ECG Variables Research Articles

Unmasking a Silent Killer and Understanding Sudden Cardiac Death in Brugada Syndrome: A Traditional Review.

Brugada syndrome (BrS) is an intricate and heterogeneous genetic disorder that engenders a formidable risk of life-threatening ventricular arrhythmias (VAs). While initially regarded as an electrophysiological aberration, emergent studies have illuminated the presence of underlying structural anomalies in select BrS cases. Although mutations in the SCN5A gene encoding the α-subunit of the cardiac sodium channel were originally identified as a primary causative factor; they account for only a fraction of the syndrome's multifaceted complexity pointing at genetic heterogeneity as a contributing factor. Remarkably, BrS has been linked to a higher incidence of fatal arrhythmic incidents and sudden cardiac death (SCD) with about 4% of SCD cases thought to be caused by BrS. Patients who spontaneously exhibit type one Brugada ECGs are more likely to experience cardiac events,emphasizing the importance of early risk stratification. To aid in risk stratification, the Shanghai score; a multifactorial risk stratification scoring system that incorporates ECG, clinical history, family history, and genetic test results; is utilized to identify those most susceptible to SCD. Beyond single ECGs, evaluation of arrhythmic findings from 24-hour Holter monitoring, ECG variables, electrophysiologic study (EPS) status in the temporal domain, and EPS data collected over time are all critical factors in risk classification. Among management options avoidance of triggers, early risk stratification, and implantation of an Implantable Cardioverter-Defibrillator (ICD) are recommended for asymptomatic patients. For symptomatic patients, pharmacotherapy and ICD implantation are available, with the latter being a highly effective choice for treating and preventing lethal arrhythmias in BrS.

Evaluation of fatigue in young female adults due to repeated exposure to heat in summer and cold in winter.

The magnitude of fatigue (MF) from psychological and physiological responses during repeated exposure to heat in summer and during repeated exposure to cold in winter was evaluated to test two hypotheses on fatigue models. The first hypothesis is that exposure time (ET, min) would be a factor determining the MF and the second hypothesis is that the same fatigue models as a function of the number of exposure repetitions (NR) could be applied to both repeated exposure to heat in summer and cold in winter. In summer, eight young adult female subjects with clothing insulation (Icl, clo) of 0.3 clo first stayed in the control room at 26 ℃ for 15min, moved to the main testing room at 30 ℃ for 25min, 33°C for 15min, or 36 ℃ for 10min, and then returned to the control room. The product of air temperature difference (ΔTa, ℃) and ET was designed to be almost equal among these latter three conditions. The exposure was repeated five times. In winter, the same female subjects with Icl of 0.84 clo first stayed in the control room at 24 ℃ for 15min, moved to the main testing room at 18 ℃ for 30min, 15 ℃ for 20min, or 12 ℃ for 15min, and then returned to the control room. Again, the product of ΔTa and ET was designed to be equal among these latter three conditions. The exposure was repeated four times. The scores of subjective fatigue feeling (SFF) and salivary amylase value (SAV) were recorded when the subjects returned to the control room. Tympanic temperature, skin temperatures and local sweat rates (Sw, mg/cm2/min) at chest, forearm, front thigh, and front shin, and ECG were continuously monitored, except for Sw in the winter experiment. In the summer experiment, the SFF showed a threshold value at ΔTa = 4 ℃ but continuously increased with NR at ΔTa = 7 ℃ and 10 ℃. It was not correlated with ECG variables, but was positively correlated with SAV (R2 = 0.50) and the mean Sw (R2 = 0.76) at ΔTa = 7 ℃ and 10 ℃. In the winter experiment, the SFF showed a threshold value at ΔTa = - 6 ℃ but continuously increased with NR at ΔTa = - 9 ℃ and - 12 ℃. It was correlated with SAV at ΔTa = - 9 ℃ (R2 = 0.77) and score of LF: HF ratio at ΔTa = - 6 ℃ and - 9 ℃ (R2 = 0.49). It was confirmed that ET may be related to the MF and that different fatigue models may be applied dependent on ΔTa during repeated exposure to heat in summer and during repeated exposure to cold in winter. Thus, the two hypotheses were verified.

Atrial fibrillation is an independent risk factor for heart failure progression and pump failure mortality in HFpEF:: a propensity score matched analysis of the TOPCAT Americas study

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) is associated with excess mortality and cardiovascular (CV) hospitalizations in HF patients (pts) with preserved systolic function (pEF) but the contributing factors to these outcomes are not known.. Purpose To analyze the independent impact of AF on clinical outcomes of HFpEF pts in the TOPCAT AMERICAS study using propensity score matched (PSM) cohorts to account for confounding by other comorbidities. Methods Study cohorts were PSM matched for 20 clinical, demographic & ECG variables. 3 matched cohorts based on baseline rhythm status at study entry were compared viz. subjects in sinus rhythm (SR), subjects in AF on baseline ECG & subjects with Any AF event by history or ECG. We analyzed CV mortality, adjudicated modes of death & morbidity during a mean follow up period of 2.9 yrs. Results 418 subjects in SR (SR cohort) were PSM with 418 subjects in AF on baseline ECG (AF on ECG cohort) & 418 pts with any AF event by history or ECG (Any AF cohort) at study entry. Any AF increased the risk of CV death (D), pump failure death (PFD), CV and HF hospitalization (H) and HF progression. AF on ECG increased risk of CVD, CVH, HFH and PFD (Tables). Neither AF cohort increased risk of sudden death (SD) {Figure}. Conclusion 1. AF is an independent risk factor for worsening CV outcomes in HFpEF. 2. This increased risk is due to a selective increase in symptomatic HF progression from early to advanced HF, HFH and PFD in advanced HF rather than SD. 3. Loss of AV synchrony & rate control in AF can independently impact HF progression in HFpEF with consequent HFH and PFD. Restoration of SR may offer benefits for CV outcomes in HFpEF & warrants evaluation.

Clinical perspectives on the adoption of the artificial intelligence-enabled electrocardiogram

To determine normal limits for major ECG variables, and the electrocardiographic impact of hypertension, in a rural sub-Saharan African setting.This cross-sectional study included adults aged ≥25 years from Tanvè Health Study (TAHES) cohort. ECG were recorded at rest at 25 mm/s using a standard 12‑lead device. Wave amplitudes and durations were measured. Corrected QT interval (QTc) was calculated using Bazett's formula. Sokolow-Lyon, Cornell and Peguero-Lo Presti criteria were determined to assess left ventricular hypertrophy (LVH).ECG was recorded among 997 out of 1407 TAHES participants. After exclusion of subjects with hypertension or diabetes, normal limits, defined as the 2nd and 98th percentiles, were evaluated in 622 healthy participants (median: 37 years; 60.1% women). The following limits were established in men (women): heart rate: 50 to 100 (55 to 102) beats/min, P wave duration: 80 to 120 (80 to 120) ms, PR interval: 120 to 200 (120 to 200) ms, QTc: 315 to 470 (323 to 465) ms, QRS duration: 50 to 120 (50 to 110) ms. Upper limits (in millimeter) for the Sokolow-Lyon, Cornell and Peguero-Lo Presti for men (women) were 47 (38), 30 (22) and 39 (30), respectively, all above current reference limits. The prevalence of LVH in hypertensive subjects according to these criteria were lower than those estimated according to current LVH criteria.The normal limits of ECG variables determined in this African population differ from those in Caucasians, indicating that ethnicity must be considered in ECG interpretation.

PO-02-235 MOVING BEYOND QRS DURATION: QRS VOLTAGE-TIME-INTEGRAL (AREA) IS A SUPERIOR PREDICTOR OF CLINICAL RESPONSE TO CARDIAC RESYNCHRONIZATION THERAPY

Cardiac resynchronization therapy (CRT) can alleviate left ventricular (LV) electrical dyssynchrony mediated systolic heart failure (HF). 15% reduction in LV end systolic volume (LVESV) with CRT is a validated surrogate of improved clinical outcomes. Prolonged baseline QRS duration (QRSd) is the only conventional quantitative ECG criteria to assess left ventricular electrical dyssynchrony. In addition to QRS duration, we evaluated the baseline QRS voltage-time-integral (VTI) and its reduction after CRT as predictors of LV reverse remodeling. We included 595 patients (68.1±11.5 yr., 32.6% women, 43.9% ischemic cardiomyopathy) who underwent CRT-defibrillator implant for clinical indications 2012-2019 and analyzed their ECGs before and after CRT. Orthogonal X, Y, Z leads were reconstructed from 12-lead ECG using Kors’s matrix. VTIQRS-X, Y ,Z and VTIQRS-3D were obtained from integration over the duration of QRS in X, Y, Z, and root-mean-squared (3D) ECGs respectively. We reviewed echocardiogram reports to obtain LV measures before and 3-12 months after CRT, including ejection fraction (LVEF), internal dimensions in diastole (LVIDd) and systole (LVIDs), end-diastolic (LVEDV) and LVESV. We used linear regression models to evaluate ECG variables as predictors of change in LV measures. We further used unadjusted and multivariable-adjusted logistic regression models to predict ≥15% reduction in LVESV from ECG variables. Baseline LVEF was 25.8±8.3%, LVIDd 5.7±0.9 cm, LVIDs 4.8±0.9 cm, LVEDV 164±67 and LVESV 109±56 mL. QRSd reduced from 153±26 to 137±22 ms with CRT. VTIQRS-3D and VTIQRS-Z of 104±49 and 75±44 respectively improved to 67±34 and 33±24 μVs. Baseline and change in VTIQRS-Z and VTIQRS-3D were more significantly associated with change in echo variables as compared to baseline and change in QRSd (Table 1). ≥15% reduction in LVESV was independently predicted by baseline VTIQRS-Z ≥71 μVs (OR 2.0, 95% CI 1.3-3.0, p=0.0009) and Δ VTIQRS-Z ≥42 μVs (OR 2.1, 1.4-3.1, p=0.004). In patients undergoing CRT, baseline QRS VTI from Z (anteroposterior) axis ECG ≥71 μVs independently predicted 2 times higher odds of salutary reverse LV remodeling post CRT. Further, a reduction in VTIQRS-Z ≥42 μVs also predicted more than 2 times odds of revrse remodeling. VTIQRS-Z is a superior automatically calculable quantitative summary ECG marker for CRT patient selection and prognostication as compared to QRS duration.

A STUDY OF ELECTROCARDIOGRAPHIC AND ECHOCARDIOGRAPHIC CHANGES IN PATIENTS OF CHRONIC KIDNEY DISEASE

Introduction: Chronic kidney disease is dened as the presence of kidney damage or an estimated glomerular ltration rate less than 60 ml/min/1.73 mt2, persisting for 3 months or more, irrespective of the cause. It is a state of progressive loss of kidney function ultimately resulting in the need for renal replacement therapy . A cardiovascular mortality that is 15 to 30 times greater than the age-adjusted cardiovascular mortality in the general population affects roughly 50% of people with ESRD. Therefore this study was undertaken for assessing electrocardiographic and echocardiographic ndings in CKD patients. Method: In this study 50 pts of chronic kidney disease as per KDIGO criteria were enrolled over a period of six months (Jan-June 2022).All relevant data were recorded and analyzed. Results: Among 50 pts, 26 percent of the patients each belonged to the age group of 61 to 70 years. 62 percent of the CKD patients were males while the remaining were females. While assessing the ECGndings among CKD patients, LVH and arrythmias were seen in 52 percent and 44 percent of the patients. While assessing the correlation of ECGndings with CKD severity grading, it was seen that ECG variables were signicantly deteriorate with increasing severity of CKD grading. While analysing ECHO ndings among CKD patients, abnormal ndings were seen in 88 percent of the patients . While assessing the correlation of ECHO ndings with CKD severity grading, it was seen that ECHO variables were signicantly deteriorate with increasing severity of CKD grading. Conclusion : LVH, LAE were very common ECG and ECHO abnormalities in CKD patients. Cardiac disorders are highly prevalent in patients with progressive CKD. All CKD patients must be evaluated for cardiac co-morbidities, since it might help to establish adequate treatment that may potentially improve patient's prognosis.

Electrocardiographic findings in healthy Cavalier King Charles Spaniels, Pugs, and English Bulldogs.

To describe the ECG findings in 3 different canine brachycephalic breeds: the Cavalier King Charles Spaniel, the Pug, and the English Bulldog (EB). 135 healthy dogs (50 Cavalier King Charles Spaniels, 50 Pugs, and 35 EBs). Medical records were retrospectively reviewed to identify healthy dogs ≥ 1 year old that had undergone an ECG. The Mann-Whitney U test or the Student t test were used to compare continuous variables between male and female dogs, whereas the χ2 test was used for categorical variables. Spearman correlation coefficients between ECG measurements and age and body weight were also calculated in the case of continuous variables, whereas the Kruskal-Wallis test was used for categorical ones. Electrocardiographic parameters of healthy Cavalier King Charles Spaniels overall fitted with traditional reference intervals cited in textbooks; in contrast, 28% of Pugs and 20% of EBs showed a shift of the QRS-complex mean electrical axis (QRS-MEA). In Pugs and EBs, the mean/median QRS-MEA value was 56° (from 0° to 100°) and 59° (from 20° to 100°), respectively. All axis shifts were left shifts (in Pugs, from 0° to 34°; in EBs, 20° to 39°). Only a few meaningful differences were found when comparing ECG variables between males and females. Similarly, only 1 statistically significant correlation was found between ECG parameters and age and body weight. Healthy Pugs and EBs present a trend to a left shift of the QRS-MEA. This should be considered when interpreting ECG tracings in these breeds.

PO-01-179 MOVING BEYOND QRS DURATION: QRS VOLTAGE-TIME-INTEGRAL (AREA) IS A SUPERIOR PREDICTOR OF CLINICAL RESPONSE TO CARDIAC RESYNCHRONIZATION THERAPY

Cardiac resynchronization therapy (CRT) can alleviate left ventricular (LV) electrical dyssynchrony mediated systolic heart failure (HF). Prolonged baseline QRS duration (QRSd) is the only conventional quantitative ECG criteria to assess left ventricular electrical dyssynchrony. Evaluate the baseline QRS voltage-time-integral (VTI), along with QRSd, and their reduction effect after CRT as predictors of future HF events. We included 595 patients (68.1±11.5 yr., 32.6% women, 43.9% ischemic cardiomyopathy, baseline LV ejection fraction 25.8±8.3%) who underwent CRT-defibrillator implant for clinical indications 2012-2019 and analyzed their ECGs before and after CRT. Orthogonal X, Y, Z leads were reconstructed from 12-lead ECG using Kors’s matrix. VTIQRS-X, Y ,Z and VTIQRS-3D were obtained from integration over the duration of QRS in X, Y, Z and root-mean-squared (3D) ECGs respectively. Follow-up clinical data including heart failure hospitalization, death, LV assist device (LVAD) implant, and orthotopic heart transplantation (OHT) were obtained from retrospective chart review. We used proportional hazard models to evaluate ECG variables as predictors of time to (a) composite death/LVAD/OHT and (b) first HF hospitalization over follow-up of 48.7±26.2 months. Models were adjusted for confounding by age, sex, ischemic cardiomyopathy and LV ejection fraction. QRSd reduced from 153±26 to 137±22 ms with CRT but neither baseline QRSd nor Δ QRSd predicted clinical outcomes. VTIQRS-3D and VTIQRS-Z of 104±49 and 75±44 respectively improved to 67±34 and 33±24 μVs. Significant unadjusted predictors of death/LVAD/OHT included VTIQRS-3D (p=0.047) and VTIQRS-Z (p=0.002) at baseline, and Δ VTIQRS-Z (p=0.01). On multivariable adjustment, VTIQRS-Z (p=0.005) and Δ VTIQRS-Z (p=0.02) remained significant. Δ VTIQRS-Z was the only significant predictor of HF hospitalizations (unadjusted p=0.02 and adjusted p=0.047). In patients undergoing CRT, a larger baseline QRS VTI from Z (anteroposterior) axis ECG predicted reduced death/LVAD/OHT. Further, a larger reduction in Z axis QRS VTI was associated with reduced death/LVAD/OHT and HF hospitalizations. VTIQRS-Z should replace QRSd for CRT patient selection and prognostication.

Comparison between a fitness tracker (EquimetreTM) and standard base-apex electrocardiography in dromedary camels.

Personalized healthcare technology has grown explosively through the use of portable and smart monitoring devices for diagnosis. The objective of this study was to determine the practicality and usability of the EquimetreTM fitness tracker on camels in comparison to the standard base-apex system in normal and clinical cases. Five apparently healthy adult camels, five clinical adult cases and two clinical calves were enrolled in this study. The camels were equipped with two monitoring systems: EquimetreTM and a standard base-apex electrocardiogarphy. Each tracing was evaluated for the normal ECG variable's measure, including heart rate beats per min, P-R, QRS, R-R, Q-T, S-T intervals, and P-R and S-T segments in seconds. The amplitudes for P, Q, R, S, and T-peaks were evaluated in millivolts. EquimetreTM showed stability on ECG tracing with less movement artifacts compared with the standard base-apex system. Different polarities were observed for the P-waves and T-waves between the standard base-apex system and EquimetreTM. Both devices showed perfect agreement for heart rate (ICC = 1.00, P ≥ 0.0001, 95% = 1.00-1.00) in healthy and clinical adults. A good correlation was observed for the R-R interval between the devices in healthy and clinical adults. A moderate correlation was observed between the devices for Q-peak in clinical adults, with no correlation in clinical calves. This study demonstrated acceptable ECG measurements between the standard base-apex and EquimetreTM device. This suggests that EquimetreTM could be a useful device in camels for initial electrocardiographic examinations in remote areas such as deserts.

Artificial intelligence for non-invasive glycaemic-events detection via ECG in a paediatric population: study protocol

PurposePaediatric Type 1 Diabetes (T1D) patients are at greater risk for developing severe hypo and hyperglycaemic events due to poor glycaemic control. To reduce the risk of adverse events, patients need to achieve the best possible glycaemic management through frequent blood glucose monitoring with finger prick or Continuous Glucose Monitoring (CGM) systems. However, several non-invasive techniques have been proposed aiming at exploiting changes in physiological parameters based on glucose levels. The overall objective of this study is to validate an artificial intelligence (AI) based algorithm to detect glycaemic events using ECG signals collected through non-invasive device.MethodsThis study will enrol T1D paediatric participants who already use CGM. Participants will wear an additional non-invasive wearable device for recording physiological data and respiratory rate. Glycaemic measurements driven through ECG variables are the main outcomes. Data collected will be used to design, develop and validate the personalised and generalized classifiers based on a deep learning (DL) AI algorithm, able to automatically detect hypoglycaemic events by using few ECG heartbeats recorded with wearable devices.ResultsData collection is expected to be completed approximately by June 2023. It is expected that sufficient data will be collected to develop and validate the AI algorithm.ConclusionThis is a validation study that will perform additional tests on a larger diabetes sample population to validate the previous pilot results that were based on four healthy adults, providing evidence on the reliability of the AI algorithm in detecting glycaemic events in paediatric diabetic patients in free-living conditions.Trial registrationClinicalTrials.gov identifier: NCT03936634. Registered on 11 March 2022, retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT05278143?titles=AI+for+Glycemic+Events+Detection+Via+ECG+in+a+Pediatric+Population&draw=2&rank=1.

Normal limits of electrocardiogram in Africans and their consequences on the prevalence of left ventricular hypertrophy in hypertensive individuals: Insights from the TAHES study

AimsTo determine normal limits for major ECG variables, and the electrocardiographic impact of hypertension, in a rural sub-Saharan African setting. MethodsThis cross-sectional study included adults aged ≥25 years from Tanvè Health Study (TAHES) cohort. ECG were recorded at rest at 25 mm/s using a standard 12‑lead device. Wave amplitudes and durations were measured. Corrected QT interval (QTc) was calculated using Bazett's formula. Sokolow-Lyon, Cornell and Peguero-Lo Presti criteria were determined to assess left ventricular hypertrophy (LVH). ResultsECG was recorded among 997 out of 1407 TAHES participants. After exclusion of subjects with hypertension or diabetes, normal limits, defined as the 2nd and 98th percentiles, were evaluated in 622 healthy participants (median: 37 years; 60.1% women). The following limits were established in men (women): heart rate: 50 to 100 (55 to 102) beats/min, P wave duration: 80 to 120 (80 to 120) ms, PR interval: 120 to 200 (120 to 200) ms, QTc: 315 to 470 (323 to 465) ms, QRS duration: 50 to 120 (50 to 110) ms. Upper limits (in millimeter) for the Sokolow-Lyon, Cornell and Peguero-Lo Presti for men (women) were 47 (38), 30 (22) and 39 (30), respectively, all above current reference limits. The prevalence of LVH in hypertensive subjects according to these criteria were lower than those estimated according to current LVH criteria. ConclusionThe normal limits of ECG variables determined in this African population differ from those in Caucasians, indicating that ethnicity must be considered in ECG interpretation.

Abstract 13585: In Patients With Right Bundle Branch Block, ECG Z-Axis QRS-T Voltage-Time-Integral Predicts Right Ventricular Structure and Function

Introduction: Right bundle branch block (RBBB) is the most common His-Purkinje conduction abnormality seen on ECG. It is currently unclear if there are any quantitative ECG differences in RBBB without and with structural right ventricular (RV) disease. Our aim was to evaluate quantitative ECG predictors of echocardiographic RV measurements [tricuspid annular plane systolic excursion (TAPSE), tissue Doppler imaging RV S’, RV basal and mid diameters, RV systolic pressure (RVSP)]. Hypothesis: QRS-T VTI in patients with RBBB is a marker for adverse RV remodeling and dysfunction. Methods: We included adults with ECG demonstrating typical RBBB and echocardiogram performed within 3 months of each other in 2010-2020. Orthogonal X, Y, Z ECG leads were reconstructed using Kors matrix. In addition to overall QRS duration, QRS voltages and QRS/QRS-T VTIs from 12 standard leads, X, Y, Z leads, and 3D (root-mean-square) ECG were evaluated. Age, sex and BSA-adjusted linear regressions were used to assess associations between ECG variables and RV measurements. We separately generated ROC curves for predicting abnormal RV measurements from ECG variables. Results: We included 782 patients (33% women, 71±14 years). Amongst the ECG variables, BSA-indexed Z-axis QRS-T VTI (VTI QRST-Z *√BSA) was the strongest independent predictor of all 5 RV measurements (Table 1a shows a comparison of QRS duration, Z-axis amplitude and VTI). VTI QRST-Z *√BSA cutoff 62 μVsm had a sensitivity 62.7% and specificity 65.7% to distinguish presence of ≥3 abnormal out of the 5 RV measurements (Table 1b). Conclusions: Adverse RV remodeling causes augmentation of the anterior-posteriorly directed QRS-T potential which is seen as a change in Z-axis VTI. VTI QRST-Z *√BSA could be used as a marker for right heart failure in patients with RBBB.

Abstract 13586: In Patients With Left Bundle Branch Block, QRS Duration is a Stronger Predictor of Left Ventricular Hypertrophy and Dilation Than QRS Voltage

Introduction: ECG criteria for left ventricular (LV) hypertrophy in absence of left bundle branch block (LBBB) rely on QRS amplitudes. ECG correlates of LVH in setting of LBBB are not well established. We sought to evaluate quantitative LBBB ECG predictors of echocardiographic LV measurements [LV mass, end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF)]. Hypothesis: QRS duration (QRSd) is a better predictor of LV hypertrophy than QRS amplitudes. Methods: We included adult patients with typical LBBB having ECG and echocardiogram performed within 3 months of each other in 2010-2020. Digital 12-lead ECGs were processed to reconstruct orthogonal X, Y, Z leads using Kors matrix. Amplitudes and voltage-time-integrals (VTIs) from all 12 leads, X, Y, Z leads and 3D (root-mean-square) ECG, and QRSd were evaluated. We used age, sex and BSA-adjusted linear regressions to predict LV measurements, and separately generated ROC curves for identifying LV abnormalities. Results: We included 413 patients (53% women, age 73±12 yr). Among all the ECG variables, QRSd was most strongly correlated with all 4 LV measurements (all p<0.00001, see Table 1a showing QRSd compared to VTI and amplitude from 3D QRS). Table 1b shows area under ROC curves to identify LV abnormalities. QRS duration ≥150 ms in women had sensitivity 56.3%, specificity 64.4% for LVMi >95 g/m 2 and sensitivity 62.7%, specificity 67.8% for LVEDVi >61 mL/m 2 . QRS duration ≥160 ms in men had a sensitivity 63.1%, specificity 72.1% for LVMi >115 g/m 2 and sensitivity 58.3%, specificity 74.5% for LVEDVi >74 mL/m 2 . Conclusions: In patients with LBBB, QRS duration ≥150 in women and ≥160 in men is a superior predictor of adverse LV remodeling esp. eccentric LV hypertrophy/dilation. The weak correlation of QRS amplitude with hypertrophy may be due to the dominant effect of electrical dyssynchrony on voltage, and the heterogeneous effects of fibrosis, infiltrative cardiomyopathy, epicardial fat and LV dilation.

Abstract 11419: Prognostic Value of Vagal Dysautonomia in Patients With Chagas Disease: 14-year Results of a Population Cohort of the Elderly

Introduction: The cardiac form is the main responsible for morbidity and mortality of Chagas disease (ChD), given its prevalence and unpredictable clinical evolution. A great part of ChD mortality occurs due to sudden ventricular arrhythmias, and the frequently observed autonomic dysfunction may be associated with unfavorable outcomes. We aimed to evaluate the predictive value of autonomic dysfunction indexes in ChD patients. Methods: The Bambuí Study of Aging is a prospective cohort of residents ≥60 years at study onset (1997), living in the southeastern Brazilian city of Bambuí (15,000 inhabitants). Consented participants underwent annual follow-up visits, and death certificates were tracked. For assessment of respiratory sinus arrhythmia (E:I ratio), patients were instructed to breathe deeply in a 10-second cycle (5 inhales and 5 exhales) while ECG was recorded. Heart rate variability indices (SDRR (standard deviation of adjacent RR intervals) and RMSSD (square root of the mean of the sum of squares of the differences between adjacent RR intervals)) were calculated using a computer algorithm, supervised by an independent cardiologist blinded to clinical data. Multivariable regression was performed to access the prognostic value of autonomic dysfunction indexes, expressed as tertiles, for all-cause mortality, after adjustment for demographic, clinical and ECG variables. Results: From 1,742 qualifying residents, 1,606 were enrolled, being 557 with positive ChD serology. Among these, mean age was 68 (64-74) years, and 32.5% were men. The most frequent ECG abnormality was right bundle branch block (23.2%). In 14 years, loss-to-follow-up was 7.9% and overall mortality was 51.9%. At total 321 ChD patients had valid autonomic indexes measurements. In univariate analyses, measurements of autonomic function predicted all-cause death: E:I ratio (HR: 1.20 (95% CI 1.09-1.33)), SDRR (HR: 1.26 (95% CI 1.14-1.40)) and RMSSD (HR: 1.12 (1.01-1.23)). After adjustment for sex, age and cardiovascular risk factors, none of these indexes remained as independent predictors of mortality. Conclusions: In a long-term cohort of elderly patients with ChD, abnormalities in autonomic function indexes were not independent predictors of 14-year mortality.

Abstract 12553: Adverse Cardiovascular Outcomes in Heart Failure (HF) With Preserved Systolic Function Associated With Atrial Fibrillation Are Due to Loss of Rhythm Control Impacting HF Status : A Propensity Score Matched Analysis of the TOPCAT Americas Study

Background: Atrial fibrillation (AF) is associated with excess mortality and cardiovascular (CV) hospitalizations in HF patients (pts) with preserved systolic function (pEF), Whether this is due to advanced co-morbidities or loss of atrioventricular (AV) synchrony & rate control in AF is unclear. Hypothesis: To analyze the independent impact of AF on clinical outcomes of HFpEF pts in the TOPCAT AMERICAS study using propensity score matched (PSM) cohorts to account for confounding by other comorbidities. Methods: Study cohorts were matched for 20 clinical, demographic & ECG variables. 3 matched cohorts based on baseline rhythm status at study entry were compared viz. subjects in sinus rhythm (SR), subjects in AF on baseline ECG & subjects with Any AF event by history or ECG. We analyzed CV mortality, adjudicated modes of death & morbidity during a mean follow up period of 2.9 yrs. Results: 418 subjects in SR (SR cohort) were PSM with 418 subjects in AF on baseline ECG (AF on ECG cohort) & 418 pts with any AF event by history or ECG (Any AF cohort) at study entry. Any AF increased risk of CV death(D), pump failure death (PFD), CV and HF hospitalization(H) and HF progression. AF on ECG increased risk of CVD, CVH, HFH and PFD (Tables). Neither AF cohort increased risk of sudden death (SD) {Figure}. Conclusion: 1. AF is an independent risk factor for worsening CV outcomes in HFpEF. 2. This increased risk is due to a selective increase in HF worsening, HFH and PFD rather than SD. 3. Loss of AV synchrony & rate control in AF can independently impact HF progression in HFpEF with consequent HFH and PFD. Restoration of SR may offer benefits for CV outcomes in HFpEF & warrants evaluation.

INITIAL ELECTROCARDIOGRAPHIC PROFILE OF THE POPULATION OF TANGIERS – MOROCCO INFECTED WITH SARS CoV2: ABOUT 1087 CASES

Abstract Introduction Coronavirus disease 2019 (COVID-19) is a pathology which initially affects the respiratory system, but also many other noble organs due to his inflammatory phase (Cytokine Storm), especially the cardiovascular system. The cardiovascular risk factors present in a population infected with SARS-COV 2 are of particular interest. The ECG is a fast available means to get an idea about the cardiac status. This permits not only to diagnose an unknown pre-existing pathology but also to detect a killing cardiac complication of the SARS COV-2 infection. Methods We performed a cross-sectional study on COVID-19 patients passing through Tangiers sorting center. Clinical characteristics and ECG variables were manually abstracted from the electronic health record and first ECG. Our aim was to describe the electrocardiographic features of Covid-19 Patients in Morocco. Results 1087 patients who presented to the COVID 19 triage center in Tangier-Morocco were systematically given a pre-treatment ECG before deciding on the type of management: outpatient, ward, intensive care.The mean age was 42.78 years, 30.5% of the cases had at least one cardiovascular risk factor, 8.6% of the patients were followed for hypertension, 8.2% for type 1 or 2 diabetes, 10.9% of the patients were obese with a BMI greater than 30, and 26.4% of the patients were either men over 50 or women over 60. The mean heart rate was 80.89 bpm ± 15.58; The mean PR interval was 149.51 ± 21.70; The mean QRS duration was 98.59 ms ± 11.71; The mean QTc interval was 406.62 ms ± 24.32. We found: A conduction disorder in 11.1% of patients, 1.6% of 1st degree BAV, 2 of incomplete right bundle branch block, 5.7% of complete BBD, 0.9% of BBG and 1.4% of left anterior hemiblock. A rhythm disorder in 5.1% of our patients, 2.1% of ventricular extrasystole, 1.6% of supraventricular extrasystole, 1.1% of atrial fibrillation, wolf- parkinson-white syndrome in 0.3% of patients and 0.5% of Brugada pattern. A repolarization disorder in 5.2% of our population. 3.6% of patients had negative T waves and 1.6% had ST segment abnormalities. We also found a significant association between the presence of cardiovascular risk factors and electrical abnormality. Conclusion We found that the majority of EKG were normal and all critically ill patients had a large spectrum of EKG abnormalities. Pending the results, we still believe that we can potentially establish a severity score including EKG to predict inpatient mortality in Moroccan covid-19 patients. Additional Content An author video to accompany this abstract is available on https://academic.oup.com/eurheartjsupp. Please click on the arrow next to ‘More Content’ and then click on ‘Author videos’.

Myocardial infarction with non-obstructive coronary arteries in hypertrophic cardiomyopathy vs Fabry disease

BackgroundLittle is known about prevalence and predictors of myocardial infarction with non-obstructive coronary arteries (MINOCA) in Fabry disease (FD) and hypertrophic cardiomyopathy (HCM). We assessed and compared the prevalence and predictors of MINOCA in a large cohort of HCM and FD patients. MethodsIn this multicenter, retrospective study we enrolled 2870 adult patients with HCM and 267 with FD. The only exclusion criterion was documented obstructive coronary artery disease. MINOCA was defined according to guidelines. For each patient we collected clinical, ECG and echocardiographic data recorded at initial evaluation. ResultsOverall, 36 patients had MINOCA during a follow-up period of 4.5 ± 11.2 years. MINOCA occurred in 16 patients with HCM (0.5%) and 20 patients with FD (7.5%; p < 0.001). The difference between the 2 groups was highly significant, also after adjustment for the main clinical, ECG and echocardiographic variables (OR 6.12; 95%CI 2.80–13.3; p < 0.001). In the FD population MINOCA occurred in 17 out of 96 patients with left ventricle hypertrophy (LVH, 17.7%) and in 3 out of 171 patients without LVH (1.7%; OR 12.0; 95%CI 3.43–42.3; p < 0.001). At multivariable analysis, voltage criteria for LVH at ECG (OR 7.3; 95%CI 1.93–27.7; p = 0.003) and maximal LV wall thickness at echocardiography (OR 1.15; 95%CI 1.05–1.27; p = 0.002) maintained an independent association with MINOCA. No major significant differences were found in clinical, ECG and echocardiographic findings between HCM patients with or without MINOCA. ConclusionsMINOCA was rare in HCM patients, and 6-fold more frequent in FD patients. MINOCA may be considered a red flag for FD and aid in the differential diagnosis from HCM.

Short P-Wave Duration Is Associated with Incident Atrial Fibrillation.

Atrial fibrillation (AF) is common and increases the risk for stroke and heart failure (HF). The early identification of patients at risk may prevent the development of AF and improve prognosis. This study, therefore, aimed to test the effect of the association between P-wave and PR-interval on the ECG and incident AF.The PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study (1016 individuals all aged 70 years; 50% women) was used to identify whether the ECG variables P-wave duration (Pdur) and PR-duration in lead V1 were related to new-onset AF. Exclusion criteria were prevalent AF, QRS-duration ≥ 130 milliseconds (msec), atrial tachyarrhythmias and implanted pacemaker/defibrillator. Cox proportional-hazards models were used for analyses. Adjustments were made for gender, RR-interval, beta-blocking agents, systolic blood pressure, body mass index, and smoking.Of 877 subjects at risk, 189 individuals developed AF during a 15-year follow-up. There was a U-shaped relationship between the Pdur and incident AF (P = 0.017) following multiple adjustment. Values below 60 msec were significantly associated with incident AF, with a hazard ratio of 1.55 (95% confidence interval 1.15-2.09) for a Pdur ≤ 42 msec. There was no significant relationship between incident AF and the PR-interval.A short Pdur derived from the ECG in V1 may be a useful marker for new-onset AF, enabling the early identification of at-risk patients.

Prognostic role of serial electrocardiographic changes in patients with acute pulmonary embolism. Data from the Italian Pulmonary Embolism Registry

BackgroundThe prognostic role of serial electrocardiographic modifications in patients with acute pulmonary embolism (PE) have been poorly investigated. We evaluate the electrocardiographic changes in PE patients during their hospitalization and the prognostic role of such ECG modifications in respect to 30-day mortality in patients enrolled in the Italian Pulmonary Embolism Registry (IPER). MethodsSubjects enrolled into the IPER (September 2006–August 2010) were stratified according to their hemodynamic status, as high- (hemodynamically unstable) and non-high-risk (hemodynamically stable) patients. ECG features were analysed at three fixed time points: at presentation, on day 3 and at discharge. ResultsOverall, 687 patients (286 males, mean age 69.0 ± 15.5 years) were included in the study. Among these, 71 (10.3 %) were at high-risk. In these patients, multivariate analysis revealed that the persistence of right ventricular strain (RVS) after three days from hospitalization was a predictor of 30-day mortality [HRa: 2.78 (95 % CI: 1.05–7.31, p = 0.003)]. Moreover, the persistence of right bundle branch block (RBBB) [HRa: 2. 48 (95 % CI: 1.03–5.09, p = 0.002)], negative T waves in V1-V4 (NTWs) [HRa: 1.63 (95 % CI: 1.04–2.55), p < 0.0001] and qR complex in lead V1 [HRa: HR: 5.44, (95 % CI: 3.22–9.44, p < 0.0001)] were associated with an increased risk of 30-day mortality. When RBBB, NTWs and qR complex in V1 lead were present concomitantly, the 30-day risk of death resulted significantly higher [HR: 12.5 (95 % CI: 3.39–46.4,) p < 0.0001]. ConclusionsPersistence of RBBB, NTWs, and qR pattern in V1 lead at day 3 of hospitalization are independent prognostic factors of death within 30 days in high-risk acute PE patients. The prognostic power of any single ECG abnormality is lower compared to the combination of the three ECG variables.

Relation of delayed intrinsicoid deflection of the QRS complex to sudden cardiac death in patients with hypertrophic cardiomyopathy

AimsPredictors of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM) do not include ECG variables. Intrinsicoid deflection (ID) represents the early ventricular depolarization on surface ECG. Delayed ID (DID) has been associated with sudden cardiac arrest (SCA) in the community.In a cohort of consecutive patients with HCM, we assessed whether DID predicts SCA or its surrogates. MethodsWe reviewed ECG, clinical and follow-up data of 344 consecutive HCM patients. DID (ID ≥50 ms) was classified as lateral (leads I or aVL), inferior (leads II, III or aVF), and precordial (leads V5 or V6). The endpoint was a combination of SCD, resuscitated SCA or appropriate ICD intervention. ResultsThe SCA group was composed by 2 secondary prevention ICD recipients and 23 patients that reached the endpoint during follow-up (108 ± 73 months). SCA patients had more frequently massive LV hypertrophy (LVH) or end-stage HCM. ECG indexes of LVH were comparable between SCA and controls. SCA patients were more likely to have DID on ECG lateral leads I/aVL (72% vs 44%; p = 0.008). A non significant trend was observed for inferior and V5/V6 leads. DID I/aVL was associated with SCA in multivariate analysis after correction for massive LVH and end-stage disease (HR: 2.86; 95%CI: 1.14–7.13; p = 0.02). ConclusionsIn HCM patients DID is associated with increased risk of SCA. Its prognostic value extends beyond that of LVH. If confirmed in prospective studies, the prognostic power of this ECG marker could be used to refine risk prediction.