Fragmented QRS Complexes Are Associated with Cardiac Fibrosis and Significant Intraventricular Systolic Dyssynchrony in Nonischemic Dilated Cardiomyopathy Patients with a Narrow QRS Interval

The Relationship between Fragmented QRS and Myocardial Injury in Patients with Acute Carbon Monoxide Poisoning

Background and Objectives: Carbon monoxide (CO) intoxication is one of the most common causes of poisoning-related deaths and complications. Myocardial injury is an important complication of CO poisoning. In our study, we aimed to evaluate the relationship between the presence and prevalence of fragmented QRS (fQRS) and myocardial injury in patients with CO intoxication. Materials and Methods: We retrospectively evaluated patients who presented to the emergency department of our tertiary care center with CO intoxication between January 2020 and December 2023. In our study, we performed subgroup analyses according to the presence of myocardial injury and fQRS. We evaluated the parameters and risk factors associated with myocardial injury. Results: Myocardial injury was detected in 44 patients, and fQRS was detected in 38 patients. In the myocardial injury (+) group, the fQRS rate was 38.6%, and the median number of leads with fQRS was 3 (2-6) and was significantly higher than in the myocardial injury (-) group (p < 0.001). We found that carboxyhemoglobin had a significant positive correlation with troponin (p = 0.001) and pro-B-type natriuretic peptide (proBNP) (p = 0.009). As a result of multivariate analysis, we determined that age, creatinine, proBNP, fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury. Conclusions: Myocardial injury in CO intoxication patients is associated with proBNP, the presence of fQRS, and the number of leads with fQRS. Age, creatinine level, proBNP, the presence of fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury in patients with CO intoxication.

Electrocardiographic frontal QRS-T angle is independently associated with panic disorder

OBJECTIVE

Panic disorder (PD) may cause serious cardiac arrhythmias by causing electrical abnormalities. Abnormal P-wave axis (aPwa), presence of fragmented QRS (fQRS), wide frontal QRS-T angle (fQRSTa), QRS duration corrected (QRSdc) and log/ logQRS duration/RR interval (log/logQRS/RR) have been correlated with increased risk of serious supraventricular and ventricular cardiac arrhythmias in a general population. The purpose of this study was to compare these newly explored atrial and ventricular arrhythmia indicators in patients with PD and in healthy subjects.

METHOD

A total of 169 newly diagnosed PD patients and 128 healthy subjects were included in the study. The Panic and Agoraphobia Scale (PAS) was administered, and 12-lead electrocardiography (ECG) measurements were obtained. Electrocardiographic parameters including aPwa, fQRSTa, presence of fQRS, QRS duration corrected (QRSdc), and log/logQRS duration/RR distance (log/logQRS/RR) were compared between the two groups.

RESULTS

aPwa and fQRS, in addition to fQRSTa, QRSdc, and log/ logQRS/RR ratio values, were significantly increased in the PD group compared to healthy controls. Correlation analyses revealed that wider fQRSTa, number of fQRS derivation, number of total fQRS, wider QRSdc, and log/logQRS/RR ratio significantly correlated with PAS score. Logistic regression analysis demonstrated that fQRSTa and the number of total fQRS were independently associated with PD.

CONCLUSION

PD is associated with wider fQRSTa, QRSdc, and log/logQRS/RR in addition to the increased abnormal aPwa and presence of fQRS. These findings suggest that untreated PD patients may be susceptible to supraventricular and ventricular arrhythmia, indicating that ECG should be routinely obtained in the management of PD patients.

[Acute heart failure with altered ejection fraction : Electrocardiographic signs with mortality at the Abidjan cardiology institute]

INTRODUCTION

Heart failure with impaired ejection fraction (HFIEF) represents the end-stage of most cardiac diseases, and is responsible for a high mortality rate. In order to identify patients at risk, numerous clinical and paraclinical prognostic factors have been proposed. The electrocardiogram (ECG), easy to perform and inexpensive, retains a powerful role in the prognostic evaluation of heart failure patients. The aim was to evaluate ECG signs associated with mortality in a retrospective cohort of patients with ICFEA.

METHODOLOGY

The study was observational and analytical based on retrospective data collected from patients benefiting from a primary hospitalization for ICFEA at the Abidjan Heart Institute from January 2018 to July 2020.

RESULTS

Of the 370 patients included, 197 had died by August 1, 2020, representing an overall mortality of 53%. Mortality progressed gradually up to one year, then remained unchanged up to 30 months. In multivariate Cox regression including ECG variables only, the presence of intra-ventricular conduction disorders (OR: 1.80; 95% CI [1.01-3.25]), microvoltage (OR: 1.82; 95% CI [1.05-16]), and pathological Q waves (OR: 1.70; 95% CI [1.02-2.83]), were significantly associated with overall mortality. When ECG variables and clinical, paraclinical and therapeutic demographic variables were included, only the presence of pathological Q waves (OR:1.74; 95% CI [1.01-3.01]) persisted as a risk factor for mortality. Hypertension and treatment of heart failure, in particular ACEI/ARII, beta-blockers and ARM, were protective factors. The presence of Q waves was associated with a significant reduction in survival, based on curves obtained using the Kaplan-Meier model.

CONCLUSION

ICFEA is responsible for high mortality, mainly in the year following the 1st hospitalization for cardiac decompensation. The presence of pathological Q waves is the only electrocardiographic sign that remains statistically associated with a poor prognosis, after adjustment.

QRS fragmentation does not predict mortality in survivors of acute myocardial infarction

BACKGROUND

Despite advances in coronary revascularization and in heart failure management, myocardial infarction survivors remain at substantially increased mortality risk. Precise risk assessment and risk-adapted follow-up care are crucial to improve their outcomes. Recently, the fragmented QRS complex, i.e. the presence of additional spikes within the QRS complexes on a 12-lead electrocardiogram, has been discussed as a potential non-invasive risk predictor in cardiac patients.

HYPOTHESIS

The aim of this study was to evaluate the prognostic meaning of the fragmented QRS complex in myocardial infarction survivors.

METHODS

609 patients with narrow QRS complexes <120 ms were included in a prospective cohort study while hospitalized for myocardial infarction and followed for 5 years.

RESULTS

The prevalence of the fragmented QRS complex in these patients amounted to 46.8% (285 patients). These patients had no increased hazard of all-cause death (HR 0.84, 95%-CI 0.45-1.57, p = 0.582) with a mortality rate of 6.0% compared to 7.1% in patients without QRS fragmentations. Furthermore, the risks of cardiac death (HR 1.28, 95%-CI 0.49-3.31, p = 0.613) and of non-cardiac death (HR 0.6, 95%-CI 0.26-1.43, p = 0.25) were not significantly different in patients with QRS fragmentations. However, patients with QRS fragmentations had increased serum creatine kinase concentrations (1438U/l vs. 1160U/l, p = 0.039) and reduced left ventricular ejection fractions (52% vs. 54%, p = 0.011).

CONCLUSIONS

The hypothesis that QRS fragmentation might be a prognostic parameter in survivors of myocardial infarction was not confirmed. But those with QRS fragmentation had larger myocardial infarctions, as measured by creatine kinase and left ventricular ejection fraction.

Electrocardiographic abnormalities in patients with cardiomyopathies

Abnormalities in impulse generation and transmission are among the first signs of cardiac remodeling in cardiomyopathies. Accordingly, 12-lead electrocardiogram (ECG) of patients with cardiomyopathies may show multiple abnormalities. Some findings are suggestive of specific disorders, such as the discrepancy between QRS voltages and left ventricular (LV) mass for cardiac amyloidosis or the inverted T waves in the right precordial leads for arrhythmogenic cardiomyopathy. Other findings are less sensitive and/or specific, but may orient toward a specific diagnosis in a patient with a specific phenotype, such as an increased LV wall thickness or a dilated LV. A "cardiomyopathy-oriented" mindset to ECG reading is important to detect the possible signs of an underlying cardiomyopathy and to interpret correctly the meaning of these alterations, which differs in patients with cardiomyopathies or other conditions.

Fragmented QRS as a predictor of hypertensive crisis in patients with newly diagnosed essential hypertension: 4-year follow-up data

BACKGROUND

Hypertensive crisis (HC) is a life-threatening condition in patients with hypertension (HT). However, there is no electrocardiography (ECG) marker that can predict which hypertensive patient may develop HC. The fragmented QRS (fQRS) complex is an important prognostic marker in ECG that might be predict cardiovascular events and mortality. Our study aimed to investigate whether fQRS can predict the development of HC in patients with HT, within 4 years of follow-up.

METHODS

Newly diagnosed patients with essential HT were recruited for the study from an outpatient clinic. The patients were divided into two groups according to the presence of HC: HC (+) and HC (-). During follow-up, the relationship between fQRS and HC was evaluated.

RESULTS

The study group included 504 patients with newly diagnosed HT. During the follow-up period, HC occurred in 98 of the patients. In 57 (11.30%) patients, fQRS was observed on ECG; fQRS was detected in the ECG of 19 (19.38%) of the HC (+) patients (p = 0.008). The results of multivariate logistic regression analysis showed that fQRS (p < 0.001) was as independent predictor for HC development. Kaplan-Meier analysis further demonstrated that the presence of fQRS affects the development of hypertensive urgency in hypertensive patients (log-rank p < 0.001).

CONCLUSION

In patients with newly diagnosed HT, the presence of fQRS was found to be an independent predictor of HC.

The pivotal role of ECG in cardiomyopathies

Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Recent technological advances in cardiovascular imaging offer an opportunity for deep phenotypic and etiological definition. Electrocardiogram (ECG) is the first-line diagnostic tool in the evaluation of both asymptomatic and symptomatic individuals. Some electrocardiographic signs are pathognomonic or fall within validated diagnostic criteria of individual cardiomyopathy such as the inverted T waves in right precordial leads (V1-V3) or beyond in individuals with complete pubertal development in the absence of complete right bundle branch block for the diagnosis of arrhythmogenic cardiomyopathy of the right ventricle (ARVC) or the presence of low voltages typically seen in more than 60% of patients with amyloidosis. Most other electrocardiographic findings such as the presence of depolarization changes including QRS fragmentation, the presence of epsilon wave, the presence of reduced or increased voltages as well as alterations in the repolarization phase including the negative T waves in the lateral leads, or the profound inversion of the T waves or downsloping of the ST tract are more non-specific signs which can however raise the clinical suspicion of cardiomyopathy in order to initiate a diagnostic procedure especially using imaging techniques for diagnostic confirmation. Such electrocardiographic alterations not only have a counterpart in imaging investigations such as evidence of late gadolinium enhancement on magnetic resonance imaging, but may also have an important prognostic value once a definite diagnosis has been made. In addition, the presence of electrical stimulus conduction disturbances or advanced atrioventricular blocks that can be seen especially in conditions such as cardiac amyloidosis or sarcoidosis, or the presence of left bundle branch block or posterior fascicular block in dilated or arrhythmogenic left ventricular cardiomyopathies are recognized as a possible expression of advanced pathology. Similarly, the presence of ventricular arrhythmias with typical patterns such as non-sustained or sustained ventricular tachycardia of LBBB morphology in ARVC or non-sustained or sustained ventricular tachycardia with an RBBB morphology (excluding the "fascicular pattern") in arrhythmogenic left ventricle cardiomyopathy could have a significant impact on the course of each disease. It is therefore clear that a learned and careful interpretation of ECG features can raise suspicion of the presence of a cardiomyopathy, identify diagnostic "red flags" useful for orienting the diagnosis toward specific forms, and provide useful tools for risk stratification. The purpose of this review is to emphasize the important role of the ECG in the diagnostic workup, describing the main ECG findings of different cardiomyopathies.

The electrocardiogram in non-ischaemic-dilated cardiomyopathy

This article summarizes the main electrocardiogram (ECG) findings in dilated cardiomyopathy (DCM) patients. Recent reports are described in the great 'pot' of DCM peculiar ECG patterns that are typical of specific forms of DCM. Patients with late gadolinium enhancement on CMR, who are at greatest arrhythmic risk, have also distinctive ECG features. Future studies in large DCM populations should evaluate the diagnostic and prognostic value of the ECG.

ECG and Biomarker Profile in Patients with Acute Heart Failure: A Pilot Study

Background: Biomarkers, electrocardiogram (ECG) and Holter ECG are basic, accessible and feasible cardiac investigations. The combination of their results may lead to a more complex predictive model that may improve the clinical approach in acute heart failure (AHF). The main objective was to investigate which ECG parameters are correlated with the usual cardiac biomarkers (prohormone N-terminal proBNP, high-sensitive cardiac troponin I) in patients with acute heart failure, in a population from Romania. The relationship between certain ECG parameters and cardiac biomarkers may support future research on their combined prognostic value. Methods: In this prospective case-control study were included 49 patients with acute heart failure and 31 participants in the control group. For all patients we measured levels of prohormone N-terminal proBNP (NT-proBNP), high-sensitive cardiac troponin I (hs-cTnI) and MB isoenzyme of creatine phosphokinase (CK-MB) and evaluated the 12-lead ECG and 24 h Holter monitoring. Complete clinical and paraclinical evaluation was performed. Results: NT-proBNP level was significantly higher in patients with AHF (p < 0.001). In patients with AHF, NT-proBNP correlated with cQTi (p = 0.027), pathological Q wave (p = 0.029), complex premature ventricular contractions (PVCs) (p = 0.034) and ventricular tachycardia (p = 0.048). Hs-cTnI and CK-MB were correlated with ST-segment modification (p = 0.038; p = 0.018) and hs-cTnI alone with complex PVCs (p = 0.031). Conclusions: The statistical relationships found between cardiac biomarkers and ECG patterns support the added value of ECG in the diagnosis of AHF. We emphasize the importance of proper ECG analysis of more subtle parameters that can easily be missed. As a non-invasive technique, ECG can be used in the outpatient setting as a warning signal, announcing the acute decompensation of HF. In addition, the information provided by the ECG complements the biomarker results, supporting the diagnosis of AHF in cases of dyspnea of uncertain etiology. Further studies are needed to confirm long-term prognosis in a multi-marker approach.

Predicting the Progression of Very Early Systemic Sclerosis: Current Insights

Systemic sclerosis (SSc) is a complex autoimmune connective tissue disease with distinct pathological hallmarks (ie, inflammation, vasculopathy, fibrosis) that may predominate at different stages in the disease course with varying severity. Initial efforts to classify patients with SSc identified a subset of patients with very early SSc. These patients possessed signs of SSc (eg, Raynaud phenomenon, SSc specific autoantibodies and/or nailfold capillary abnormalities) without fulfilling complete SSc classification criteria. Recognizing the inherent value in early diagnosis and intervention in SSc, researchers have endeavored to identify risk factors for progression from very early SSc to definite SSc. The present review summarizes the clinical phenotype of patients with very early and early SSc. Through a scoping review of recent literature, this review also describes risk factors for progression to definite SSc with a focus on the specific clinical features that arise early in the SSc disease course (eg, diffuse cutaneous sclerosis, interstitial lung disease, esophageal dysfunction, renal crisis, cardiac involvement). In addition to clinical risk factors, this review provides evidence for how biological data (ie, serological, genomic, proteomic profiles, skin bioengineering methods) can be integrated into risk assessment models in the future. Furthering our understanding of biological features of very early SSc will undoubtedly provide novel insights into SSc pathogenesis and may illuminate new therapeutic targets to prevent progression of SSc.

Fragmented QRS in the relatives of patients with coronary artery disease

Background

Coronary artery disease (CAD) is one of the important causes of mortality. It has been emphasized that the risk of CAD may be increased in the relatives of CAD patients. Fragmented QRS (fQRS) is an electrocardiography (ECG) marker showing myocardial damage.

Methods

A study group of 62 symptomatic individuals (31 males, mean age 38.5 ± 7.12 years) with first‐degree relatives with coronary artery disease and 64 healthy volunteers (24 males, mean age 37.9 ± 11.6 years) were included in this study. The study did not include those with known cardiac disease, metabolic disease, or drug use that may cause a change in ECG parameters.

Results

There was no significant difference between the groups regarding gender, heart rate, QRS complex, QTc, frontal QRS‐T angle, and left ventricle ejection fraction. Compared to the control group, the QT interval and fQRS count were significantly higher in the study group (p < .05 for both). Low‐density lipoprotein cholesterol (LDL‐C), hemoglobin, and neutrophil counts were significantly higher in the study group compared to the control group (p < .05 for all).

Conclusions

Our study showed that fQRS was increased in individuals with symptomatic first‐degree relatives with coronary artery disease compared to healthy volunteers.

Association of QTc Interval and V4-S Wave With Appropriate ICD Therapy in Hypertrophic Cardiomyopathy

Background

Ventricular arrhythmias in patients with hypertrophic cardiomyopathy (HCM) may lead to sudden cardiac death (SCD). We aimed to investigate the relationship between electrocardiogram (ECG) indicators and the risk of appropriate implantable cardioverter-defibrillator (ICD) therapy in HCM.

Methods

The HCM patients receiving ICD implantation were enrolled consecutively. QT interval correction (QTc) was calculated using Bazett's formula. Long or deep S wave in V4 lead was defined as duration time >50 ms and/or voltage amplitude >0.6 mV. The endpoint in our study was at least one ICD appropriate therapy triggered by ventricular tachyarrhythmia (VT) or ventricular fibrillation (VF), including anti-tachyarrhythmia pacing (ATP) and electrical shock.

Results

A total of 149 patients with HCM (mean age 53 ± 14 years, male 69.8%) were studied. Appropriate ICD therapies occurred in 47 patients (31.5%) during a median follow-up of 2.9 years. Cox regression analysis showed that long or deep S wave in V4 lead [hazard ratio (HR) 1.955, 95% confidence interval (CI) 1.017–3.759, P = 0.045] and QTc interval (HR 1.014, 95% CI 1.008–1.021, P < 0.001) were independent risk factors for appropriate ICD therapy. The ROC showed that the optimal cut-off point value for the QTc interval to predict the appropriate ICD therapy was 464 ms, and the AUC was 0.658 (95% CI 0.544–0.762, P = 0.002). The AUC for S wave anomalies in V4 lead was 0.608 (95% CI 0.511–0.706, P = 0.034). We developed a new model that combined the QTc interval and S wave anomalies in V4 lead based on four patient groups. Patients with QTc ≥464 ms and long or deep V4-S wave had the highest risk of developing appropriate ICD therapy (log-rank P < 0.0001). After adding QTc interval and V4-S wave anomalies into the HCM-risk-SCD model, the prediction effect of the new model was significantly improved, and the NRI was 0.302.

Conclusions

In this HCM cohort, QTc and S wave anomalies in V4 lead were found to be significant and strong predictors of the risk of appropriate ICD therapy. Patients with QTc ≥464 ms and long or deep S wave had the highest risk. After QTc interval and V4-S wave anomalies adding to the HCM-risk-SCD model, the prediction effect is significantly improved.

Early Diagnosis of Acute Myocarditis in the ED: Proposal of a New ECG-Based Protocol

The diagnosis of acute myocarditis (AM) is based on a multi-parametric assessment including clinical presentation, ECG, imaging and biomarkers. Fragmented QRS (fQRS) might be an additional diagnostic sign in patients with proven AM. The main objective of this study was to assess the diagnostic yield of fQRS in patients with suspected AM presenting to the emergency department (ED). Patients admitted between January 2016 and March 2021 with a proven diagnosis of AM, according to clinical, cardiac magnetic resonance (CMR) and/or histologic criteria, were included in the analysis. In total, 51 patients were analyzed (41 men, 78%), with a median age of 36 (29–45) years. Thirty-three (65%) patients had prodromal flu-like symptoms. Patients presented to the ED mostly complaining of chest pain (68%) and palpitations (21%). Seven (14%) patients experienced cardiac arrest, one of whom died. At presentation, 40 patients (78%) displayed fQRS, and 10 (20%) presented ventricular arrhythmias. All the surviving patients underwent CMR and displayed late gadolinium enhancement (LGE). ECG leads showed that fQRS matched the LGE distribution in 38 patients (95%). The presence of fQRS is a simple clinical bedside tool to support the initial suspect of AM in the emergency department and to guide the most appropriate clinical workup.

Fragmented QRS complex may predict long-term mortality after isolated surgical aortic valve replacement in patients with severe aortic stenosis

OBJECTIVES

Fragmented QRS (fQRS), related to myocardial fibrosis, is an important prognostic marker of cardiovascular events and mortality. Aortic stenosis (AS), the most frequent valvular heart disease in developed countries, causes myocardial fibrosis due to ventricular pressure overload. The current study aimed to investigate whether fQRS is associated with long-term mortality after isolated surgical aortic valve replacement (SAVR) in patients with severe AS.

METHODS

A total of 289 patients who underwent SAVR for severe AS between May 2009 and January 2020 with interpretable electrocardiogram were included. Patients were divided into 2 groups according to the presence of fQRS. Kaplan-Meier survival analyses were used to detect cumulative survival rates. Univariable and multivariable Cox proportional hazards models were used to determine the predictors of all-cause mortality.

RESULTS

fQRS occurred in 126 (43.5%) patients. A total of 59 (20.4%) patients died over a follow-up period of 54 ± 32 months. All-cause mortality was higher in the fQRS group (23 [14.1%] vs 36 [28.6], log-rank test P = 0.002) in the long term. The presence of fQRS [hazard ratio (HR): 1.802, confidence interval (CI): 1.035-3.135, P = 0.037], electrocardiographic left ventricular strain (HR: 1.836, CI: 1.036-3.254, P = 0.038) and history of stroke or transient ischaemic attack (HR: 3.130, CI: 1.528-6.412, P = 0.002) were independent predictors of all-cause mortality in the multivariable Cox regression model.

CONCLUSIONS

fQRS is associated with a 1.8-fold increase in long-term mortality in patients undergoing isolated SAVR for severe AS. Detecting fQRS in electrocardiograms may provide prognostic information about the long-term outcomes.

Electrocardiography clues in assessment of patients with premature ventricular contractions

Background/aim

Some electrocardiography (ECG) parameters such as Tp-e interval, Tp-e / QT ratio, fragmented QRS (fQRS), and heart rate variability (HRV) are related to cardiovascular mortality and morbidity. We aim to investigate the relation between premature ventricular contraction burden and these parameters on 24-h ECG recording.

Materials and methods

The study is a retrospective investigation of the 24-h Holter ECG and echocardiography of 199 patients who underwent the procedures due to complaints of palpitation. A frequency of < 10% PVCs / 24 h was classified as seldom group (98 patients), while > 10% PVCs / 24 h was designated as frequent group (101 patients).

Results

Tp-e interval was significantly longer (62 [54–78] vs 75 [60–84], p < 0.001), Tp-e / QT ratio was significantly increased (0.18 [0.16–0.20] vs 0.21 [0.18–0.22], p = 0.001) in frequent PVC group. The percentage of fQRS was significantly increased in frequent PVC group (30.6% vs 47.5%, p = 0.015). When the groups were compared, no significant difference was found in HRV time domain indices. Positive correlations were observed between PVC burden and Tp-e (r = 0.304, p < 0.001), Tp-e / QT (r = 0.275, p < 0.001).

Conclusion

Our study showed that Tp-e interval, Tp-e / QT and fQRS are associated with frequency of PVCs. These measurements in patients with PVCs may form part of assessment of cardiovascular risk.

Fragmented QRS is a marker of mortality in patients with severe COVID-19: A retrospective observational study

OBJECTIVE

In this study, we aimed to investigate the association of fragmented QRS (f-QRS) with in-hospital death in patients with severe novel coronavirus disease 2019 (COVID-19).

METHODS

This was a retrospective and observational study. A total of 201 consecutive patients with severe COVID-19 were enrolled. Demographic data, laboratory parameters, medications, electrocardiographic (ECG) findings, and clinical outcomes were recorded. Patients with and without f-QRS were compared, and predictors of all-cause in-hospital mortality were analyzed.

RESULTS

A total of 135 patients without f-QRS (mean age of 64 years, 43% women) and 66 patients with f-QRS (mean age of 66 years, 39% women) were included. C-reactive protein (CRP), D-dimer, troponin I, ferritin levels, and CRP to albumin ratio were significantly higher in patients with f-QRS. The need for invasive mechanical ventilation (63.6% vs. 41.5%, p=0.003) and all-cause in-hospital mortality [54.5% vs. 28.9%, log rank p=0.001, relative risk 1.88, 95% confidence interval (CI) 1.16-4.78] were significantly higher in patients with f-QRS. A number value of f-QRS leads ≥2 yields sensitivity and specificity (85.3% and 86.7%, respectively) for predicting in-hospital all-cause mortality. Multivariable analysis showed that f-QRS (odds ratio: 1.041, 95% Cl: 1.021-1.192, p=0.040) were independently associated with in-hospital death.

CONCLUSION

This study revealed that the presence of f-QRS in ECG is associated with higher in-hospital all-cause mortality in patients with severe COVID-19. f-QRS is an easily applicable simple indicator to predict the risk of death in these patients.

Relation between fragmented QRS complex and cardio-ankle vascular index in asymptomatic subjects

OBJECTIVES

Stiffness of large arteries has been related to cardiovascular mortality. Cardio-ankle vascular index (CAVI) is a novel marker of arterial stiffness. Herein, we aimed to study the relationship between fragmented QRS (fQRS) in electrocardiogram and CAVI.

METHODS

Asymptomatic patients with fQRS and without fQRS were enrolled in the study consecutively. The fQRS complexes were analyzed in the 12-lead electrocardiogram. Arterial stiffness was assessed by using cardio ankle vascular index (CAVI). It was measured by a VaSera VS-1000 CAVI instrument.

RESULTS

CAVI values of the patients with fQRS was significantly higher compared to those without fQRS (8.625 (7.9-9.2) versus 6.65 (6.7-8.4) p < .001). In a univariate analysis, it was revealed that there was a significant correlation between increased CAVI and fQRS, age, and epicardial fat thickness. Multiple binary logistic regression analysis revealed that age [95% confidence interval (CI): 1,068-1.214, p < .001] and fQRS [95% (CI): 1.766-23.117, p: 0.005] were the independent determinants of increased CAVI values.

CONCLUSIONS

ECG is a widely and readily available, inexpensive, reproducible technique that can be examined by almost every physician. fQRS values in electrocardiogram may provide a significant predictive value for arterial stiffness in asymptomatic subjects.

MicroRNA‑331 inhibits isoproterenol‑induced expression of profibrotic genes in cardiac myofibroblasts via the TGFβ/smad3 signaling pathway

Cardiac fibrosis in the failing heart is modulated by activated myofibroblasts, and is a pathology marked by their deposition of extracellular matrix proteins. The TGFβ signaling pathway is important in stimulating fibrosis and therefore seems an attractive new target for anti-fibrotic therapy. The relationship between ncRNAs and TGFβ signaling pathway has been extensively studied. Here, we have provided several lines of evidence to prove that the fibrosis process could be regulated by miR-331 through targeting TGFβ signaling. First, bioinformatics analysis and dual luciferase assay validated a direct interaction between the miR-331 and TGFβ-R1 3'UTR sequence which results in the downregulation of TGFβ signaling pathway. Second, miR-331 expression was inversely related to the expression of a number of genes which are involved in extracellular matrix (ECM) production and deposition processes, both in the in vivo and in vitro fibrosis models. Third, in cultured mouse and human cardiac myofibroblasts (CMyoFbs) under ISO treatment, overexpression of miR-331 decreased the expression level of fibrosis-related genes. Consistently, western blot analysis confirmed that miR-331 overexpression ended in both Smad3 and Col1A1 protein level reduction in mouse cardiac myofibroblasts. Finally, flow cytometry analysis, cyclin D1 and D2 gene expression analysis, and wound-healing assay confirmed the inhibitory effect of miR-331 against cell proliferation and migration in ISO-treated cardiac myofibroblasts. Taken together, accumulative results showed that miR-331 reduced the level of fibrosis-related proteins in cardiac myofibroblasts culture via regulating TGFβ signaling pathway.

Proarrhythmic electrophysiological and structural remodeling in rheumatoid arthritis

Chronic inflammatory disorders, including rheumatoid arthritis (RA), are associated with a twofold increase in the incidence of sudden cardiac death (SCD) compared with the healthy population. Although this is partly explained by an increased prevalence of coronary artery disease, growing evidence suggests that ischemia alone cannot completely account for the increased risk. The present review explores the mechanisms of cardiac electrophysiological remodeling in response to chronic inflammation in RA. In particular, it focuses on the roles of nonischemic structural remodeling, altered cardiac ionic currents, and autonomic nervous system dysfunction in ventricular arrhythmogenesis and SCD. It also explores whether common genetic elements predispose to both RA and SCD. Finally, it evaluates the potential dual effects of disease-modifying therapy in both diminishing and promoting the risk of ventricular arrhythmias and SCD.

A Predictive Model for Super-Response to Cardiac Resynchronization Therapy: The QQ-LAE Score

Objectives

It is important to identify super-responders who can derive most benefits from cardiac resynchronization therapy (CRT). We aimed to establish a scoring model that can be used for predicting super-response to CRT.

Methods

We retrospectively reviewed 387 CRT patients. Multivariate logistic regression analysis was performed to identify predictors for super-response (defined as an absolute increase in left ventricular ejection fraction of ≥15% at 6-month follow-up) and to create a score model. Multivariate Cox proportional-hazard regression analysis was conducted to assess associations with the long-term endpoint (defined as cardiac death/heart transplant, heart failure (HF) hospitalization, or all-cause death) across the score categories at follow-up.

Results

Among 387 patients, 109 (28.2%) met super-response. In multivariable analysis, 5 independent predictors (QQ-LAE) were identified: prior no fragmented QRS (odds ratio (OR) = 3.10 (1.39, 6.94)), QRS duration ≥170 ms (OR = 2.37 (1.35, 4.12)), left bundle branch block (OR = 2.57 (1.04, 6.37)), left atrial diameter <45 mm (OR = 3.27 (1.81, 5.89)), and left ventricular end-diastolic dimension <75 mm (OR = 4.11 (1.99, 8.48)). One point was attributed to each predictor, and three score categories were identified. The proportion of super-response after 6-month CRT implantation in patients with scores 0-3, 4, and 5 was 14.6%, 40.3%, and 64.1%, respectively (P < 0.001). Patients with score 5 had an 88% reduction in the risk of cardiac death/heart transplant (P=0.042), a 71% reduction in the risk of HF hospitalization (P=0.048), and an 89% reduction in the risk of all-cause mortality (P=0.028) compared to patients with scores 0-3.

Conclusions

The QQ-LAE score can be used for prediction of super-response to CRT and selection of most suitable patients in clinical practices.

Fragmented QRS is associated with intraventricular dyssynchrony and independently predicts nonresponse to cardiac resynchronization therapy—Systematic review and meta‐analysis

Background

Fragmented QRS (fQRS) is postulated to be associated with ventricular dyssynchrony and might be able to predict a nonresponse to cardiac resynchronization therapy (CRT) implantation. In this systematic review and meta‐analysis, we aim to assess whether fQRS can be a marker of intraventricular dyssynchronies in patients with ischemic and nonischemic cardiomyopathy and whether it is an independent predictor of nonresponse in patients receiving CRT.

Methods

We performed a comprehensive search on topics that assesses fQRS and its association with intraventricular dyssynchrony and nonresponse to CRT up until September 2019.

Results

Fragmented QRS is associated with intraventricular dyssynchrony (OR 10.34 [3.39, 31.54], p < .001; I²: 80% with sensitivity 76.8%, specificity 77%, LR+ 3.3, and LR− 0.3). Subgroup analysis showed that fQRS is associated with intraventricular dyssynchrony in patients with narrow QRS complex (OR 20.92 [12.24, 35.73], p < .001; I²: 0%) and nonischemic cardiomyopathy (OR of 19.97 [12.12, 32.92], p < .001; I²: 0%). Fragmented QRS was also associated with a higher time‐to‐peak myocardial sustained systolic (Ts‐SD) (OR 15.19 [12.58, 17.80], p < .001; I²: 0% and positive Yu index (OR 15.61 [9.07, 26.86], p < .001; I²: 0%). Fragmented QRS has a pooled adjusted OR of OR of 1.70 [1.35, 2.14], p < .001; I²: 62% for association with a nonresponse to CRT. QRS duration is found to be higher in nonresponders group mean difference −8.54 [−13.38, −3.70], p < .001; I²: 70%.

Conclusion

Fragmented QRS is associated with intraventricular dyssynchrony and is independently associated with nonresponse to cardiac resynchronization therapy.

Fragmented QRS complex in patients with systemic lupus erythematosus at the time of diagnosis and its relationship with disease activity

Objective

Cardiovascular disease is an important contributor to the mortality rate of patients with systemic lupus erythematosus (SLE), which is related to SLE disease activity. Fragmented QRS (fQRS) complexes, defined by additional spikes in the QRS complex, are useful for identifying myocardial scars on electrocardiography and can be an independent predictor of cardiac events. We aimed to assess the relationship between disease activity in patients with SLE and fQRS at the time of diagnosis.

Methods

Forty-four patients with SLE were included. Patients with cardiac diseases, other rheumatic diseases, and prior treatment at the time of electrocardiography measurement were excluded. The appearance of fQRS represented exposure. The primary outcome was SLE Disease Activity Index 2000 (SLEDAI-2K). Multiple regression analysis was conducted to assess the association between fQRS and SLEDAI-2K adjusted for age, sex, and time from the estimated onset date to the date of diagnosis.

Results

Among patients with SLE at diagnosis, 26 (59.1%) had fQRS. The median SLEDAI-2K was 18 (interquartile range [IQR], 12–22) and 9 (IQR, 8–15) in the fQRS(+) and fQRS(-) groups, respectively. SLEDAI-2K was significantly higher in the fQRS(+) group than in the fQRS(-) group (regression coefficient, 2.69; 95% confidence interval, 0.76–4.61; p = 0.008).

Conclusion

Our results suggested that fQRS(+) patients with SLE had high disease activity. fQRS could likely detect subclinical myocardial involvement in patients with SLE and predict long-term occurrence of cardiac events.

The prevalence of fragmented QRS and its relationship with left ventricular systolic function in chronic kidney disease

Objective

To investigate the prevalence of fragmented QRS (fQRS) on electrocardiograms (ECG) in patients with different stages of chronic kidney disease (CKD) and to examine the association between fQRS and left ventricular systolic function.

Methods

This retrospective study analysed clinical and laboratory data from consecutive patients with CKD. The relationship between fQRS and left ventricular systolic function was evaluated using univariate and multivariate logistic regression analyses.

Results

A total of 310 patients (186 males; mean ± SD age, 52.24 ± 15.72 years) with CKD participated in this study. The prevalence of fQRS was 30.32% (94 of 310 patients). The prevalence of fQRS was more common in the inferior leads (53.19%; 50 of 94) compared with the anterior leads (21.28%; 20 of 94) and the lateral leads (25.53%; 24 of 94). Multivariate logistic regression analysis showed that left ventricular ejection fraction (odds ratio [OR] 1.356; 95% confidence interval [CI] 1.022, 2.036) and coronary artery disease (OR 2.355; 95% CI 1.056, 5.251) were independent risk factors of fQRS in patients with CKD.

Conclusion

The fQRS was prevalent in patients with CKD regardless of the CKD stage.

Electrocardiographic Fragmented Activity (II): A Machine Learning Approach to Detection

Hypertrophic cardiomyopathy, according to its prevalence, is a comparatively common disease related to the risk of suffering sudden cardiac death, heart failure and stroke. This illness is characterized by the excessive deposition of collagen among healthy myocardium cells. This situation, which is medically known as fibrosis, constitutes effective conduction obstacles in the myocardium electrical path, and when severe enough, it can be outlined as additional peaks or notches in the QRS, clinically entitled as fragmentation. Nowadays, the fragmentation detection is performed by visual inspection, but the fragmented QRS can be confused with the noise present in the electrocardiogram (ECG). On the other hand, fibrosis detection is performed by magnetic resonance imaging with late gadolinium enhancement, the main drawback of this technique being its cost in terms of time and money. In this work, we propose two automatic algorithms, one for fragmented QRS detection and another for fibrosis detection. For this purpose, we used four different databases, including the subrogated database described in the companion paper and incorporating three additional ones, one compounded by more accurate subrogated ECG signals and two compounded by real and affected subjects as labeled by expert clinicians. The first real-world database contains QRS fragmented records and the second one contains records with fibrosis and both were recorded in Hospital Clínico Universitario Virgen de la Arrixaca (Spain). To deeply analyze the scope of these datasets, we benchmarked several classifiers such as Neural Networks, Support Vector Machines (SVM), Decision Trees and Gaussian Naïve Bayes (NB). For the fragmentation dataset, the best results were 0.94 sensitivity, 0.88 specificity, 0.89 positive predictive value, 0.93 negative predictive value and 0.91 accuracy when using SVM with Gaussian kernel. For the fibrosis databases, more limited accuracy was reached, with 0.47 sensitivity, 0.91 specificity, 0.82 predictive positive value, 0.66 negative predictive value and 0.70 accuracy when using Gaussian NB. Nevertheless, this is the first time that fibrosis detection is attempted automatically from ECG postprocessing, paving the way towards improved algorithms and methods for it. Therefore, we can conclude that the proposed techniques could offer a valuable tool to clinicians for both fragmentation and fibrosis diagnoses support.

Simple Electrocardiographic Score Can Predict Left Ventricular Reverse Remodeling in Patients With Non-Ischemic Cardiomyopathy

Background: Left ventricular reverse remodeling (LVRR) is a favorable response in non-ischemic, non-valvular cardiomyopathy (NICM) patients. Recently, 18-lead body surface electrocardiography (ECG), the standard 12-lead ECG with synthesized right-sided/posterior chest leads, has been developed, but its predictive value for LVRR has not been evaluated.

Methods and Results: Of 216 consecutive hospitalized NICM patients with LV ejection fraction (LVEF) ≤35%, we studied 125 who received optimization of their heart failure treatment and had 18-lead ECG and echocardiography data available for evaluating LVRR, defined as an absolute increase in LVEF ≥10% concomitant with LVEF ≥35% after 1-year optimized treatment. Most 18-lead ECG parameters in the NICM patients differed from those in 312 age- and body mass index-matched subjects with normal echocardiography. LVRR occurred in 59 NICM patients and they had a larger QRS amplitude in the limb leads (I, II, aVR, and aVF), precordial leads (V3–V6), and synthesized leads (syn-V4R–5R), decreased QRS axis and duration, and lower prevalence of fragmented QRS than those without LVRR. The ECG score using 3 selected parameters (QRS amplitude in aVR ≥675 µV; QRS duration <106 ms without fragmentation; and QRS axis <67°) was associated with the incidence of LVRR even after adjusting for optimized treatment.

Conclusions: The standard 12-lead ECG parameters are sufficiently predictive of LVRR in NICM patients.

The prognostic value of fragmented QRS in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Although transcatheter aortic valve implantation (TAVI) can successfully correct aortic narrowing, pre-existing pathophysiological alterations in the left ventricle are still a concern in terms of long-term mortality. This study aimed to examine the predictive role of fQRS morphology on long-term prognosis in patients undergoing TAVI due to severe aortic stenosis.

METHODS

A total of 117 patients undergoing TAVI due to severe aortic stenosis were included in this retrospective cohort study. Patients were assigned into two groups based on the presence (n = 36) or absence (n = 81) of fQRS. Predictors of long-term survival were estimated.

RESULTS

In-hospital mortality was higher in fQRS group (5.5% vs. 1.2%, p = 0.0224). In the long-term, fQRS (OR: 3.06, 95% CI 1.29-7.27, p: 0.01), LVEF <50% (OR: 2.54, 95% CI 1.07-6.02, p: 0.03) and presence of atrial fibrillation (OR: 2.42, 95% CI 1.05-5.60, p: 0.03) emerged as significant independent predictors of short survival.

CONCLUSION

Presence of fQRS on ECG, an indirect indicator of myocardial fibrosis, seems to have the potential to be used as a prognostic marker after TAVI procedure. Large prospective studies are warranted.

Investigation of mindin levels in hypertensive patients with left ventricular hypertrophy and QRS fragmentation on electrocardiography

PURPOSE

Mindin was associated with diabetic nephropathy, podocyte injury, colitis, allergic asthma, liver ischaemia and reperpusion injury and ischaemic brain injury. On the other hand, it was reported as a protective factor against obesity, cardiac hypertrophy, fibrosis and remodelling. Fragmented QRS complexes (fQRS) are markers of altered ventricular depolarisation owing to a prior myocardial scar and fibrosis. In this study, we aimed to investigate mindin levels in hypertensive patients with left ventricular hypertrophy and fQRS on electrocardiography.

METHODS

This observational case-control study enrolled 70 (36 female) hypertensive patients with fQRS and 38 (23 female) hypertensive control patients. All patients were evaluated by transthoracic echocardiography. Mindin levels were measured by the enzyme-linked immunosorbent assay (ELISA). Clinical, echocardiographic and laboratory data were compared between patient and control groups.

RESULTS

There was no significant difference between patient and control groups in terms of clinical, echocardiographic and routine laboratory parameters. The mindin levels were significantly higher in the patient group than controls (11.3 (7.21-19.31) vs 4.15 (2.86-6.34); p < .001). Multiple logistic regression analyses defined increased mindin levels as an independent predictor for the presence of fQRS (Odds ratio: 1.733; p = .034). Mindin levels >6.74 predicted the presence of fQRS with a sensitifity of 84.3% and specificity of 79.9% on receiver operating characteristic (ROC) curve analysis (The area under the curve:0.889; Confidence Interval: 0.827-0.951; p < .001).

CONCLUSION

Mindin expressin is upregulated in hypertensive patients with fQRS complexes. In contrary to previous studies, increased mindin levels may be associated with myocardial fibrosis.

Could fragmented QRS predict mortality in aortic stenosis patients after transcatheter aortic valve replacement?

BACKGROUND

Fragmented QRS evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. The prognostic value of that marker has been demonstrated, particularly, in cardiac diseases that accompany myocardial scar and fibrosis. Myocardial fibrosis is also an issue in patients with aortic stenosis. In this study, we wanted to determine whether fragmented QRS could predict all-cause mortality in aortic stenosis patients after transcatheter aortic valve replacement (TAVR).

METHOD

In this study, we evaluated a total of 116 eligible patients on whom we performed TAVR between 2014 and 2018. Patients' demographic and clinical findings, echocardiography results, in-hospital and 30-day mortality, long-term survival statuses were noted. Patient's ECGs before the procedure were evaluated in regard to the occurrence of fragmented QRS. Predictors of mortality were evaluated using univariable and multivariable Cox regression analysis.

RESULTS

The study population consisted of 116 patients of median age 79 (IQR 75-83), 64 females (55.2%). Mortality occurred in 27 (23%) patients; median follow-up time was 319 (IQR 122-719) days. Fragmented QRS was observed in 44 out of 116 (37.9%) patients. The presence of a fragmented QRS (HR = 2.178, 95% CI 0.999-4.847, p = 0.050), a history of stroke (HR = 3.463, 95% CI 1.276-9.398, p = 0.015), and the creatinine levels at admission (HR = 2.198, 95% CI 1.068-4.520, p = 0.030) were associated with the long-term mortality in multivariable Cox regression analysis.

CONCLUSION

Like in the case of the other diseases associated with myocardial fibrosis, fragmented QRS could also predict mortality in aortic stenosis patients after TAVR procedure.

Electrocardiogram changes and atrial arrhythmias in individuals carrying sodium channel SCN5A D1275N mutation

INTRODUCTION

The cardiac sodium channel SCN5A regulates atrioventricular and ventricular depolarization as well as cardiac conduction. Patients with cardiac electrical abnormalities have an increased risk of sudden cardiac death (SCD) and cardio-embolic stroke. Optimal management of cardiac disease includes the understanding of association between the causative mutations and the clinical phenotype. A 12-lead electrocardiogram (ECG) is an easy and inexpensive tool for finding risk patients.

MATERIALS AND METHODS

A blood sample for DNA extraction was obtained in a Finnish family with 43 members; systematic 12-lead ECG analysis was performed in 13 of the family members carrying an SCN5A D1275N mutation. Conduction defects and supraventricular arrhythmias, including atrial fibrillation/flutter, atrioventricular nodal re-entry tachycardia (AVNRT) and junctional rhythm were searched for.

RESULTS

Five (38%) mutation carriers had fascicular or bundle branch block, 10 had atrial arrhythmias; no ventricular arrhythmias were found. Notching of the R- and S waves - including initial QRS fragmentation - and prolonged S-wave upstroke were present in all the affected family members. Notably, four (31%) affected family members had a stroke before the age of 31 and two experienced premature death.

CONCLUSIONS

A 12-lead ECG can be used to predict arrhythmias in SCN5A D1275N mutation carriers. Key messages The 12-lead ECG may reveal cardiac abnormalities even before clinical symptoms occur. Specific ECG findings - initial QRS fragmentation, prolonged S-wave upstroke as well as supraventricular arrhythmias - were frequently encountered in all SCN5A D1257N mutation carriers. ECG follow-up is recommended for all SCN5A D1275N mutation carriers.

The relation between coronary artery disease severity and fragmented QRS complex in patients with left bundle branch block

Background

The diagnosis of coronary artery disease (CAD) in patients with LBBB represents a clinical challenge. The presence of fragmented QRS (fQRS) complex on surface ECG may be related to myocardial ischemia, scarring or fibrosis.

Objectives

To investigate the relation between fQRS and the presence and severity of CAD in patients with LBBB.

Patients and methods

56 patients with symptoms suggesting CAD and complete LBBB were submitted to full history taking and clinical examination, complete 12-leads electrocardiography (ECG) to confirm the diagnosis of LBBB and to diagnose the fragmented wide QRS (f-wQRS) complex, echocardiography, and coronary angiography; lesions with ⩾70% narrowing in major epicardial artery or ⩾50% narrowing in the left main coronary artery were considered significant; and Gensini score was calculated. Patients were classified into two groups according to the presence or absence of f-wQRS.

Results

There were significantly more patients with obstructive CAD among patients with f-wQRS (p = 0.000053). Gensini score was significantly higher in patients with than in patients without fwQRS (p < 0.00001). f-wQRS was the only significant independent predictor of obstructive CAD. Sensitivity of f-wQRS in predicting obstructive CAD was 80.1%, specificity was 73.3%, positive predictive value was 72.4%, negative predictive value was 81.5%, and overall accuracy was 76.8%, p = 0.0022.

Conclusion

Seeking for f-wQRS in patients with LBBB and suspected CAD is a simple, easy, available, method that may be helpful in noninvasive prediction of obstructive CAD.

Prognostic Significance of Fragmented QRS in Patients with Hypertrophic Cardiomyopathy

OBJECTIVES

The relationship between a fragmented QRS (fQRS) and clinical outcomes in patients with hypertrophic cardiomyopathy (HCM) remains unclear. This study aimed to investigate the prognostic significance of fQRS in patients with HCM.

METHODS

Between 2000 and 2012, 326 unrelated patients with HCM (72% male with a mean age of 52 years) were included and were divided into 2 groups: those with fQRS and those without fQRS.

RESULTS

A total of 105/326(32.2%) patients with HCM presented with fQRS at enrollment. During a follow-up of 5.3 ± 2.4 years, 33 patients died, 30 of cardiovascular disease (CVD). Cox regression analysis revealed that fQRS predicted a higher risk of all-cause mortality (adjusted hazard ratio [HR] 2.24; 95% confidence interval [CI] 1.08-4.64; p = 0.030) and CVD mortality (adjusted HR 2.68; 95% CI 1.22-5.91; p = 0.014). Our study also showed that fQRS increased the risk of heart failure-related death (adjusted HR 3.75; 95% CI 1.24-11.30; p = 0.019).

CONCLUSIONS

Our results indicate that fQRS is associated with adverse clinical outcomes in patients with HCM.

Assessment of the association between the presence of fragmented QRS and the predicted risk score of sudden cardiac death at 5 years in patients with hypertrophic cardiomyopathy

OBJECTIVE

It has been shown that the presence of fragmented QRS (fQRS) is associated with poor prognosis in many cardiovascular diseases and in patients with hypertrophic cardiomyopathy (HCM). However, no study has shown an association with the absolute risk score of sudden cardiac death. The aim of this study was to determine the relationship between QRS and the predicted risk score of sudden cardiac death at 5 years (HCM Risk-SCD) in HCM patients.

METHODS

In total, 115 consecutive HCM patients were included in this prospective observational study. The patients were divided into two groups according to the presence [fQRS(+) group (n=65)] or absence [fQRS(-) group (n=50)] of fQRS on a 12-lead electrocardiogram (ECG).

RESULTS

The HCM Risk-SCD (%) HCM Risk-SCD (>6%) values and some echocardiographic parameters, including ventricular extrasystole, ventricular tachycardia, cardiopulmonary resuscitation, implantable cardioverter defibrillator implantation, appropriate shock, and heart failure at the time of admission, were significantly higher in the fQRS(+) group than in the fQRS(-) group (all p<0.05). Both univariate and multivariate analyses revealed fQRS and New York Heart Association (NYHA) class as independent predictors of HCM Risk-SCD. In a receiver operating characteristic (ROC) curve analysis, an HCM Risk-SCD value of >4 was identified as an effective cut-off point in fQRS for HCM. An HCM Risk-SCD value of >4 yielded a sensitivity of 77% and a specificity of 76%.

CONCLUSION

fQRS is determined to be an independent high-risk indicator of HCM Risk-SCD. It seems to be associated with increased ventricular arrhythmias and some echocardiographic parameters.

Fragmented QRS complex as a predictor of coronary artery disease in patients with acute coronary syndrome (A study from Egypt)

Methods

Two groups according to the presence of fQRS in ECG.

Results

fQRS has higher sensitivity for LAD, LCX &RCA, more specific for LAD.

Conclusions

fQRS is a good, simple, applicable positive test to predict the presence of significant CAD in acute coronary syndrome (ACS), even without enzyme elevation.

Utility of High-Resolution Magnetocardiography to Predict Later Cardiac Events in Nonischemic Cardiomyopathy Patients With Normal QRS Duration

BACKGROUND

Nonischemic dilated cardiomyopathy (NIDCM) patients, even those with a narrow QRS, are at increased risk for major adverse cardiac events (MACE). We hypothesized that 64-channel magnetocardiography (MCG) would be useful to detect prognostic left intraventricular disorganized conduction (LiDC) by overcoming the limitations of fragmented QRS (fQRS, qualitative definitions, low specificity) and late potential (abnormality undetectable in earlier QRS).Methods and Results:We evaluated LiDC on MCG, defined as significant deviation from a global clockwise left ventricular (LV) activation pattern, and conventional noninvasive predictors of MACE, including fQRS and late potential, in 51 NIDCM patients with narrow QRS (LV ejection fraction, 22±7%; QRS duration, 99±11 ms). MACE was defined as cardiac death, lethal ventricular arrhythmias, or LV assist device (LVAD) implantation. LiDC was present in 22 patients. Baseline characteristics were comparable between patients with and without LiDC, except for the ratio of positive late potential. During a mean follow-up of 2.9 years, MACE developed in 16 NIDCM patients (3 cardiac deaths, 9 lethal ventricular arrhythmias, and 4 LVAD). MACE was more incident in patients with LiDC (13/22) than in those without (3/29, P<0.001). Multivariate analysis revealed LiDC, but not fQRS or late potential, as the strongest independent predictor of MACE (hazard ratio 4.28, 95% confidence interval 1.30-19.39, P=0.015).

CONCLUSIONS

MCG accurately depicts LiDC, a promising noninvasive predictor of MACE in patients with NIDCM and normal QRS.

[Fragmented QRS. Relevance in clinical practice]

The QRS complex represents the electrical depolarization of ventricular myocardium. In the case of an undisturbed depolarization, the QRS complex has a normal configuration and duration, but abnormal electrical conduction leads to widening of the QRS complex. The block of one of the Tawara branches results in a typical bundle branch block pattern. A QRS complex that cannot be classified as bundle branch block due to an atypical configuration and contains notched R or S waves is called a fragmented QRS. The underlying pathophysiologies are manifold and include myocardial scars induced by ischemic heart disease, myocardial fibrosis due to other diseases, primary cardiac pathologies as well as systemic diseases with cardiac involvement. Pathologies on the cellular level, such as ion channel dysfunctions, also correlate with fragmented QRS. Besides the diagnostic relevance, fragmented QRS is known to have prognostic properties, for example in identifying high risk patients with coronary artery disease, cardiomyopathy, Brugada syndrome and acquired long QT syndrome; however, fragmented QRS may also be detected in ECGs of healthy individuals.

Fragmented QRS as a Marker of Electrical Dyssynchrony to Predict Inter-Ventricular Conduction Defect by Subsequent Echocardiographic Assessment in Symptomatic Patients of Non-Ischemic Dilated Cardiomyopathy

Background

Left ventricular (LV) dyssynchrony frequently occurs in patients with heart failure (HF). QRS ≥ 120 ms is a surrogate marker of electrical dyssynchrony, which occurs in only 30% of HF patients. In contrary, in those with normal QRS (nQRS) duration, LV dyssynchrony has been reported in 20-50%. This study was carried out to investigate the role of fragmented QRS (fQRS) on the surface electrocardiography (ECG) as a marker of electrical dyssynchrony to predict the presence of significant intraventricular dyssynchrony (IVD) by subsequent echocardiographic assessment.

Methods

A total of 226 consecutive patients with non-ischemic cardiomyopathy were assessed for fQRS on surface ECG as defined by presence of an additional R wave (R prime), notching in nadir of the S wave, notching of R wave, or the presence of more than one R prime (fragmentation) in two contiguous leads corresponding to a major myocardial segment. Tissue Doppler imaging (TDI) was performed in the apical views (four-chamber, two-chamber and long-axis) to analyze all 12 segments at both basal and middle levels. Time-to-peak myocardial sustained systolic (Ts) velocities were calculated. Significant systolic IVD was defined as Ts-SD > 32.6 ms as known as “Yu index”.

Result

Of the total patients, 112 had fQRS (49.5%), while 114 had nQRS (50.5%) with male dominance (M/F = 71:29). Majority of patients were in NYHA class II (n = 122, 54%) followed by class III (n = 83; 37%), and class IV (n = 21; 9%). There were no significant differences among both groups for baseline parameters except higher QRS duration (102.42 ± 14.05 vs. 91.10 ± 13.75 ms; P = 0.001), higher Yu index (35.64 ± 12.79 vs. 20.45 ± 11.17; P = 0.01) and number of patients with positive Yu index (78.6% vs. 21.1%; P = 0.04) in group with fQRS compared with group with nQRS. fQRS complexes had 84.61% sensitivity and 80.32% specificity with positive predictive value of 78.6% and negative predictive value of 85.9% to detect IVD. On detailed segmental analysis for fQRS distribution, inferior segment had maximum (37%), followed by anterior (23%), lateral (19%), inferior and lateral (11%), anterior and inferior (8%), and anterior and lateral (2%). Among 104 patients with significant dyssynchrony, 88 patients (84.6%) had fQRS in the dyssynchronic segment.

Conclusion

Fragmentation of QRS complex is an important predictor of electro-mechanical dyssynchrony. It is also helpful in localizing the dyssynchronous segment. In future, larger studies may be carried out to investigate the role of fQRS as a predictor of response to cardiac resynchronization therapy (CRT) in this subgroup of HF patients with narrow QRS.

Frequency of fragmented QRS in patient with psoriasis vulgaris without cardiovascular disease

Myocardial fibrosis causes the fragmentation of QRS complexes on electrocardiogram. We hypothesized that the frequency of fragmented QRS (fQRS) could be more common in patients with psoriasis vulgaris than in healthy control subjects. In this prospective study, 100 patients with psoriasis vulgaris who did not have any cardiovascular disease were compared with 50 healthy volunteers in control group. The Psoriasis Area Severity Index (PASI) was used for expressing the severity of psoriasis. Patients with psoriasis were categorized according to presence of fQRS in ECG [fQRS (+) group and fQRS (-) group]. Patients with psoriasis had higher frequency of fQRS, higher levels of C reactive protein (CRP) and sedimentation rate (ESR) than the control group (n = 49, 49 % vs. n = 3, 6 %, p < 0.001; 9.91 ± 17.86 vs. 3.59 ± 0.79 mg/dL, p = 0.014; 17.37 ± 17.40 vs. 5.66 ± 5.22 mm/h, p < 0.001, respectively). Within the patient group there was no statistically significant difference between fQRS (+) and fQRS (-) subgroups with regards to sex, disease duration, CRP, ESR, medications and PASI score. It was suggested that presence of fQRS in ECG may be related with myocardial fibrosis in patients with psoriasis who do not have cardiovascular disease. For this reason, in our opinion, fQRS could be used as a predictive marker for myocardial fibrosis in patients with psoriasis.

Fragmented QRS frequency in patients with cardiac syndrome X

Objective:

Cardiac syndrome X (CSX) is characterised by typical exertional chest pain, a positive response to exercise testing, and a normal coronary angiography. The relationship of CSX with myocardial fibrosis and ischemia has been clearly demonstrated in previous studies. In addition, fragmented QRS (fQRS) has been reported in the literature as an indicator of myocardial fibrosis. The aim of this study was to investigate the frequency of fQRS in patients with CSX.

Methods:

This prospective case-control study included 37 patients (CSX group) with typical complaints of angina, ischemia on an exercise test, and normal coronary arteries as detected by angiography and 47 patients (control group) with normal coronary arteries. Echocardiographic examinations were performed according to the recommendations of the American Society of Echocardiography. Continuous variables were expressed as mean±standard deviation (SD), and the qualitative variables were expressed as a percentage or ratio. Data were compared statistically with Shapiro–Wilk test, Student’s t-test, Mann-Whitney U, chi-square and Fisher exact test.

Results:

There was no significant difference between the CRX and control groups with respect to basic characteristics such as age and sex. fQRS and the frequency of its presentation with stable angina pectoris at the clinic were significantly higher in the CSX group than in the control group (p values: 0.001 and <0.001, respectively).

Conclusion:

A close follow-up would be useful in CSX patients in whom fQRS is detected in an electrocardiogram (ECG) because of the association between fQRS and poor prognosis with respect to the prevention of late complications. We believe that the presence of fQRS in the ECG aids in the diagnosis of CSX in clinical practice and in the recognition of this group of patients. (Anatol J Cardiol 2016; 16: 616-20)

Relationship between fragmented QRS and paradoxical septal motion in coronary artery bypass graft patients

OBJECTIVE

Paradoxical septal motion (PSM) can cause confusion in the assessment of ventricular function with scintigraphy even in the absence of ventricular septal damage and ischemia. Fragmented QRS (fQRS) is associated with various cardiac disorders. In this study, we aimed to determine the correlation between paradoxical septal motion and fQRS after coronary artery bypass grafting (CABG).

METHODS

We retrospectively reviewed the hospital records showing scintigraphic images and electrocardiograms (ECG) of the patients who had undergone CABG. The patients were classified based on the evaluation of motion and thickening of the septal wall. The patients with regular thickening of the septal wall and abnormal motion were classified as PSM (+) group. The patients with normal motion and thickening of the septal wall were classified as PSM (-) group. fQRS complexes are defined as various RSR patterns either with or without Q-waves on a 12-lead resting ECG.

RESULTS

PSM was found to be more common in fQRS patients (p < 0.001). PSM was seen in 91.4 % of cases with fQRS and in 79.8 % of cases without fQRS. No significant differences were found in the phase analysis parameters. A correlation was found between septal wall motion values and the presence of fQRS (r = 0.197, p = 0.012).

CONCLUSION

fQRS was associated with PSM. fQRS may cause PSM in patients with CABG without left bundle branch block due to a conduction defect. PSM and fQRS are predictive of cardiac mortality. Patients diagnosed with PSM and fQRS, should be monitored closely.

Radiotherapy Induces Development of Fragmented QRS in Patients with Breast Cancer

BACKGROUND

Myocardial fibrosis is a well-known side effect of radiotherapy. Fragmented QRS (fQRS) has been shown to be a marker of myocardial fibrosis. We postulated that radiotherapy induces development of fQRS in breast cancer patients.

PATIENTS AND METHODS

Breast cancer patients receiving locoregional radiotherapy were enrolled. Patients who had fQRS on electrocardiography (ECG) before radiotherapy were excluded. All patients were revaluated for the development of fQRS at 1-year follow-up. An age-matched healthy group served as controls.

RESULTS

A total of 52 breast cancer patients receiving locoregional radiotherapy were included (median age 49 years, interquartile range (IQR) 13). Of these, 19 (37%) had developed fQRS at 1-year follow-up. Compared with the control group, prevalence of fQRS was significantly higher in the irradiated group (37 vs. 12%; p < 0.002). Median total cardiac radiation dose was significantly higher in patients who had developed fQRS (5 Gy, IQR 5.2 vs. 1.7 Gy, IQR 4.4; p = 0.003). Cardiac radiation dose, entered either as a continuous variable (odds ratio (OR) 1.35, 95% confidence interval (CI) 104-1.74) or as a dichotomized variable (≥ 2.2 Gy, OR 6.48, 95% CI 1.47-28.61), was independently associated with the development of fQRS at 1-year follow-up.

CONCLUSION

Radiotherapy for breast cancer induces development of fQRS on ECG. Cardiac radiation dose is independently associated with the development of fQRS.

Pathophysiological links, echocardiographic characteristics, and clinical implications of QRS morphology in patients with dilated cardiomyopathy

Heart failure is an important clinical problem worldwide. There is great interest in evaluating the relationship between electrocardiographic variations and dilated cardiomyopathy (DCM) since it has been used as a predictor of increased morbidity and mortality. The presence of fragmentation in the QRS complexes on 12-lead electrocardiogram (ECG) was reported as a marker of depolarization abnormality in patients with DCM. Previous studies have investigated the relation between QRS morphology and DCM. QRS morphology and duration are associated with clinical deterioration and increased mortality in patients with DCM. Although surface ECG provides valuable information on prognosis of these patients, echocardiographic methods have been used for further investigation of patients with DCM. The aim of the present review is to provide an overview of the pathophysiological links, echocardiographic characteristics and clinical implications of QRS morphology in patients with DCM.