bluuebunny/crossref_metadata_2025 huggingface dataset:
ECG characteristics associated with adverse outcomes in COVID-19, a tertiary centre experience
Authors: Bistrovic P , Manola S , Delic-Brkljacic D , Lucijanic M
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

COVID-19 is a systemic disease with dominantly respiratory symptoms, however numerous other presentations involving practically any organ system have been described. Older patients and those with other comorbidities are at higher risk for critical COVID, increased respiratory requirements and death. (1) Those with cardiovascular comorbidities seem to be at a particular risk of detrimental outcomes. (2)

Purpose

The aim of our research was to see if certain ECG characteristics at admission could be predictive of unfavourable events in severe and critical COVID-19 patients.

Methods

We analyzed patient data and available ECG records at admission for 1752 consecutively hospitalized patients with severe and critical COVID-19 at our institution from March 2020 to June 2021. ECG records were obtained from our institution's medical archives, while patient data and outcomes were analyzed through electronic medical records. We analyzed the available ECGs recorded at admission for rhythm abnormalities, heart rate, ST segment changes, presence and localisation of Q waves, interventricular conduction abnormalities, AV conduction, PR, QRS and QTc interval duration, P, QRS and T wave axis, QRS-T angle and Sokolow-Lyon hypertrophy criteria. We defined primary outcomes as mechanical ventilation requirement and intrahospital death.

Results

Our results show that patients who required mechanical ventilation were significantly (P<0.05) more likely to have atrial fibrillation at admission, be tachycardic, have ST depression, have prolonged PR and QTc intervals, as well as pathological T wave axis and QRS-T angle. In multivariate analysis atrial fibrillation (OR 1.55, CI 1.07-2.23), tachycardia (OR 1.45, CI 1.17-1.80), prolonged PR interval (OR 1.88, CI 1.12-3.15) were independently associated with increased need for mechanical ventilation. Intrahospital mortality was significantly (P<0.05) increased in patients who had atrial fibrillation, were tachycardic, had ST depression or elevation, right bundle branch block, left bundle branch block, prolonged PR interval and QRS duration, short and long QTc interval, pathological T wave axis and QRS-T angle. Following multivariate adjustment, atrial fibrillation (OR 2.30, CI 1.59-3.32), tachycardia (OR 1.30, CI 1.05-1.61), ST depression (OR 1.91, CI 1.34-2.72), prolonged PR interval (OR 2.55, CI 1.53-4.25), short QTc interval (OR 8.64, CI 0.95-78.57) and pathological T wave axis (OR 0.71, CI 0.47-1.07) and QRS-T angle (OR 1.85, 1.25-2.73) independently significantly increased mortality.

Conclusion

Specific ECG changes seen already at admission seem to be associated with the need for mechanical respiratory support and increased mortality in COVID-19 patients. This readily available and easily utilised method can potentially help in early identification of those at risk in order to monitor patients more carefully and potentially alter early treatment approach.
A data-driven cluster analysis of stroke phenotypes in Asian patients with atrial fibrillation: refinement of the CHA2DS2-VASc score
Authors: Hsu J C , Yang Y Y , Chung S L , Lin L Y
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial fibrillation (AF) is a disease with heterogeneous underlying conditions which usually encompass several cardiovascular comorbidities. There is a lack of large studies investigating the heterogeneity of patients with AF in Asian population. A refined classification may contribute on individual precise treatment and prognosis.

Methods

This cohort study was conducted utilizing a database from a tertiary medical center. Between 2014 and 2019, a total of 5002 adult patients with AF were enrolled for analysis. We performed an unsupervised hierarchical cluster analysis based on CHA2DS2-VASc score after model assessment. The risk of transient ischemia accident (TIA)/ischemic stroke, heart failure (HF) hospitalization, cardiovascular mortality, and all-cause mortality were assessed.

Results

We identified four replicable distinct clusters of patients with AF: cluster I included diabetic patients with HF with preserved ejection fraction and chronic kidney disease; cluster II included elder patients with a low BMI and pulmonary hypertension; cluster III included patients with metabolic syndrome and atherosclerotic disease; and cluster IV included patients with left heart dysfunction including reduced ejection fraction and enlarged left atrium. The incidence of stroke were 12.7%, 15.1%, 9.9%, and 6.3% in clusters I to IV respectively. Cox regression analyses showed that the differences in risk of TIA/ischemic stroke risk across clusters (cluster I, II, III vs. IV) were statistically significant (Hazard ratio (HR) 1.87 [95% CI 1.00–3.48], 2.06 [95% CI 1.06–4.01], 1.70 [95% CI 1.02–2.84]). Cluster II was independently associated with highest risk for stroke (HR 2.06 [1.06-4.01]), HF hospitalization (HR 1.19 [95% CI 0.79-1.80]), cardiac death (HR 2.51 [95% CI 1.21-5.22]), and all-cause death (HR 2.98 [95% CI 1.98-4.50]).

Conclusion

The study indicated the feasibility of clinical application of the cluster analysis in a highly heterogeneous cohort of patients with AF after accounting for CHA2DS2-VASc risk scores. Patients can be divided into four phenotypes with distinct patient characteristics and cardiovascular outcomes.
Comparison of amplified P-wave analysis to artificial intelligence-derived analysis for diagnosis of atrial cardiomyopathy and outcome prediction following pvi for persistent atrial fibrillation
Authors: Jadidi A , Pilia N , Huang T , Mueller-Edenborn B , Allgeier J , Nairn D , Loewe A , Westermann D , Arentz T
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left atrial cardiomyopathy (ACM) is invasively diagnosed by presence of low voltage substrate (LVS) in electro-anatomical mapping. ACM is associated with high (50%) AF recurrence rates after PVI, but also with increased risk for de-novo AF and ischemic stroke.

Aims

We establish and compare ACM-diagnosis based on 12-lead-ECG analysis, using (A) digital amplified p-wave analysis during SR versus (B) a neural network trained to diagnose ACM using automatically determined sinus-p-wave features (duration, morphology) in 12-lead-ECG as inputs.

Methods

Left atrial (LA) voltage mapping was acquired during SR in 270 AF (50% paroxysmal; 43% female; age: 64+/-11years) prior to PVI. ACM was defined as presence of left atrial LVS<0.5mV at >2cm2 during SR, and was detected in 95/270 (35.2%) of patients. P-wave-analysis was assessed for outcome prediction in a prospective cohort of persistent AF patients undergoing rhythm monitoring using 7-day Holter at 6 and 12 months post PVI-only approach.

Results

The duration of amplified sinus-p-wave (APWD) >151ms (left top panel) enabled to diagnose ACM with an AUC 0.87 (sensitivity: 78% and specificity: 76%, left bottom panel). The accuracy of the AI-neural-network-derived ECG-analysis (using automatically determined APWD and p-morphology criteria) for ACM diagnosis was: AUC 0.85, sensitivity 74%, specificity 78%, accuracy: 77% (see right panel top and bottom). Application of AI-derived ACM-diagnosis on a prospective cohort of persistent AF patients undergoing PVI-only approach (n=58) enabled arrhythmia outcome prediction: Patients with vs. without ACM (based on AI-derived p-wave-analysis) had significantly higher arrhythmia recurrences at 12 months following PVI (46% vs. 23%, p=0.017).

Conclusion

Both the measurement of the APWD and the automatic neural network-based p-wave-analysis enable diagnosis of individuals with left atrial cardiomyopathy with high accuracy in a large cohort of patients with paroxysmal and persistent AF. Diagnosis of ACM based on automatic neural-network-based P-wave analysis enables identification of patients at high risk for arrhythmia recurrence post PVI-only ablation approach.
Analysis of the Amplified P-Wave or Artificial Intelligence-Derived P-wave-Analysis Enable Identification of Patients with Atrial Fibrillation during Sinus Rhythm
Authors: Jadidi A , Huang T , Pilia N , Mueller-Edenborn B , Eichenlaub M , Allgeier J , Trenk D , Westermann D , Arentz T
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction / Aims

This study sought to develop and validate diagnostic models to identify individuals with atrial fibrillation (AF) using amplified p-wave analysis or neural-network-trained p-wave-analysis during sinus rhythm (SR).

Methods

1492 patients (491 healthy controls, 499 with paroxysmal AF and 502 with persistent AF) underwent digital 12-lead-ECG recording during sinus rhythm. The patient cohort was divided into training and validation set in a 3:2 ratio. P-wave indices including duration of standard p-wave (standard PWD; 10mm/mV, 25mm/sec, see ECG in the left panel), amplified digital p-wave (APWD, 60-100mm/mV, 175mm/sec; see ECG in the middle panel) and advanced inter-atrial block (aIAB) along with the parameters body surface area (BSA) and LA diameter (LAD) were used to develop diagnostic models using logistic regression. Each model was developed from the training set and further tested in both training and validation sets for its diagnostic performance in identifying individuals with AF. A neural-network was trained to identify the p-wave and its features (duration, morphology) to differentiate between individuals with known versus those without AF.

Results

Compared to standard PWD (Reference model, AUC=0.637 and 0.632, for training and validation set, respectively), APWD (Basic model) importantly improved the accuracy to identify individuals with AF (AUC=0.86 and 0.866). The ECG-based model combining APWD, aIAB and body surface area (BSA) further improved the diagnostic performance for AF (AUC=0.892 and 0.885). The integrated model, which further combined left atrial diameter (LAD) with parameters of the ECG-based model, achieved the highest diagnostic performance (AUC=0.916 and 0.902). Notably, the neural network-based p-wave-analysis identified AF patients with high accuracy during sinus rhythm (AUC: 0.85; sensitivity: 77%; specificity: 78%).

Conclusions

Both, the analysis of amplified p-wave and a neural-network-based automatic p-wave analysis during sinus rhythm allow identification of individuals with atrial fibrillation. The current diagnostic models provide a new basis for identifying individuals at high risk for AF, who would most benefit from AF screening.
Artificial intelligence-enhanced electrocardiography for predicting severity prognosis in patients with COVID-19
Authors: Baek Y , Jo Y , Lee D H , Lee S C , Choi W I , Kim D H
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

There were no artificial intelligence (AI) tools to predict the severity and prognosis of patients hospitalized with COVID-19 using initial electrocardiography (ECG).

Purpose

We assessed whether AI using 12-lead ECG could assist in the early determination of COVID-19 severity and predict prognosis of hospitalized patients.

Methods

Patients diagnosed with COVID-19 via polymerase chain reaction and admitted to our institution during February 2020–October 2021 were enrolled. We identified 642 patients (mean age, 56±19 years; 41.7% male) who underwent 12-lead ECGs within 2 days of admission for COVID-19. Patients were divided according to severity: mild-to-moderate illness (oxygen or low-flow oxygen therapy not required) and severe-to-critical illness (required high-flow oxygen, invasive mechanical ventilation, or extra corporeal membrane oxygenation).

Results

Severe-to-critical illness occurred in 243 (37.8%) patients, including 23 (3.6%) in-hospital mortalities. Experimental results using our developed AI enhanced ECG demonstrated better outcomes for mild-to-moderate illness based on an area under the curve (AUC), sensitivity, specificity, and F1 score of 0.71, 0.95, 0.70, and 0.81, respectively. The AUC for detecting severe-to-critical illness was 0.71 (95% confidence interval [CI]: 0.58– 0.82; sensitivity: 0.70; specificity: 0.35; F1 score: 0.35; and overall accuracy: 0.70). When analyzing individuals without COVID-19, the AI algorithm for identifying COVID-19 showed an AUC of 0.85 (95% CI: 0.82–0.88; sensitivity: 0.60; specificity: 0.84; F1 score: 0.70; overall accuracy: 0.85).

Conclusion

AI-enhanced ECG could reasonably predict severity in patients hospitalized for COVID-19, suggesting that AI-ECG assists in the early determination of COVID-19 severity, helping physicians improve patient management.
sST2 association with atrial fibrillation development in patients with acute myocardial infarction with ST elevation
Authors: Rodionova I , Kutya I N N A , Hilova Y , Kopytsya M Y K O L A , Samburg Y A N A , Shelest B O R Y S
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is considered a significant myocardial infarction complication. Recent investigations found that soluble suppression of tumorigenicity 2 (sST2) is an important player in ST-segment elevation myocardial infarction (STEMI) development. However, sST2 role in the prognosis for atrial fibrillations in STEMI patients remains not fully clear.

Purpose

The study aimed to investigate the sST2 role in the prognosis of atrial fibrillations development in STEMI patients.

Methods

193 STEMI patients were enrolled into the study. 101 males, 92 females, with average age of 61.23±7.45 years. The follow-up period was 6 month. Plasma sST2 levels were measured at admission by ELISA.

Results

Plasma sST2 concentrations in patients with developed AF were 47.56 IQR [29.87; 61.33] ng / mL, which was significantly higher than in those patients without developed AF 39.67 IQR [22.16; 49.77] ng / mL, p < 0.01.Logistic regression analysis indicated that increased sST2 as a significant predictor for AF development (OR = 1.121, 95% CI: 1.055–1.971, p < 0.01). It remained significant even after adjustment for age and sex (OR = 1.023, 95% CI: 1.009–1.865, p < 0.01). ROC analysis showed that sST2 cut-off level for AF development was 49.12 ng/ml with a sensitivity of 77.8% and specificity of 73.5%, AUC 0.811; 95 % CI 0.633-0.873; p <0.001

Conclusion

The elevated sST2 plasma level is associated with an increased risk of atrial fibrillation in STEMI patients. Our findings suggest new approaches for better management of high-risk STEMI patients.
Cardiac digital twins of the adult population: linking electrophysiological functions to anatomy
Authors: Qian S , Ugurlu D , Fairweather E , Strocchi M , Dal Toso L , Deng Y , Young A , Bishop M , Lamata P , Niederer S
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This project is supported by the Wellcome Trust and EPSRC Centre for Medical Engineering.

Background

QRS duration derived from 12-lead ECGs provides an estimate of the ventricular depolarization time and is an important metric to assess cardiac function. The QRS duration is determined in part by the combination of heart size and conduction velocity (CV). Differences in QRS duration in terms of gender, body mass index (BMI) and age have been well-documented, however, the relative impact of concurrent changes in heart size and CV on QRS duration is poorly understood. Cardiac digital twins, as in-silico replicas, provide a non-invasive physics and physiology-constrained framework to separate the impact of CV and heart anatomy on the QRS duration across populations.

Purpose

This study aims to identify the impact of CV and heart size on differences in QRS duration and quantify their difference in the general population in different groups of gender, BMI and age.

Methods

Patient-specific biventricular models (n=400) were constructed using long- and short-axis cardiac magnetic resonance (CMR) images from patients without self-reported cardiovascular diseases in the UK Biobank. Cardiac electrophysiology was simulated using a physiological-detailed model that includes fiber orientation, anisotropic conductivity, the His-Purkinje system activation, and fast endocardial conductivity[1]. 12-lead ECGs were reconstructed from the simulations and the QRS duration was computed based on corresponding vectorcardiogram (VCG) reconstructed from ECG data [2]. We calibrated patient-specific CVs to match the clinically measured QRS duration in ECGs at rest and then compare the heart size, QRS duration and estimated CVs for different patient groups.

Results

QRS duration was approx. 7% longer in males than females (median: 90ms vs 84ms, P<0.001). Consistent with a longer QRS duration in males had larger hearts (male: 165.5 mL vs 123 mL, P<0.001), while the median CVs were the same between genders (both: 0.594 m/s). QRS duration was longer for obese (BMI≥30) and overweight group compared to healthy (BMI<25) groups (88ms and 86 ms vs 84 ms, P=0.05 and 0.3). Again, the change in QRS duration with BMI was reflected with a corresponding increase in heart size (healthy: 127 mL, overweight: 147.6 mL, obese:160 mL), while CV remained unchanged (healthy: 0.58 m/s vs overweight and obese: 0.594 m/s, P=0.051 and 0.32). There was no significant difference in QRS duration, CV or myocardial volume for different age groups (medians: 86-88 ms and 0.573-0.594 m/s and 138.7-143 mL).

Conclusions

QRS duration is shorter in females and individuals with healthy weights. Most of the change in QRS duration can be explained by heart size, with the estimated CV remaining consistent across groups.
Evidence of cytokine activation in patients with post-acute COVID-19 syndrome with- and without postural orthostatic tachycardia syndrome
Authors: Fredengren E , Mahdi A , Fedorowski A , Brodin P , Nygren-Bonnier M , Runold M , Bruchfeld J , Nickander J , Desta L , Pernow J , Stahlberg M
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swedish Research Council

Swedish Heart- and Lungfoundation

Introduction

Post-acute COVID-19 syndrome (PACS) affects approximately 10% of non-hospitalized COVID-19 patients with mild primary infection and constitutes an increasing burden for society and healthcare systems. We have previously reported that a proportion of PACS patients develop postural orthostatic tachycardia syndrome (POTS). The pathophysiological mechanisms behind PACS and associated POTS remain largely unknown but cytokine activation and inflammation have been proposed.

Purpose

To test the hypothesis that PACS and POTS-specific phenotype are associated with cytokine activation.

Methods

We recruited 20 patients with PACS and POTS verified by head-up TILT test (95% female, 39±11 years, 18±3 months after acute SARS-CoV-2 infection) and 22 patients with PACS without POTS (100% female, 44±11years, 19±3 months after acute SARS-CoV-2 infection). Age- and sex matched healthy volunteers (n=21; 95% female, 43±6 years) without- (n=16) and with (n=5) a history of SARS-Cov-2 infection but without symptoms served as control group. Peripheral blood samples were collected and analyzed for concentrations of 45 cytokines and inflammatory markers using Proximity Extension Assay. Protein-protein interactions and signaling pathway analysis were assessed using String database, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO).

Results

Several cytokines and inflammatory biomarkers were overexpressed in patients with PACS compared to healthy controls irrespective of the presence of POTS (Figure 1). Protein-protein interaction analysis revealed a cluster including IL-7, CXCL12, CXCL11, CCL8 and CCL13. Cytokine-receptor activation, viral protein – cytokine receptor interaction and chemokine signaling were the most significantly upregulated KEGG pathways. Cytokine-mediated signaling, and cell- and leukocyte migration and chemotaxis were the most significantly upregulated GO biological processes.

Conclusion

PACS is associated with increased levels of circulating cytokines regardless of concomitant POTS up to 18 months after a mild primary SARS-CoV-2 infection. This suggests that PACS-associated POTS exist on a background of cytokine activation but other specific pathophysiological mechanisms for PACS induced POTS needs to be established. Whether the cytokine profile of PACS is associated with persistent viral load or prolonged activation of the innate immune system and chronic inflammation, constituting a potential treatment target should be explored in future studies.
Added value of 12-lead 24-hour ambulatory ECG monitoring in the identification of a spontaneous type 1 Brugada pattern and its prognostic role. A sub-study of the BHF RASE Brugada project
Authors: Scrocco C , Ben-Haim Y , Ensam B , Aldous R , Miles C , Specterman M , Tome M , Papadakis M , Sharma S , Behr E R
Published: May 2023

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Background

A spontaneous type 1 Brugada (spT1-BrS) pattern is a recognised marker of arrhythmic risk. However, its fluctuations may underestimate the risk in subjects with concealed T1-BrS at presentation.

Aim

To investigate the yield of repeat resting and high-lead 12-lead ECG and the additional role of 12-lead 24-hour Holter monitoring with leads V1 and V2 in standard and high precordial ECG positions (12-HPL Holter), and evaluate the prognostic role of spT1-BrS in a large, single-centre, cohort of BrS patients.

Methods

Three-hundred and eighty-one subjects with BrS enrolled in our Registry from 2008 to December 2021 and with at least 3 months follow-up data were included in this study. Seventy-seven had spT1-BrS pattern at presentation (Group 1), and 304 did not (Group 2). All received lifestyle recommendations and had regular follow-up appointments with 12-lead ECG; the majority of them were also screened with 12-HPL Holter. Medical notes and tracings were reviewed to identify a dynamic spT1-BrS and events at f-up (SCD/appropriate ICD shock).

Results

The mean age at presentation was 44±15 years; 52% of participants were males. All had at least 2 resting ECGs recorded; in 281 subjects at least one 12-HPL Holter was available (total 643, median 2, range 1-8). Over a median follow-up of 66 months (IQR 75), 37 subjects in Group 2 showed a spT1-BrS at least once: 10 during a repeat resting ECG, 2 during/after exercise tolerance test, 25 at 12-HPL Holter. The average time at spT1 appearance during follow-up was 23 months (range 1- 225). Those with a newly detected spT1-BrS were more frequently males and less likely to have a familial history of sudden cardiac death (Table 1). Excluding subjects with previous aCA/documented VT, 6 events occurred at f-up, all in subjects with spT1 (Figure 1). Univariate models showed that the presence of a spT1-BrS pattern was consistently associated with increased risk of events (at presentation: HR 10, 95% C.I. 1.8-54; at follow-up: HR 5.3, 95% C.I. 1.6-17).

Conclusions

A spontaneous T1-BrS can be detected in up to 12% of subjects with concealed BrS at presentation using 12-HPL Holter monitoring. Its presence is consistently associated with arrhythmic risk at f-up up, regardless of the time at detection. Prolonged ambulatory ECG monitoring is fundamental for risk stratification in this population.
Precordial reverse pattern break on ECG: could it be a discriminator endo/epicardial ablation site of left posteroseptal accessory pathways
Authors: Turan O E , Yilancioglu R Y , Ozcan E E
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Backrounds

The posteroseptal (PS) region may pose difficulty in WPW ablation due to its complex anatomical structure. The posteroseptal region may require the need for a transeptal puncture, CS venogram or coronary angiography due to its right and left endocardial and epicardial proximity. ECG prediction may prevent unnecessary procedures. Negative V1 double QRS transition pattern in the precordial leads is highly specific and validated for a right endocardial AP

Purpose

To investigate the presence of a reverse pattern break in the left posteroseptal [V1 (+) V3 (+)] WPW patient and compare between endocardial-epicardial ablation localization.

Methods

We retrospectively included 338 WPW patients into the study. 97 of them successfully ablated with posteroseptal area.

Results

Thirty-two of the total PS patient (33%) patients had a reverse pattern break or double transition pattern. A total of 4 patients with the middle cardiac vein (MCV) and diverticulum origin were identified. The left pattern break predicts endocardial localization 75% of the time while the right pattern predicts it 95% of the time.

Conclusion

Double transition and reverse pattern break are common in posteroseptal AP’s ECG. Left reverse pattern break is also highly predictive of endocardial ablation, similar to the right.
Using a smartwatch to record precordial electrocardiograms: a validation study
Authors: Van Der Zande J L , Strik M , Dubois R , Ploux S , Abu-Alrub S , Donker D W , Oppersma E , Bordachar P
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work received financial support from the French Government as part of the “Investments of the Future” program managed by the National Research Agency (ANR)

Background

Smartwatches which support recording of a single-lead electrocardiogram (ECG) are increasingly being used worldwide, mainly for detection of atrial fibrillation. Recordings beyond the wrist are anecdotal as their reliability remains unknown.

Aim

This clinical validation study assessed the reliability of an Apple Watch (AW) to obtain frontal and precordial leads as compared with standard 12-lead ECGs in both healthy subjects and patients with underlying heart disease.

Methods

In 100 subjects (80 with ECG anomalies), a standard 12-lead ECG was performed, followed by AW recordings of the standard Einthoven leads (leads I, II, and III) and precordial leads V1, V3, and V6. Seven parameters (P, QRS, ST and T-wave amplitudes, PR, QRS, and QT intervals) were compared through a Bland-Altman analysis including bias (mean difference), absolute offset (mean absolute difference), and 95% limits of agreement.

Results

No significant differences were observed for any parameter across any lead, except for R-wave measured across precordial leads V1, V3, and V6 where significantly greater amplitudes were measured by the AW, (0.20 mV; 0.19mV; 0.49 mV respectively; p = 9x10-7; p = 7x10-4; p = 6x10-14, respectively), indicating overestimation by the AW. There were no significant differences in absolute offset or bias for any parameters of any leads (p > 0.05).

Conclusion

ECGs recorded with the AW on the wrist but also on other positions had comparable durations and amplitudes compared to standard 12-lead ECG. The AW can be used to record frontal and precordial leads, paving the way for broader clinical applications.
Robustness of electrocardiographic imaging in the presence of electrical noise
Authors: Molero R , Martinez-Perez M , Reventos-Presmanes J , Mont L , Climent A M , Guillem M S
Published: May 2023

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Ministerio de Ciencia, Innovación y Universidades; Generalitat Valenciana

Background

Electrocardiographic Imaging (ECGI) allows evaluating the cardiac substrate non-invasively. However, the inverse solution is strongly dependent on the noise of the body surface signals. Zero-order Tikhonov regularization together with L-curve optimization, widely used in ECGI studies, allows minimizing the sources of noise to find an optimal solution.

Objective

Evaluate the effect of electrical and noise on the L-curve optimization in computer simulations of atrial activity and in the physiological interpretation of the inverse solution.

Methods

Five atrial simulations of regular rhythms (3 atrial flutter and 2 sinus rhythm) were used for computing the ECGI with five signal-to-noise ratios (SNR) (from 3dB to 40dB). ECGI was computed by zero-order Tikhonov regularization and L-curve optimization. The regularization parameter (λ) and the shape of the curve were analysed. Electrical noise was added to signals from an atrial flutter patient to study the effect on real ECGI signals. Local activation time (LAT) maps were obtained to evaluate the quality of the ECGI in front of noise. Correlation coefficient (CC) of LAT maps was computed between simulated electrograms and ECGIs.

Results

The level of noise was found to be correlated with the optimal regularization parameter (λ), (SNR 3dB, λ>10-6, SNR 40dB, λ<10-9). LAT maps for the optimal λ and higher were able to find relevant information about the simulation and patient independently on the SNR (CC3dB-EGM = 0.66±0.1, CC40dB-EGM = 0.76±0.1). Similar behaviour was observed in real atrial flutter signals (CC3dB-Ref = 0.83, CC10dB-Ref = 0.93). LAT maps from the atrial flutter were able to accurately locate the reentry circuit, as found in the electroanatomical map independently on the SNR.

Conclusion

LAT maps derived from ECGI are robust against the presence of noise. Although the reconstructed potentials are smoother with increasing levels of noise, LAT maps with and without noise show a good correlation thanks to an increased regularization.

Figure 1. A. Local activation times (LAT) map of a reference electrogram (EGM) from a computer simulation of sinus rhythm in the atria. B. Electrocardiographic imaging maps (ECGI) obtained from the simulation A for different levels of electrical noise and regularization parameters. C. Example of LAT map obtained with ECGI and the endocardial map of a typical atrial flutter together with LAT maps with increased electrical noise but comparable results (CC > 0.83).
The predictive ability of the QT response in supine-standing test for drug induced QT prolongation
Authors: Hochstadt A , Viskin D , Moses A , Romer D , Viskin S , Chorin E
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

A significant cause of sudden cardiac death is arrhythmias induced by QT prolongation. The acquired long QT syndrome is much more common than the congenital form. A major cause of acquired long QT prolongation is drug exposure. Drug-induced QT prolongation is common when taking cardiac drugs such as antiarrhythmics but also common with other medication groups such as antibiotics, antihistamines, and psychiatric drugs. These medications prolong QT by inhibiting the HERG channel which controls the rectifier potassium current (IKr) and prolong depolarization. As HERG inhibition is multifactorial an individual’s effect of medications on QT is difficult to predict and thus leaving many patients with significant risk once they initiate treatment with such medications.

In the last decade, tests that measure the QT reaction to sudden changes in heart rate while changing position for supine to standing have shown usefulness in assessing the possibility of congenital long QT in patients with equivocal QT interval, probably by measuring the repolarization reserve which is deficient in patients with congenital long QT syndrome. Lol

Purpose

We sought to identify whether the same tests can be useful in prediction of acquired QT prolongation after exposure to HERG potassium channel suppressing medications.

Methods

Fifty four healthy volunteers undergone a supine-standing test where QT changes: QT stretching, and QT stunning were examined after brisk standing. Afterward the volunteers received one 400 mg dose of moxifloxacin, a drug known to prolong QT by affecting the HERG channel. Results of the standing test were compared to the drug effects on QTc and predictive ability was assessed.

Results

There was no significant correlation between the maximal drug evoked QTc prolongation and either change in QTc during the stretching or stunning phase (R=0.090, p= 0.538 and R=0.224, p=0.176 accordingly). Both stunning and stretching tests results did not differ significantly between patient with a significant (>20msecs) QT prolongation in response to drugs and no such prolongation (p> 0.361).

The area under the ROC curves of the QTc prolongation during both phases stunning phase did not show usefulness in predicting substantial QTc prolongation (>20msec) during drug therapy with an AUCs of 0.593 (95% CI 0.418-0.769) and 0.617 (95%CI 0.375-0.859) accordingly.

Conclusions

Repolarization reserve assessment using a simple brisk standing test did not efficiently aid in predict QT drug response in patients treated with HERG inhibiting drugs.
Correlation of NT-proBNP and left atrial pressure in patients with atypical atrial flutter after cardiac surgery and previous catheter ablation
Authors: Bakytzhanuly A , Nuralinov O , Esilbayev Z H , Turubayev E , Bagibayev S , Smagulova A , Abdrakhmanov A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Atypical atrial flutter (AFL) is often associated with cardiac surgery or extensive catheter ablation (CA) for the treatment of atrial fibrillation (AF). Therefore, the increase in the number of cardiac surgery procedures leads to the development of substrates for atypical AFL onset. Described several prognostic factors for the development of AF in the long-term period after cardiac interventions. To our knowledge, the prognostic factors of atypical AFL in patients after cardiac surgery are not described.

Objective

the aim of our study was to determine the relationship between increased left atrial pressure and the NT-proBNP biomarker in patients after cardiac surgery and catheter ablation.

Methods

Sixty-five adult patients with AFL after cardiac surgery and catheter ablation were included in a single-center prospective study. The patients' age varied from 18 to 76 years, and the mean age was 57.1±12.2 years. Of these, 36 patients were male (55.4%) and 29 women (49.3%), respectively. Patients were observed for NT-proBNP before index radiofrequency ablation (RFA). All patients underwent RFA of atypical AFL in the left atrium (LA) and measurement of LA pressure. The patients were discharged safely and were monitored for 12 months.

Results

According to basic characteristics of patients with atypical AFL cardiac surgery for valvular heart disease was performed in 30 (46.1%) cases, for ischemic and congenital heart diseases occurred with the same frequency, 8 (12.3%). Atypical AFL occurred in 20 (30.8%) cases after cryoballoon pulmonary veins isolation (PVI), after RFA of a typical AFL in 14 (21.3%) cases, and radiofrequency PVI in 13 (20%) cases. The mean invasive LA pressure before index RFA was 22.3±5 mm. Hg, mean LA size on transthoracic echocardiography was 42.3±6.9mm. The parameters of the left ventricle: mean EDV 93.3±26.1ml, mean ESV 41.7±16.9ml, and mean EF 56±7.6%. Mean NT-proBNP was 974.8±440.5 pg/ml. In our cohort of patients, we identified a positive correlation between NT-proBNP and LA pressure (p<0.001, r=0.761), as well as a positive relationship between NT-proBNP and LA diameter (r=0.512, p<0.001), between LA pressure and LA diameter (r=0.438, p<0.001). Additionally, a correlation was found between the pulmonary artery systolic pressure and LA diameter (r=0.314, p=0.011).

Conclusions

Our study demonstrates a strong direct linear relationship of NT-proBNP with an increase of LA pressure in patients with atypical AFL in patients previously undergone cardiac surgery and catheter ablation. Thus, these parameters can serve as possible prognostic criteria for the development of complex cardiac arrhythmias such as atypical AFL.
Incidence of infranodal conduction delay in patients with left bundle branch block after transcatheter aortic valve replacement: impact of the 2021 ESC guidelines for cardiac pacing
Authors: Maeder N , Badertscher P , Serban T , Weidlich S , Nestelberger T , Leibundgut G , Kaiser C , Osswald S , Sticherling C , Knecht S , Kuehne M
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Left bundle branch block (LBBB) remains the most frequent conduction disorder after transcatheter aortic valve replacement (TAVR). Electrophysiological (EP) testing is recommended in the 2021 ESC Guidelines for cardiac pacing with a IIa indication in patients with new LBBB with QRS ≥ 150ms or PR ≥ 240ms or with pre-existing LBBB with a delta of QRS/PR intervals of ≥ 20ms after TAVR. A cut-off for the HV interval of ≥ 70ms to consider pacemaker implantation was proposed. However, evidence for these proposed cutoffs is scarce in LBBB patients after TAVR.

Aims

To assess the incidence of infranodal conduction delay in patients with LBBB after TAVR and assess safety of predefined criteria for PR and QRS width to identify infranodal conduction delay.

Methods

We analyzed a consecutively included cohort of patients who underwent TAVR between August 2014 and May 2022. A 12-lead surface electrocardiogram (ECG) was available in all patients before and the day after TAVR. Patients with LBBB also received an EP testing the following day, irrespective of surface ECG measurements.

Results

Of 1033 patients who received TAVR between August 2014 and May 2022, 708 were included in the study (Figure). Mean age was 82 years, 53% were female. The used valve types were homogenously distributed. Among 708 patients, 180 patients demonstrated LBBB (25%) the next day (86%new-onset LBBB). Infranodal conduction delay, defined as a HV interval ≥ 70ms, was observed in 18/180 patients (10%) with LBBB on the day after TAVR. Using the new ESC guidelines, EP testing was indicated in 86 of 177 patients (49%) with LBBB after TAVR, with 14 of 18 (78%) being identified with an HV interval of ≥ 70ms (sensitivity 78%, negative predictive value 94%). Thus, in 4 patients (3 men) with new LBBB, the HV interval of ≥ 70ms would have been missed based on surface ECG readings suggested by current guidelines. Stratified by sex, the predefined criteria for PR and QRS demonstrated a sensitivity and negative predictive value of 86% and 98% in women and 72% and 90% in men, respectively.

Conclusion

In patients with LBBB after TAVR the incidence of infranodal conduction delay defined as a HV interval ≥ 70ms is 10%. Predefined surface ECG criteria offer excellent safety for rule out of infranodal conduction delay, especially in women, while caution might be advisable using the same criteria in men.
Mortality and ventricular arrhythmias in patients with atrial fibrillation on sotalol
Authors: Lenhoff H , Darpo B , Tornvall P , Petersson H , Frick M
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Karolinska Institue at Stockholm South hospital.

Background

In atrial fibrillation (AF), anti-arrhythmic drugs are an option for rhythm control. Guidelines regarding treatment with sotalol varies worldwide. The risk of serious adverse events in AF patients on sotalol is estimated from small studies, with short follow-up, not designed for mortality analysis.

Purpose

To evaluate mortality in patients with a rhythm control strategy for AF.

Methods

In Swedish registries, 7473 sotalol-treated and 107255 patients on betablockers underwent cardioversion or were diagnosed with paroxysmal AF between 2006 and 2017. Mortality and ventricular arrhythmias were estimated in unadjusted, and propensity score matched cohorts.

Results

Mean follow up was 474 (SD 599) and 481 (SD 515) days in sotalol/betablocker respectively. Crude all-cause mortality was lower in the sotalol group (HR 0.3 CI 0.3-0.4), also in multi-adjusted analysis (HR 0.6 CI 0.5-0.6). In the propensity-matched comparison, HR remained lower on sotalol (0.6 CI 0.5-0.7). Ventricular arrhythmias were more common among patients on sotalol (1.5 vs 1,0%, p<0,001. 1,1% vs 0,8%/100 personyears). There were no significant differences in CPR or sudden cardiac death.

Conclusions

This real-world data did not show increased mortality in sotalol-treated patients. Ventricular arrhythmias were relatively rare. Careful patient selection and follow-up probably reduce the proarrhythmic risk during sotalol-treatment.
Radiofrequency catheter denervation of sinus node by targetting the right anterior ganglionated plexus: towards minimizing the lesions set
Authors: Stiavnicky P , Wichterle D , Jansova H , Stojadinovic P , Peichl P , Haskova J , Cihak R , Kautzner J
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Radiofrequency catheter (RF) ablation of the superior ganglionated plexus (RAGP) that modifies parasympathetic innervation of the sinus node (SAN) is used for the treatment of functional bradyarrhythmias. The RAGP is usually targeted from the endocardial aspect of both the right and left atria.

Purpose

To investigate the acute effect of a minimized biatrial set of ablation lesions aimed at denervating the SAN.

Methods

In patients with cardioinhibitory reflex syncope (n=25) or symptomatic functional sinus bradycardia (n=7), a minimum of 2x2 and a maximum of 2x3 RF lesions (at the discretion of the operator) were created from both sides of the superior interatrial septum with a setting of 30 W / 30 s and strictly contralateral configuration. The response to extracardiac vagus nerve stimulation (ECVS) was assessed before and after ablation. This response was quantified by the ratio of the maximum induced P-P interval and the cycle length of the current sinus rhythm (MaxPPratio).

Results

In 32 patients (41±13 years, 56% men), ablation of RAGP (2x3 and 2x2 lesions in 23 and 9 patients, respectively) resulted in attenuation of the response to ECVS from 7.9±3.5 s to 0.9±0.2 s (Figure, left panel). After ablation, only 9 patients had MaxPPratio >1.1 and none of the patients had MaxPPratio >1.6 (Figure, right panel). In 6 patients with MaxPPratio >1.3, the extension of original lesions easily suppressed the residual responsiveness of SAN to ECVS.

Conclusion

Biatrial RAGP ablation with a total RF time of 2-3 minutes resulted acutely in virtually complete SAN denervation in 72% of patients. Highly significant, but incomplete SAN denervation in remaining patients was successfully treated by extension of original ablation clusters. The long-term durability of SAN denervation associated with this ablation strategy remains to be investigated.
Immediate pericardial protamine administration in acute pericardial tamponade
Authors: Candemir B , Kuru B , Ersoy I , Atan S , Yamanturk Y Y , Izci I C , Beton O
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Aims

Cardiac tamponade (CT) is the most common life-threatening complication of interventional electrophysiology. Urgent drainage by percutaneous pericardiocentesis and anticoagulation reversal are required. Immediate direct protamine administration to the pericardial space to the patient has not been described. This study was designed to assess the efficacy and safety of immediate intrapericardial protamine administration (IPPA) in CT as a complication of interventional electrophysiologic procedure.

Methods

A retrospective case series of IPPA performed for CT was collected. Urgent drainage by percutaneous pericardiocentesis and IPPA were performed to achieve hemodynamic stabilization without emergent surgery.

Results

Eleven cases of IPPA were included in two tertiary heart centres. Electrophysiological procedures were performed for ventricular tachycardia (n =3), atrial fibrillation (n = 3), left accessory pathway (n = 1), and premature ventricular contraction (n =4) with transseptal (n = 10) and/or retroaortic routes (n =3). Pericardial drainage was performed by percutaneous pericardiocentesis for all 11 patients. Surgical haemostasis was not required for our cohort. The mean volume of drained pericardial fluid was 486ml (200-1200) Mean IPPA dosage was 209mg (100-800). Mean systemic protamine dosage was 86mg(50-100). No complication was observed on the follow-up.

Conclusion

IPPA is a feasible, safe, and useful technique for salvage therapy in CT.

Conclusion

IPPA is a feasible, safe, and useful technique for salvage therapy in ACT in interventional electrophysiology.
Impact of ultra-short pauses between stacked lesions with and without active esophageal cooling
Authors: Mercado Montoya M , Gomez Bustamante T , Kulstad E , Berjano E , Mickelsen S , Hernandez Arango P , Gonzalez Suarez A , Schieber J , Daniels J
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Research reported in this abstract was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R44HL158375 (the content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health).

Background

Placing lesions at the same point (stacking lesions) in the left atrium during radiofrequency (RF) ablation can increase the risk of collateral injury. The use of active esophageal cooling has been shown to significantly reduce the risk of thermal injury to the esophagus, but stacking of lesions may overcome these protective effects. Longer pauses between lesions may reduce this risk, but the effect of very short pauses has not been previously quantified.

Purpose

To examine the impact of ultra-short pauses between stacked lesions with and without active esophageal cooling.

Methods

Using a computational model of the left atrium, we measured the effect of RF ablation in the left atrium on injury formation in the esophagus. Models with and without active esophageal cooling, using a dedicated esophageal cooling device, were created. Using a power of 50 W for 10 s, with up to 3 sequential lesions placed in the same location, we used the Arrhenius equation to quantify the fraction of damage (FOD) in the esophageal wall. The time between lesions was set to as short as 1 s, and results were compared to prior studies using longer pauses of up to 20 s. To account for thermal latency, measures of esophageal damage were taken both immediately after RF ablation, and again 90 s afterwards.

Results

With active cooling in place, esophageal injury was eliminated with active esophageal cooling after the first lesion placement, but reached 21% transmurality without cooling. Lesion transmurality increased after each lesion due to thermal latency, but active esophageal cooling prevented this effect when only one lesion was placed. Subsequent lesions resulted in esophageal injury when placed in the same location. After 3 lesions with 1 s pauses between each, esophageal injury transmurality reached 91% without cooling in place, and 22% with active cooling in place (Figure 1). In contrast, analysis of the intended lesions in the atrial wall demonstrated minimal effects from cooling (Figure 2).

Conclusions

Active esophageal cooling significantly reduces esophageal injury from RF ablation, but placing additional lesions at the same point can overcome the heat extraction capacity of a dedicated cooling device. Decreased time between lesions exacerbates this risk, with an ultra-short pause of one second posing the greatest risk.