QRS Complex Duration Research Articles

Triggers of Ventricular Fibrillation in Patients With Inferolateral J-Wave Syndrome

BackgroundThere are few data on ventricular fibrillation (VF) initiation in patients with inferolateral J waves. ObjectivesThis multicenter study investigated the characteristics of triggers initiating spontaneous VF in inferolateral J-wave syndrome. MethodsA total of 31 patients (age 37 ± 14 years, 24 male) with spontaneous VF episodes associated with inferolateral J waves were evaluated to determine the origin and characteristics of triggers. The J-wave pattern was recorded in inferior leads in 11 patients, lateral leads in 3, and inferolateral leads in 17. ResultsThe VF triggers (n = 37) exhibited varying QRS durations (176 ± 21 milliseconds, range 119-219 milliseconds) and coupling intervals (339 ± 46 milliseconds, range 250-508 milliseconds) with a right (70%) or left (30%) bundle branch block (BBB) pattern. Trigger patterns were associated with J-wave location: left BBB triggers with inferior J waves and right BBB triggers with lateral J waves. Electrophysiologic study was performed for 22 VF triggers in 19 patients. They originated from the left or right Purkinje system in 6 and from the ventricular myocardium in 10 and were undetermined in 6. Purkinje vs myocardial triggers showed distinct electrocardiographic characteristics in coupling interval and QRS-complex duration and morphology. Abnormal epicardial substrate associated with fragmented electrograms was identified in 9 patients, with triggers originating from the same region in 7 patients. Catheter ablation resulted in VF suppression in 15 patients (79%). ConclusionsVF initiation in inferolateral J-wave syndrome is associated with significant individual heterogeneity in trigger characteristics. Myocardial triggers have electrocardiographic features distinct from Purkinje triggers, and their origin often colocalizes with an abnormal epicardial substrate.

Clinical and prognostic significance of left ventricular dysfunction predictors in patients with ventricular ectopy and without structural heart disease

Aim. To determine the predictors of left ventricular dysfunction in patients with ventricular ectopic beats without structural heart disease.Material and Methods. We modeled ventricular ectopy in rats through early afterdepolarization (aconitine-induced arrhythmia) and delayed afterdepolarization (adrenaline arrhythmia). In addition, we modeled ventricular ectopy in rabbits and cats by delayed afterdepolarization (barium chloride-induced and strophanthin arrhythmias, respectively) and also modeled ventricular ectopy in dogs by re-entry hydrogen peroxide-induced arrhythmia. In addition to conventional electrocardiography parameters, we analyzed pre-ectopic interval, its variability, and the internal deviation index. Further, the study included 514 patients aged 16 to 34 years (mean 21.2 ± 0.2 years), and the number of premature ventricular contractions (PVCs) per day of observation ranged from 6,157 to 37,254 (mean 19,706 ± 656 PVCs). We registered the same parameters as in experimental arrhythmias but calculated them separately for mono- and polymorphic, left and right ventricular out-flow tract arrhythmias. The duration of follow-up of patients was up to 10 years. The endpoint was the detection or absence of cardiovascular and/or extracardiac pathology.Results. We recorded polymorphic PVCs and early monomorphic PVCs when modeling ventricular arrhythmias by the mechanism of delayed post-depolarization and early post-depolarization, respectively. Both early and late monomorphic PVCs were documented when inducing ventricular arrhythmias by re-entry. When modeling hydrogen peroxide-induced and strophanthin arrhythmias, we observed significantly higher values of PVC-QRS complex and ventricular arrhythmia internal deviation index in comparison with aconitine-induced arrhythmia. Favourable outcome was registered in 50.97% of patients, whilst coronary artery disease, arterial hypertension, and mitral valve prolapse were documented in 7.98%, 16.73% and 2.92% patients. The rest of the patients had gastrointestinal diseases. In patients with favourable outcome, the signs of monomorphic PVCs correlated with those revealed during the modeling of ventricular ectopy by early afterdepolarization (r = 0.92), whereas those signs of polymorphic PVCs correlated with those observed at barium chloride-induced delayed afterdepolarization (r = 0.94). In patients with CAD, signs of PVCs correlated with those registered during re-entry hydrogen peroxide-induced arrhythmia (r = 0.93), Finally, in patients with arterial hypertension and mitral valve prolapse signs of PVCs correlated with those documented at strophanthin-(r = 0.92) and adrenaline-induced delayed afterdepolarization (r = 0.89). In these patients, the values for both monomorphic and polymorphic PVCs, ventricular arrhythmia internal deviation index, duration of PVC-QRS complex and PVC-QRS/QRSaverage did not exceed 0.42 units, 149 ms and 1,44 units, respectively. The development of coronary artery disease and arterial hypertension well correlated with an increase in ventricular arrhythmia internal deviation index ≥ 0.56 units and QRS complex duration ≥ 157 ms. Mitral valve prolapse was associated with the duration of the QRS complex ≥ 159 ms of polymorphic PVCs.Conclusion. In patients with ventricular ectopy but without structural heart disease, an increase in the values of ventricular arrhythmia internal deviation index and the duration of PVC-QRS complex was ≥ 0.48 units and 149 ms, respectively, associated with the development of cardiovascular pathology. Development of coronary artery disease and hypertension correlated with ventricular arrhythmia internal deviation index ≥ 0.56 units, and QRS complex duration ≥ 157 ms in monomorphic and polymorphic PVCs, whereas development of mitral valve prolapse correlated QRS complex duration ≥ 159 ms in polymorphic PVCs.

Prognostic significance of quantitative electrocardiographic parameters in patients with non-high-risk pulmonary embolism

BackgroundElectrocardiogram (ECG) abnormalities indicating right ventricular strain have been reported to have prognostic value in severe cases of acute pulmonary embolism (PE). We aimed to analyze the prognostic significance of other quantitative ECG parameters in non-high-risk acute PE. MethodsConsecutive patients with non-high-risk acute PE were prospectively enrolled. The following baseline ECG parameters were collected: rhythm, heart rate, QRS axis, right bundle branch block (RBBB) pattern, S1Q3T3 pattern, T-wave inversion, ST-segment elevation, Qr in lead V1, PR Interval, QRS complex duration, QT interval, P-wave amplitude and duration, R- and S-wave amplitudes. The primary endpoint was early discharge within three days. Associations between ECG parameters and early discharge were analyzed. ResultsOverall, 383 patients were enrolled (median age: 67 years, 57% female): 277 (72.3%) with low-risk and 106 (27.7%) with intermediate-risk. The two groups of patients differed in several ECG signs of right ventricular strain and many other quantitative parameters like R- and S-wave amplitudes. In the multivariate logistic regression analysis, the S-wave depth in lead V5 (S-V5) was the only independent prognostic factor for early discharge (odds ratio = 0.137, 95% confidence interval = 0.031-0.613, p = 0.009). The optimum cutoff value of S-V5 for predicting early discharge derived from the receiver operative characteristic curve was 0.15 mv (c-statistic = 0.66, p =0.003). ConclusionsSeveral ECG signs of right ventricular strain and many other quantitative parameters were associated with disease severity in non-high-risk acute PE. An S-V5 lesser than 0.15 mv was predictive for early discharge in these patients.

Upgrade of right ventricular pacing to cardiac resynchronization therapy in heart failure: a randomized trial.

De novo implanted cardiac resynchronization therapy with defibrillator (CRT-D) reduces the risk of morbidity and mortality in patients with left bundle branch block, heart failure and reduced ejection fraction (HFrEF). However, among HFrEF patients with right ventricular pacing (RVP), the efficacy of CRT-D upgrade is uncertain. In this multicentre, randomized, controlled trial, 360 symptomatic (New York Heart Association Classes II-IVa) HFrEF patients with a pacemaker or implantable cardioverter defibrillator (ICD), high RVP burden ≥ 20%, and a wide paced QRS complex duration ≥ 150 ms were randomly assigned to receive CRT-D upgrade (n = 215) or ICD (n = 145) in a 3:2 ratio. The primary outcome was the composite of all-cause mortality, heart failure hospitalization, or <15% reduction of left ventricular end-systolic volume assessed at 12 months. Secondary outcomes included all-cause mortality or heart failure hospitalization. Over a median follow-up of 12.4 months, the primary outcome occurred in 58/179 (32.4%) in the CRT-D arm vs. 101/128 (78.9%) in the ICD arm (odds ratio 0.11; 95% confidence interval 0.06-0.19; P < .001). All-cause mortality or heart failure hospitalization occurred in 22/215 (10%) in the CRT-D arm vs. 46/145 (32%) in the ICD arm (hazard ratio 0.27; 95% confidence interval 0.16-0.47; P < .001). The incidence of procedure- or device-related complications was similar between the two arms [CRT-D group 25/211 (12.3%) vs. ICD group 11/142 (7.8%)]. In pacemaker or ICD patients with significant RVP burden and reduced ejection fraction, upgrade to CRT-D compared with ICD therapy reduced the combined risk of all-cause mortality, heart failure hospitalization, or absence of reverse remodelling.

Impact of Different Right Ventricular Lead Positions on QRS Complex Duration Post Cardiac Resynchronization Therapy Device Implantation

Abstract Aim and objectives The aim of the study was to evaluate the effect of different RV lead positions on QRS complex duration post CRT device implantation in patients indicated for CRT as a treatment of chronic heart failure based on the recommendations of ESC guidelines for diagnosis and treatment of acute and chronic heart failure published in 2016 and to assess the effect of change of QRS complex duration and morphology according to different RV lead positions on clinical response. Patients and Methods This study included 100 patients (age 60.02 ± 7.18) post CRT device implantation presented for follow up at electrophysiology clinics of the cardiology department of Ain Shams university hospitals at least 3 months post CRT device implantation, during the period form from December 2020 till May 2021. The patients were divided into 2 groups according to the site of RV lead implantation after confirmation of the RV lead position by fluoroscope in Right anterior oblique (RAO) and left anterior oblique (LAO) views, 54 patients had the RV lead implanted in the RV Apex (RVA n = 54) and 46 patients had the RV lead implanted in the RV Septum (RVS n = 46). Results OF the total 100 patients that enrolled in our study the rate of non-responders was 19% of the patients showed no clinical improvement, no improvement of NYHA class by at least one grade, 30% of the patients were non-Echocardiographic responders, no improvement of LVEF (Δ EF) by at least 5% with no decrease of LVES diameter by at least 15%, and 15% of the patient were nonECG responders, delta QRS (ΔQRS) didn`t increase by at least 20%. There was no significant difference between the two groups regarding clinical response (NYHA class) (P-value = 0.583), LVEF (Δ EF 6.26 ± 1.64 in RVS group vs. 6.07 ± 1.67 in RVA group, P-value = 0.575) LVES diameter (47.70 ± 8.03 in RVS group vs. 45.39 ± 7.48 in RVA group, P-value = 0.141) or QRS complex narrowing (ΔQRS 60.93 ± 24.68 in RVS group vs. 54.07 ± 26.12 in RVA group, P-value = 0.182). There was no significant difference in the rate of non-responders between the two groups (clinical non responders in RVS group n = 8 vs. RVA group n = 11, P value = 0.547) (Echo non responders in RVS group n = 13 vs. RVA group n = 17, P value = 0.726) (ECG non responders in RVS group n = 6 vs. RVA group n = 9, P value = 0.613), There was an inverse relationship between ΔQRS and clinical response (NYHA) class post CRT device implantation in both RVS and RVA groups (P value 0.016 in RVS group, P value 0.007 in RVA group). Conclusion The study demonstrates that septal RV pacing in CRT is non-inferior to apical RV pacing regarding the primary objective of the study regarding clinical outcome, narrowing of QRS complex (ΔQRS) or LV reverse remodeling, thus no recommendation for optimal RV lead position can hence be drawn from this study. Also, delta QRS complex duration may be used as indicator for electric remodeling and CRT response.

Left Ventricular Global Strain and Duration of QRS Complex as Predictors of Prognosis After Cardiac Resynchronization Therapy

Left Ventricular Global Strain and Duration of QRS Complex as Predictors of Prognosis After Cardiac Resynchronization Therapy

Relationship between parameters of myocardial electrical remodeling and parameters of contractile function, deformation and myocardium work in patients with chronic heart failure with low left ventricular ejection fraction and atrial fibrillation.

Aim To compare electrocardiographic parameters and characteristics of myocardial contractility by echocardiography data in patients with chronic heart failure (CHF) with low left ventricular ejection fraction (LV EF) and atrial fibrillation (AF).Material and methods The study included 66 patients with CHF and LV EF ≤40%. Electrocardiography was used to assess the QRS complex duration, QRS fragmentation, frontal QRS-T angle (fQRS-Ta), and 3D vectorcardiographic parameters, including the planarity of QRS loop, and the spatial QRS-T angle (sQRS-Ta). Echocardiography assessed LV EF, global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE).Results Statistically significant correlations between electrocardiographic parameters and LV EF were not found. The presence of QRS fragmentation was associated with impaired GLS, higher GWW values, and lower GWE. A number of weak but significant correlations was observed: GLS worsened with increasing QRS duration, fQRS-Ta, and sQRS-Ta and decreasing QRS planarity index; GWW increased with increasing QRS duration; GWI, GCW, and GWE decreased as the QRS planarity index decreased. GWI decreased with increasing sQRS-Ta; GCW decreased with increasing fQRS-Ta and sQRS-Ta; GWE decreased with increasing QRS duration, fQRS-Ta and sQRS-Ta.Conclusion Correlations were found between indicators of myocardial electrical remodeling and parameters of myocardial contractility, strain, and performance in CHF patients with low LV EF and AF. Further study of these parameters may be promising for assessing the severity of changes in myocardial structure and function in patients with various cardiovascular pathologies.

Left ventricular global strain and duration of QRS complex as predictors of prognosis after cardiac resynchronization therapy

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National heart institute and Menoufia university, Egypt. Background cardiac resynchronization therapy is effective for patients with chronic heart failure with reduced left ventricular ejection fraction and wide QRS (≥120 ms). We aimed to verify that a baseline left ventricular global longitudinal strain(LVGLS) and qrs duration may be beneficial as predictors of prognosis of CRT response. purpose We aimed to evaluate if LVGLS &amp; QRS duration may be of additive prognostic value in CRT response. Methods Transthoracic echocardiography was performed prior to and 6 months after CRT implantation. Echocardiography was performed to assess left ventricular function as LVGLS. The response to CRT was defined as improvement in NYHA functional class (at least one class) and ≥ 15% reduction in the left ventricular end-systolic volume or improvement in left ventricular ejection fraction &amp;gt; 10. Comparison between responders and not responders was done using the appropriate test, and ROC analyses were done for QRS duration and LVGLS to predict CRT response. Results fifty-five HF patients (age 58 ±8 years, LVEF 23 ±5%, QRS duration 159 ±8ms, 30.9% ischemic aetiology of HF) underwent CRT implantation. The percentage of responders was 72.72% (Table). Baseline LVGLS differed significantly according to CRT response (P &amp;lt; 0.019). The best cutoff for LVGLS to predict response was 6.2, at which sensitivity and specificity were 70% and 73.3%, respectively with AUC of 0.793, with a 95% confidence interval (CI) of 0.651 - 0.936 (P = 0.001). Also, there was a statistically significant difference of the baseline QRS duration between the patients who had and hadn’t CRT response (P &amp;lt;0.001). The best cutoff was &amp;gt;154 ms,at which sensitivity and specificity were 87.5% and 86.7%, respectively. (AUC was of 0.793, with a 95% CI ranging from 0.651 - 0.936 (P = 0.001). Conclusion Baseline LVGLS and QRS duration may have a prognostic value in prediction CRT response. Baseline LVGLS (&amp;gt;6.2) and QRS duration (&amp;gt;154ms) may help to select CRT responders.

Enlarged dimensions of cardiac chambers and the root of the aorta as a significant cardiovascular impact of pandemic COVID-19: a population-based study

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Centre of Science. Background The long-term complications in the cardiovascular (CV) system that the acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may cause are not fully understood. The aim of the study was to assess the impact of a coronavirus disease of 2019 (COVID-19) pandemic on echocardiographic (ECHO) and electrocardiographic (ECG) parameters. Methods This was single-center prospective cohort study. The study population consisted of 2 groups: the group before the COVID-19 pandemic (713 probands tested from 18. March 2018 to 17. March 2020) compared to the group during the COVID-19 pandemic (425 probands tested from 14. July 2020 to 02. March 2022). The comprehensive assessment was performed including laboratory parameters, ECHO and ECG. Results The studied populations did not differ by sex, age, body mass index and systolic blood pressure (BPs), while diastolic BP (BPd) was significantly lower in the group during the COVID-19 pandemic (p&amp;lt;0.001). In the group during COVID-19 the dimensions of all cardiac chambers, i.e., left atrial dimension (p&amp;lt;0.001), left atrial volume index (LAVI) (p&amp;lt;0.001), right atrial volume (p&amp;lt;0.001), left ventricular dimension (p=0.013), right ventricular dimension (p=0.046) and aortic root dimension (p=0.001) were larger compared to the pre-pandemic population. The ECG showed longer P-wave (p=0.022), PQ segment (&amp;lt;0.001) and QRS complex durations (p=0.042) in the pandemic population compared to the pre-pandemic population. In contrast, there was no significant statistical difference between the analyzed groups in terms of left ventricular hypertrophy (LVH) assessed by ECHO or ECG criteria. In addition, N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations was significantly higher in the population during COVID-19 (p=0.011). Conclusion SARS-CoV-2 has had an impact on the cardiovascular system by increasing the size of all heart chambers and the root of the aorta which may have deleterious effects in the future. Careful monitoring of long-term effects is needed.

Age and Sex Determine Electrocardiogram Parameters in the Octodon degus.

Cardiovascular diseases represent the leading cause of mortality and morbidity worldwide, and age is an important risk factor. Preclinical models provide supportive evidence toward age-related cardiac changes, as well as allow for the study of pathological aspects of the disease. In the present work, we evaluated the electrocardiogram (ECG) recording in the O. degus during the aging process in both females and males. Taking into account the age and sex, our study provides the normal ranges for the heart rate, duration and voltage of the ECG waves and intervals, as well as electrical axis deviation. We found that the QRS complex duration and QTc significantly increased with age, whereas the heart rate significantly decreased. On the other hand, the P wave, PR and QTc segments durations, S wave voltage and electrical axis were found to be significantly different between males and females. The heart rhythm was also altered in aged animals, resulting in an increased incidence of arrhythmias, especially in males. Based on these results, we suggest that this rodent model could be useful for cardiovascular research, including impacts of aging and biological sex.

Ventricular pre-excitation in cats: 17 cases

ObjectivesAtrioventricular accessory pathways are abnormal electrical connections between the atria and ventricles that predispose to ventricular pre-excitation (VPE) and tachycardias. AnimalsSeventeen cats with VPE and 15 healthy matched-control cats. Material and methodsMulticenter case-control retrospective study. Clinical records were searched for cats with VPE, defined as preserved atrioventricular synchrony, reduced PQ interval, and increased QRS complex duration with a delta wave. Clinical, electrocardiography, echocardiographic, and outcome data were collated. ResultsMost cats with VPE were male (16/17 cats), non-pedigree cats (11/17 cats). Median age and mean body weight were 5.4 years (0.3–11.9 years) and 4.6 ± 0.8 kg, respectively. Clinical signs at presentation included lethargy (10/17 cats), tachypnea (6/17 cats), and/or syncope (3/17 cats). In two cats, VPE was an incidental finding. Congestive heart failure was uncommon (3/17 cats). Nine (9/17) cats had tachyarrhythmias: 7/9 cats had narrow QRS complex tachycardia and 2/9 cats had wide QRS complex tachycardia. Four cats had ventricular arrhythmias. Cats with VPE had larger left (P < 0.001) and right (P < 0.001) atria and thicker interventricular septum (P = 0.019) and left ventricular free wall (P = 0.028) than controls. Three cats had hypertrophic cardiomyopathy. Treatment included different combinations of sotalol (5/17 cats), diltiazem (5/17 cats), atenolol (4/17 cats), furosemide (4/17 cats), and platelet inhibitors (4/17 cats). Five cats died, all from cardiac death (median survival time 1882 days [2–1882 days]). ConclusionsCats with VPE had a relatively long survival, albeit showing larger atria and thicker left ventricular walls than healthy cats.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension.

The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

Clinical, hemodynamic and biochemical improvement related to left bundle branch area pacing.

Right ventricular pacing is associated with risk of heart failure and left ventricular dysfunction. Left bundle branch area pacing (LBBP) has emerged as an alternative method for delivering physiological pacing. The effect of LBBP on N-terminal pro-brain natriuretic peptide (NT-proBNP) has not been investigated. Finally, 50 patients referred for pacemaker implantation were included. LBBP was performed as described previously by Huang et al. Transthoracic echocardiogram and NT-proBNP were performed before and four weeks after the procedure. 50 patients were analyzed. There were not differences between ventricular thresholds during the procedure and 3 months later, LBBP significantly reduced QRS complex duration (148 ± 21 vs. 107 ± 11 ms; p = 0.029). LBBP significantly improved NYHA functional class and reduced NT-proBNP concentration (2888.2 ± 510 vs. 1181 ± 130 pg/ml; p = 0.04). In patients showing left ventricular ejection fraction (LVEF) < 50% and ventricular desynchrony LBBP showed a significant LVEF increase (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). LBBP was feasible and safe in most of patients. LBBP was associated with reduction in QRS width and with increase in LVEF in patients with ventricular desynchrony, while in patients with normal LVEF it remained unchanged during follow-up.

Predictors of Developing Heart Failure in Adults with Congenital Heart Defects.

The population of adults with congenital heart defects (ACHD) is growing. The leading cause of premature death in these patients is heart failure (HF). However, there is still limited information on the predictive factors for HF in ACHD patients. This study re-examined a group of patients with repaired or palliated congenital heart defects (CHD) that were initially studied in 2003. A follow-up period of 15 years has allowed us to identify and evaluate predictors for the development of HF in ACHD. All patients with repaired or palliated CHD who participated in the initial study (n = 364) were invited for a follow-up examination. The effects of maximum oxygen uptake ( ) during exercise stress testing, the cardiac biomarker N-terminal pro brain natriuretic peptide (NT-proBNP), and QRS complex on the development of HF during the follow-up period were investigated. From May 2017 to April 2019, 249 of the initial 364 (68%) patients participated in the follow-up study. Of these, 21% were found to have mild CHD, 60% had moderate CHD, and 19% had complex CHD. Significant predictors for the development of HF were: NT-proBNP level 1.7 times the upper normal limit, 73% of predicted values, and QRS complex duration 120 ms. Combination of these three parameters resulted in the highest area-under-the-curve of 0.75, with a sensitivity of 75% and specificity of 63% for predicting the development of HF. In this cohort of ACHD patients, the combination of , NT-proBNP, and QRS duration was predictive of HF development over a 15-year follow-up period. Enhanced surveillance of these parameters in patients with ACHD may be beneficial for the prevention of HF and early intervention.

CRT-700.75 Left Ventricular Global Strain and Duration of QRS Complex as Predictors of Prognosis After Cardiac Resynchronization Therapy

CRT-700.75 Left Ventricular Global Strain and Duration of QRS Complex as Predictors of Prognosis After Cardiac Resynchronization Therapy

Decreased levels of s-nitrosylated Cx43 prevent arrhythmogenicity and myocardial infarction upon cardiac stress in duchenne muscular dystrophy.

Connexin43 (Cx43) plays a critical role in action potential propagation and cardiac contractility. In healthy cardiomyocytes, Cx43 is located at the intercalated disk, however, in cardiac diseases such as hypertrophic and dilated cardiomyopathy, it is remodelled to the lateral side of ventricular cardiomyocytes. In Duchenne muscular dystrophy (DMD) mice, lateralized cardiac Cx43 is found forming hemichannels at the plasma membrane that activate upon cardiac stress evoking triggered activity and arrhythmogenic behaviours. S-nitrosylated levels of Cx43 strongly correlate with changes in membrane excitability in cardiomyocytes from DMD mice. To unequivocally demonstrate a direct role of S-nitrosylated Cx43 in DMD cardiomyopathy, we developed a specific knockin mouse line, in which the Cx43 site for S-nitrosylation, cysteine 271, was specifically substituted for a serine (Cx43C271S). We then crossed the C271S mouse line with DMD mice to obtain DMD:Cx43C271S+/- mice with reduced levels of S-nitrosylated Cx43. Littermate mice (4-6-month-old) were used to assess isoproterenol-induced cardiac stress and, consequently, heart dysfunction in WT, DMD and DMD:Cx43C271S+/- mice. DMD mice displayed increased number of arrhythmogenic events, but without changes in RR and QRS complexes within 1-h post-isoproterenol treatment. However, elevated number of deadly arrhythmias, bradycardia, and increased QRS complex duration were detected in DMD mice for 24-h following isoproterenol stimulation. Strikingly, the number of arrhythmogenic events were significantly reduced in DMD:Cx43C271S+/- mice. β-adrenergic stimulation with isoproterenol induced cardiac hypertrophy, myocardial infarction, and 40% mortality in DMD mice, which was prevented in DMD:Cx43C271S+/- mice. Therefore, these findings strongly suggest that S-nitrosylation of Cx43 proteins at site cysteine 271 represents a fundamental nitric oxide-mediated mechanism involved in the induction of arrythmias and myocardial infarction in DMD mice after β-adrenergic stress.

The study of electrocardiographic changes in type II diabetes mellitus

Background: The predictions of the silent ischemia in the asymptomatic patients were done with the Electrocardiographic (ECG) abnormalities findings. The high risk of the cardiac morbidity and mortality was statistically associated with abnormal ECG findings. Aims and Objectives: To reduce patient mortality and morbidity, the current analysis was performed on diabetes patients to look for ECG alterations. Materials and Methods: A total of 100 people were used, 50 of whom had type-2 diabetes mellitus and 50 of whom were healthy, non-diabetic volunteers whose ages and sexes matched the patients with type-2 diabetes. The 12-lead ECG instrument was used to record the electrographic markings. For fasting blood sugar blood was collected after a minimum 8 h overnight fasting and for PP2BS blood was collected 2 h after lunch. Results: In people with type II diabetes mellitus, the P wave’s amplitude significantly decreased. When compared to controls, type II diabetics’ QRS complex duration was noticeably longer. When compared to controls, (type II DM) Type 2 diabetes mellitus sufferers had a significantly longer QT and QTC interval. When type II diabetics were compared to controls, the ST segment alterations were significantly different. When compared to controls, type II diabetes showed a considerable T-wave alteration. Conclusion: The ST segment deviation from the isoelectric line is a predictor of coronary events in an asymptomatic diabetic population. The incidence of sudden mortality due to cardiovascular disease in diabetics is reduced as a result of early detection of QT and QTC alterations, which are good indicators of cardiovascular disease risk in diabetics.

Single-arm diagnostic electrocardiography with printed graphene on wearable textiles.

Stimulated by the COVID-19 outbreak, the global healthcare industry better acknowledges the necessity of innovating novel methods for remote healthcare monitoring and treating patients outside clinics. Here we report the development of two different types of graphene textile electrodes differentiated by the employed fabrication techniques (i.e., dip-coating and spray printing) and successful demonstration of ergonomic and truly wearable, single-arm diagnostic electrocardiography (SADE) using only 3 electrodes positioned on only 1 arm. The performance of the printed graphene e-textile wearable systems were benchmarked against the "gold standard" silver/silver chloride (Ag/AgCl) "wet" electrodes; achieving excellent correlation up to ∼ 96% and ∼ 98% in ECG recordings (15s duration) acquired with graphene textiles fabricated by dip-coating and spray printing techniques, respectively. In addition, we successfully implemented automatic detection of heartrate of 8 volunteers (mean value: 74.4 bpm) during 5min of static and dynamic daily activities and benchmarked their recordings with a standard fingertip photoplethysmography (PPG) device. Heart rate variability (HRV) was calculated, and the root means successive square difference (rMMSD) metric was 30ms during 5min of recording. Other cardiac parameters such as R-R interval, QRS complex duration, S-T segment duration, and T-wave duration were also detected and compared to typical chest ECG values.

Signal Processing Framework for the Detection of Ventricular Ectopic Beat Episodes.

The Holter monitor captures the electrocardiogram (ECG) and detects abnormal episodes, but physicians still use manual cross-checking. It takes a considerable time to annotate a long-term ECG record. As a result, research continues to be conducted to produce an effective automatic cardiac episode detection technique that will reduce the manual burden. The current study presents a signal processing framework to detect ventricular ectopic beat (VEB) episodes in long-term ECG signals of cross-database. The proposed study has experimented with the cross-database of open-source and proprietary databases. The ECG signals were preprocessed and extracted the features such as pre-RR interval, post-RR interval, QRS complex duration, QR slope, and RS slope from each beat. In the proposed work, four models such as support vector machine, k-means nearest neighbor, nearest mean classifier, and nearest RMS (NRMS) classifiers were used to classify the data into normal and VEB episodes. Further, the trained models were used to predict the VEB episodes from the proprietary database. NRMS has reported better performance among four classification models. NRMS has shown the classification accuracy of 98.68% and F1-score of 94.12%, recall rate of 100%, specificity of 98.53%, and precision of 88.89% with an open-source database. In addition, it showed an accuracy of 99.97%, F1-score of 94.54%, recall rate of 98.62%, specificity of 99.98%, and precision of 90.79% to detect the VEB cardiac episodes from the proprietary database. Therefore, it is concluded that the proposed framework can be used in the automatic diagnosis system to detect VEB cardiac episodes.

PS-C24-10: HAEMODYNAMIC CHARACTERISTICS OF THE HEART BEFORE AND AFTER CRT IN PATIENTS WITH HEART FAILURE

The aim of the study: to evaluate the clinical and hemodynamic effects of resynchronization therapy in patients with congestive heart failure. Materials and Methods: seventy-six consecutive patients underwent echocardiography, NYHA classification, 6-minute walk test before and after cardiac resynchronization therapy. All had complete left bundle branch block, with a QRS complex duration greater than 130 ms. and left ventricular ejection fraction less than 35%. Also, all patients had received optimal medical therapy for at least 3 months before inclusion to the study. Results: we observed significant increase in left ventricular ejection fraction (on 35.4 ± 3.7%, p &lt; 0.001, compared with baseline) and decrease in end-systolic volume of the left ventricle (on 20.2 ± 3.0%, p &lt; 0.001 compared with baseline). Improvement in functional class of congestive heart failure by NYHA classification by more than 1 was observed in 68.4% of individuals, in 26.3% of participants demonstrated no change and 5.3% of patients had worsening of CHF symptoms. Conclusions: the response of patients with congestive heart failure to cardiac resynchronization therapy is heterogeneous. The relationship between left ventricular reverse remodeling and the functional class of the congestive heart failure was not significant.