycle. Transcriptional factors including nuclear respiratory factor 1 and peroxisome proliferative activated receptor, gamma, coactivator 1 alpha involved in mitochondrial biogenesis were predicted downregulated and TP53 linked to mitochondrial depolarization upregulated. Phosphoproteome detected 641 phosphorylated proteins, 168 of which have changes in phosphorylation state in ES versus CTL (P<0.05). Aberrant phosphorylation-patterns occurred in Z-disc proteins of sarcomeres and Ca2+-handling proteins. Protein-kinase A and G, calcium, Ca2+/calmodulin protein-kinase, AMP-activated protein-kinase, and extracellular signal-regulated kinases/mitogen-activated protein-kinase signalings were activated, all coupling to nuclear integrators and mitochondrial transcription, which showed prediction opposite to proteomic data.

Conclusions

ES may cause mitochondrial damage, which can explain mechanical dysfunction and associated mortality. Direct effects of ICD-shocked VT/VF merit further investigations.