Rest ECG Research Articles

Use of the Resting ECG in the Evaluation of Individuals Experiencing Recent Chest Pain

Use of the Resting ECG in the Evaluation of Individuals Experiencing Recent Chest Pain

Cardiopulmonary Exercise Testing in Children and Young Adolescents after a Multisystem Inflammatory Syndrome: Physical Deconditioning or Residual Pathology?

Multisystem inflammatory syndrome in children (MIS-C) is a serious health condition that imposes a long-term follow-up. The purpose of our pilot study is to evaluate the usefulness of the cardiopulmonary stress test (CPET) in the follow-up after MIS-C. All patients admitted for MIS-C in our hospital in the 12 months preceding the date of observation were considered for inclusion in the study. Pre-existing cardio-respiratory diseases and/or the lack of collaboration were the exclusion criteria. At enrolment, each subject passed a cardiological examination, rest ECG, echocardiogram, 24 h Holter-ECG, blood tests, and a CPET complete of spirometry. A total of 20 patients met the inclusion criteria (11.76 ± 3.29 years, 13 male). In contrast to the normality of all second-level investigations, CPET showed lower-than-expected peakVO2 and peak-oxygen-pulse values (50% of cases) and higher-than-expected VE/VCO2-slope values (95% of cases). A statistically significant inverse correlation was observed between P-reactive-protein values at admission and peakVO2/kg values (p = 0.034), uric acid values at admission, and peakVO2 (p = 0.011) or peak-oxygen-pulse expressed as a percentage of predicted (p = 0.021), NT-proBNP values at admission and peakVO2 expressed as a percentage of predicted (p = 0.046). After MIS-C (4-12 months) relevant anomalies can be observed at CPET, which can be a valuable tool in the follow-up after this condition.

Effect of Fabric Electrode Surface Coating Medium on ECG Signal Quality under Dynamic and Static Conditions

This study intends to explore the influence of a fabric electrode skin interface filling medium on ECG signals under dynamic and static conditions, so as to be able to better monitor both stable and dynamic ECG signals. In this paper, cotton fabric electrodes were prepared using electroless silver-plated conductive cotton fabric, and then the electrodes were integrated into a physiotherapy-grade elastic bandage to assemble the fabric ECG tape. The electrode impedance tester and the BIOPAC physiological recorder were used to measure the fabric electrode-skin impedance and electrocardiogram under dynamic and static conditions, respectively. Later, the influence of the fabric electrode coated medium on the acquisition effect of an electrocardiogram signal under dynamic and static conditions is discussed. The results show that in the absence of a dielectric reagent coating, the cotton fabric electrode is easily disturbed by external noise which leads to large electrode-skin contact impedance. However, the electrode-skin contact impedance is greatly reduced after coating the fabric electrode with the dielectric reagent. At the same time, after applying the conducive paste coating, the corresponding change curve of the fabric electrode became more stable, and the impedance value was less than 0.005 MΩ·cm2, which meets the standard requirement for textile dry electrode skin impedance. In a state of rest, a clear and stable ECG can be collected regardless of whether the medium reagent is coated or not. However, only after applying the conductive paste can a stable ECG signal be collected under the three motion modes, or can a P wave, QRS wave group, or T wave be clearly distinguished. In addition, there is a high correlation with the disposable gel electrode, which can satisfy the requirements of the long-term monitoring of ECG signals under dynamic conditions.

Improved health-related quality of life after cardioneuroablation in patients with vasovagal syncope.

As the most common cause of syncope, vasovagal syncope (VVS) is mediated by parasympathetic overactivity and/or sympathetic withdrawal. Although catheter ablation of ganglionated plexi or cardioneuroablation has been used to treat VVS, its role in quality of life (QoL) has not been formally evaluated. The aim of this study was to demonstrate if this novel treatment results in improvement QoL of patients with VVS. Twenty-seven consecutive patients (age: 34 ± 14years, 51.8% male) with dominant cardioinhibitory type VVS were prospectively enrolled in the study. After confirmation of > 3s asystole on head-up tilt testing (HUT), all patients underwent cardioneuroablation. ECGs were obtained prior to procedure and at 12-month follow-up visit. HUTs were repeated 1month after cardioneuroablation procedures. QoL was assessed with the use of SF-36, EQ-5D, and EQ VAS questionnaires. ECG, HUT, and QoL data were available in all patients. At 12-month follow-up, heart rate on rest ECG significantly increased (from 74 ± 15 to 84 ± 14bpm, p = 0.003). Repeated HUTs were negative in 23 (85.1%) patients. All of 27 patients remained free of syncope. QoL assessed by SF-36 score significantly improved in postprocedural follow-up (92 ± 9 and 96 ± 11, p = 0.016). Similarly, significant improvements in mobility, self-care, and usual activity domains of EQ-5D were observed (mean scores of 3.0 ± 1.5 and 2.1 ± 1.3, p < 0.001; 1.3 ± 0.9 and 1.2 ± 0.6, p = 0.041; 1.7 ± 1.0 and 1.4 ± 0.8 respectively). EQ-VAS score also improved significantly (39 ± 24 to 77 ± 18, p < 0.001). Our findings suggest that cardioneuroablation may be associated with intermediate term improvement in QoL in patients with VVS.

Unsupervised machine learning improves risk stratification of patients with visual normal SPECT myocardial perfusion imaging assessments

Abstract Background Unsupervised machine learning has the potential to identify new cardiovascular phenotypes and more accurately assess individual risk in an unbiased fashion. Purpose We aimed to use unsupervised learning to identify, analyze, and risk-stratify subgroups of patients with normal perfusion by visual interpretation on single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Methods We included consecutive patients with visual normal clinical assessment (summed stress score of 0) from the multicenter (9 sites), REFINE SPECT registry. We considered 23 clinical, 17 image-acquisition, and 26 imaging variables. Optimal dimensionality reduction (Uniform Manifold Approximation and Projection), clustering (Gaussian Mixture Model), and number of clusters were selected to maximize the silhouette coefficient (how similar a patient is to those in their own cluster compared to other clusters). Risk stratification for all-cause mortality (ACM) and major adverse cardiac events (MACE) was assessed within these clusters and compared to risk stratification by quantitative ischemia (&amp;lt;5%, 5–10%, &amp;gt;10%) using Kaplan-Meier curves and Cox Proportional-Hazards analysis. Results In total, 17,527 (of 30,351) patients in the registry had visually normal perfusion, 49.7% female, median age of 64 [55, 72] years. There were 1,138 ACM events and 2,091 MACE events with a median follow-up of 4.1 [2.9, 5.7] years. Unsupervised learning provided better risk stratification for both ACM and MACE compared to quantitative ischemia (Figure). Notably, the high-risk cluster by unsupervised learning had a hazard ratio (HR) of 9.5 (95% confidence interval [CI]: 7.7–11.7) compared to 1.4 (95% CI: 1.1–1.9) for quantitative ischemia &amp;gt;10%. The high-risk cluster had proportionally more women (45% [low-risk], 51% [medium-risk], 57% [high-risk], all p&amp;lt;0.001), higher body mass indices (26.9, 27.4, 29.6, all p&amp;lt;0.001), prevalence of diabetes (17%, 22%, 33%, all p&amp;lt;0.001), and abnormal rest ECGs (30%, 43%, 64%, p&amp;lt;0.001); with lower rates of family history of coronary artery disease (40%, 33%, 24%, p&amp;lt;0.001). Patients in the low-risk cluster were more likely to undergo exercise stress (100%, 38%, 0%, all p&amp;lt;0.001), had lower rest peak systolic blood pressure (130, 131, 140 mmHg, all p&amp;lt;0.001), and higher stress peak systolic blood pressure (164, 150, 131 mmHg, all p&amp;lt;0.001). Patients in the high-risk cluster had higher left ventricular mass (129, 135.45, 143.9 g, all p&amp;lt;0.001) and stress volume (57, 59, 66 ml, all p&amp;lt;0.001). Conclusion Unsupervised learning identified new phenotypic clusters for SPECT MPI patients with visual normal assessments which provided improved risk stratification for ACM and MACE compared to SPECT ischemia. Such individualized risk assessment may allow better targeted management of patients with visually normal perfusion. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Research reported in this publication was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R01HL089765. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

COMPARATIVE EFFICACY OF ANTIARRHYTHMIC MEDICATIONS FOR SINUS RHYTHM MAINTENANCE AFTER ELECTRICAL CARDIOVERSION FOR ATRIAL FIBRILLATION

Objective: Sinusa rhythm maintenance while using IC class medications is not practically studied. IC class medications aethacizinum is widely used, but has no large studies proving safety and efficacy. The aim of this study was to compare the efficacy of class IC antiarrhythmic medications, for sinus rhythm maintenance, after ECV (electrical cardioversion), in patients with atrial fibrillation (AF). Design and method: It is an open-label, one-center prospective study that held in the Latvian Centre of Cardiology, Pauls Stradins Clinical University Hospital from September 2019 to June 2020. Before hospitalisation patients have not received any antiarrhythmic drugs except of amiodarone and beta blockers. Patients with persistent form of AF received beta blockers (bisoprolol 5 mg daily), amiodarone (200 mg daily), propaphenone (300 mg daily) or aethacizinum (100 mg daily) for 6 months after conversion to sinus rhytm by ECV. Rest ECG, Holter monitoring, echocardiography, ergometer stress test, blood tests were performed. Results: The total number of patients finished study per protocol – n = 52. On echocardiographical study no significant changes in AFR (AF paroxysm group) and MSR (maintained sinus rhythm) groups were found. No safety parameters were significantly changed in this group. All patients were followed up for 6-month period. Reccurance rate of AF in aethacizinum group showed a statistically significant superiority compared to propafenone (55,6% vs 72,5%) (p = 0,05). Patients with higher atrial strain and strain rate appear to have a greater likelihood of staying in sinus rhythm. In our research, duration of AF was not predictive value of maintenance of SR at follow-up after 6 months from ECV. Conclusions: Antiarrhythmic medications of Ic class may be safe in patients with persistent form of atrial fibrillation and have no negative impact on inotropic function of myocardium. The most commonly used drug from Ic class ir etacizin. The observed efficacy provides the rationale for a larger, double-blind controlled study with different antiarrhythmic medications in different daily dosage.

A COMBINATION OF HYPERTENSION AND A HIGH ATHEROGENIC INDEX OF PLASMA AS AN INDICATOR OF A CORONARY HEART DISEASE RISK

Objective: Our study demonstrated the changes in the prevalence of coronary heart disease (CHD) depending on hypertension and atherogenic index of plasma Design and method: The atherogenic index of plasma (AIP) is a common logarithm of a ratio of triglycerides and HDL-cholesterol molar concentrations. According to M. Dobiasova (2006), at AIP &lt; 0.10, cardiovascular risk is low; at the range of 0.10 to 0.24, the risk is medium, and if AIP is higher than 0.24, the risk is high. For the randomized sample of the ESSE-RF study, which included 1603 Krasnoyarsk Krai inhabitants, we used a standard questionnaire, anthropometry, office blood pressure measurement, and biochemical blood analyses to find a prevalence of known cardiovascular diseases and their risk factors. We registered hypertension if a person took antihypertensive medications or their measured blood pressure was at 140/90 mm Hg or higher. Coronary heart disease was diagnosed with a Rose angina questionnaire and 12-lead rest ECG encoded by the Minnesota system (the authors wish to thank the National Medical Research Center for Therapy and Preventive Medicine for assistance in laboratory tests and ECG encoding). Results: In 14.7% (95% CI = 13.8%-15.6%) of the study participants, we found CHD. Along with it, 73.5% of people had a low risk by AIP; in 10.4%, AIP indicated a medium risk, and 16.1% of the study participants had a high risk. People with normal blood pressure had no significant interrelation between the prevalence of CHD and AIP level (p = 0.669). Contrary, hypertensives with low risk by AIP had 23.2% (95% CI = 19.5%-27.0%) cases of CHD; at the medium risk, the prevalence of CHD was at 31.5% (95% CI = 21.8%-41.1%), and in the group of high risk, there were 17.5% (95% CI = 11.9%-23.1%) people with CHD. Chi-square was for trend at p = 0.036. Conclusions: The atherogenic index of plasma and coronary heart disease had no interrelation in normal blood pressure. In hypertension, however, the atherogenic index of plasma at a medium level may indicate a higher probability of coronary heart disease.

Atrial fibrillation and 13-year risk of CVD mortality in Russian population cohort

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The study was supported by RFBR #20-313-90015, RAS # АААА-А17-117112850280-2 Introduction Given the worldwide increase in life expectancy, ageing-related conditions are becoming increasingly important. Atrial fibrillation (AF) is the most common arrhythmia and a serious predictor of the progression of heart failure and thromboembolic events (largely, stroke). Thus, the study of AF impact on cardiovascular (CVD) mortality is of particular relevance. Objectives We aimed to analyze the impact of AF on the 13-year risk of CVD mortality in the Russian population sample of elderly age. Methods A random population sample (n=9360, age 45-69 years) was examined at baseline in 2003-2005 in the Russian arm of the HAPIEE project. The cohort was re-examined twice and was followed up for end points up to end of 2017 (12.7 years on the average). Fatal end-points were ascertained by local mortality register; the current study focused on CVD deaths. Baseline AF was defined by rest ECG with evaluation by the Minnesota code (MC 8-3-1, 8-3-2; 6-8 with "fibrillation" for atrium). Those with prevalent CVD at baseline and with inadequate ECGs were excluded from analysis; Cox-regression age- and multivariable-adjusted models were estimated. Results In total, data on 8565 persons aged 45-69 years at baseline were analyzed. Among those, 145 (1.6%) subjects had AF at baseline and of those 100 subjects had no existing CVD. During the 13-year follow-up, there were 431 cases of CVD death (10.9%) in the cohort, among them 63% (n=272) were fatal coronary heart disease (CHD) and 23% (n=101) were fatal stroke (2.5%). In age-adjusted models, men with baseline AF had increased risk of CVD death (HR=5.76; 95%CI 3.88-8.55), fatal stroke (HR=6.26; 95%CI 2.96-13.22), and fatal CHD (HR=5.86; 95%CI 3.58-9.59). After adjusting for other risk factors, the increased risk remained for all CVD outcomes: 4.49 (95%CI 2.84-7.09) for CVD death, 3.62 (95%CI 1.46-8.96) for fatal stroke, and 4.95 (95%CI 2.81-8.70) for fatal CHD. In women, the age-adjusted HR for CVD death in women with baseline AF was 3.92 (95%CI 1.60-9.62) but in fully-adjusted models the HR was attenuated (HR=2.22; 95%CI 0.87-5.70). The numbers of deaths from CHD and stroke in women were too small for meaningful analyses. Conclusion In this urban population-based cohort of subjects free from CVD at baseline, 11% of participants died from CVD death during 13 years follow-up. Men and women with baseline AF had approximately 4-fold increase in CVD mortality risk. The estimated CVD excess mortality risk associated with AF in this Russian cohort is consistent with findings from Western European and North American populations.

Changes in the prevalence of atrial fibrillation in the Russian population over a 13-year follow-up

Aim. To study the prevalence of atrial fibrillation (AF) in the Russian urban population cohort aged 45-69 years and its changes over 13-year follow-up during aging.Material and methods. This cross-sectional long-term prospective study included random population sample of men and women 45-69 years (n=9360, HAPIEE project, Novosibirsk), which was examined in 2003-2005 and was re-examined twice and followed up for about 13±1,00 years in men and 13,1±2,17 years in women. The incidence of AF was assessed for individuals without AF or cardiovascular disease (CVD) at the baseline examination. Statistical analysis was performed using the SPSS software package (v.13.0).Results. In a population sample over a 13-year follow-up, AF prevalence increased from 1,6% (1,1% among women and 2,1% among men) at the age of 45-69 years to 4,2% (3,0% among women and 6,1% among men) aged 55-84 years according to screening rest ECG examinations. The prevalence of new AF cases over a 13-year followup in the cohort of 45-69 years old without previous CVD and AF was 5,6%, of which 40% were paroxysmal. The mean age at the time of first registered AF was 69±6,93 years, and was 2 years higher in women (70,0±6,83) than in men (68±6,93). The average period before the AF onset among people aged 45-69 years without baseline CVD and AF was 7,5±3,83 years for men and 8,1±4,02 years for women. The total prevalence of AF in the population sample was 8,3%. The highest AF prevalence was registered at the age of 65-69 years (11,4%) for men and 5 years later for women (12,0%) (p80 years decreased and amounted to 4,1% among men and 5,7% among women.Conclusion. In the Russian population sample (Novosibirsk) aged 45-69, the AF prevalence increased from 1,6 to 8,3% over 13 years of follow-up. In addition, 473 new AF cases were identified, ~40% of which were paroxysmal AF. The prevalence of AF in the Siberian population sample for the 45-60 years age group is comparable with the large Russian and North American studies, but higher for persons aged 60-74 years and lower for older age group, for both men and women.

A PATIENT WITH CHEST PAIN AND ST-SEGMENT ELEVATION ON A RESTING ECG – A CASE STUDY

The study aimed to discuss selected causes of chest pain in patients with ischemic changes on the resting ECG. The Emergency Medical Service (EMS) team was dispatched to a 49-year-old patient reporting crushing, retrosternal chest pain radiating to the left upper limb. The research material was obtained from the analysis of the patient’s medical records during his stay in the Emergency Department (ED), the Interventional Cardiology Department, as well as from the medical emergency card and the dispatch order of the EMS team. The study used an individual case study method. An urgent qualification for coronary angiography and percutaneous coronary intervention is the priority in providing healthcare service to a patient with the suspected acute coronary syndrome with ST-segment elevation. The ED staff followed the guidelines on management of acute coronary syndrome with ST-segment elevation.

The History and Challenges of SCP-ECG: The Standard Communication Protocol for Computer-Assisted Electrocardiography

Ever since the first publication of the standard communication protocol for computer-assisted electrocardiography (SCP-ECG), prENV 1064, in 1993, by the European Committee for Standardization (CEN), SCP-ECG has become a leading example in health informatics, enabling open, secure, and well-documented digital data exchange at a low cost, for quick and efficient cardiovascular disease detection and management. Based on the experiences gained, since the 1970s, in computerized electrocardiology, and on the results achieved by the pioneering, international cooperative research on common standards for quantitative electrocardiography (CSE), SCP-ECG was designed, from the beginning, to empower personalized medicine, thanks to serial ECG analysis. The fundamental concept behind SCP-ECG is to convey the necessary information for ECG re-analysis, serial comparison, and interpretation, and to structure the ECG data and metadata in sections that are mostly optional in order to fit all use cases. SCP-ECG is open to the storage of the ECG signal and ECG measurement data, whatever the ECG recording modality or computation method, and can store the over-reading trails and ECG annotations, as well as any computerized or medical interpretation reports. Only the encoding syntax and the semantics of the ECG descriptors and of the diagnosis codes are standardized. We present all of the landmarks in the development and publication of SCP-ECG, from the early 1990s to the 2009 International Organization for Standardization (ISO) SCP-ECG standards, including the latest version published by CEN in 2020, which now encompasses rest and stress ECGs, Holter recordings, and protocol-based trials.

Cardiac magnetic resonance in athletes with ventricular arrhythmias

Abstract Funding Acknowledgements Type of funding sources: None. Background Ventricular arrhythmias in athletes represent an important issue in sport eligibility as they may be a marker of a concealed cardiomyopathy, potentially at risk of sudden cardiac death during sport activity. Purpose to assess the utility of cardiac magnetic resonance (CMR) to identify cardiac abnormalities in athletes with documented frequent premature ventricular beats (PVB) or complex ventricular arrhythmias (VA) undergoing competitive sport eligibility screening. Methods We enrolled 65 athletes with documented ventricular arrhythmias as follows: 1) frequent PVB at 24-hour ambulatory ECG monitoring (&amp;gt;100 PVB/24h); 2) polymorphic PVB; 3) repetitive PVB (couplets, triplets, or nonsustained ventricular tachicardia). All athletes were studied with rest ECG, exercise stress testing, 24-hour ambulatory ECG monitoring, transthoracic echocardiography and contrast-enhanced CMR. Results Sixty-five athletes (56 males, 9 females, age 30 ± 15years) underwent CMR with gadolinium contrast. In 55 patients (84.6%) CMR was normal, in 10 patients (15.4%) the following abnormalities were reported at CMR: four patients with isolated late gadolinium enhancement (LGE) of whom 3 patients with subepicardial LGE in the inferolateral wall and 1 patient with intramyocardial basal inferior LGE; 1 patient with hypertrophic cardiomyopathy with septal LGE; 1 patient with left ventricular non compaction; 3 patients with right ventricular abnormalities (a 13-year-old patient with dilated right ventricle and LGE located at the superior interventricular insertion point, 1 patient with a dilated and hypokinetic right ventricle, 1 patient with a focal right ventricular aneurysm). Transthoracic echocardiography was normal in 7/10 (70%) athletes with CMR abnormalities. Conclusion In athletes with frequent or complex ventricular arrhythmias cardiac magnetic resonance identifies cardiac abnormalities in a significant proportion of subjects and it may offer a diagnostic incremental value.

ECG modifications, life-threatening ventricular arrhythmias and relation to mitral valve apparatus phenotype in mitral valve prolapse

Abstract Background Mitral valve prolapse (MVP) is a common condition in the general population, which can be associated to non-specific ECG abnormalities described initially as ST segment depression, T waves flattening or inversion, especially in the inferior leads. Lately, this type of ECG abnormalities has been reported in patients with MVP and ventricular arrhythmias (VA) or sudden death (SD). However, the prevalence of ECG abnormalities has never been studied in a large series of patients, and the link between ECG abnormalities, VA and SD to echocardiography examination has never been prospectively assessed. Objective To study the prevalence of ECG abnormalities including ventricular arrhythmias in MVP patients and their link with echocardiographic characteristics. Methods All patients (n=731, MVP = 486, Controls = 245) were prospectively enrolled and underwent a comprehensive echocardiography and ECG. In MVP patients 81 had minimal systolic displacement (MSD), 92 isolated MVP, 108 mild-moderate MR, and 196 severe MR. A comprehensive qualitative and quantitative analysis of ECG obtained from rest ECG, 24-hours ECG recording or exercise stress tests, was carried out. Mean follow-up was 4.4 years. Results The mains ECG abnormalities were an inversion of T wave in the inferior leads found in 12 MVP vs 1 control (2.5 vs 0.4%, P=0.047) or a QRS notch (5.1 vs 2.9%, P=0.13). In bileaflet MVP T wave inversion was more frequent as compared with other MVP patients (3.8 vs 0.8%, P=0.039). In addition there was a progressive prolongation of PR interval, QRS duration and increase QT dispersion associated with worsening of MR and heart chambers remodeling. None of ECG findings were significantly linked with the presence of MVP only. Out of 731 individuals, 27 (3.7%) had an history of VA or SD. In a multivariate analysis, bileaflet prolapse and mitral annulus disjunction were associated with VA or SD, whereas none of ECG criterion was associated with. Conclusion In this large prospective series of MVP patients, prevalence of inferior leads ECG abnormalities is very low. Prolongation of atrio-ventricular and ventricular conduction, as well increased QT dispersion is associated with worsening of MR and LV remodeling. Bileaflet prolapse and mitral annulus disjunction are associated with VA or SD. Funding Acknowledgement Type of funding source: None

Prognostic value of a normal Artificial Intelligence applicative response in subjects with stable chest pain. From the ARTICA co-operative registry

Abstract Background An innovative artificial intelligence (AI) Decision Support System (DSS) ESC guidelines based has already been used at point of care with efficacy for evaluating subjects with stable chest pain (SCP) and it has been proved to correctly identify absence of significant coronary artery disease (CAD) versus standard care approach (SD) without known prognostic implication yet. Purpose The aim is to determine the prognostic value of “no testing/Follow up” AI DSS response in a referral population evaluated for SCP. Methods From 2016 to 2019, an AI DSS ESC guidelines based applicative was used on 1.291 subjects with SCP to determine testing appropriateness compared with human specialist standard evaluation. 590 of them, 332 males, mean age 62±11 years deemed to be completely negative – by “no testing/follow up” response - were evaluated. The negative response was defined and confirmed by a normal Coronary Tomography Angiography scan executed in all these subjects. Mean follow-up was 3.46±1.76 years. Two groups based on pre-test likelihood of having CAD were analyzed – low and intermediate. No subjects with high pre-test likelihood were present. The primary endpoint was cumulative incidence of cardiovascular death, hospitalizations for acute coronary syndrome and coronary revascularizations. Results The primary endpoints classification is displayed in the Table. The unadjusted hazard ratio for primary endpoint was 3.84 (95% CI 0.32–8.68, p=0.009) in patients with intermediate compared to those with low pre-test likelihood of CAD. Moreover, the “no testing and Follow up” response showed an incremental prognostic value over conventional risk factors (χ2=7, P=0.022) and over a combination of conventional factors and ST-T changes (χ2=9, P=0.014). Conclusions In an outpatient population without known CAD evaluated for chest pain, after the administration of AI DSS, a “No tests/Follow up” confers an excellent prognosis regardless of the ESC SCORE Charts and rest ECG abnormalities. These preliminary data confirms the safety of ARTICA AI DSS use in subjects with stable chest pain. Funding Acknowledgement Type of funding source: None

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

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

Predictors of cardiac neuromodulation achieved by cryoballoon ablation performed in patients with atrial fibrillation who were in sinus rhythm before the ablation

BackgroundThe impact of pulmonary vein isolation (PVI) performed with cryoballoon (CB) on the intrinsic cardiac autonomic nervous system (ICANS) remains unclear. ObjectiveThe purpose of this study was to evaluate the predictors and the clinical meaning of cardiac neuromodulation achieved by CB-ablation as assessed by sinus heart rate (HR) response after the procedure. MethodsPatients who underwent CB-ablation for drug-resistant atrial fibrillation (AF) from January 2014 to October 2018 were included. Twelve‑leads rest ECG was taken both before and after the procedure. After discharge, patients were scheduled for follow-up visits at 1, 3, 6, and 12 months and 24 h Holter recordings were obtained at each follow-up visit. All documented AF episodes of >30 s were considered as recurrence. ResultsFour-hundred seventy-two patients (62.3% male, age 56.7 ± 13.6 years, 97.2% paroxysmal AF) were included. Mean HR before the procedure was 60.17 ± 10.4 bpm, while the morning after the procedure mean HR was 75.48 ± 12.0 bpm. Age at enrollment (R = −0.26; p < 0.001), baseline HR before the CB-A (R = −0.32; p < 0.001), nadir temperature in each right pulmonary vein (R = −0.11, p = 0.022; R = −0.16; p = 0.001) were significantly associated with the ∆HR. At 2-year follow-up, freedom from recurrences was 83.1% for the patients with HR increase ≥15 bpm after CB-A and 66.3% in patients with HR increase ˂15 bpm (p = 0.021). ConclusionSinus HR increase is a frequent phenomenon after CB-A, that can be predicted by both clinical and procedural factors and that correlates with better outcome after cryo-PVI.

P945 Should children, with exercise induced intra-ventricular gradients, be treated with beta blockers?

Abstract Background In our experience, treadmill exercise echocardiography (SE) is feasible and safe in children (C). Regional wall motion abnormalities (RWMA) are of limited usefulness, but Doppler often - (in 39% from 258 previously studied C) - documents significant intraventricular gradients (IVG), occult at rest, and allowing to document a possible explanation for exercise related symptoms, or abnormal resting or stress-ECG findings. Purpose - To assess the effect of ß blockers on the occurrence of IVG, in C, with symptoms or abnormal resting or stress-ECG findings. Methods – We repeated SE in 66 of the 101 C – (with normal echocardiogram at rest) - that developed IVG on exertion, under treatment with ß blockers. These 66 C who repeated the SE under treatment with ß blockers are the study group. 15 (23%) of them were female and the mean age of the group was 14,6 ± 1,7 years old (11 to 17). They all underwent SE with 2D and Doppler echocardiographic evaluation of, and during treatment with ß blockers. Results Mean IVG in those 66 C submitted to SE was 105 ± 38 mmHg in the first SE evaluation. In SE evaluation performed under ß blockers, 37 of them didn’t develop IVG and in 29 of them IVG was significantly reduced to a mean IVG of 58 ± 32 mmHg (p&amp;lt; 0,0001). The mean heart rate attained at peak exercise was 178 ± 15 bpm in the first SE evaluation and 157 ± 9 bpm in the evaluation performed under treatment with ß blockers (p &amp;lt; 0, 0001). 47 of these C reproduced clinical symptoms (that were indication to SE) of beta-blockers, and only 7 reproduced the symptoms under treatment with beta blockers (p&amp;lt; 0,0001). Conclusions In C with symptoms, abnormal rest or exercise ECG on medical evaluation and IVG on exertion, treatment with oral ß blockers prevented the occurrence of IVG or significantly reduced its magnitude. These changes were associated to significant clinical improvement in 85 % of the symptomatic population. Abstract P945 Figure. SE without and with beta-blockers

Diagnostic value of additional right precordial leads both at rest and at peak stress test in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D) patients

ECG late depolarization abnormality called epsilon wave (ɛ) is a major diagnostic criterion in ARVC/D patients according to Task Force. As ARVC/D induces progressive right ventricular enlargement, whether or not additional right precordial leads (X1, X2, V3R, V4R) may increase ECG diagnostic sensitivity at rest and/or during exercise has never been systematically investigated. We studied 3 groups (G) of subjects. G1: 17 propositus patients with desmosomal mutation; G2: 17 first degree relative gene carriers; G3: 20 controls. All subjects were paired between groups for age, BSA, sex and sport practice. A 16 leads ECG including additional right precordial leads X1, X2, V3R, V4R was performed in each case both at rest and at peak stress. Recordings were amplified up to 100 mm/s and 40 mm/mV and retrospectively analyzed by two investigators blinded to patient status. All subjects reached a sustained power of similar strength (160 ± 50 W) on cycloergometer. At rest, by including standard (V1, V2) and additional right precordial leads, an ɛ was shown in 14/34 patients (41%, 7 in G1, 7 in G2). Among them 4 (12%, 2 in G1, 2 in G2) showed an ɛ exclusively in at least one additional lead. At peak stress, an ɛ was noticed in 19/34 patients (56%, 12 in G1, 7 in G2). Among them, 9 patients (26%, 7 in G1, 2 in G2) showed an ɛ exclusively in at least one additional lead. In other words, in 5/34 patients (15%, all in G1) not showing any ɛ at rest, peak stress unmasked a new ɛ, exclusively in at least one additional right precordial lead. No ɛ was detected in G3, neither at rest nor at stress. By combining rest and stress test ECG, the use of additional right precordial leads X1, X2, V3R, V4R, enhances by 27% the detection of ɛ waves (major criterion), more often in propositus than in relatives, as compared to usual precordial derivations alone, and should be proposed for inclusion among ARVC/D Task Force criteria.

Make a point on left ventricular noncompaction

Hypertrabeculation is a feature of the left ventricle that, by itself, does not coincide with left ventricular non compaction (LVNC), which represents a specific cardiomyopathy. Nowadays, in the absence of gold standard diagnostic criteria, the clinician must integrate imaging aspects together with medical history. The family inheritance for LVNC, presence of neuromuscular disorders, symptoms or signs of heart failure, thromboembolic events, unexplained syncope, pathological findings at rest ECG, Holter ECG, stress test, systolic/diastolic dysfunction at rest echocardiogram, late gadolinium enhancement at cardiac magnetic resonance, and identification of specific mutations are all considered features useful for the diagnosis. Many aspects are not fully understood: multicenter studies, registers and observational studies are needed for a better comprehension of the pathology, adequate risk stratification and targeted follow-up.

Heart Rate Variability: An Old Metric with New Meaning in the Era of Using mHealth technologies for Health and Exercise Training Guidance. Part Two: Prognosis and Training.

It has been demonstrated that heart rate variability (HRV) is predictive of all-cause and cardiovascular mortality using clinical ECG recordings. This is true for rest, exercise and ambulatory HRV clinical ECG device recordings in prospective cohorts. Recently, there has been a rapid increase in the use of mobile health technologies (mHealth) and commercial wearable fitness devices. Most of these devices use ECG or photo-based plethysmography and both are validated for providing accurate heart rate measurements. This offers the opportunity to make risk information from HRV more widely available. The physiology of HRV and the available technology by which it can be assessed has been summarised in Part 1 of this review. In Part 2 the association between HRV and risk stratification is addressed by reviewing the current evidence from data acquired by resting ECG, exercise ECG and medical ambulatory devices. This is followed by a discussion of the use of HRV to guide the training of athletes and as a part of fitness programmes.