Baseline 12-lead Electrocardiogram Research Articles

Revealing the unrevealed: echocardiography for non-ischemic scar tissue detection.

The detection of myocardial scar tissue profoundly influences athletes care and prognostic categorization. Athletes appear to be at risk of developing fatal arrhythmias when harboring a quiescent cardiac disorder. Early identification of disease in asymptomatic individuals through preparticipation screening is means to prevent these events. We presented a male marathon runner master athlete who came at our Department of Sports Medicine for a preparticipation screening. Baseline 12-lead standard electrocardiogram was normal. A maximal cycle ergometer exercise test revealed exercise-induced premature ventricular contractions (PVCs) with uncommon morphology. Echocardiography revealed an hyperechogenic zone at mid-basal posterior segments of the left ventricle. Twenty-four-hours ECG Holter monitoring, with training session, showed some isolated polymorphic PVCs even during training session. Cardiac magnetic resonance (CMR) confirmed the presence of a non-ischemic left ventricular scar (subepicardial) into the mid-basal segment of the posterior wall. Echocardiography is a first-line, economic, and accessible diagnostic test for athletes and it can be useful, when abnormalities are detected, to indicate further investigations, such as CMR. Although non-ischemic left ventricular scarring is difficult to detect on echocardiography, this event is sometimes possible and require further investigation when observed.

Predictors of paroxysmal atrial fibrillation in patients with a cryptogenic stroke: Selecting patients for long-term rhythm monitoring

BackgroundAfter a cryptogenic stroke, patients often will require prolonged cardiac monitoring; however, the subset of patients who would benefit from long-term rhythm monitoring is not clearly defined. ObjectiveThe purpose of this study was to create a risk score by identifying significant predictors of atrial fibrillation (AF) using age, sex, comorbidities, baseline 12-lead electrocardiogram, short-term rhythm monitoring, and echocardiographic data and to compare it to previously published risk scores. MethodsPatients admitted to Montefiore Medical Center between May 2017 and June 2022 with a primary diagnosis of cryptogenic stroke or transient ischemic attack who underwent long-term rhythm monitoring with an implantable cardiac monitor were retrospectively analyzed. ResultsVariables positively associated with a diagnosis of clinically significant AF include age (P <.001), race (P = .022), diabetes status (P = .026), chronic obstructive pulmonary disease status (P = .012), presence of atrial runs (P = .003), number of atrial runs per 24 hours (P <.001), total number of atrial run beats per 24 hours (P <.001), number of beats in the longest atrial run (P <.001), left atrial enlargement (P = .007), and at least mild mitral regurgitation (P = .009). We created a risk stratification score for our population, termed the ACL score. The ACL score demonstrated superiority to the CHA2DS2-VASc score and comparability to the C2HEST score for predicting device-detected AF. ConclusionThe ACL score enables clinicians to better predict which patients are more likely to be diagnosed with device-detected AF after a cryptogenic stroke.

Clinical significance and prognostic value of right bundle branch block in permanent pacemaker patients.

In patients undergoing pacemaker implantation with no prior history of heart failure (HF), the presence of left bundle branch block (LBBB) has been identified as an independent predictor of HF-related death or hospitalization, while the prognostic significance of right bundle branch block (RBBB) remains uncertain. We aimed to assess the long-term risk of all-cause mortality in patients with a standard indication for permanent pacing and normal or moderately depressed left ventricular function when RBBB is detected at the time of implantation. We retrospectively enrolled 1348 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center, from January 1990 to December 2022. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded. The baseline 12-lead electrocardiogram revealed an RBBB in 241 (18%) and an LBBB in 98 (7%) patients. During a median follow-up of 65 [25th-75th percentile: 32-117] months, 704 (52%) patients died. The combined endpoint of cardiovascular death or HF hospitalization was reached by 173 (13%) patients. On multivariate analysis, RBBB was confirmed as an independent predictor of death [hazard ratio, 1.33; 95% confidence interval (CI), 1.09-1.63; P = 0.005]. However, when considering the combined endpoint of cardiovascular death and HF hospitalization, this endpoint was independently associated with LBBB (hazard ratio, 2.13; 95% CI, 1.38-3.29; P < 0.001), but not with RBBB. In patients with standard pacemaker indications and normal or moderately depressed left ventricular function, the presence of basal RBBB was an independent predictor of mortality. However, it was not associated with the combined endpoint of cardiovascular death and HF hospitalization.

Clinical significance and prognostic value of right bundle branch block in permanent pacemaker patients

Abstract Aim In patients undergoing pacemaker implantation with no prior history of heart failure (HF), the presence of left bundle branch block (LBBB) has been identified as an independent predictor of HF-related death or hospitalization, while the prognostic significance of right bundle branch block (RBBB) remains uncertain. We aimed to assess the long-term risk of all-cause mortality in patients with a standard indication for permanent pacing and normal or moderately depressed left ventricular function when RBBB is detected at the time of implantation. Methods We retrospectively enrolled 1348 consecutive patients who had undergone single- or dual-chamber pacemaker implantation at the study center, from January 1990 to December 2022. Patients with a left ventricular ejection fraction ≤35% or a prior diagnosis of HF were excluded. Results The baseline 12-lead electrocardiogram revealed an RBBB in 241 (18%) and an LBBB in 98 (7%) patients. During a median follow-up of 65 [25th-75th percentile: 32-117] months, 704 (52%) patients died. The combined endpoint of cardiovascular death or HF hospitalization was reached by 173 (13%) patients. On multivariate analysis, RBBB was confirmed as independent predictor of death (Hazard Ratio, 1.33; 95% CI, 1.09–1.63; P=0.005). However, when considering the combined endpoint of cardiovascular death and HF hospitalization, this endpoint was independently associated with LBBB (Hazard Ratio, 2.13; 95% CI, 1.38–3.29; P&amp;lt;0.001), but not with RBBB. Conclusions In patients with standard pacemaker indications and normal or moderately depressed LV function the presence of basal RBBB was an independent predictor of mortality. However, it was not associated with the combined endpoint of cardiovascular death and HF hospitalization.Time to event

Utilizing median and maximum QTc values improves prediction of breakthrough cardiac events in pediatric long QT syndrome.

Although prior studies indicate that a QTc > 500 ms on a single baseline 12-lead electrocardiogram (ECG) is associated with significantly increased risk of arrhythmic events in long QT syndrome (LQTS), less is known about the risk of persistent QT prolongation. We sought to determine QTc persistence and its prognostic effect on breakthrough cardiac events (BCEs) among pediatric patients treated for LQTS. We performed a retrospective analysis of 433 patients with LQTS evaluated, risk-stratified, and undergoing active guideline-based LQTS treatment between 1999 and 2019. BCEs were defined as arrhythmogenic syncope/seizure, sudden cardiac arrest (SCA), appropriate VF-terminating ICD shock, and sudden cardiac death (SCD). During the median follow-up of 5.5 years (interquartile range [IQR] = 3-9), 32 (7%) patients experienced a total of 129 BCEs. A maximum QTc threshold of 520 ms and median QTc threshold of 490 ms were determined to be strong predictors for BCEs. A landmark analysis controlling for age, sex, genotype, and symptomatic status demonstrated models utilizing both the median QTc and maximum QTc demonstrated the highest discriminatory value (c-statistic = 0.93-0.95). Patients in the high-risk group (median QTc > 490 ms and maximum QTc > 520 ms) had a significantly lower BCE free survival (70%-81%) when compared to patients in both medium-risk (93%-97%) and low-risk (98%-99%) groups. The risk of BCE among patients treated for LQTS increases not only based upon their maximum QTc, but also their median QTc (persistence of QTc prolongation). Patients with a maximum QTc > 520 ms and median QTc > 490 ms over serial 12-lead ECGs are at the highest risk of BCE while on guideline-directed medical therapy.

Surface electrocardiogram f wave analysis in patients with atrial fibrillation undergoing thoracoscopic epicardial ablation.

To investigate the predictive values of surface electrocardiogram-derived parameters in patients with atrial fibrillation who underwent thoracoscopic epicardial ablation. The present study included 102 patients with atrial fibrillation who underwent thoracoscopic epicardial ablation and whose baseline 12-lead electrocardiograms were available. Frequency domain analysis was performed to calculate the electrocardiogram-derived parameters. Cox proportional hazards regression was used to identify predictive risk factors for postoperative recurrence. At 36-month interval, the overall rate of freedom from atrial tachyarrhythmia without antiarrhythmic drugs was 58.5%. The results of the univariable and multivariable analyses showed that larger left atrial diameter (hazard ratio: 1.074, 95% confidence interval: 1.021-1.130, P = 0.006) was an independent risk factor for atrial fibrillation recurrence, while higher fibrillatory wave amplitude was a protective factor (hazard ratio: 0.292, 95% confidence interval: 0.157-0.542, P < 0.001). The associations were clarified by the restricted cubic splines. The dominant frequency and organization index were not identified as statistically significant parameters. The fibrillatory wave amplitude has the highest predictive value for atrial fibrillation recurrence in electrocardiogram-derived parameters. Together with left atrial diameter, it may help identify patients in whom thoracoscopic ablation is likely to be effective.

Morphology-Voltage-P-wave-duration (MVP) score to select patients for continuous atrial fibrillation screening to prevent stroke

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The LOOP Study was funded by Innovation Fund Denmark [grant number 12-1352259], The Research Foundation for the Capital Region of Denmark, The Danish Heart Foundation [grant number 11-04-R83-A3363-22625], Aalborg University Talent Management Program, Arvid Nilssons Fond, Skibsreder Per Henriksen, R og Hustrus Fond, the European Union’s Horizon 2020 program [grant number 847770], Læge Sophus Carl Emil Friis og hustru Olga Doris Friis’ Legat, and an unrestricted grant from Medtronic. Background It is well known that atrial fibrillation (AF) confers a substantially increased risk of ischemic stroke, but data on health benefits from AF screening are scarce. The newly proposed MVP risk score combining the duration, voltage and morphology of P-wave has been demonstrated to be predictive of AF and might therefore also be useful in risk-stratifying individuals for AF screening and subsequent treatment. Purpose The present study sought to examine MVP risk score and its P-wave components for prediction of AF screening effects. Methods The LOOP Study randomized AF-naïve individuals aged 70-90 years with additional stroke risk factors to either continuous AF screening with implantable loop recorder (ILR) and subsequent anticoagulation initiation upon detection of AF episode ≥6 minutes, or usual care. In this secondary analysis, the LOOP participants with a baseline 12-lead electrocardiogram (ECG) suitable for P-wave measurement were included. Results Of 5759 participants included, 265 (4.6%) had had ischemic stroke during follow-up: 213 (4.9%) of 4311 in the control group versus 64 (3.6%) of 1448 in the ILR group. Among the participants in the control group, a significantly increased risk of ischemic stroke was observed for MVP score 5-6 versus score 0-2 (hazard ratio (HR) 1.66 [95% confidence interval (CI): 1.01-2.75]) and for the presence of interatrial block (IAB) versus no IAB (HR 1.85 [95% CI: 1.19-2.86]), whereas a P-wave voltage in lead I (PWVI) &amp;lt;100 µV was associated with risk reduction compared to higher voltage (HR 0.65 [95% CI: 0.45-0.93]). Further spline analysis revealed longer P-wave duration (PWD) to also be correlated with higher stroke risk (HR 1.49 [95% CI: 1.11-2.00] for &amp;gt;110 versus ≤110 ms). Compared with usual care, ILR screening did not significantly reduce the stroke risk regardless of MVP risk score, PWD, PWVI, or IAB pattern at baseline. Conclusions In an elderly population with additional stroke risk factors, both the P-wave parameters and the combined MVP risk score based on 12-lead ECG were associated with ischemic stroke, but these did not successfully demonstrate an association with effects of AF screening on stroke prevention.

Defining myocardial infarction in trials of people receiving hemodialysis: consensus report from the SONG-HD MI Expert Working group

Cardiovascular disease is the leading cause of death in patients receiving hemodialysis. Currently, there is no standardized definition of myocardial infarction (MI) for patients receiving hemodialysis. Through an international consensus process MI was established as the core CVD measure for this population in clinical trials. The Standardised Outcomes in Nephrology Group-Hemodialysis (SONG-HD) initiative convened a multidisciplinary, international working group to address the definition of MI in this population. On the basis of current evidence, the working group recommends using the Fourth Universal Definition of Myocardial Infarction with specific caveats with regard to the interpretation of "ischemic symptoms" and performing a baseline 12-lead electrocardiogram to facilitate interpretation of acute changes on subsequent tracings. The working group does not recommend obtaining baseline cardiac troponin values, though does recommend obtaining serial cardiac biomarkers in settings where ischemia is suspected. The application of an evidence-based uniform definition should increase the reliability and accuracy of trial results.

Ondansetron Safety Regarding Prolong QTc for Children with Head Trauma

BackgroundThere have been recent reports of increased QT interval after head trauma in concussed athletes and adult patients. Ondansetron, which is widely used in treatment of nausea and vomiting symptoms in head injuries, was issued a safety warning from the U.S. Food and Drug Administration regarding QT prolongation and risk of fatal dysrhythmias. ObjectiveThe purpose of this study was to evaluate the safety of ondansetron regarding QT prolongation for patients experiencing nausea or vomiting after head trauma. MethodsPatients aged 1–20 years presenting to a pediatric emergency department with head trauma and who required a dose of ondansetron for nausea or vomiting were enrolled in the study. Patients received a baseline 12-lead electrocardiogram (ECG) prior to administration of either oral or IV ondansetron. A second post-ondansetron 12-lead ECG was performed after administration of ondansetron. All ECGs were reviewed and the QTc calculated manually by a board-certified pediatric cardiologist. ResultsForty-two patients met enrollment criteria. Five patients received IV ondansetron and 37 received oral ondansetron. Mean QTc pre ondansetron was 387.5 ms and mean QTc post ondansetron was 400.9 ms (p = 0.120). We found no statistically significant difference in other ECG parameters pre and post ondansetron. ConclusionsOndansetron is safe in regard to QTc prolongation in patients with head trauma. Based on this research, ondansetron should continue to be used for the treatment of nausea and vomiting in emergency department patients who present with head injury.

Impact of bundle branch block morphology on outcomes of patients with syncope and bifascicular block: A SPRITELY (POST 3) substudy

Permanent pacing is often considered for patients with syncope and bifascicular block. The purpose of this study was to determine whether QRS morphology or other electrocardiographic characteristics can identify patients who may benefit from permanent pacing. The Syncope: Pacing or Recording in the Later Years (SPRITELY) trial was a multicenter trial that randomized patients with bifascicular block and syncope (n = 115) to empiric pacemaker implantation vs implantable loop recorder (ILR) monitoring. In this SPRITELY subanalysis, baseline 12-lead electrocardiograms were evaluated for bundle branch block (BBB) morphology, QRS width, and PR and QT intervals and their impact on clinical outcomes was assessed. There were 41 patients with left BBB (36%), 69 patients with right bundle branch block (RBBB) and left anterior fascicular block (60%), and 5 patients with RBBB and left posterior fascicular block (4%). Pacemaker implant compared with ILR was associated with a significant reduction of major study-related events (MSREs) in both patients with left BBB (23.8% vs 78.9%; P = .001) and those with RBBB (27% vs 72.9%; P < .0001). Similarly, a reduction of MSREs was observed in both patients with trifascicular block (23% vs 84.6%; P < .0001) and those with bifascicular block (26.6% vs 68.9%; P = .002). In the group randomized to ILR monitoring, the type of BBB was not a predictor of recurrent syncope (P = .30), bradycardia requiring pacemaker (P = .15), or MSREs (P = .42). The presence ofPR interval prolongation or QRS width in this group did not predict MSREs (P = .22 and P = .96, respectively). In patients with syncope and bifascicular block, pacemaker implantation reduces adverse events as compared with ILR monitoring, irrespective of the type of BBB or the presence of PR interval prolongation.

The latest cutoff value of high-sensitivity cardiac troponin I (access hs-TnI) for major adverse cardiac events during the perioperative period of coronary artery bypass grafting: a retrospective study from a single heart center

Abstract Objectives To investigate the latest cutoff value of high-sensitivity cardiac troponin I for major adverse cardiac events (MACEs) during the perioperative period of coronary artery bypass grafting (CABG). Methods A total of 200 patients, into MACEs and non-MACEs groups according to the occurrence of MACEs over a 12 day postoperative period underwent a complete baseline history survey, physical examination, 12-lead electrocardiogram (ECG), and laboratory examination during a preoperative cardiology consultation. Serum levels of hs-TnI, myohemoglobin, creatine kinase MB isoform (CK-MB), and B-type natriuretic peptide were assessed using a Beckman DXI800 automatic chemiluminescence immune analyzer. Results The 200 patients were classified into the MACEs (n=10) and non-MACEs (n=190) groups. Based on a receiver-operating characteristic analysis, the optimal 4–6 h postoperative hs-TnI, CK-MB, and MYO joint cut-off levels for predicting perioperative MACEs were 2,622.3 pg/mL, 17.9 ng/mL, and 190.2 ng/mL, respectively. The AUC was 0.779 (95% confidence interval: 0.622–0.937; p&lt;0.05) with a sensitivity of 80.0% and a specificity of 74.0%. When the hs-TnI, CK-MB, and MYO levels exceeded the joint cut-off levels, the incidence of MACEs was significantly increased during the perioperative period (Log rank p&lt;0.05). Cox regression analysis showed that dyslipidemia, left ventricular ejection fraction &lt;50%, hs-TnI level, and myohemoglobin level were the main risk factors for MACEs after CABG (p&lt;0.05). Conclusion An hs-TnI level of 2,622.3 pg/mL, CK-MB level of 17.9 ng/mL, and MYO level of 190.2 ng/mL were the cutoff values for predicting MACEs. Dyslipidemia, left ventricular ejection fraction &lt;50%, hs-TnI level, and myohemoglobin level were the main risk factors for MACEs after CABG.

Two P waves followed by 1 QRS complex: What is the mechanism?

A 71-year-old man with a history of inferior myocardial infarction was referred to the hospital for management of subarachnoid hemorrhage. The baseline 12-lead electrocardiogram showed sinus rhythm with a left bundle branch block configuration as well as 2:1 atrioventricular (AV) block (Figure 1A). After several hours, the electrocardiogram exhibited a slower rhythm with a right bundle branch block pattern following 2 narrow P waves (red arrows, Figure 1B). The slow ectopic rhythm converted to sinus rhythm after a spontaneous premature ventricular complex (PVC).

Triangular ECG Pattern in a Young Female with COVID-19

A 32-year-old female intravenous drug abuser with hepatitis C infection presented to our institution complaining of 1 day of worsening shortness of breath. Coagulation panel was within normal limits and troponin-I < 0.01 ng/mL. Chest x-ray showed bilateral infiltrates. Baseline 12-lead electrocardiogram showed sinus tachycardia with no acute ischemic changes (Figure 1). Transthoracic echocardiogram demonstrated normal biventricular function. Ultimately, SARS-CoV-2 RT-PCR was detected in a nasal specimen.

Atrial Fibrillation and the Prognostic Performance of Biomarkers in Heart Failure.

Consideration of circulating biomarkers for risk stratification in heart failure (HF) is recommended, but the influence of atrial fibrillation (AF) on prognostic performance of many markers is unclear. We investigated the influence of AF on the prognostic performance of circulating biomarkers in HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP), mid-regional-pro-atrial natriuretic peptide, C-type natriuretic peptide (CNP), NT-proCNP, high-sensitivity troponin-T, high-sensitivity troponin-I, mid-regional-propeptide adrenomedullin, co-peptin, growth differentiation factor-15, soluble Suppressor of Tumorigenicitiy (sST2), galectin-3, and procalcitonin plasma concentrations were measured in a prospective, multicenter study of adults with HF. AF was defined as a previous history of AF, and/or presence of AF/flutter on baseline 12-lead electrocardiogram. The primary outcome was the composite of HF-hospitalization or all-cause mortality at 2 years. Among 1099 patients (age 62 ± 12years, 28% female), 261(24%) patients had AF. Above-median concentrations of all biomarkers were independently associated with increased risk of the primary outcome. Significant interactions with AF were detected for galectin-3 and sST2. In considering NT-proBNP for additive risk stratification, sST2 (adjusted hazard ratio [AHR]1.85, 95%confidence interval [C.I.] 1.17-2.91) and galectin-3 (AHR1.85, 95%C.I. 1.09-2.45) were independently associated with increased primary outcome only in the presence of AF. The prognostic performance of sST2 was also stronger in AF for all-cause mortality (AF: AHR2.82, 95%C.I. 1.26-6.21; non-AF: AHR1.78, 95% C.I. 1.14-2.76 without AF), while galectin-3 predicted HF-hospitalization only in AF (AHR1.64, 95%C.I. 1.03-2.62). AF modified the prognostic utility of selected guideline-endorsed HF-biomarkers. Application of markers for prognostic purposes in HF requires consideration of the presence or absence of AF. ACTRN12610000374066.

Irregular narrow QRS complex tachycardia with intermittent atrioventricular dissociation: What is the mechanism?

A 39-year-old woman with frequent palpitations was referred for radiofrequency ablation. A baseline 12-lead electrocardiogram showed normal sinus rhythm. At baseline, atrio-His (AH) and His-ventricular (HV) intervals were 80 and 45 ms, respectively. This article is protected by copyright. All rights reserved.

6123A novel ECG parameter predicts lack of eligibility for Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) in patients with Brugada Syndrome

Abstract Background A conclusive estimate of the eligibility rate for the use of subcutaneous implantable cardioverter defibrillators (S-ICD) in patients with Brugada Syndrome (BrS) is lacking. Objective We aimed to: 1) evaluate the eligibility for S-ICD in patients with BrS using a novel automated tool; 2) investigate predictors of ineligibility for S-ICD, based on baseline 12-lead electrocardiogram. Methods Automated screening for S-ICD was performed in 118 consecutive BrS patients using the programmer provided by the S-ICD producer. The system automatically assessed the acceptability of each of the three sense vectors used by the S-ICD for the detection of cardiac rhythm. Eligibility was defined when at least one vector was acceptable both in supine and standing position. Results The clinical characteristics of 118 BrS patients were as follow: age 43±11 years; 89% males; 2% with aborted cardiac arrest; 14% with a history of syncope; 81% with spontaneous type 1 ECG pattern; 21% with a familial history of sudden cardiac death; 24% with an SCN5A mutation. No patients had an indication for pacing. Only 8/118 (7%) patients were ineligible for S-ICD. Of note, 5/8 (63%) patients who failed the screening exhibited a slurred S wave of ≥80 ms duration in the peripheral lead aVF on the 12-lead baseline electrocardiogram, vs. 4/110 (4%) of those who passed the screening (sensitivity of S wave in aVF for screening failure 63%, specificity 97%; p&lt;0.001). Remarkably, the presence of a slurred S wave of ≥80 ms duration in lead aVF remained significantly associated to the failure of eligibility for S-ICD (odds ratio 50, p&lt;0.001) in a multivariable analysis that included the previous history of symptoms, the presence of a spontaneous type 1 ECG pattern, the gender and the presence of SCN5A mutations. ECG predictor of S-ICD screening Conclusion Up to 93% of BrS patients are eligible for S-ICD when the automated screening tool is used. The presence of a slurred S wave in lead aVF on the 12-lead electrocardiogram is a powerful predictor of screening failure.

Correlation of cumulative ST elevation with left ventricular ejection fraction and 30-day outcome in patients with ST elevation myocardial infarction.

Background:The electrocardiogram (ECG) is the first and often the only investigation available prior to definitive therapy in patients with ST elevation myocardial infarction (STEMI). A good prognostic marker is the left ventricular ejection fraction (LVEF) on ECG. Our aim was to assess the correlation between ST elevation (STE) in ECG and the LVEF and thereby aid the prognosis of patients with STEMI.Methods:This was a prospective cohort study of 230 patients with STEMI. A baseline 12-lead ECG was taken to calculate the sum of STE at the J point in all the leads showing elevation. The STE was measured 90 min after revascularization to calculate the ST resolution percentage (STR%). All patients underwent echocardiography, and the LVEF was measured using biplane Simpson's method.Results:A total of 136 patients with anterior myocardial infarction (MI), 35 with inferior MI, and 59 with inferoposterior MI were included in the study. Mean STE was 13 mm and was significantly higher among patients with anterior MI. There was a good inverse correlation between the STE and the LVEF with a correlation coefficient of −0.64. STR% had a correlation coefficient of 0.59 to the LVEF. A formula was generated to calculate the LVEF based on the STE as follows: LVEF = (37.34 − STE)/0.567. An STE ≥15 mm predicted an LVEF <35% with a sensitivity and specificity of 70%.Conclusion:The STE and STR% are useful surrogate markers in prognosticating patients irrespective of the type of STEMI.

Copy number variations of SCN5A in Brugada syndrome

Loss-of-function mutations in SCN5A are associated in ∼20% of Brugada syndrome (BrS) patients. Copy number variations (CNVs) have been shown to be associated with several inherited arrhythmia syndromes. The purpose of this study was to investigate SCN5A CNVs among BrS probands. The study cohort consisted of 151 BrS probands who were symptomatic or had a family history of BrS, sudden death, syncope, or arrhythmic diseases. We performed sequence analysis of SCN5A by the Sanger method. For detecting CNVs in SCN5A, we performed multiplex ligation-dependent probe amplification analysis of the 151 BrS probands. We identified pathogenic SCN5A mutations in 20 probands by the Sanger method. In 140 probands in whom multiplex ligation-dependent probe amplification was successfully performed, 4 probands were found to present different CNVs (deletion in 3 and duplication in 1). Three of them had fatal arrhythmia events; the remaining 1 was asymptomatic but had a family history. Mean age at diagnosis was 23 ± 14 years. All of the baseline 12-lead electrocardiograms showed PQ-interval prolongation. The characteristics of these 4 probands with CNVs were similar to those of the probands with mutations leading to premature truncation of the protein or missense mutations causing peak INa reduction >90%. We identified SCN5A CNVs in 2.9% of BrS probands who were symptomatic or had a family history.

Abstract P367: Association Between Resting Heart Rate and Progression of Valvular Calcification

Background: Mitral annular calcification (MAC) and aortic valvular calcification (AVC) are progressive and linked to increased cardiovascular disease (CVD) morbidity and mortality. Few known modifiable risk factors associated with the progression of MAC and AVC exist. Resting heart rate (RHR) is an established independent risk factor for CVD. Due to the potential hemodynamic effects of RHR on development or progression of valve calcification, we assessed whether RHR is associated with the incidence and progression of MAC and AVC in a community-based cohort free of CVD and atrial fibrillation at baseline. Methods: We obtained RHR from baseline 12-lead electrocardiograms of 5,498 MESA cohort participants. We studied RHR as a continuous variable (per 1 SD increment) and also categorized at clinical cut points of &lt; 60, 60 - 69, 70 - 79, and ≥ 80 bpm. MAC and AVC were quantified (using Agatston scoring) from cardiac computed tomography scans obtained at baseline and at follow-up examinations 2 or 3. We examined associations between RHR and incident MAC/AVC and annual change in MAC/AVC scores, after adjusting for demographics, CVD risk factors, physical activity, and atrioventricular nodal blocker medication use. We used progressively adjusted parametric survival models for incident MAC/AVC and linear regression models for annual change in MAC/AVC. Results: At baseline, participants had a mean age of 62±10 years and mean RHR of 63±10 bpm; 12.3% and 8.9% had prevalent AVC and MAC [Agatston Units (AU) &gt;0], respectively. Over a median follow up time of 2.3 years, 4.1% and 4.5% developed incident AVC and MAC, respectively. Each 10 bpm higher RHR was significantly associated with incident MAC [Hazard Ratio 1.18 (95% CI 1.03-1.36)], but not incident AVC. However, RHR (per 10 bpm) was associated with AVC progression [β coeff 1.62 (0.45-2.80) AU/year], but not MAC progression. The association of RHR on annual change in AVC was modified by age and sex (p-interactions 0.006 and &lt;0.02, respectively) but not race/ethnicity. Each 10 bpm higher RHR was significantly associated with AVC progression for age &gt; 62 years [β coeff 2.94 (0.55, 5.34) AU/year] and male sex [3.49 (1.31, 5.67) AU/year]. The association between RHR and AVC progression was not significant for age ≤ 62 or female sex. Similar trends were seen using clinical cut-points for RHR. Conclusion: Higher RHR predicted incident MAC and AVC progression independent of traditional CVD risk factors. Future studies are needed to determine whether this association is causal and whether modification of RHR through lifestyle or pharmacologic interventions can reduce valvular calcium progression.

Tpeak-Tend interval during therapeutic hypothermia can predict upcoming ventricular fibrillation in subjects with aborted arrhythmic sudden cardiac death: 3-years follow-up results.

Prolonged Tpeak-Tend interval has been shown to be markers of arrhythmogenesis in various cardiac disorders. However, its dynamicity is one of the obstacles to predict fatal ventricular arrhythmia. This study investigated whether Tpeak-Tend interval during therapeutic hypothermia (TH) is associated with ventricular fibrillation (VF) inducibility and clinical arrhythmia in subjects with aborted arrhythmic sudden cardiac death (SCD). The study group included 31 patients (24 males, age 39.1 ± 17.6 years) presenting with arrhythmic SCD in whom Tpeak-Tend interval and J-wave amplitude were measured in electrocardiogram (ECG) of the earliest medical contact and during TH; these patients underwent programmed ventricular stimulation. The summation of J-wave amplitude and QTc interval increased during TH. However, it was not associated with VF inducibility. Patients with inducible VF showed a small Tpeak-Tend interval dispersion in the baseline 12-lead ECG (68.8 ± 24.7 vs. 94.0 ± 55.6 ms, P = 0.044) and a marked increase of the dispersion during the TH (36.2 ± 51.2 vs. -6.1 ± 45.5 ms, P = 0.039). Twenty-four patients underwent implantable cardioverter defibrillator (ICD) implantation. Among them, the patients with long QTc, Tpeak-Tend, and precordial Tpeak-Tend during the TH developed VF more frequently (QTc, 511.9 ± 53.71 ms vs. 566.5 ± 56.08 ms, P = 0.038; Tpeak-Tend interval, 145.6 ± 38.4 ms vs. 185.7 ± 49.95 ms, P = 0.048; precordial Tpeak-Tend interval, 139.3 ± 35.11 ms vs. 185.7 ± 49.95 ms, P = 0.018). The initial VF inducibility was not related with the VF development in follow-up. In patients with aborted arrhythmic SCD, long Tpeak-Tend interval and QTc interval during TH could predict VF development in their follow-up.