bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of continuous photoplethysmography-based heart rate assessment during atrial fibrillation
Authors: Hermans A N L , Isaksen J L , Gawalko M , Pluymaekers N A H A , Van Der Velden R M J , Snippe H , Evens S , De Witte G , Luermans J G L M , Manninger M , Lumens J , Kanters J K , Linz D
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Aim

Although mobile health tools using photoplethysmography (PPG) technology have been validated for the detection of atrial fibrillation (AF), their utility for heart rate assessment during AF remains unclear. Therefore, we aimed to evaluate the accuracy of continuous PPG-based heart rate assessment during AF.

Methods

Persistent AF patients were provided with Holter electrocardiography (ECG) (for ≥24 hours) simultaneously with a PPG-equipped smartwatch. Both the PPG-based smartwatch and Holter ECG automatically and continuously monitored patients’ heart rate/rhythm. ECG and PPG recordings were synchronised and divided into 1-minute segments from which a PPG-based and an ECG-based average heart rate estimation were extracted.

Results

In total, 47,661 simultaneous ECG and PPG 1-minute heart rate segments were analysed in 50 patients (34% women, age 73±8 years). The agreement between ECG-determined and PPG-determined heart rate was high (root-mean-squared error [RMSE]: 4.7 bpm). Heart rate estimated using PPG was accurate within ±10% in 93.7% of the corresponding ECG-derived heart rate segments. PPG-based heart rate estimation was more often accurate during night- (97%) than during day-time (91%, P<0.001) and during low levels (96%) compared to high levels of motion (92%, P<0.001). A neural network with a 10-minute history of the recording did not further improve the PPG-based heart rate assessment (RMSE: 4.4 [95% confidence interval: 3.5-5.2 bpm]. Only chronic heart failure was associated with a lower agreement between ECG-derived and PPG-derived heart rates (P=0.040).

Conclusions

During persistent AF, continuous PPG-based heart rate assessment is feasible and shows high accuracy compared to Holter ECG. Motion and recording quality among other PPG-derived covariates did not introduce a systematic and correctable bias in the heart rate assessment.
Follow-up of implantable cardiac electronic devices during the Covid-19 pandemic: organizational model and results of a single center experience
Authors: Miracapillo G , Addonisio L , De Sensi F , Orselli P , Piccinetti E , Aramini C , Del Maestro M , Limbruno U
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

During the SARS-CoV-2 COVID-19 pandemic, the global health system has had to review important processes involved in daily routines such as outpatient activities within the hospital, including follow-up visits of implantable cardiac electronic devices (CIEDs), pacemakers (PMs) and implantable defibrillators (ICDs) carried out in office. The aim of this study was to prospectively evaluate the success rate of remote transmissions of all devices followed by the CIED control clinic and verify the adopted organizational models.

Methods

All patients with remote monitoring system were considered in the study if automatic algorithm such as autocapture and autosensing were activated and well-functioning. Between January 2021 and November 2022, they were completely followed by remote monitoring and called for unscheduled in-office visit only because of remote yellow or red alarms. Patients were divided into two groups: Manual Transmission System (MTS) and Automatic Transmission System (ATS), based on the available technology. Organizational models shown in figures 1-2, were followed for the two groups. The technology of the ATS group, in addition to ensuring a daily transmission of any yellow or red alarms, allowed a control of missed communication at least every 14 days. The MTS group provided a manual transmission every 6 months. The ATS group was controlled at least once in the year, even if no alarms occurred.

Results

At the end of 2022 a total of 1193 patients were followed remotely by our center. Of these, 238 from the MTS group and 955 from the ATS group. 3314 remote transmission required medical intervention, which generated 182 unscheduled outpatient visits, mainly due to lack of transmission for prolonged periods, failure of the autocapture test and newly onset atrial fibrillation. 3496 transmissions were generated and 120 transmissions were missed; the overall success rate of transmissions with the organizational model adopted was 96.6% (connectivity index). On average, the monthly rate of unconnected manual devices was 5.1% while 3.5% for automatic devices. 2-year mortality was 12.7%.

Conclusions

By adopting an appropriate organizational model, it is possible to maintain high transmission success rates. The available technology allows you to change hospital outpatient habits in the cardiology field for CIED checks and move to a virtual clinic safely. The automatic transmission technology allows a more frequent control of patients with CIED, the impact on the patients' health must be assessed.
Accuracy of real time heart rate monitoring using smartwatch in a stroke care unit
Authors: Pagola J , Meza C M B
Published: May 2023

Funding Acknowledgements

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

Smartwatch with heart rate (HR) tracker measures may allow for identification of people with high resting HR who have a higher risk of atrial fibrillation (AF), a potent independent risk factor for embolic strokes. In this research, we propose a new protocol for collecting real time data of patients with cryptogenic stroke including HR at rest along with monitoring electrocardiogram (ECG). First, we assess the concordance of HR measurement between telemetry (TLM) and two smartwatches in acute stroke patients, as well as the determinants of measurement error.

Method

We included patients over 50 years of age hospitalized in our Stroke Unit who were monitored by TLM and used the Garmin Vivosmart HR® (S1) and Fitbit Charge 5® (S2) devices. Mean HR was collected at 5, 10, 15, 20, and 25 minutes. We applied the Bland-Altman method in combination with Lin's Concordance Correlation Coefficient (CCC) to assess agreement between measurements. A coefficient CCC > 0.9 indicates acceptable agreement.

Results

The experimental setup was performed using 49 stroke patients (59% women, mean age 78 ± 9.86 years, and 69% with a history of AF). Poor agreement was observed between HR measurements by SI or S2 and TLM (CCC = 0.48 and 0.57 respectively), which was conditioned by the presence of AF during the measurement (CCC = -0.17 and -0.06). There was only good concordance in the absence of AF (CCC = 0.97 and 0.92). A higher percentage of error between measurements was significantly associated with a HR > 90 bpm, a history of AF, or presenting AF during the measurement (p<0.001).

Conclusions

Real-time monitoring of HR at rest in each smartwatch was not accurate in acute stroke patients who had presented AF during the intake, or when HR by TLM was greater than 90. This suggests certain limitations when considering the application of processed data from this wearable technology.
miR-328 - a novel diagnostic and predictive atrial fibrillation biomarker in spontaneously hypertensive rats
Authors: Scridon A , Balan A I , Halatiu V B , Cozac D A , Bobarnac R L , Moldovan V , Banescu C
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Romanian Ministry of Education and Research, CNCS-UEFISCDI

Purpose

Atrial fibrillation (AF) is the most common cardiac arrhythmia and a major cause of morbidity and mortality worldwide. To date, there are no reliable biomarkers for the diagnosis and prediction of AF. Alterations in the atrial expression of various microRNAs contributes to the pathogenesis of AF, suggesting that certain miRNAs may emerge as promising AF diagnostic and/or predictive biomarkers. We aimed to evaluate miR-328 as a potential biomarker for the prediction and diagnosis of AF in an experimental model of spontaneous AF in rats.

Method

Male spontaneously hypertensive rats (SHR) and their normotensive counterparts (WKY) were divided into 6 groups: young (12 weeks, n = 8 each), adult (26 weeks, n = 8 each), and elderly (46 weeks, n = 10 each) SHR and WKY. All animals were implanted with ECG radiotelemetry devices, the ECG was continuously monitored for 72 hours, and the number of spontaneous AF episodes was assessed. At the end of the protocol, blood and left atrium tissue samples were taken and miR-328 levels were quantified. miR-328 levels were normalized with U6 snRNA and compared between groups. Correlations between atrial and blood miR-328 levels, and between mir-328 levels and arrhythmic load were also assessed.

Results

None of the WKY rats and none of the young SHRs presented arrhythmic episodes; two of the adult SHRs and all elderly SHRs had spontaneous AF episodes. Young SHR and WKY rats had similar atrial miR-328 levels (p = 0.67). At adult age, atrial miR-328 levels were significantly higher in SHRs than in WKYs (1.20 ± 0.02 vs. 1.07 ± 0.04; p = 0.01). Between-groups differences were even higher in the elderly rats (1.59 ± 0.01 vs. 1.03 ± 0.03; p< 0.01). Among the SHRs, atrial miR-328 levels increased progressively with age (p = 0.02) and were strongly correlated with the circulating blood levels of miR-328 (r = 0.71; p = 0.04). Moreover, among the elderly SHRs, atrial miR-328 levels correlated positively with the number of arrhythmic episodes (r = 0.72; p< 0.01).

Conclusions

The present study demonstrates a strong association between increased miR-328 expression levels and the presence and burden of AF in the hypertensive rats, suggesting that miR-328 could be a promising biomarker for the diagnosis of AF. Moreover, our results demonstrate that in this model the increase in miR-328 levels precedes the onset of AF, suggesting that dynamic evaluation of miR-328 could be used to predict AF, at least in a hypertensive context. Further studies will have to validate these results in clinical settings and to assess miR-328 manipulation as a potential prophylactic and/or therapeutic strategy in AF.
Unraveling direction- and rate-dependent unipolar electrogram morphology using spontaneous atrial extraystoles
Authors: Van Schie M S , Liao R , Ramdat Misier N L , Heida A , Taverne Y J H J , De Groot N M S
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial extrasystoles (AES) are notorious for triggering episodes of atrial fibrillation (AF). AES provoke conduction disorders due to (dispersion in) refractoriness and enhanced non-uniform anisotropy of atrial tissue, which are related to initiation and perpetuation of AF. However, the direction- and rate-dependency of electrophysiological tissue properties on epicardial unipolar electrogram (EGM) morphology is unknown.

Purpose

To examine the impact of spontaneous AES on potential amplitude, -type (single-, double-, fractionated), -duration and low-voltage areas (LVA), and to correlate these differences with various degrees of prematurity and aberrancy.

Methods

Intra-operative high-resolution epicardial mapping of the right and left atrium (RA, LA), Bachmann’s Bundle (BB) and pulmonary vein area (PVA) was performed during SR in 298 patients. EGM characteristics were quantified during SR and AES, and subsequently compared. AES were categorized according their prematurity index (> 25% shortening) and degree of aberrancy (none, mild, moderate and severe). LVA were defined as the amount of unipolar voltages <1 mV.

Results

During 917 unique AES (495 premature; 364 mild-, 186 moderate- and 167 severe aberrant), average voltage decreased (-1.1 [-1.2, -0.9] mV, P<0.001) at all atrial regions, whereas the amount of LVA and fractionation increased (respectively +3.6 [2.9, 4.3]% and +3.2 [2.7, 3.7]%, P<0.001). Although potential voltages were mainly decreased during AES, in 910 (99.2%) AES, at least 0.8% (median 33.3 [19.0–52.1] %) of the recorded voltages was locally larger during AES compared to SR. Only weak or moderate correlations were found between each of the parameters and prematurity indices (R2<0.592, P<0.001). On the other hand, voltages decreased and the amount of fractionation increased with increasing degree of aberrancy. The effect of AES with opposite propagation direction was frequently similar as compared to severely aberrant AES. All parameters were most severely affected by either opposite or severely aberrant AES, without clear relation with degree of prematurity.

Conclusions

Unipolar EGM characteristics during spontaneous AES are mainly directional-dependent and not rate-dependent. This indicates enhanced non-uniform anisotropy that is induced by spontaneous AES.
Update on rare variants in inherited arrhythmogenic syndromes: when to reclassify?
Authors: Martinez Barrios E , Sarquella Brugada G , Cruzalegui Gomez J , Cesar Diaz S , Chipa Ccasani F , Greco A , Fiol V , Cerralbo P , Brugada Terradellas J , Campuzano Larrea O
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Discerning a definite pathogenic role of rare variants in genes associated with inherited arrhythmogenic syndromes (IAS) is critical because of their potential implications for clinical decision-making. The discovery of new gene-disease associations, the publication of functional studies and update on population genetic data may lead to changes in the interpretation of genetic variants classified in previous studies.

Aim

To update the classification of rare variants previously identified in genetic testing of IAS cases.

Methods

This is a retrospective descriptive analysis that enrolled rare variants previously identified in genetic tests from 145 families with a clinical diagnosis of any IAS between 2015-2020. These variants were re-evaluated and reclassified following the American College of Medical Genetics and Genomics guidelines, including newly available data.

Results

In their previous study, 78% of all cases harboured a rare variant classified as a variant of uncertain significance (VUS). Only 22% had a definitive diagnosis with a variant classified as pathogenic (P) or likely pathogenic (LP). In our comprehensive reanalysis following current available data, the classification of 26.7% of these variants changed, mainly due to updated population frequencies, but also to the addition of clinical data and segregation studies. As showed in 2015, the majority of variants were now classified as VUS (57.5%). The percentage of rare variants classified as potentially deleterious increased from 22% to 30%. In addition, 76.5% of reclassified variants gained certainty.

Conclusions

The large number of variants remaining as VUS is one of the main limitations in current diagnosis of IAS. Clarifying the role of rare variants can help to obtain a definitive genetic diagnosis, allowing the identification of those carriers at risk of developing the disease and ruling out those who are not. We propose that a periodic review of rare variants no later than 5 tears may help to improve clinical decision-making in the diagnosis, follow-up, treatment and risk stratification of families with IAS.
Cardiac hereditary diseases: genetic insights from a single center 15-year experience
Authors: Porretta A P , Pavlidou D , Atallah Gonzalez M I , Unger S , Monney P , Pruvot E , Superti-Furga A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

In the last decades, the implementation of high-throughput next-generation (NGS) technologies has profoundly changed the landscape of human genome sequencing. However, the molecular diagnosis in cardiac hereditary diseases is still hampered by the incomplete penetrance, variable expressivity, and genetic heterogeneity of the diseases.

Objective

We report our 15-year experience on a cohort of consecutive patients (pts) with suspicion of cardiac hereditary disease referred to the specialized cardiogenetic outpatient clinic of our center.

Methods

We retrospectively reviewed DNA sequencing results of pts referred to our center from July 1st 2007 through December 31st 2021, who were tested with NGS technologies for suspected cardiac hereditary diseases including channelopathies, inherited cardiomyopathies and unexplained sudden cardiac death.

Results

Among the 488 tested pts, the most frequent clinical indication were presymptomatic screening (37.3%) for a known familial variant, followed by suspected arrhythmic syndrome (28.3%) and hereditary cardiomyopathy (26.8%). A likely pathogenic/pathogenic variant was found in 198 pts for an overall diagnostic yield of 40.6% and of 23.6% considering only index cases. The rate of identified mutation-carriers was higher among pts with cardiomyopathy (45.8%) than among pts with inherited arrhythmic syndromes (37%). Panel A and B display variant distribution in arrhythmic syndromes and cardiomyopathies respectively. In particular, the highest diagnostic yield was observed among pts with suspected hypertrophic cardiomyopathy (60.7%) and catecholaminergic polymorphic ventricular tachycardia (50%), followed by congenital long QT syndrome (48.6%). The pathogenic variants were mainly identified in genes with definitive scientific evidence of causal association with the disease.

Conclusions

The 15-year experience of our specialized cardiogenetic outpatient clinic has demonstrated the pivotal role of genetic analysis for the diagnostic confirmation and, hence for the therapeutic management of pts with suspected cardiac hereditary disease.
Familial cardiolaminopathy due to a previously undescribed LMNA gene mutation
Authors: Ibarra R , Laso Bayas J L , Zambrano A K
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cardiolaminopathies are rare genetic alterations, which present diverse mechanical and electrical alterations.

OBJECTIVE

To present a family carrying an LMNA gene mutation that although not described manifest clinical and electrocardiographic characteristics of the disease.

Methods

We present the case of two sisters and one brother, aged 65, 57 and 51 years, respectively. At the beginning of their fourth decade, all of them debuted with atrial flutter associated with second and third degree atrioventricular block. Two of them (one or the sisters and the brother) underwent ablation of isthmus-dependent atrial flutter. However, in both, the flutter recurred and no new interventional treatment was further offered. The male subject received a pacemaker implant for treatment of AV block; some years later, he presented a cerebrovascular event and subsequently a recurrence, both while in oral anticoagulation and, actually remains with moderate motor deficit and dysarthria. The youngest woman suffered an embolic cerebrovascular event when she was 50 y/o; she remained asymptomatic in relation to the rhythm disorder and refused a pacemaker. The oldest sister who is asymptomatic, received a pacemaker when she was 45 y/o and now is anticoagulated. By echocardiography, all siblings presented left ejection fraction in between 40 and 50% with decreased strain values and normal left ventricular geometry.

Results

Recently in our country it is possible to carry out a genetic test, for which the three were subjected to it. In this family, the genetic testing was done using a comercial kit for 172 genes. The result was a Frameshift Indels (non misense) mutation NM_170707.3 c.1526del p.(Pro509LeufsTer39) Exon:9/12, in all three. The caveat is that this LMNA gene mutation has not been previously described. In light of these results, the youngest woman with total AV block and sequelae of cerebrovascular disease and mild left ventricular dysfunction, received an implantable cardiac defibrillator (ICD) implant for primary prevention of sudden death and her siblings are undergoing an upgrade to ICD.

Conclusion

The mutation found in this family is unique and for the first time reported in the LMNA gene in the world. Genetic diagnosis is limited in our country, which makes it difficult to determine this type of pathology. However, given the clinical presentation of an electrical disorder in all the siblings of a family, in this particular case, it was mandatory to perform this test. These results allow us to better understand the prognosis and intervene appropriately to prevent sudden death, even though there is no treatment to avoid the progression of the disease.
Positive Ajmaline provocation test for Brugada syndrome: acute and long-term outcomes
Authors: Sabbag A , Tomer O , Ozkartal T , Ollitrault P , Laredo M , Tovia-Brodie O , Amoroso G , Gandjbakhch E , Conte G , Milman A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Diagnosis of Brugada Syndrome (BrS) is established either by a observing a spontaneous Type 1 Brugada pattern on ECG or by unmasking Type 1 pattern with a drug challenge using a sodium channel blocker in suspected individuals. There are no clear indications on when to apply the Ajmaline provocation test and how to manage positive case. Data regarding the long-term outcome of this population is limited. The present study was designed to evaluate the incidence and identify predictors of arrhythmic events among subjects with Ajmaline induced Brugada ECG.

Objectives

To evaluate the long-term outcomes of subjects diagnosed with drug induced Brugada ECG.

Methods

A multicenter international consecutive cohort including all cases of positive Ajmaline provocation test from 5 large electrophysiology centers form Israel, France, and Switzerland

Results

A total of 130 patients were recruited, the majority were males (70.8%) and Caucasian (97.7%). In our cohort the most frequent indication for performing an ajmaline test was a family history of BrS or sudden cardiac death (43.1%), then a suspicious ECG (38.5%), syncope (16.1%) and 3 with ventricular fibrillation (VF) (2.3%). The common infusion protocols used were 1mg/kg over 5 minutes (56%) and 1mg/kg over 10 minutes (26%). In all centers ajmaline infusion was stopped when type 1 Brugada pattern was observed. No adverse events occurred during the studies. All patients received instructions regarding the avoidance of arrhythmic triggers (specific drugs, alcohol and reduction of fever). During a median follow up time of 36 (7.5-66.9) months, 9 syncope occurred, 15 ICD (3 for secondary prevention because of VF as initial presentation) and 29 ILRs were implanted. No VF or deaths occurred in any of the study groups.

Conclusion

In the present study of consecutive patients with a positive Ajmaline provocation test, there were no adverse outcomes during a median follow up of 3 years, irrespective of the indication for the test. Our results, indicating a low risk, are in agreement with the current ESC guidelines limiting the diagnosis of Brugada syndrome. Further research is warranted to test whether these patients maybe be managed safely solely by education to avoid arrhythmic triggers.
Electroanatomical voltage mapping with a force-sensing technology catheter for diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
Authors: Rossi V A , Lunk D , Mohsen M , Akdis D , Costa S , Gasperetti A , Duru F , Brunckhorst C B , Saguner A M
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Invasive three-dimensional electroanatomical mapping (EAM) can be helpful to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC). Contact force sensing catheters (CFSC) represent the gold standard to verify adequate tissue contact during EAM. However, normal reference values for right ventricular (RV) EAM as well as substrate characterization in patients with ARVC using CFSC have not been systematically investigated, which was the aim of this prospective study.

Methods

EAM of the RV during sinus rhythm was performed with the Thermocool SmartTouch catheter via a long sheath in the CARTO3 system in 11 patients with definite ARVC and 5 age- and gender-matched control subjects without structural heart disease. Only points with a mean contact force of ≥4G were analyzed. To account for differences due to RV anatomy, it was divided into 5 segments: RV outflow tract (RVOT), septum, free wall, sub-tricuspid region and apex. Endocardial bipolar and unipolar voltages, signal characteristics and signal duration were analyzed. The impact of catheter orientation on endocardial signals was also assessed.

Results

A median of 227 (IQR:120-364) endocardial RV points were analyzed. Median bipolar voltage in healthy controls was 3.8mV (range 3.6-4.6, IQR 2.7-5.4), with lower values in the RVOT and higher values in the RV septum. ARVC patients showed significantly lower bipolar voltages as compared to controls (repeated measures ANOVA; between-subjects effect: F=6.443,p=0.024), showing significantly lower bipolar voltage values in the sub-tricuspid region (1.8±1.9vs.4.6±2.9mV,p=0.031) and in the RV apex (2.9±1.4vs.7.2±5.2mV,p=0.024), Figure 1c. Bipolar voltage values in all RV regions yielded a high sensitivity and specificity for ARVC diagnosis (AUC62-78%,p<0.001 for all), with the highest performance for the sub-tricuspid region (AUC78%,95%CI0.75-0.81,p<0.001). A bipolar voltage value <1.5mV in the sub-tricuspid region yielded a sensitivity of 98% and a specificity of 53% for ARVC diagnosis (Figure 1a-b, showing the typical RV free wall "C-scar" in ARVC and normal values for the RV apex in less advanced disease stages). A positive correlation between bipolar voltage values and an orthogonal catheter orientation (46°-90°: r=0.106,p<0.001) as well as a higher catheter contact force (r=0.054,p=0.008), and a negative correlation between bipolar voltage values and QRS duration (r=-0.370,p<0.001) was found.

Conclusions

For the first time a systematic analysis of RV endocardial low voltage areas in ARVC patients as compared to controls by using CFSC was performed, and confirmed that RV voltages are generally lower in ARVC as compared to controls, with the sub-tricuspid area showing the lowest values and highest discriminatory power vs controls.
Diagnostic gain of cardiac MR in patients with premature ventricular complexes and structurally normal hearts on echocardiography
Authors: Ahmed T , Aagaard-Nilsen S , Anfinsen O G , Hegbom F , Holm T , Bosse G , Edvardsen T , Kongsgaard E , Dejgaard L A , Korseberg Stokke M
Published: May 2023

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway

Background

An important part of the diagnostic evaluation of patients with premature ventricular complexes (PVCs) is to identify underlying cardiac disease. The majority of these patients referred to catheter ablation have PVCs with inferior axis and left bundle branch block morphology (I-LBBB). Although this is the most common morphology in patients with idiopathic PVCs, cardiac magnetic resonance (CMR) is recommended to exclude potential other underlying pathology. However, the diagnostic gain of CMR in patients with I-LBBB PVCs is uncertain.

Purpose

The purpose of this study was to explore the prevalence of cardiac abnormalities identified by CMR in patients with I-LBBB PVCs evaluated for catheter ablation without signs of underlying cardiac disease from resting ECG, stress test, or echocardiography.

Methods

We retrospectively collected data from consecutive patients with I-LBBB PVCs evaluated for catheter ablation at our tertiary referral centre from 2011 to 2022. We included patients with normal ECG and stress test, and no evidence of functional or structural heart disease by echocardiography. We categorized CMR examinations as normal or as having signs of functional or structural abnormalities.

Results

We identified a total of 63 patients with I-LBBB PVCs evaluated for catheter ablation, with no signs of underlying conditions from sinus rhythm ECG, stress test or echocardiography. All were studied by CMR at our institution. The median age was 49 years (IQR 36-61), and 39 were females (62 %). The maximum PVC burden recorded in each patient prior to referral was 20 % (IQR 11-29.5). Left ventricular (LV) ejection fraction by echocardiography was 56±4 %. CMR was normal in 52 patients (83 %), while functional or structural abnormalities were detected in 11 patients (17 %). These abnormalities comprised reduced LV systolic function (2 patients), dilated right ventricle (2 patients), dilated LV (1 patient), ventricular septal defect (2 patients), non-compaction cardiomyopathy (1 patient), mitral annular disjunction (2 patients), tricuspidal annular disjunction (1 patient), and myocardial fibrosis by late contrast enhancement (3 patients).

Conclusions

In patients with I-LBBB PVCs evaluated for catheter ablation, and with no signs of underlying pathology from standard diagnostic work-up, CMR detected abnormalities in 17 %. These results support the routine use of CMR in the evaluation of patients with I-LBBB PVCs referred for catheter ablation.
Predictive value of left and right atrial strain for the detection of atrial fibrillation in patients with cryptogenic stroke and implant of loop recorder
Authors: Arabia G , Cersosimo A , Cerini M , Salghetti F , Falco R , Calvi E , Dell'aquila A , Bontempi L , Mitacchione G , Magdi M , Curnis A
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

Structural and functional remodeling of left and right atrium (LA-RA) are predictors of the risk of hospitalization and mortality. These are chronic and complex processes, dependent on an adaptive response implemented by the atrial myocytes against stressors of an electrical, mechanical and metabolic nature. Atrial fibrillation (AF) is the most common condition associated with remodeling of both atria, of which it can be cause and effect at the same time: atrial enlargement, interstitial fibrosis and myocardial distension. Often the first manifestation of AF is cryptogenic stroke (CS) which is associated with a high rate of recurrence and adverse long-term follow-up outcomes, mainly due to its unknown etiology often leading to secondary prevention ineffective. Asymptomatic (AF) may play an important pathophysiological role to detect CS. Evidence has demonstrated the efficacy of AF ablation in restoring the structure of the LA and, consequently, in favoring the maintenance of sinus rhythm. However, little is known regarding the evaluation of RA remodeling and its variation over time in patients with FA.

Aim of the study

Evaluate the relationship between echocardiographic parameters of LA and RA function, and the occurrence of AF revealed by continuous ECG monitoring through insertable cardiac monitors (ICM) implant in a cohort of patients with CS

Methods

Single-center retrospective study. A total of 204 patients who suffered from cryptogenic stroke underwent ICM between May 2013 and July 2022. All detected AF episodes lasting more than 30 seconds were considered, according to Guidelines. All patients underwent to Transthoracic Echocardiography (TTE) to study on LA and RA function, including both standard and longitudinal strain-derived parameters. Transesophageal Echocardiography (TEE) was also performed to exclude embolic sources.

Results

During a median follow-up period of 15.3 months (interquartile range, 7.4 / 23.5), continuous ECG monitoring revealed AF in 96 patients (47.0%). Many echocardiographic parameters, such as LA maximum and minimal volume were significantly associated with the occurrence of AF, suggesting the worst atrial function in the AF group. Furthermore, multivariable regression analysis revealed that peak atrial contraction strain of both atria were independently associated with AF (p < 0.001,respectively).

Conclusion

In patients with cryptogenic CS, LA and RA strain analysis are strong and independent predictors of the occurrence of AF despite clinical and morpho-functional echocardiographic parameters.
Clinical evaluation of the new 12-lead ECG noninvasive epi-endocardial mapping technology
Authors: Chmelevsky M , Zubarev S , Khamzin S , Dokuchaev A , Bazhutina A , Sinitca A , Budanova M , Auricchio A
Published: May 2023

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): XSpline S.p.a.

Aim

Noninvasive electrocardiographic mapping systems may require multichannel (150-250) ECG body surface recordings which is a huge limitation for the adoption into clinical practice. However, most of the currently available noninvasive mapping systems accurately represent epicardial activation. Over the last few years, various technical solutions have been implemented to increase the accuracy of ECG forward-inverse calculations including machine learning algorithms. We developed a novel 12-lead ECG-based, fully automated system for noninvasive full transmural (epi-endocardial) mapping. The aim of this study was to evaluate accuracy of this system in heart failure patients with typical LBBB.

Methods

Eight consecutive patients (median age: 65; 25-75% range 59-64; 5 male) with typical LBBB QRS morphology (QRS duration 146–224 ms), scheduled for CRT implantation underwent a cardiac CT scan and 12-lead ECG recording, followed by detailed bi-ventricular endocardial electroanatomical contact mapping (EAM). A median of 258 (181-576) local electrograms in LV and 86 (70-139) in RV were collected during EAM. Cardiac CT data were semiautomatically processed using a Unet-like neural network to obtain meshes containing the heart (each chamber with both endocardial and epicardial contour as well as coronary sinus and its branches), lungs and torso using different segmentation module. Noninvasive epi-endocardial activation maps were calculated using state-of-the-art mathematical models including machine learning methods. These data were compared with EAM from the invasive mapping system using Spearman correlation (r), mean absolute error (MAE) and relative distance metrics.

Results

All early and latest activation patterns were correctly identified (see figure). The average correlation (r) of endocardial activation maps was 0.92 for all cases (min-max: 0.82-0.96). MAE was rather small (9-15 mm) when the non-invasive late activation zone nearly matches the CARTO data (average distance error 14 mm). Overall, the QRS complex was correctly reproduced by our method in all cases (r = 0.96).

Conclusions

This study shows that new mapping technique can accurately reconstruct endocardial electrical activation maps based on 12-lead ECG and cardiac CT scan. The approach may be very useful in pre-procedural planning of device implantation and catheter ablation. Larger validation studies are however needed for confirming method accuracy at epicardial site.
Atrial stimulation protocols to test inducibility of atrial fibrillation
Authors: Fischer P , Wintrich J , Pavlicek V , Boehm M , Mahfoud F , Ukena C
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background

The electrophysiological inducibility of atrial fibrillation (AF) after pulmonary vein isolation (PVI) has been identified as a predictor of future AF recurrence. Stimulation protocols have not been sufficiently studied prospectively with respect to their reliability for inducing AF.

Methods and results

We conducted a prospective monocentric randomized clinical trial to evaluate different standardized electrical stimulation protocols on their potential to induce AF. Patients with symptomatic AF presenting in sinus rhythm scheduled for PVI were enrolled. The primary outcome was induction of AF. A total of 30 patients (age=62±2 years, 17% female, 13% persistent AF, left atrial systolic volume (LASV) 93±5 ml) were enrolled and randomized. To one of three different stimulation protocols performed at the beginning of PVI. Atrial fibrillation was induced in 4 out of 10 patients (40%) with fixed cycle length stimulation followed by up to 3 extrastimuli (protocol A), 6 out of 10 patients (60%) with burst stimulation (protocol B) and 9 out of 10 patients (90%) with fixed stimulation using the shortest cycle length with 1:1 atrial capture (protocol C), respectively. Time from start of stimulation to inducibility of AF was significantly lower in protocol C vs. protocol B and A (29±10 sec vs 40±14 sec vs 366±71 sec; p<0.0001). Isoprenaline was used in 10% in protocol A, 40% in protocol B and 80% protocol C. Overall, there were no significant differences concerning age (61±3 vs. 63±4 years; p=0.74), LASV (93±6 vs. 94±8 ml; p=0.98) or other parameters between patients with inducible and non-inducible AF.

Conclusion

With systematic stimulation protocols AF can be induced in up to 90%. Further studies are warranted to assess the specifity of these stimulations.
Invasive electrophysiology study guided loop recorder implantation in myotonic dystrophy type 1: a prospective single-center study
Authors: Debreceni D , Janosi K , Fodi E , Faludi R , Simor T , Pal E , Tenyi D , Lovadi E , Varga D , Becze T , Kupo P
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

In one third of the patients with myotonic dystrophy type 1 (DMT1) the cause of death is of cardiac origin. The most common cardiac manifestations are arrhythmias and conduction disturbances.

Purpose

Due to its extreme long monitoring properties, implantable loop recorders (ILRs) are highly suitable to detect rare cardiac arrhythmias. To date, there are only limited data using ILRs in DMT1. We aimed to evaluate the role of the invasive electrophysiology study (EPS)-guided loop recorder implantation in patients with DMT.

Methods

In our prospective study 18 genetically confirmed DMT1 patients underwent non-invasive cardiac examination including transthoracic echocardiography, 24-hour Holter monitoring and surface ECG. In addition, EPS was performed in all cases to evaluate the risk of sudden cardiac death and infra-Hisian conduction properties. Based on the performed non-invasive diagnostic evaluation and EPS findings, patients were divided into low, intermediate and high-risk groups. For patients with normal investigation results and normal HV interval (<55 ms) only annual cardiac follow-up visits were planned (low-risk group). Patients with increased PR interval (>240 ms), QRS duration (>120 ms), or slightly prolonged HV interval (55-70 ms) underwent implantable loop recorder (ILR) implantation (intermediate-risk group). Permanent pacemaker (PM) or implantable cardiac defibrillator (ICD) was implanted in patients with 2nd/3rd degree atrioventricular block (AVB), significantly prolonged HV interval (>100 ms) or if sustained ventricular tachyarrhythmia could be induced during EPS. All patients were followed for at least 3 years.

Results

According to our study criteria, 8 patients could be categorized as "intermediate risk", 7 of them received implantable loop recorder (ILR). 1 ILR had to be removed 3 weeks after implantation due to skin infarction. During three-years of follow-up, 2 patients had many asymptomatic atrial high-rate episodes, but no 2nd or 3rd degree AVB, significant asystole or malignant ventricular arrhythmia were detected.

Conclusions

Our single-center prospective study examined the EPS-guided ILR implantation for the risk stratification of DMT1 patients for the first time. A more extensive, multicenter study is warranted to define optimal management of DMT1 patients with slightly impaired infrahisian conduction.
Zero or minimal fluoroscopy catheter ablation: feasibility, efficacy, and safety results
Authors: Melero Polo J , Cabrera Ramos M , Montilla Padilla I , Ruiz Arroyo J R , Ramos Maqueda J
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

Fluoroscopy has been used to guide catheter ablation since the beginning of this technique, despite its important secondary effects on both patients and operators. However, three-dimensional electroanatomic mapping systems (3D-EAMP) enable ablation of some substrates using zero or minimal fluoroscopy. The aim of this study is to explore the feasibility, efficacy and safety of a zero or minimal fluoroscopy approach in our center.

Methods

We performed a retrospective observational study with consecutive patients that underwent catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT), accessory pathways (AP), focal atrial tachycardia and typical atrial flutter in our center, between January 2020 and November 2022. Vascular access was obtained by ultrasound guidance. The objective was zero-fluoroscopy for all patients except those with left AP, in which minimal fluoroscopy was allowed for the transseptal access (ablations with retrograde aortic approach were excluded).

Results

319 consecutive patients were included. 56% were male, mean age was 55 ± 16 years. The following substrates were included: AVNRT (43%), typical atrial flutter (41%), AP (12%) and focal atrial tachycardia (5%). We achieved zero-fluoroscopy use in 99.3% of right substrates, using fluoroscopy in just two cases to introduce catheters through femoral access. Mean fluoroscopy time in left AP was 6.1 minutes. Ablation was successful in 97% of cases, and we just experienced three complications (moderate pericardial effusion, femoral hematoma and femoral arteriovenous fistula, all of them solved without requiring intervention). After a mean follow- up of 17 ± 14 months, we noticed three recurrences, performing in all of them a successful second ablation procedure. Baseline characteristics and procedure details are shown in table 1.

Conclusions

Catheter ablation of simple substrates with zero or minimal fluoroscopy using 3D mapping systems is feasible, effective and safe, with high success rate and low complications rate.
Impact of hemodynamic support in high-risk VT ablation procedures
Authors: Luik A , Haas A , Schmidt K , Widder J
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Introduction

It is an ongoing debate whether VT ablation is better performed in SR or during VT. During SR patients are in stable conditions, however, VT mechanisms can only be visualized during VT. Hemodynamic stability during VT is critical and is shorter in patients with structural heart disease and severely reduced left ventricular ejection fraction (LVEF). In unstable VT with need for cardioversion, the risk of map anatomy shifts is increased, but a precise anatomical reconstruction is crucial for successful ablation. Considering hemodynamic support during VT ablation, handling must be easy and as little disruptive to the ablation procedure as possible. Percutaneous left ventricular support systems with appropriate access size seem to be the most suitable, but are limited in their support capacity. The aim of this study was to evaluate, whether a hemodynamic support of a maximum of 3,5 L/min is sufficient to ensure hemodynamic stability even in faster VT.

Methods

The study enrolled patients with a history of one or more sustaining VTs and severely reduced LVEF. Procedure was performed under deep sedation. Transseptal and transaortal access was prepared to access the LV. In epicardial cases an additional subxiphoidal access was used. Impella CP with SmartAssist was introduced via the opposite groin. Hemodynamic support was started immediately after placement. VTs were induced via programmed RV and burst pacing. VT was mapped and ablated with the Carto 3 Mapping system. The need to frequently adjust pump setting, duration of hemodynamic stability during VT, identification of VT mechanism and ablation success were evaluated.

Results

8 patients with a total of 21 VTs have been mapped, analyzed and ablated. 4/8 patients received epi-/endocardial ablation. With hemodynamic support, all VTs could be mapped under stable conditions (CLmedian VT = 360ms). 87,5% could be terminated during catheter ablation, in 50% no VT was reinducible after ablation. The median time for Impella placement was 20min. The Smart Assist Mode enabled an easy handling without the necessity of manual adjustments during the course of the case. The Impella could be explanted at the end of the procedure in 7 out of 8 cases. Femoral closure was done with either Proglide or AngioSeal closure device. Post procedural, one patient developed a segmental stenosis of the A. femoralis superficialis, most likely due to the Proglide device. This case was treated conservatively and recovered after a few months.

Conclusion

Hemodynamic support of a maximum of 3,5L/min provides adequate and effective support for mapping of sustained VTs. No manual adjustment was required and patients could in general be weaned directly at the end of the procedure. Broader benefits of this concept need to be evaluated in further studies.
High-density open window mapping vs conventional mapping in accessory pathways ablation
Authors: Martinez-Sande J L , Minguito-Carazo C , Gonzalez-Melchor L , Garcia-Seara J , Fernandez-Lopez X A , Rodriguez-Manero M , Gonzalez-Ferrero T , Ruiz-Donate J , Tasende-Rey P , Jimenez-Ramos V , Gonzalez-Juanatey J R
Published: May 2023

Funding Acknowledgements

Type of funding sources: None.

Background and purpose

High density (HD) mapping is associated with a reduction in fluoroscopy time compared to conventional mapping in accessory pathway (AP) ablation. The Open Window (OW) technique (CARTO 3, Biosense Webster) is a new tool that automatically uses conventional electrophysiology criteria for AP location, as shorter local EGM AV interval (extended early meets late tool), earliest local activation time (LAT) and annotation at unipolar signal (wavefront annotation). However, no studies comparing its feasibility to conventional mapping have been conducted. Therefore, the aim of the present study was to assess the feasibility and the clinical implications of high-density OW mapping when compared to conventional HD mapping.

Methods

A prospective, unicentric cohort study was conducted. Consecutive patients which were referred to our institution for AP ablation with OW mapping technique were included and compared to a recent retrospective cohort of patients who underwent conventional HD mapping. Total fluoroscopy time, total mapping time and the rate of recurrence of the AP were compared between groups.

Results

A total of 29 consecutive patients (32.28 ± 18 years, 58% males) were included in the OW group and compared with a cohort of 29 patients (29.6 ± 18 years, 52% males) who underwent conventional HD mapping. An example of Right Superior AP ablation is showed in figure 1. No differences in the location of the AP were observed (p=NS). OW mapping was associated to a lower mapping time (29.3 vs 37.8 min; p=0.04), lower fluoroscopy time (14.3 vs 21.3 min; p= 0.04) and lower radiofrequency time (p=0.007). After a median follow up of 6 months, there were no differences in the rate of recurrence of the AP conduction between groups (p=NS). A schematic step by step graphic of the workflow procedure is represented in figure 2.

Conclusions

In our experience, OW mapping was a feasible tool for AP location associated to a lower mapping time, lower radiofrequency time and lower X-ray exposure time with no differences in recurrence rate when compared to conventional HD mapping. However, more studies should be performed to corroborate these conclusions.