Fragmented ECG as a risk marker in cardiovascular diseases

Significance of dynamic changes in the fragmented QRS complex in acute pulmonary embolism

BACKGROUND

Dynamic changes in the fQRS complex between the initial and follow-up ECG in patients with acute pulmonary embolism (APE) have rarely been studied.

OBJECTIVE

The purpose of this study was to investigate the significance of dynamic changes in the fragmented QRS complex in APE patients.

METHODS

APE patients (n = 222) were divided into three groups based on their ECG data to determine whether there were dynamic changes in the fQRS complex from admission to follow-up at one month: the fQRS shallower group (n = 49), fQRS deeper group (n = 25) and fQRS unchanged group (n = 148). Each patient was observed and followed for 12 months.

RESULTS

Cox multivariate logistic regression analysis indicated that the dynamic deeper fQRS complex was an independent predictor of long-term mortality (HR: 5.563, 95 % CI: 1.079-28.678, P = 0.040) in patients with APE. Kaplan-Meier curve analysis revealed that the event-free survival of the fQRS shallower group significantly increased relative to that of the fQRS deeper group and that of the fQRS deeper group significantly decreased relative to that of the fQRS unchanged group and shallower group (P = 0.022, P = 0.041).

CONCLUSION

Compared with the deeper fQRS complex, the dynamic shallower fQRS complex was an indicator of a good prognosis in APE patients, while the dynamic deeper fQRS complex indicated a poor prognosis. Dynamical changes in fQRS may assist clinicians in risk stratification and individualized treatment for APE, as well as in predicting APE regression or progression.

Beating the heart failure odds: long-term survival after myocardial ischemia in juvenile rainbow trout

Salmonid fish include some of the most valued cultured fish species worldwide. Unlike most other fish, the hearts of salmonids, including Atlantic salmon and rainbow trout, have a well-developed coronary circulation. Consequently, their hearts' reliance on oxygenation through coronary arteries leaves them prone to coronary lesions, believed to precipitate myocardial ischemia. Here, we mimicked such coronary lesions by subjecting groups of juvenile rainbow trout to coronary ligation, assessing histomorphological myocardial changes associated with ischemia and scarring in the context of cardiac arrhythmias using electrocardiography (ECG). Notable ECG changes resembling myocardial ischemia-like ECG in humans, such as atrioventricular blocks and abnormal ventricular depolarization (prolonged and fragmented QRS complex), as well as repolarization (long QT interval) patterns, were observed during the acute phase of myocardial ischemia. A remarkable 100% survival rate was observed among juvenile trout subjected to coronary ligation after 24 wk. Recovery from coronary ligation occurred through adaptive ventricular remodeling, coupled with a fast cardiac revascularization response. These findings carry significant implications for understanding the mechanisms governing cardiac health in salmonid fish, a family particularly susceptible to cardiac diseases. Furthermore, our results provide valuable insights into comparative studies on the evolution, pathophysiology, and ontogeny of vertebrate cardiac repair and restoration.NEW & NOTEWORTHY Juvenile rainbow trout exhibit a remarkable capacity to recover from cardiac injury caused by myocardial ischemia. Recovery from cardiac damage occurs through adaptive ventricular remodeling, coupled with a rapid cardiac revascularization response. These findings carry significant implications for understanding the mechanisms governing cardiac health within salmonid fishes, which are particularly susceptible to cardiac diseases.

Association between uterine leiomyoma and fragmented QRS waves: a prospective case-control study

OBJECTIVE

The aim of this study was to evaluate the relationship between uterine leiomyoma and fragmented QRS, a non-invasive indicator of cardiovascular risk and myocardial ischemia, in women with uterine leiomyoma.

METHODS

In this prospective case-control study, a total of 47 patients diagnosed with uterine leiomyoma (case group) and 47 healthy individuals without uterine leiomyoma (control group) who had undergone bilateral tubal ligation surgery were included. Various demographic, clinical, and laboratory parameters and the presence of fragmented QRS were recorded.

RESULTS

The leiomyoma group showed significantly higher body mass index (27.46±2.18 vs. 25.9±2.87 kg/m2, p=0.005) and waist circumference (91.34±9.30 vs. 84.97±9.3 cm, p=0.001) compared with the control group. Uterine volumes were also significantly higher in the leiomyoma group (235.75±323.48 vs. 53.24±12.81 mm3, p<0.001). The presence of fragmented QRS was detected in 18.1% of the patients. Multiple regression analysis identified age, fasting blood glucose value, and the presence of fragmented QRS as independent risk factors for the presence of leiomyoma.

CONCLUSION

This study provides valuable insights into the relationship between uterine leiomyoma and fragmented QRS. The presence of fragmented QRS was identified as an independent risk factor for the presence of leiomyoma. Further research is needed to better understand the underlying mechanisms connecting uterine leiomyoma and cardiovascular health.

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.

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.

Clinical and electrocardiographic correlates of myocardial dysfunction after COVID-19 in nonhospitalised patients in long-term follow-up. Data from the polish long-covid cardiovascular study

Clinical evidence indicates that COVID-19 is a multiorgan disease that significantly impacts the cardiovascular system. However, little is known about the predictors of myocardial dysfunction after SARS-CoV-2 infection. Therefore, this research aimed to evaluate the clinical and electrocardiographic correlates of myocardial dysfunction after SARS-CoV-2 infection in nonhospitalised patients without previously diagnosed cardiovascular disease. This observational study included 448 patients selected from the database of 4142 patients in the Polish Long-Covid Cardiovascular study. All patients underwent a 12-lead electrocardiogram (ECG); 24-h Holter ECG monitoring, 24/7 ambulatory blood pressure monitoring, echocardiography, and cardiac magnetic resonance imaging. According to the results of diagnostic tests, patients were divided into two groups depending on the occurrence of myocardial dysfunction after COVID-19. Group 1-without myocardial dysfunction after COVID-19-consisted of 419 patients, with a mean age of 48.82 (SD ± 11.91), and Group 2 (29 patients)-with myocardial dysfunction after COVID-19, with a mean age of 51.45 (SD ± 12.92). When comparing the analysed groups, there were significantly more men in Group 2 (p = 0.006). QRS (corresponds to the time of ventricular contraction in an electrocardiographic examination) fragmentation (p = 0.031), arrhythmias (atrial fibrillation, supraventricular extrasystole, ventricular extrasystole) (p = 0.008), and male gender (p = 0.007) were independently associated with myocardial dysfunction after COVID-19. The study showed that myocardial damage after COVID-19 affects men more often and is independent of typical clinical factors and the severity of the disease course. The QRS fragmentation and arrhythmias observed in the ECG indicate the possibility of myocardial dysfunction in patients after COVID-19, which may be a valuable marker for physicians.

QRS fragmentation versus QRS prolongation in predicting right ventricular enlargement and dysfunction in children and adults with repaired Tetralogy of Fallot

Patients with repaired Tetralogy of Fallot (rTOF) have risks of late life-threatening sequelae, including right ventricular (RV) dilation and failure, arrhythmias, and sudden death. QRS prolongation is a well-known ECG predictor of these outcomes but has poor sensitivity for mortality. Growing evidence demonstrates QRS fragmentation (fQRS) as a better prognostic marker for mortality in adults with rTOF, though the two markers have not been directly compared as correlates for CMR abnormalities. Additionally, fQRS has never been studied in pediatric TOF. This single institution retrospectively reviewed 138 CMRs in rTOF patients (median age 21.7 years) who had a corresponding 12-lead ECG within 1 year. fQRS was defined as ≥3 R-waves/notches in the R/S complex (>2 in right bundle branch block) in ≥2 contiguous leads. QRS prolongation was defined as QRS ≥160 ms. Nearly half (46%) the sample had fQRS (42.1% of pediatric subgroup), and 26% had QRS prolongation. Both markers were significantly associated with reduced RV ejection fraction (EF%) (p < 0.01) and larger RV end-diastolic volumes (p < 0.01). QRS prolongation alone predicted lower LV EF% (p = 0.02). Regression analyses showed both QRS prolongation (p < 0.01) and fQRS (p < 0.01) independently associated with reduced RV EF%; QRS prolongation alone predicted RV dilation (p < 0.01). We concluded that both QRS prolongation and fQRS are equivalent as significant markers of RV dysfunction in rTOF patients. QRS prolongation may be a better surrogate for RV dilation specifically. fQRS was frequently seen in children with rTOF and was significantly associated with similar late structural sequelae.

Ventricular Arrhythmia in Cancer Patients: Mechanisms, Treatment Strategies and Future Avenues

Cardiovascular disease and cancer are the leading causes of morbidity and mortality in the US. Despite the significant progress made in cancer treatment leading to improved prognosis and survival, ventricular arrhythmias (VA) remain a known cardiovascular complication either exacerbated or induced by the direct and indirect effects of both traditional and novel cancer treatments. Although interruption of cancer treatment because of VA is rarely required, knowledge surrounding this issue is essential for optimising the overall care of patients with cancer. The mechanisms of cancer-therapeutic-induced VA are poorly understood. This review will discuss the ventricular conduction (QRS) and repolarisation abnormalities (QTc prolongation), and VAs associated with cancer therapies, as well as existing strategies for the identification, prevention and management of cancer-treatment-induced VAs.

Investigation of High-Risk Electrocardiographic Markers as Predictors of Major Arrhythmic Events in Brugada Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

Numerous studies have demonstrated that a type I Brugada electrocardiographic (ECG) pattern, history of syncope, prior sudden cardiac arrest, and previously documented ventricular tachyarrhythmias are still insufficient to stratify the risk of sudden cardiac death in Brugada syndrome (BrS). Several auxiliary risk stratification parameters are pursued to yield a better prognostic model. Our aim was to assess the association between several ECG markers (wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion pattern) with the risk of developing poor outcomes in BrS.

METHODS

A systematic literature search from several databases was conducted from database inception until August 17^th, 2022. Studies were eligible if it investigated the relationship between the ECG markers with the likelihood of acquiring major arrhythmic events (MAE).

RESULTS

This meta-analysis comprised 27 studies with a total of 6552 participants. Our study revealed that wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion ECG pattern were associated with the incremental risk of syncope, ventricular tachyarrhythmias, implantable cardioverter-defibrillator shock, and sudden cardiac death in the future, with the risk ratios ranging from 1.41 to 2.00. Moreover, diagnostic test accuracy meta-analysis indicated that the repolarization dispersion ECG pattern had the highest overall area under curve (AUC) value amid other ECG markers regarding our outcomes of interest.

CONCLUSION

A multivariable risk assessment approach based on the prior mentioned ECG markers potentially improves the current risk stratification models in BrS patients.

Assessment of the incidence of fragmented QRS in electrocardiography in patients with systemic sclerosis and systemic lupus erythematosus

OBJECTIVE

In systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) cardiac involvement is very common, and it might be asymptomatic. We aimed to assess the presence of fragmented QRS (fQRS) - possible indicator of a scar, diffuse damage or conduction system disturbances in those patients.

METHODS

We examined 74 patients with SSc, 77 with SLE and 40 healthy controls. The incidence of fQRS in ECG was examined according to criteria by Das et al. Disease severity was estimated by Rodnan and SLICCC/ACRDI scores in SSc and SLE respectively.

RESULTS

Patients with SSc were slightly older than those with SLE (53 ± 14 vs 46 ± 14 yrs), women constituted 91% and 88% of studied groups (p = 0.80). The duration of disease in both groups was similar (p = 0.59). Median of Rodnan and SLICCC/ACR-DI scores were 5 and 4 points, respectively. Left ventricle ejection fraction in both groups was similar (65.5 vs 65.1%, p = 0.51), hypertension incidence was lower in SSc (24 vs 48%, p = 0.004), patients with SLE presented prolonged corrected QT interval (432 vs 424 ms, p = 0.03). Of note, fQRS were observed in 34 (46%) SSc and 29 (38%) SLE patients, p = 0.33. Notched S waves were significantly more frequent in SSc (in 26% vs 10%, p = 0.02). fQRS occurred in 3 (7.5%) of healthy subjects only.

CONCLUSION

The incidence of fQRS is similar in SSc and SLE, but is much more common than in healthy subjects. It is possible that fQRS may be considered an additional marker of heart involvement in these rare diseases.

Electrical storm in hypertrophic cardiomyopathy: Cardiac magnetic resonance and sudden cardiac death risk stratification: a case report

Background

Risk stratification for sudden cardiac death (SCD) is a key factor in the management of patients with hypertrophic cardiomyopathy (HCM). Cardiac magnetic resonance (CMR) has a unique role in the evaluation of HCM and offers superior diagnostic and prognostic information to assess the indication for a prophylactic implantable cardioverter-defibrillator (ICD).

Case summary

A 39-year-old patient with non-obstructive HCM with a low ESC HCM Risk-SCD score underwent a CMR revealing a left ventricular apical aneurysm and extensive late gadolinium enhancement; a prophylactic ICD was thus implanted. A month later, the patient was admitted in refractory electrical storm with over 50 appropriate ICD shocks due to sustained ventricular tachycardia. Despite anti-arrhythmic therapy and mechanical ventilation, the evolution was unfavourable with haemodynamic instability; veno-arterial extracorporeal membrane oxygenation was implanted. The patient was submitted to CMR-guided epicardial VT catheter ablation with complications of LV thrombus and severe pericardial effusion.

Discussion

This case details the complex risk stratification for SCD in patients with HCM, highlighting the important role of CMR in the integrated approach to risk stratification.

Dilated left ventricle with multiple outpouchings — a severe congenital ventricular diverticulum or left-dominant arrhythmogenic cardiomyopathy: A case report

BACKGROUND

Left-dominant arrhythmogenic cardiomyopathy (LDAC) is a relatively rare disease characterized by poor prognosis that exacerbates the incidence of sudden cardiac death and ventricular arrhythmias. Clinically, LDAC is constantly overlooked or misdiagnosed as myocardial infarction, myocarditis, and dilated cardiomyopathy, owing to atypical and nonspecific clinical manifestations at an early stage.

CASE SUMMARY

A 57-year-old woman was diagnosed with sinus bradycardia and chronic bifascicular block during a health check. She occasionally experienced mild chest pain and paroxysmal palpitation during activity in the past 2 years. Comprehensive auxiliary examinations, including electrocardiogram, echocardiography, coronary computerized tomography angiography, and magnetic resonance imaging, revealed that she had LDAC instead of congenital ventricular diverticulum. The physicians prescribed standard oral therapy for heart failure and implantable cardioverter-defibrillator. Consequently, her left ventricular systolic function and symptoms remained stable at the 2-year follow-up after discharge.

CONCLUSION

Based on this case, clinicians need to be aware of LDAC in patients with localized left ventricular lesions and multiple electrocardiographic abnormalities. Multimodality cardiovascular imaging is effective in identification of multiple types of cardiomyopathy and cardiac inner structures.

Relationship between Fragmented QRS and Microvascular Dysfunction in Masked Hypertension

Aim

The aim of this study was to investigate the presence of fQRS and its association with subclinical systolic and microvascular dysfunction in patients with masked hypertension (MH).

Methods

The study population consisted of 95 (mean age 48.9 ± 11.3, 61% males) subjects with MH and 80 age- and gender-matched healthy individuals who served as a control group. Coronary flow reserve (CFR) using transthoracic echocardiography and for left ventricular global longitudinal strain (LVGLS) using speckle-tracking strain imaging were performed. Patients with MH were stratified into two groups according to the presence of fQRS on surface electrocardiogram.

Results

Fragmented QRS was more common among MH patients compared with controls (38.9% vs. 6.25%, p < 0.003). CFR was significantly lower in patients with fQRS compared with those without fQRS and controls (p < 0.001). Likewise, LVGLS values were lower in MH patients with fQRS (p < 0.001) compared with subjects without fQRS and controls. Fragmented fQRS was significantly correlated with systolic blood pressure, CFR, and LVGLS. Multivariate analysis showed that the presence of fQRS, number of leads, and CFR were independent predictors of subclinical systolic dysfunction. With ROC cure analysis, number of leads with fQRS ≥4 was the optimal value for predicting the presence of subclinical systolic dysfunction in subjects with MH.

Conclusions

Fragmented QRS is more frequent among subjects with MH compared with controls. The presence of fQRS is related with pronounced subclinical left ventricular systolic dysfunction. Furthermore, CFR was significantly reduced in subjects with MH, a finding supposed that microvascular dysfunction to be a mechanistic link.

QRS fragmentation and prolongation as predictors of exercise capacity in patients after Fontan palliation

INTRODUCTION

Patients with Fontan anatomy are at increased risk for exercise intolerance and early morbidity and mortality. QRS complex fragmentation (fQRS) and prolongation have been studied in multiple heart diseases, but their clinical importance is unknown in the Fontan population.

METHODS

A retrospective cross-sectional study was performed. ECGs were evaluated for QRS prolongation (>98 %ile for age) and fQRS [ ≥3 R-waves/ notches in the R/S complex (more than 2 in RBBB) in ≥2 contiguous leads]. The primary outcome measures was CPET performance.

RESULTS

Ninety patients (median age 18 years, 57% male, 59% RV dominant) were included; 13% had fQRS and 31% had prolonged QRS. Demographically, patients with fQRS or prolonged QRS were like those without. Peak VO2 (64% vs 63%, p 0.45), VE/VCO2 slope (85% vs 88%, p = 0.74), and O2 pulse (149% vs 129%, p = 0.83) were similar in the fQRS group versus those without. Upon multi-variable regression, body mass index (β = -0.38, p < 0.01) and QRS duration (β = -0.29, p < 0.01) were independently associated with % predicted VO2; fQRS was not. Lower cardiac index (2.2 vs 2.8 L/min/m2, p = 0.03) and higher ventricular end-diastolic pressure (13 vs 10 mmHg, p = 0.02) was seen with fQRS.

CONCLUSIONS

QRS fragmentation is present in patients with Fontan physiology. fQRS showed no association with CPET performance but was related to invasive hemodynamic markers of ventricular performance. QRS duration may be a better predictor of exercise function following Fontan. This article is protected by copyright. All rights reserved.

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.

Increased Prevalence of Fragmented QRS in Randomly Selected Group of Multiple Myeloma Patients: A Pilot Study to Assess Prevalence

The presence of fragmented QRS (fQRS) on surface electrocardiograms (ECGs) has been associated with the myocardial scar in certain cardiac conditions and has been proposed as a potential marker of adverse cardiac outcomes. Since myocardial fibrosis not only has been recognized as a side effect of certain cancer therapies but also, fQRS have been shown in some breast cancer and lymphoma survivors post-chemotherapy treatment, we decided to investigate if fQRS could also be seen in multiple myeloma (MM) patients since this association has never been described. For this pilot study, we analyzed ECGs from 137 randomly selected MM patients during different stages of their treatment, and fRQS was found in 42% of these cases. The prevalence was much higher than the reported prevalence for the general population (19.0%) but closer to that reported for patients with myocardial infarction (39.5%). We also found that female MM patients are more commonly affected than women in the general population. Based on this small random sampling analysis, fQRS appears highly prevalent among unselected MM patients. This novel finding of fQRS in MM patients certainly adds to the growing data of cases among different cancer patients, opening the door to conduct larger prospective studies that undoubtedly will help to create a more robust database regarding the potential utility of this ECG abnormality.

Pathogenesis, Diagnosis and Risk Stratification in Arrhythmogenic Cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined myocardial disease associated with sudden cardiac death (SCD). It is most frequently caused by mutations in genes encoding desmosomal proteins. However, there is growing evidence that ACM is not exclusively a desmosome disease but rather appears to be a disease of the connexoma. Fibroadipose replacement of the right ventricle (RV) had long been the hallmark of ACM, although biventricular involvement or predominant involvement of the left ventricle (LD-ACM) is increasingly found, raising the challenge of differential diagnosis with arrhythmogenic dilated cardiomyopathy (a-DCM). A-DCM, ACM, and LD-ACM are increasingly acknowledged as a single nosological entity, the hallmark of which is electrical instability. Our aim was to analyze the complex molecular mechanisms underlying arrhythmogenic cardiomyopathies, outlining the role of inflammation and autoimmunity in disease pathophysiology. Secondly, we present the clinical tools used in the clinical diagnosis of ACM. Focusing on the challenge of defining the risk of sudden death in this clinical setting, we present available risk stratification strategies. Lastly, we summarize the role of genetics and imaging in risk stratification, guiding through the appropriate patient selection for ICD implantation.

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.

Retrospective evaluation of notched and fragmented QRS complex in dogs with naturally occurring myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs. The association of QRS notching (nQRS) or fragmentation (fQRS) with disease severity is currently unknown. The study objective was to assess the prevalence of nQRS and fQRS in dogs with MMVD and its severity according to ACVIM classification and to compare the results with a group of healthy dogs. This retrospective cross-sectional study included 34 healthy control dogs and 155 dogs with spontaneous MMVD (42% of dogs in class B1, 23% in class B2 and 35% in class C). fQRS was defined as nQRS complexes in two contiguous leads in the frontal plane (leads I and aVL) and (II, III or aVF). A one-way ANOVA with Bonferroni post-hoc test was used to assess the differences in continuous data between control and MMVD groups. Of the MMVD group, 58% showed nQRS in at least one lead and 27% presented fQRS. There was no difference between the number of leads with a nQRS and disease severity (p = 0.75) nor did the number of leads with a nQRS correlate with left atrial size (r = 0.48; p = 0.5). The number of dogs with fQRS did not differ among classes of MMVD (p = 0.21). nQRS and fQRS were more prevalent in dogs with MMVD compared to control dogs (p < 0.01). This study did not identify any relationship between the number of leads with a nQRS and disease severity. However, dogs with MMVD had a higher prevalence of nQRS and fQRS compared to control group.

How safe are children with COVID-19 from cardiac risks? Pediatric risk assesment; insights from echocardiography and electrocardiography

Background/aim

Approximately 40 million individuals worldwide have been infected with SARS-CoV-2, the virus responsible for the novel coronavirus disease-2019 (COVID-19). Despite the current literature about the cardiac effects of COVID-19 in children, more information is required. We aimed to determine both cardiovascular and arrhythmia assessment via electrocardiographic and echocardiographic parameters.

Materials and methods

We evaluated seventy children who were hospitalized with COVID-19 infections and seventy children as normal control group through laboratory findings, electrocardiography (ECG), and transthoracic echocardiography (TTE).

Results

We observed significantly increased levels of Tp-Te, Tp-Te/QT, and Tp-Te/QTc compared with the control group. Twenty-five of 70 (35.7%) patients had fragmented QRS (fQRS) without increased troponin levels. On the other hand, none of the patients had pathologic corrected QT(QTc) prolongation during the illness or its treatment. On TTE, 20 patients had mild mitral insufficiency, among whom only five had systolic dysfunction (ejection fraction < 55%). There was no significant difference between the patient and control groups, except for isovolumic relaxation time (IVRT) in terms of mean systolic and diastolic function parameters. IVRT of COVID patients was significantly lower than that of control group.

Conclusion

Despite all the adult studies, the effects of COVID‐19 on myocardial function are not well established in children. The thought that children are less affected by the illness may be a misconception.

Electrocardiographic differences in patients with true and pseudo-resistant hypertension

Cardiovascular disease is the leading cause of mortality in hypertensives, and patients with true resistant hypertension have an increased risk for premature cardiovascular events. Electrocardiography (ECG) has an essential role in the monitoring of hypertensive heart disease; however, little is known about the importance of ECG parameters in patients with resistant hypertension. We aimed to investigate whether fragmented QRS (fQRS) and frontal plane QRS-T angle, which are novel ECG parameters indicating myocardial damage, predict true resistant hypertension in patients with uncontrolled blood pressure. Four hundred six hypertensive patients with resistant hypertension were prospectively enrolled for the study. Patients were divided into two groups as 'true resistant' or 'pseudo-resistant' hypertensives and compared regarding the ECG parameters. While 73 (18%) patients had true resistant hypertension, 333 (82%) patients had pseudo-resistant hypertension. The frequency of fQRS (47.9% vs. 20.1%, p < 0.001) and average frontal plane QRS-T angle (93.0° ± 19.7° vs. 53.8° ± 10.2°, p < 0.001) were significantly higher in patients with true resistant hypertension compared to those with pseudo-resistant hypertension. Also, fQRS in anterior leads was significantly more frequent in patients with true resistant hypertension (57.1% vs. 23.8%, p < 0.001). Moreover, ROC curve analysis demonstrated that an increased frontal plane QRS-T angle > 90.75° predicted true resistant hypertension with a sensitivity 96% and specificity 61% (AUC:0.874, p < 0.001). Furthermore, multivariate analysis demonstrated that fQRS in anterior leads (OR: 1.251, 95% CI: 1.174-1.778, p = 0.002) and frontal plane QRS-T angle (OR: 1.388, 95% CI: 1.073-1.912, p < 0.001) were independent predictors of true resistant hypertension. In conclusion, fQRS and frontal plane QRS-T angle may be useful to predict true resistant hypertension in patients with uncontrolled blood pressure.

Evolution of electrocardiographic abnormalities and arrhythmias in adult patients with beta-thalassemia major during a short-term follow-up

OBJECTIVE

Adult beta-thalassemia major (TM) patients exhibit electrocardiographic abnormalities and cardiac autonomic dysfunction. We aimed to investigate the evolution of electrocardiographic abnormalities and arrhythmias in TM patients during a 12-month follow-up period.

METHODS

Forty-seven adult TM patients (median age: 36 years, 57% men) without overt heart failure were studied. We examined 12-lead electrocardiograms, 24-hour electrocardiographic Holter recordings, and treadmill exercise stress tests at baseline and after 12 months. Conventional electrocardiographic measurements, as well as contemporary indexes of depolarization and repolarization/dispersion of repolarization (QRS fragmentation; T peak-to-end; T peak-to-end/QT) were assessed. Moreover, we examined markers of autonomic dysfunction such as heart rate variability, and heart rate recovery after exercise testing.

RESULTS

The electrocardiographic markers of atrial/ventricular depolarization and repolarization, as well as indexes of autonomic imbalance, were not significantly changed. However, the recorded supraventricular ectopic beats increased significantly. Paroxysmal atrial fibrillation (PAF) detection was greater in 12 months (4/47 at baseline vs. 8/47 at 12 months; P=0.38). However, 5/8 patients who were diagnosed with PAF at the second examination did not have the arrhythmia at the initial evaluation. Thus, PAF was present in a total of 9/47 (19%) TM patients. Notably, 3/9 of the patients were asymptomatic. The mean duration of PAF was 5±2 minutes and the mean number of these episodes was 8±2.

CONCLUSION

TM patients have repolarization and autonomic function abnormalities that do not significantly change during a 12-month follow-up period. However, supraventricular ectopy and AF burden further evolve.

Cardiac electrical and structural alterations in preeclampsia

BACKGROUND

Preeclampsia increases the risk of cardiovascular mortality and morbidity both during pregnancy and long term after the labor by causing cardiac changes that may lead to atrial and ventricular arrhythmias.

OBJECTIVE

We aimed to investigate noninvasive predictors of atrial and ventricular arrhythmias and cardiac structural changes in preeclampsia.

METHODS

The study included 34 preeclampsia patients as the study group and 33 healthy pregnant women as the control group. The presence of fragmented QRS morphology, P dispersion, QT dispersion, Tp-e/QTc ratio, inter- and intra-atrial electromechanical delay, left ventricular mass index was evaluated in the groups by 12 lead- ECG and standard and tissue Doppler echocardiography.

RESULTS

Left ventricular mass index and relative wall thickness, and E/Em ratio was significantly higher in preeclampsia. Inter- and intra-atrial electromechanical delay and Tp-e were prolonged, and P dispersion, QT dispersion, and Tp-e/QTc ratio were increased significantly in patients with preeclampsia. In addition, fragmented QRS morphology was seen in 76.5% of patients with preeclampsia while it was present in only 27.3% of the control group (p < .001).

CONCLUSION

Preeclampsia causes significant cardiac structural and electrocardiographic alterations that may increase the risk of atrial and/or ventricular arrhythmias. A more thorough and earlier cardiac assessment and closer follow-up of these patients would be useful to avoid further complications.

Conduction Disorders: The Value of Surface ECG

PURPOSE OF REVIEW

The purpose of the current mini-review is to describe the importance of surface ECG for the diagnosis of conduction disorder.

METHODS

The MEDLINE/PubMed database was used, with the keywords "ECG" and "conduction disorders"; over the past 10 years. Other documents were included because of their relevance.

MAIN FINDINGS

Data on the anatomy and function of the cardiac electrical system have been described. Conduction disorders including sinus node dysfunction, atrioventricular blocks, intraventricular conduction disorders are exposed as to their epidemiology, etiology, presentation, anatomical site of impaired conduction of the electrical stimulus. The importance of ECG in patients with a cardiac implantable electronic device was also discussed, in addition to future perspectives.

CONCLUSION

Surface ECG allows the diagnosis of atrioventricular and intraventricular conduction disorder and its anatomical block site most of the time, without the need for invasive tests such as electrophysiological study. Dysfunctions of cardiac implantable electronic devices can be diagnosed by ECG, as well as the prediction of response to cardiac resynchronization therapy.

Early Repolarization, Fragmented QRS and Tpeak-Tend Interval as Electrocardiographic Markers in Patients with Idiopathic Ventricular Arrhythmias: a Brief Review

Introduction: Idiopathic ventricular tachycardia and ventricular fibrillation, as causes of sudden cardiac death, are entities with mechanisms poorly studied and understood to date. The electrocardiogram (ECG) is a simple tool, but with great diagnostic and prognostic value, which has allowed the identification of certain markers associated with increased risk of development of malignant ventricular arrhythmias and sudden cardiac death. Methods: To identify the electrocardiographic markers related to the risk of developing idiopathic malignant ventricular arrhythmias, a review of the literature was performed, looking for the most recent articles with the greatest scientific impact on the topic. Outcome: Although the number of studies published to date is scarce, the published evidence has shown three electrocardiographic risk markers that have emerged in recent years and which have been related to the development of idiopathic malignant ventricular arrhythmias: the early repolarization (ER) pattern, QRS fragmentation (QRSF) and the Tpeak-Tend (Tp-Te) interval. The ECG marker that has shown most evidence to date is the pattern of ER, as a cause of changes in both ventricular depolarization and repolarization. The QRSF and the Tp-Te interval have also been related to the development of idiopathic ventricular arrhythmias, although with less evidence in this regard. Conclusion: In the last years, three electrocardiographic markers have appeared as variables related to the development of malignant ventricular arrhythmias, as is the case of ER, QRSF and Tp-Te interval. However, evidence is scarce in this specific patient profile and further randomized clinical trials are necessary to demonstrate its true relationship and usefulness.

Big Data and Artificial Intelligence: Opportunities and Threats in Electrophysiology

The combination of big data and artificial intelligence (AI) is having an increasing impact on the field of electrophysiology. Algorithms are created to improve the automated diagnosis of clinical ECGs or ambulatory rhythm devices. Furthermore, the use of AI during invasive electrophysiological studies or combining several diagnostic modalities into AI algorithms to aid diagnostics are being investigated. However, the clinical performance and applicability of created algorithms are yet unknown. In this narrative review, opportunities and threats of AI in the field of electrophysiology are described, mainly focusing on ECGs. Current opportunities are discussed with their potential clinical benefits as well as the challenges. Challenges in data acquisition, model performance, (external) validity, clinical implementation, algorithm interpretation as well as the ethical aspects of AI research are discussed. This article aims to guide clinicians in the evaluation of new AI applications for electrophysiology before their clinical implementation.

Interatrial block, P terminal force or fragmented QRS do not predict new-onset atrial fibrillation in patients with severe chronic kidney disease

Background

The prevalence of left atrial enlargement (LAE) and fragmented QRS (fQRS) diagnosed using ECG criteria in patients with severe chronic kidney disease (CKD) is unknown. Furthermore, there is limited data on predicting new-onset atrial fibrillation (AF) with LAE or fQRS in this patient group.

Methods

We enrolled 165 consecutive non-dialysis patients with CKD stage 4–5 without prior AF diagnosis between 2013 and 2017 in a prospective follow-up cohort study. LAE was defined as total P-wave duration ≥120 ms in lead II ± > 1 biphasic P-waves in leads II, III or aVF; or duration of terminal negative portion of P-wave > 40 ms or depth of terminal negative portion of P-wave > 1 mm in lead V₁ from a baseline ECG, respectively. fQRS was defined as the presence of a notched R or S wave or the presence of ≥1 additional R waves (R’) or; in the presence of a wide QRS complex (> 120 ms), > 2 notches in R or S waves in two contiguous leads corresponding to a myocardial region, respectively.

Results

Mean age of the patients was 59 (SD 14) years, 56/165 (33.9%) were female and the mean estimated glomerular filtration rate was 12.8 ml/min/1.73m². Altogether 29/165 (17.6%) patients were observed with new-onset AF within median follow-up of 3 [IQR 3, range 2–6] years. At baseline, 137/165 (83.0%) and 144/165 (87.3%) patients were observed with LAE and fQRS, respectively. Furthermore, LAE and fQRS co-existed in 121/165 (73.3%) patients. Neither findings were associated with the risk of new-onset AF within follow-up.

Conclusion

The prevalence of LAE and fQRS at baseline in this study on CKD stage 4–5 patients not on dialysis was very high. However, LAE or fQRS failed to predict occurrence of new-onset AF in these patients.

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.

QRS fragmentation in children with suspected myocarditis: a possible additional diagnostic sign

AIMS

We aim to assess the diagnostic role of QRS fragmentation in children with suspected acute myocarditis.

BACKGROUND

Diagnosis of myocarditis in the paediatric population is challenging. Clinical suspicion, electrocardiogram, and laboratory tests are the main diagnostic features at presentation. However, electrocardiogram in patients with myocarditis is usually considered aspecific. We have previously described QRS fragmentation in adult patients with acute myocarditis.

METHODS

Patients aged less than 18 years, admitted between 2003 and 2019, and discharged with a diagnosis of acute myocarditis were included. Standard electrocardiogram, laboratory, and echocardiographic findings at admission and follow-up were reviewed. QRS fragmentation was defined by the presence of multiphasic R' spikes. Cardiac magnetic resonance and biopsy were performed in selected patients.

RESULTS

Twenty-one patients were analysed, 16 males (76%), median age 9.5 (2.5-16) years. At presentation, 12 patients (57%) displayed QRS fragmentation. Median ejection fraction was 40% (27-60). Nine patients (43%) underwent cardiac magnetic resonance and displayed late gadolinium enhancement. One patient underwent biopsy that showed borderline findings. Electrocardiogram leads showing QRS fragmentation correlated with distribution of late gadolinium enhancement. Median follow-up was 600 (190-2343) days. All patients were alive at last follow-up. Six patients (33%) patients displayed persistence of QRS fragmentation. Median ejection fraction was 60% (60-65%). In three patients (14%), ejection fraction remained depressed, two of which showed persistence of QRS fragmentation.

CONCLUSION

In this cohort of children with suspected myocarditis, QRS fragmentation was confirmed as a new additional diagnostic finding to look for at admission and during follow-up.

Subclinical cardiac structural and electrical abnormalities in fibromyalgia syndrome

Background/aim

In the literature, there is a paucity of data about the effects of fibromyalgia syndrome (FMS) on myocardial function and electrophysiological properties of atrium and ventricles. In this study, we investigated cardiac functions and noninvasive predictors of arrhythmias in patients with FMS.

Materials and methods

The study included 43 female patients diagnosed with FMS and 30 age- and sex-matched healthy subjects. The presence of fragmented QRS (fQRS) morphology, P dispersion, QT dispersion, inter- and intraatrial electromechanical delay was evaluated in the groups with 12-lead ECG and standard and tissue Doppler echocardiography.

Results

Among electrocardiographic parameters, P dispersion, QT dispersion, and the ratio of presence of fQRS morphology were found to be significantly higher in the study group as compared to the control group. In lateral and septal, the ratio of the early transmitral flow velocity to the early diastolic tissue velocity (E/Em) was significantly higher in the study group. Additionally, intra- and interatrial electromechanical delay was found significantly prolonged in the study group.

Conclusion

FMS is found to be associated with significant cardiac electrical alterations that may indicate the increased risk of atrial and ventricular arrhythmias in this group of patients.

QRS fragmentation as a possible electrocardiographic diagnostic marker in patients with acute myocarditis: preliminary histopathological validation

Aims

We aim to assess the reproducibility of QRS fragmentation (fQRS) on a multi‐centre dataset of patients with acute myocarditis (AM), including a histopathological validation in a subgroup with biopsy‐proven disease. Electrocardiogram (ECG) in patients with myocarditis is usually considered aspecific. ST changes and conduction anomalies have been commonly reported so far. We have previously described fQRS in patients with AM.

Methods and results

Patients admitted between 2008 and 2019 in two centres with a diagnosis of AM were included. Standard ECG, echocardiography, and cardiac magnetic resonance (CMR) findings were recorded at baseline and at follow‐up (FU). Eighty patients were analysed, 66 men (82%), with median age of 34 (26–43) years. Twenty‐two patients had biopsy‐proven AM. At presentation, 61 patients (76%) displayed fQRS. Median ejection fraction (EF) was 55% (43–60). Seventy‐two patients (90%) underwent CMR and displayed late gadolinium enhancement (LGE). ECG leads showed that fQRS correlated with distribution of LGE. In patients with positive biopsy, fQRS was present in 18 (81%). Median FU was 419 days (224–956). Complete FU was available for 64 patients (80%), and 33 patients (52%) displayed persistence of fQRS. Median EF was 60% (57–64). Eleven patients underwent a repeated biopsy at FU, eight of whom had persistent inflammation and fQRS. Fifteen patients (23%) had ventricular tachycardia, 14 of whom still showed fQRS.

Conclusions

In this cohort fQRS was confirmed as an additional useful ECG sign. Persistence of fQRS was associated with ongoing inflammation and with a poorer outcome in terms of ventricular function and occurrence of arrhythmias.

Quantitative fragmented QRS has a good diagnostic value on myocardial fibrosis in hypertrophic obstructive cardiomyopathy based on clinical-pathological study

Background

To investigate the relationship between fragmented QRS (fQRS) quantified by a new method and myocardial fibrosis (MF) and the diagnostic value of quantitative fQRS (Q-fQRS) to detect MF in hypertrophic obstructive cardiomyopathy (HOCM) patients based on histological validation.

Methods

We performed a retrospective study that included 69 patients with HOCM who underwent ventricular septal surgery. Nine individuals who died from accidents were studied as a control reference for the histological parameters. Septal myocardium samples were subjected to Masson’s trichrome staining to quantify the collagen volume fraction (CVF). An fQRS pattern was defined as the presence of additional R waves or RSR’, evidenced by notched R or S wave on electrocardiography (ECG). The Q-fQRS was quantified as the total amount of deflections in the QRS complex in all 12 routine ECG leads together. Cardiac magnetic resonance imaging was conducted, and late gadolinium enhancement (LGE) was measured at 2, 4, 6 and 8 standard deviations (SDs).

Results

Of the 69 patients, fQRS was documented in 38 (55.1%) patients, the mean number of leads with fQRS was 3.7 ± 1.6, and the mean Q-fQRS was 17 ± 7.2. Compared with HOCM patients without fQRS, HOCM patients with fQRS had a higher CVF and more LGE at 6 SD (P < 0.001; P = 0.040). Q-fQRS was correlated with CVF (r = 0.640, P < 0.001), and Q-fQRS showed the best correlation with LGE measured at 8 SD (r = 0.379, P = 0.002). Multivariate regression analyses revealed that Q-fQRS was independently associated with the extent of CVF in HOCM patients after adjusting for age, sex, body surface area and the extent of LGE at 6 SD (P < 0.001). When the patients were divided into subgroups with normal CVF or high CVF according to the CVF in controls, Q-fQRS and LGE at 6SD showed similar diagnostic value in detecting patients with high CVF, with sensitivities of 66.7% vs 68.6%, specificities of 76.7% vs 72.4%, and accuracies of 71% vs 70.3%.

Conclusions

HOCM patients with fQRS showed more extensive MF. Q-fQRS was an independent predictor for MF and had a good diagnostic value, with a sensitivity of 66.7% and specificity of 76.7%, in identifying patients with higher fibrotic burden.

Gender differences in prevalence and prognostic value of fragmented QRS complex

BACKGROUND

Fragmented QRS (fQRS) on 12-lead electrocardiogram (ECG) is associated with scarred myocardium and adverse outcome. However, the data on gender differences in terms of its prevalence and prognostic value is sparse. The aim of this study was to evaluate whether gender differences in fQRS exist among subjects drawn from populations with different risk profiles.

METHODS

We analyzed fQRS from 12-lead ECG in 953 autopsy-confirmed victims of sudden cardiac death (SCD) (78% men; 67.0 ± 11.4 yrs), 1900 coronary artery disease (CAD) patients with angiographically confirmed stenosis of ≥50% (70% men; 66.6 ± 9.0 yrs, 43% with previous myocardial infarction [MI]), and in 10,904 adults drawn from the Finnish adult general population (52% men; 44.0 ± 8.5 yrs).

RESULTS

Prevalence of fQRS was associated with older age, male sex and the history and severity of prior cardiac disease of subjects. Among the general population fQRS was more commonly found among men in comparison to women (20.5% vs. 14.8%, p < 0.001). The prevalence of fQRS rose gradually along with the severity of prior cardiac disease in both genders, yet remained significantly higher in the male population: subjects with suspected or known cardiac disease (25.4% vs. 15.8% p < 0.001), CAD patients without prior MI (39.9% vs. 26.4%, p < 0.001), CAD patients with prior MI (42.9% vs. 31.2%, p < 0.001), and victims of SCD (56.4% vs. 44.4%, p < 0.001).

CONCLUSIONS

The prevalence of QRS fragmentation varies in different populations. The fragmentation is clearly related to the underlying cardiac disease in both genders, however women seem to have significantly lower prevalence of fQRS in each patient population in comparison to men.

Relationship between fragmented QRS complexes and ejection fraction recovery in anterior ST-segment elevation myocardial infarction patients undergoing thrombolytic treatment

BACKGROUND

Acute anterior ST-segment elevation myocardial infarction (STEMI) is a life-threatening disease. Adverse cardiac events of acute anterior STEMI include cardiovascular death or worsening congestive heart failure. This study investigated the role of fragmented QRS complex (fQRS) in predicting insufficient ejection fraction (EF) recovery in acute anterior STEMI.

METHODS

Patients with acute anterior STEMI who received thrombolytic therapy were prospectively enrolled in this study. Twelve-lead electrocardiography (ECG) was obtained from all patients during admission and 24 and 48 h after admission. We divided the patients into two groups according to the presence of fQRS appearance within 48 h: absence of fQRS in any lead (fQRS-), and its presence in two or more contiguous leads (fQRS+). All patients were evaluated with transthoracic echocardiography at admission, and at follow-up 6 and 12 months later.

RESULTS

A total of 138 consecutive patients were included in the study. Seventy-three patients (52.9%) had fQRS in the ECG. EF recovery in the fQRS(+) group was significantly lower than that of the fQRS(-) group (39% vs. 43.9%, P < 0.001). Multiple logistic regression analysis showed that the fQRS (odds ratio: 4.147, 95% confidence interval: 1.607-10.697, P = 0.003) were an independent predictor of poor EF recovery.

CONCLUSION

The presence of fQRS is an independent predictor for inadequate EF recovery in acute anterior STEMI patients undergoing thrombolytic treatment. Assessment of fQRS on surface ECG may be used in determining high-risk patients for poor EF recovery after acute anterior STEMI.

Association of ECG parameters with late gadolinium enhancement and outcome in patients with clinical suspicion of acute or subacute myocarditis referred for CMR imaging

BACKGROUND

Risk stratification of myocarditis is challenging due to variable clinical presentations. Cardiovascular magnetic resonance (CMR) is the primary non-invasive imaging modality to investigate myocarditis while electrocardiograms (ECG) are routinely included in the clinical work-up. The association of ECG parameters with CMR tissue characterisation and their prognostic value were investigated in patients with clinically suspected myocarditis.

METHODS AND RESULTS

Consecutive patients with suspected myocarditis who underwent CMR and ECG were analysed. Major adverse cardiovascular event (MACE) included all-cause death, hospitalisation for heart failure, heart transplantation, documented sustained ventricular arrhythmia, or recurrent myocarditis. A total of 587 patients were followed for a median of 3.9 years. A wide QRS-T angle, low voltage and fragmented QRS were significantly associated with late gadolinium enhancement. Further, a wide QRS-T angle, low voltage and prolonged QTc duration were associated with MACE in the univariable analysis. In a multivariable model, late gadolinium enhancement (HR: 1.90, 95%CI: 1.17-3.10; p = 0.010) and the ECG parameters of a low QRS voltage (HR: 1.86, 95%CI: 1.01-3.42; p = 0.046) and QRS-T-angle (HR: 1.01, 95%CI: 1.00-1.01; p = 0.029) remained independently associated with outcome. The cumulative incidence of MACE was incrementally higher when findings of both CMR and ECG were abnormal (p<0.001).

CONCLUSION

In patients with clinically suspected myocarditis, abnormal ECG parameters are associated with abnormal tissue characteristics detected by CMR. Further, ECG and CMR findings have independent prognostic implications for morbidity and mortality. Integrating both exams into clinical decision-making may play a role in risk stratification in this heterogeneous patient population.

Fragmented QRS - Its significance

Fragment QRS (fQRS) complex is a myocardial conduction abnormality that indicates myocardial scar. It is defined as additional notches in the QRS complex. Though initially fQRS was defined in the setting of normal QRS duration (<120 m s), later it has been expanded to include conditions with wide QRS complexes as in bundle branch block, ventricular ectopy and paced rhythm, when more than 2 notches are present. It is an important, yet often overlooked marker of mortality and arrhythmic events in many cardiac diseases. The significance of fQRS lies in the fact that it just requires a surface ECG for its recording and the value of information about the condition of the heart it dispenses based on the clinical setting. We review the role of fQRS in predicting adverse cardiac events in various conditions.

Clinical Diagnosis, Imaging, and Genetics of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia: JACC State-of-the-Art Review

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiomyopathy that can lead to sudden cardiac death and heart failure. Our understanding of its pathophysiology and clinical expressivity is continuously evolving. The diagnosis of ARVC/D remains particularly challenging due to the absence of specific unique diagnostic criteria, its variable expressivity, and incomplete penetrance. Advances in genetics have enlarged the clinical spectrum of the disease, highlighting possible phenotypes that overlap with arrhythmogenic dilated cardiomyopathy and channelopathies. The principal challenges for ARVC/D diagnosis include the following: earlier detection of the disease, particularly in cases of focal right ventricular involvement; differential diagnosis from other arrhythmogenic diseases affecting the right ventricle; and the development of new objective electrocardiographic and imaging criteria for diagnosis. This review provides an update on the diagnosis of ARVC/D, focusing on the contribution of emerging imaging techniques, such as echocardiogram/magnetic resonance imaging strain measurements or computed tomography scanning, new electrocardiographic parameters, and high-throughput sequencing.

Fragmented QRS as a Marker of Myocardial Fibrosis in Hypertension: a Systematic Review

PURPOSE OF REVIEW

Hypertension cause damage in cardiac structure and induce pathological myocardial fibrosis that leads to hypertensive cardiomyopathy. A narrow fragmented QRS complex (fQRS) is associated with myocardial fibrosis and scar tissue in various cardiovascular diseases. It is also associated with myocardial fibrosis in hypertensive patients even in the absence of any structural heart diseases. This article aimed to demonstrate importance and usefulness of fQRS in hypertensive patients.

RECENT FINDINGS

Current evidence suggest that the frequency of fQRS is significantly higher in hypertensive patients compared to normotensives. Also, fQRS seems to be a predictor of left ventricular hypertrophy, increased systolic blood pressure, non-dipping, deterioration of the left ventricular geometry, and worse systolic and diastolic functions in hypertensive patients. As a simple and easy detectable electrocardiographic finding, fQRS may indicate myocardial fibrosis, uncontrolled blood pressure, and deteriorated cardiac structure in hypertensive patients even in the absence of other structural heart diseases, and may also be useful to predict high-risk hypertensives.

Ventricular Arrhythmias in Patients with Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a prevalent condition thought to increase in the future. Being mostly undiagnosed, the most serious complications are cardiovascular diseases, among which are arrhythmias. Controversy remains as to whether OSA is a primary etiologic factor for ventricular arrhythmias, because of the high incidence of cardiovascular comorbidities in OSA patients. Howev-er, there is mostly a strong evidence of a relation between OSA and ventricular arrhythmias. A few mechanisms have been proposed to be responsible for this association and some electrocardiographic changes have also been demonstrated to be more frequent in OSA patients. Treatment of OSA with Continuous Positive Airway Pressure (CPAP) has the potential to reduce arrhythmias and confer a mortality benefit.

Association Between Non-Dipping and Fragmented QRS Complexes in Prehypertensive Patients

Background

Fragmented QRS (fQRS) is a sign of adverse cardiovascular events in various cardiovascular diseases. It is also associated with increased blood pressure and non-dipping in hypertensive patients. However, no study has investigated the importance of fQRS in prehypertensive patients.

Objectives

The aim of our study is to investigate the relationship between fQRS and non-dipper status in prehypertensive patients.

Methods

Two hundred and sixteen eligible, newly diagnosed prehypertensive patients who underwent 24-hour ambulatory blood pressure monitoring (ABPM) for further evaluation of blood pressure between June 2015 and July 2016 were included into the study. Patients were divided into three groups according to ABPM results: normotensives, dipper prehypertensives, and non-dipper prehypertensives. Groups were compared regarding presence of fQRS on electrocardiography. Additionally, multinomial logistic regression analysis was used to determine the relationship between fQRS and blood pressure pattern in prehypertensive patients.

Results

According to ABPM recordings, 61 patients had normotensive blood pressure pattern (systolic blood pressure < 120 mmHg and diastolic blood pressure < 80 mmHg). Of the remaining 155 prehypertensive patients, 83 were dippers and 72 were non-dippers. Non-dipper prehypertensives had a significantly higher frequency of fQRS compared to normotensives (p = 0.048). Furthermore, multinomial logistic regression analysis revealed that fQRS is an independent predictor of non-dipping blood pressure pattern in prehypertensive patients (p = 0.017, OR: 4.071, 95% CI: 1.281-12.936).

Conclusions

We found that fQRS is a predictor of non-dipping in prehypertensives. As a marker of fibrosis and higher fibrotic burden within myocardium, fQRS may be useful in identifying high-risk prehypertensive patients before the development of hypertension.

Fragmented QRS on surface electrocardiogram as a predictor of perfusion defect in patients with suspected coronary artery disease undergoing myocardial perfusion imaging

Background

Fragmented QRS (FQRS) on surface electrocardiogram (ECG) is associated with the presence of myocardial scar tissue and may have prognostic value after certain ischemic events. We aimed to examine the anatomical correlation of FQRS with the presence of perfusion abnormalities in patients with suspected coronary artery disease (CAD).

Methods

Patients without a known history of CAD, who were referred for myocardial perfusion imaging (MPI) between January 2016 and May 2016, were enrolled. The presence of FQRS on surface ECG was evaluated. The presence of FQRS, number of leads with FQRS, and the location of FQRS as well as patient characteristics were compared in patients with normal versus abnormal MPI. Multivariate model was constructed to identify independent factors associated with perfusion defect.

Results

One hundred four women and 94 men were enrolled. Fragmentation of anterior, lateral, and inferior leads was detected in 13 (6.5%), 17 (8.5%), and 36 (18.1%) subjects, respectively. MPI was normal in 134 (67.6%) patients. FQRS was significantly more common in patients with abnormal MPI (p < 0.001). Age (odds ratio [OR]: 1.05 [1.02–1.08]; p = 0.001), number of the leads presenting FQRS (OR: 1.46 [1.12–1.92] p = 0.006), and diabetes (OR: 2.33 [1.16–4.69]; p = 0.018) were independent predictors of the presence of perfusion defect on MPI.

Conclusion

In the absence of known CAD, FQRS is associated with the presence of perfusion abnormalities. Incorporating FQRS in diagnostic armamentarium may aid us in selecting patients who may benefit from MPI.

Fragmented QRS (fQRS) Complex Predicts Adverse Cardiac Events of ST-Segment Elevation Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention and Thrombolysis

BACKGROUND ST-segment elevation myocardial infarction (STEMI) is an acute and life-threatening disease. Adverse cardiac events (ACEs) are defined as cardiovascular death or worsening congestive heart failure in STEMI patients. The present study investigated the predictive role of fragmented QRS complex (fQRS) in risks of ACEs in STEMI. MATERIAL AND METHODS This study was a retrospective analysis involving patients who underwent percutaneous coronary intervention (PCI) or thrombolysis. STEMI patients were divided into the fQRS group (259 cases) and the non-fQRS group (161 cases). Basic information and clinical parameters were evaluated. ACEs, including hemodynamic instability, electrical instability (ventricular tachycardia event, ventricular fibrillation or atrioventricular heart-block) and death, were observed. The 12-lead ECG was used to obtain fQRS recordings. Thrombolytic recanalization was evaluated to confirm clinical outcomes of PCI and thrombolysis therapy. RESULTS Hemodynamic instability rates, electrical instability rates, and death in the fQRS group were significantly higher compared to the non-fQRS group (P=0.002, 0.000, and 0.010, respectively). PCI triggered significantly fewer ACEs compared to thrombolytic therapy in the fQRS group (P=0.000, 0.000, and 0.019, respectively). The fQRS group had higher thrombolysis failure rates and three-vessel lesion of coronary artery rates compared to the non-fQRS group (P=0.009 and 0.029, respectively). There were no differences between fQRS and non-fQRS groups in death rates of STEMI patients undergoing PCI and thrombolytic therapy. GRACE scores more than 140, EF less than 35%, and fQRS illustrated predictive potential for ACEs of STEMI patients. CONCLUSIONS fQRS is an independent predictor for the adverse cardiac events of STEMI patients undergoing PCI or thrombolysis.

Use of fragmented QRS in prognosticating clinical deterioration and mortality in pulmonary embolism: A meta-analysis

BACKGROUND

Fragmented QRS (fQRS) on electrocardiography is potentially valuable in prognosticating acute pulmonary embolism (PE). ECG is one of the first tests performed in the emergency department, quickly interpretable, noninvasive, inexpensive, and available in remote areas. We aimed to review fQRS's role in PE prognostication.

METHODS

We searched MEDLINE, EMBASE, Google Scholar, Web of Science, abstracts, conference proceedings, and reference lists until October 2017. Eligible studies used fQRS to prognosticate patients for the main outcomes of death and clinical deterioration or escalation of therapy. Two authors independently selected studies, with disagreement resolved by consensus. Ad hoc piloted forms were used to extract data and assess risk of bias. We used a random-effects model to pool relevant data in meta-analysis with odds ratios (OR) and 95% confidence intervals (CI), while all other data were synthesized qualitatively. Statistical heterogeneity was assessed using the I² index.

RESULTS

We included five studies (1,165 patients). There was complete agreement in study selection. fQRS significantly predicted in-hospital mortality (OR [95% CI], 2.92 [1.73-4.91]; p < .001), cardiogenic shock (OR [95% CI], 4.71 [1.61-13.70]; p = .005), and total mortality at 2-year follow-up (OR [95% CI], 4.42 [2.57-7.60]; p < .001). Adjusted analyses were generally consistent with these results.

CONCLUSION

Although few studies have explored the current study's question, they showed that fQRS is potentially valuable in PE prognostication. fQRS should be considered as an entry, along with other clinical and ECG findings, in a PE risk score.

Retrospective evaluation of notched QRS complexes in dogs: 85 cases

INTRODUCTION

Notched QRS complexes on electrocardiography (ECG) have been described in veterinary and human reports, but little is known about this finding in veterinary patients. Therefore, the objectives of this study were to describe the signalment and cardiac disease diagnosis in dogs with notched QRS complexes, as well as to describe the specific leads and number of leads with notched QRS complexes on ECG.

ANIMALS

Eighty-five dogs with notched QRS complexes of normal duration in at least one ECG lead.

METHODS

Retrospective review of digitally stored ECGs and associated medical records of dogs with a recorded ECG as part of routine clinical evaluation.

RESULTS

Age at time of ECG recording was 9.15 ± 3.38 years for the 85 dogs with notched QRS complexes in at least one ECG lead. The number of ECG leads with notched QRS complexes did not increase with age. Most dogs (69.4%) with notched QRS complexes had cardiac disease. The odds ratio of a dog having cardiac disease if more than one lead was identified with notched QRS complexes was 3.97. The most common cardiac disease identified was chronic atrioventricular valvular degeneration, and the majority of these dogs (80%) had two or less leads with notched QRS complexes.

CONCLUSIONS

Dogs with and without cardiac disease can have notched QRS complexes. The likelihood of a dog having cardiac disease that has more than one ECG lead with notched QRS complexes is significant, and this should warrant diagnostic evaluation.