Ventriculo-arterial (VA) coupling and fQRS as new selection criteria for primary prevention ICD placement.

For decades, left ventricular ejection fraction (LVEF < 35%) has been a mainstay for identifying heart failure (HF) patients most likely to benefit from an implantable cardioverter defibrillator (ICD). However, LVEF is a poor predictor of sudden cardiac death (SCD) and ignores 50% of HF patients with mildly reduced and preserved LVEF. The current international guidelines for primary prophylaxis ICD therapy are inadequate. Instead of LVEF, which is not a good measure of LV contractility or hemodynamic characterization, we hypothesize ventriculo-arterial (VA) coupling combined with fragmented QRS (fQRS) will improve risk stratification and patient suitability for an ICD. Quantifying cardiac and aortic mechanics, and predicting active arrhythmogenic substrate, from varying fQRS morphologies, may help to stratify ischemic and non-ischemic patients with different functional capacities and predisposition for lethal arrhythmias. We propose HF patients with a low physiological reserve may not benefit from ICD therapy, whereas those patients with higher reserves and extensive arrhythmogenic substrate may benefit. Our hypothesis combining VA coupling with fQRS changes has the potential to widen HF patient participation (low and high LVEF) and advance personalized medicine for HF patients at high risk of SCD.

Significance of fragmented QRS and predictors of outcome in ST-elevation myocardial infarction.

Background: Fragmented QRS (fQRS) might be associated with certain characteristics in ST-elevation myocardial infarction (STEMI) patients and inhospital adverse events. Materials and Methods: A sum of 500 patients were gone over retrospectively. Patients with STEMI, all undergone percutaneous coronary intervention, were grouped as fQRS (-) and fQRS (+). Characteristics of the patients, major adverse cardiac event (MACE), death in hospital, nonfatal myocardial infarction (MI), stent thrombosis, slow flow myocardial perfusion, development of ventricular tachycardia (VT) and fibrillation, cardiogenic shock and cardiopulmonary arrest were filtered. Results: FQRS (-) group was composed of 207 patients whose mean age was 61.1 ± 12.1, whereas 293 patients were there in fQRS (+) with a mean age of 66.7 ± 10.6 (P < 0.001). Thrombolysis in MI (TIMI) (P < 0.01), the global registry of acute coronary events (GRACE) (P < 0.01) scores, white blood cell count, neutrophil/lymphocyte ratio, MACE and the ratio of death in hospital and VT in the hospital were significantly higher in fQRS (+) group (P < 0.001, for remaining all). In multivariate logistic regression analysis, TIMI scores above 2 and GRACE scores above 109 were determined as independent predictors of MACE in the entire patient group (odds ratio [OR]: 2.022; 95% confidence interval [CI]; 1.321-3.424, P = 0.003; OR: 1.712; 95% CI: 1.156-2.804, P = 0.008). Conclusion: FQRS (+) and fQRS (-) patients markedly differ from each other in terms of certain demographic and clinical features and TIMI and GRACE scores have a significant predictive value for MACE in all STEMI patients' group.

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.

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.

Fragmented Ventricular Complexes and Blood Pressure Variability Assessed by Ambulatory Blood Pressure Monitoring in Patients With Metabolic Syndrome.

Introduction Hypertension is a leading risk factor for the development of cardiovascular and metabolic derangements. In patients with metabolic syndrome (MetS), hypertension is one of the cornerstones showing high variability which is detected in ambulatory blood pressure monitoring. Fragmented ventricular complexes on ECG are seen as hypertensives and are a viable and easy measure of myocardial fibrosis even in the absence of obvious hypertrophy. Aim The present study was undertaken to study the blood pressure variability in patients of MetS with fragmented QRS (fQRS) versus normal ventricular complexes (QRS). Results Out of 100 patients, 22 (22%) had fQRS complexes. Hypertension and diabetes were the most prevalent associated in both groups but a difference was seen with coronary artery disease, which was significantly associated in the fQRS group (8.97% vs 95.45%, p<0.001) as compared to the non-fQRS group. Significant differences were observed in waist circumference (p=0.019), triglyceride (p=0.006) and left ventricular ejection fraction (p<0.001) between the two groups. There was a marked difference (p<0.05) between heart rate variability during day and night time between normal and fQRS sub-groups, being higher in the latter. A similar pattern of change was observed for systolic and diastolic blood pressures and associated dipping. Conclusion Significant differences exist between heart rate and blood pressure changes in patients with fQRS of MetS, thus making fQRS a potent indicator of cardiovascular status.

Evaluation of QRS duration and presence of fragmented QRS in patients with inflammatory bowel disease.

Background: Inflammatory Bowel Disease (IBD) is mostly characterized by gastrointestinal tract involvement, however can also be accompanied with cardiac manifestations. QRS prolongation and the presence of QRS fragmentation (fQRS) have been previously evaluated in many chronic inflammatory diseases, as an independent predictor of cardiac events. In this study, we aimed to evaluate the QRS duration and fQRS in patients with IBD. Methods: The presented study was designed as a single-center retrospective cohort study. The study population consisted of 217 patients with IBD and 195 healthy controls. QRS duration and presence of fQRS were evaluated using a 12-lead electrocardiogram. These parameters were compared between groups. Results: QRS duration was demonstrated to be higher in the IBD group compared to the control group (92 (86-98) vs. 82 (75-90), p<0.001). The presence of fQRS was significantly higher in the IBD group (n=101 (47%) vs n=59 (30%), p=0.006). In addition, a positive correlation was demonstrated between QRS duration and disease duration (Spearman's Rho= 0.4, p<0.001). Notably, disease and QRS duration were significantly higher in the fQRS (+) group (102 (56.5-154) vs. 55 (24.3-118.3), <0.001; 94 (86-100) vs. 92 (84-96), 0.016; respectively). Conclusion: Our results demonstrated that QRS prolongation and the presence of fQRS (+) were more common in IBD patients, and associated with longer disease duration. These findings may indicate subclinical cardiac involvement in IBD. Therefore, IBD patients, especially those with long-standing disease, should be followed more closely in terms of cardiac manifestations.

Relationship between fragmented QRS complex and early left ventricular dysfunction after mitral valve repair.

BACKGROUND: Preoperative left ventricular (LV) ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair (MVR). Fragmented QRS (fQRS) evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. In the present study, we aimed to evaluate the relationship between fQRS in preoperative 12­lead electrocardiography (ECG) and postoperative LV dysfunction that develop after MVR in patients with severe primary mitral regurgitation (MR) due to mitral valve prolapse (MVP). METHODS: From 2019 to 2022, 49 patients who had undergone successful MVR surgery for severeMR caused by MVP were enrolled in the study. The preoperative and postoperative echocardiographic data were collected retrospectively. We analyzed the demographic, echocardiographic, operative and postoperative parameters to assess the relationship between fQRS and early postoperative LV dysfunction, defined as an LVEF<60%. RESULTS: PreLVEF of all patients were ≥ %65. A total of 22 patients had fQRS (44.9%) and postoperative LV dysfunction was found to be 36.7%. A significantly higher rate of fQRS was observed in the group with postoperative LV dysfunction compared to the group without (12 (66.7%) vs 10 (32.3%), p: 0.036). In multivariate analysis for fQRS, PreESD, preoperative pulmonary artery systolic pressure (PrePASP), preoperative atrial fibrillation (PreAF), and male gender, only fQRS was found to be a significant predictor of postoperative LV dysfunction (p: 0.003, OR: 4.28, 95% CI (1.15-15.96). CONCLUSION: fQRS was found to be a predictor of postoperative LV dysfunction in the early period after MVR. fQRS may be a readily available and cost-effective test that can be used in clinical practice to predict postoperative LV dysfunction in patients undergoing MVR.

Fragmented QRS complex could predict all-cause mortality in patients with connective tissue disease-associated pulmonary arterial hypertension.

OBJECTIVES: To investigate the prognostic impact and pathophysiological characteristics of fragmented QRS complex (fQRS) on patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH). METHODS: This was a multicentre retrospective study recruiting 141 patients with CTD-PAH diagnosed by right heart catheterization (114 cases in the discovery cohort and 27 cases in the validation cohort). fQRS and ST-T change were detected on conventional 12-lead electrocardiogram (ECG). Patients were followed up every 3 months to update their status and the primary end point was all-cause death. Clinical information and ECG characteristics were compared between survival and death groups and Kaplan-Meier curve was used for survival analysis. RESULTS: There were significant differences in age, gender, 6-min walk distance, NT-proBNP, WHO class, presence of fQRS and presence of ST-T change in inferior leads between survival group and death group. Inferior fQRS and ST-T change were significantly associated with right ventricular (RV) dilatation and reduced RV ejection fraction (RVEF). Kaplan-Meier curve showed that all-cause mortality was higher in CTD-PAH with fQRS (p= 0.003) and inferior ST-T change (p= 0.012). Low- and intermediate-risk CTD-PAH with inferior ST-T change had higher all-cause mortality (p= 0.005). The prognostic value of fQRS and inferior ST-T change was validated in external validation cohort. CONCLUSION: The presence of inferior fQRS and ST-T change could predict poor prognosis in CTD-PAH. CLINICAL TRIAL REGISTRATION NUMBER: NCT05980728, https://clinicaltrials.gov.

Fragmented QRS, a strong predictor of mortality and major arrhythmic events in patients with nonischemic cardiomyopathy: A systematic review and meta-analysis.

Background and Aims: Fragmented QRS (fQRS), which is associated with rhythm disturbances, can predispose the heart to fatal ventricular arrhythmias. Recently, accumulating studies indicates that fQRS is associated with poor prognosis in various types of cardiomyopathies. Therefore, we assessed the association between fQRS with all-cause mortality and major arrhythmic events (MAEs) in patients with nonischemic cardiomyopathy, in this systematic review and meta-analysis study. Methods: We performed a comprehensive search in databases of PubMed/Medline, EMBASE, and Web of Science from the beginning to December 31, 2022. Published observational studies (cohorts, case-control, or analytical cross-sectional studies) were included that report the prognostic value of fQRS in patients with different types of nonischemic cardiomyopathies for MAEs (sudden cardiac death, sudden cardiac arrest, sustained ventricular tachycardia [VT], ventricular fibrillation [VF], and appropriate shock) and all-cause mortality. We pooled risk ratios (RRs) through raw data and adjusted hazard ratios (aHRs) using "Comprehensive Meta-Analysis" software, Version 2.0. Results: Nineteen cohort and three analytical cross-sectional studies were included in this meta-analysis involving a total of 4318 subjects with nonischemic cardiomyopathy (1279 with fQRS and 3039 without fQRS). FQRS was significantly associated with an increased risk of all-cause mortality in patients with nonischemic cardiomyopathy (pooled RR: 1.920; 95% confidence interval [CI]: 1.388-2.656, p < 0.0001/pooled HR: 1.729; 95% CI: 1.327-2.251, p < 0.0001). Also, the risk of developing MAEs in the presence of fQRS was significantly increased (pooled RR: 2.041; 95% CI: 1.644-2.533, p < 0.0001/pooled HR: 3.626; 95% CI: 2.119-6.204, p < 0.0001). In the subgroup analysis, the strongest association between fQRS presence and increased MAEs was observed in patients with hypertrophic cardiomyopathy (HCM) (pooled RR: 3.44; 95% CI: 2.07-5.71, p < 0.0001/pooled HR: 3.21; 95% CI: 2.04-5.06, p < 0.0001). Conclusion: Fragmented QRS could be a prognostic marker for all-cause mortality and MAEs in patients with various types of nonischemic cardiomyopathies, particularly HCM.

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.

The impact of fragmented QRS on clinical findings and outcomes in children with dilated cardiomyopathy with or without left ventricular non-compaction.

OBJECTIVE: The aim of this study is to investigate the frequency of fragmented QRS and its associations with clinical findings and prognosis in children diagnosed with dilated cardiomyopathy with or without left ventricular non-compaction. METHODS: This retrospective study was conducted between 2010 and 2020. Patients with dilated cardiomyopathy were classified into two groups according to the presence of left ventricular non-compaction: Dilated cardiomyopathy with left ventricular non-compaction and dilated cardiomyopathy without left ventricular non-compaction. Patients were also divided into two groups according to the presence of fragmented QRS (fragmented QRS group and non-fragmented QRS group). RESULTS: Twenty-three of 44 patients (52.3%) were male. Among left ventricular non-compaction patients, the fragmented QRS group had more complex ventricular arrhythmias (p = 0.003). Patients with fragmented QRS had a significantly higher rate of major adverse cardiac events and/or cardiac death in both cardiomyopathy groups (p = 0.003 and p = 0.005). However, the rate of major adverse cardiac events and/or cardiac death was similar between dilated cardiomyopathy patients with and without left ventricular non-compaction. Multivariate logistic regression analysis showed that the presence of fragmented QRS strongly predicts major adverse cardiac events and/or cardiac death (odds ratio, 31.186; 95% confidence interval, 2.347-414.307). Although the survival rates between cardiomyopathy groups were similar, patients with fragmented QRS had a markedly lower survival rate during the follow-up period, as mean of 15 months (p = 0.001). CONCLUSION: Our study showed that the presence of fragmented QRS may be an important ECG sign predicting an major adverse cardiac event and/or cardiac death in patients with dilated cardiomyopathy. We believe that recognising fragmented QRS could be valuable in forecasting patient prognosis and identifying high-risk patients who require additional support.

Unveiling cardiac insights: Exploring early left ventricular dysfunction in polycythemia vera through 4D-STE and fragmented QRS analysis.

BACKGROUND: Polycythemia vera (PV), characterized by elevated red blood cell counts, poses challenges to cardiovascular health with potential impacts on cardiac function. Myocardial infarction (MI) and heart failure are major causes of mortality in PV patients. Early detection of left ventricular systolic dysfunction is crucial for optimizing outcomes. METHODS: Fifty-two PV patients and 45 healthy controls were recruited. Four-dimensional speckle tracking echocardiography (4D-STE) and fragmented QRS complexes (fQRS) on electrocardiograms were utilized to assess cardiac mechanics. Hematological and echocardiographic parameters were measured, and statistical analyses were performed. RESULTS: PV patients exhibited significantly higher hematocrit and red cell distribution width compared to controls. Global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) were lower in PV patients. fQRS complexes were associated with longer disease duration and reduced GCS and GAS values. Hematocrit correlated positively with LV-GCS and LV-GAS. Multiple linear regression revealed that disease duration and fQRS presence independently predicted LV-GAS. CONCLUSION: This study underscores the intricate link between elevated red blood cell counts, disease duration, and cardiac function in PV patients. Combining 4D-STE and fQRS complexes enhances the identification of early left ventricular systolic dysfunction. These findings offer potential improvements in recognizing and managing cardiovascular complications in PV patients, with implications for future research and clinical practice. Further investigations are needed to elucidate underlying mechanisms and validate these markers in larger cohorts.

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.

Four-dimensional speckle tracking echocardiography and fragmented QRS in detection of early left ventricular systolic dysfunction in patients with subclinical hyperthyroidism.

BACKGROUND: Thyroid disorders are associated with many cardiovascular risk factors. The importance of thyroid hormones in the pathophysiology of heart failure is underlined by the European guidelines of the European Society of Cardiology. However, the role of subclinical hyperthyroidism (SCH) in subclinical left ventricular (LV) systolic dysfunction is not entirely clear. METHODS: This cross-sectional study included 56 SCH patients and 40 healthy volunteers. The 56 SCH group was divided into two subgroups depending on the presence of fragmented QRS (fQRS). In both groups, left ventricular global area strain (LV-GAS), global radial strain (GRS), global longitudinal strain (GLS), and global circumferential strain (GCS) were obtained with four-dimensional (4D) echocardiography. RESULTS: GAS, GRS, GLS, and GCS values were significantly different in SCH patients and in healthy volunteers. GLS and GAS values were lower in the fQRS+ than in the fQRS- group (-17.06 ± 1.00 vs. -19.08 ± 1.71, p < .001, and -26.61 ± 2.38 vs. -30.61 ± 2.57, p < .001, respectively). ProBNP was positively correlated with LV-GLS (r = 0.278, p = .006) and LV-GAS (r = 0.357, p < .001). Multiple linear regression analysis showed that fQRS was an independent predictor of LV-GAS. CONCLUSIONS: 4D strain echocardiography may be helpful for the prediction of early cardiac dysfunction in patients with SCH. The presence of fQRS may be an indicator of subclinical LV dysfunction in SCH.

Prognostic value of fragmented QRS in acute pulmonary embolism: a cross-sectional-analytic study of the Iranian population.

BACKGROUND: Acute Pulmonary embolism (APE) is considered one of the deadliest cardiovascular diseases. Electrocardiographic (ECG) abnormalities in pulmonary embolism (PE) are increasingly reported. A growing number of studies have recommended that ECG plays a crucial role in the prognostic assessment of PE patients. However, there is scarce data on the prognostic importance of fragmented QRS (fQRS) on outcomes in patients with APE. This study aims to investigate the prognostic value of fQRS in APE patients. MATERIALS AND METHODS: This is a cross-sectional-analytic study. This study included 280 patients diagnosed with APE admitted to Shahid Madani hospital, Tabriz, Iran. Computed tomography pulmonary angiography (CTPA) was used to diagnose APE. A checklist was prepared for all patients, demographic, clinical characteristics, and Major Adverse Cardiopulmonary events (MACPE), including in-hospital mortality, need for thrombolysis, mechanical ventilation, and surgical embolectomy, were recorded. Patients were divided into two groups: patients who manifested fQRS on their ECG and patients who did not; Then, demographic, clinical characteristics, and MACPE were compared in the two groups, as mentioned earlier. Furthermore, all statistical analyses were carried out using SPSS software. RESULTS: 48 patients (17.14%) had fQRS(+) on their ECG, and 232 patients (82.86%) did not have it on their ECG. In data analysis, 22 patients (8.7%) had in-hospital mortality, 35 patients (13.9%) needed thrombolysis, nine patients (3.9%) required mechanical ventilation, and 13 patients (5.1%) needed surgical embolectomy. fQRS was not significantly associated with in-hospital mortality (P = 0.225), need for thrombolysis (P = 0.684), mechanical ventilation (P = 1.000), and surgical embolectomy (P = 1.000). Demographic and clinical characteristics were also similar in both groups. CONCLUSIONS: This study does not support the idea that fQRS on ECG is a valuable predictor of in-hospital mortality, the need for thrombolysis, mechanical ventilation, and surgical embolectomy.

QRS Fragmentation in Preserved Ejection Fraction Heart Failure: Functional Insights, Pathological Correlates, and Prognosis.

Background Fragmented QRS (fQRS) morphology as a surrogate marker of the possible presence of myocardial scarring has been shown to confer a higher risk in patients with reduced ejection fraction heart failure. We aimed to investigate the pathophysiological correlates and prognostic implications of fQRS in patients with heart failure with preserved ejection fraction (HFpEF). Methods and Results We consecutively studied 960 patients with HFpEF (76.4±12.7 years, men: 37.2%). fQRS was assessed using a body surface ECG during hospitalization. QRS morphology was available and classified into 3 categories among 960 subjects with HFpEF as non-fQRS, inferior fQRS, and anterior/lateral fQRS groups. Despite comparable clinical features in most baseline demographics among the 3 fQRS categories, anterior/lateral fQRS showed significantly higher B-type natriuretic peptide/troponin levels (both P<0.001), with both the inferior and anterior/lateral fQRS HFpEF groups demonstrating a higher degree of unfavorable cardiac remodeling, greater extent of myocardial perfusion defect, and slower coronary flow phenomenon (all P<0.05). Patients with anterior/lateral fQRS HFpEF exhibited significantly altered cardiac structure/function and more impaired diastolic indices (all P<0.05). During a median of 657 days follow-up, the presence of anterior/lateral fQRS conferred a doubled HF re-admission risk (adjusted hazard ratio 1.90, P<0.001), with both inferior and anterior/lateral fQRS having a higher risk of cardiovascular and all-cause death (all P<0.05) by using Cox regression models. Conclusions The presence of fQRS in HFpEF was associated with more extensive myocardial perfusion defects and worsened mechanics, which possibly denotes a more severe involvement of cardiac damage. Early recognition in such patients with HFpEF likely benefits from targeted therapeutic interventions.

Fragmented QRS on 12-lead electrocardiogram predicts long-term prognosis in patients with cardiac sarcoidosis.

Fragmented QRS (fQRS) on a 12-lead electrocardiogram is a known marker of fatal arrhythmias or cardiac adverse events in ischemic and non-ischemic cardiomyopathy patients. Nonetheless, the association between fQRS and clinical outcomes in patients with cardiac sarcoidosis (CS) remains unclear. Herein, we investigated whether fQRS is associated with long-term clinical outcomes in CS patients. A total of 78 patients who received immunosuppressive therapy (IST) for clinically diagnosed CS were retrospectively examined. Patients were classified into two groups according to the presence (n = 19) or absence (n = 59) of fQRS on electrocardiogram before IST. The primary outcome was the composite event of all-cause death, ventricular tachyarrhythmias (VTs), and hospitalization for heart failure. Results of late gadolinium enhancement on cardiac magnetic resonance imaging were also analyzed. During a median follow-up period of 3.7 years (interquartile range: 1.6-6.2 years), the primary outcome occurred more frequently in patients with fQRS than in those without (47% vs. 13%, log-rank p = 0.002). Multivariable Cox regression analyses showed that fQRS was an independent determinant of the primary outcome. The incidence of VTs, within 12 months of IST initiation, was comparable between the two groups; however, late-onset VTs, defined as those occurring ≥ 12 months after IST initiation, occurred more frequently in the fQRS group (21% vs. 2%, log-rank p = 0.002). The scar zone and scar border zone were greater in patients with fQRS than in those without it. In conclusion, our analysis suggests that fQRS is an independent predictor of adverse events, particularly late-onset VTs, in patients with CS.

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.

Validation of CalECG software for primary prevention heart failure patients: Reducing inter-observer measurement variability.

BACKGROUND: In primary prevention heart failure patients the 12­lead electrocardiogram (ECG) may be useful for the prediction of ventricular arrhythmias. However, inter-observer measurement variability first needs to be identified and any software used, validated. OBJECTIVE: To compare manual ECG measures with CalECG software and to assess the reliability of visual recognition of fragmented QRS (fQRS) by advanced cardiology trainees. METHODS: 30 pre-implant ECGs were assessed on patients who met guidelines for primary prevention Implantable Cardiac Defibrillator. Parameters included RR, PR, QT, QRS duration, axis location, fQRS and T wave peak to T wave end (TpTe). ECGs were analyzed by members of the cardiology department with different levels of experience, and compared to CalECG software. Interobserver agreement was assessed using Fleiss' Kappa (κ) and intraclass correlation coefficients (ICC). Pearson correlation coefficient (r) was used to compare human and software measures. RESULTS: Strong/very strong correlation was recorded across manual ECG measures (ICC = 0.749-0.979, p ≤ 0.0001) with moderate/strong correlation for TpTe (ICC = 0.547-0.765, p ≤ 0.001). Advanced cardiology trainees demonstrated substantial agreement on ECG interpretation (κ = 0.788, p ≤ 0.0001), however, reliability of fQRS assessment was only moderate for identification (κ = 0.5, p ≤ 0.0001) and fair for location (κ = 0.295, p = 0.001). CalECG software showed strong/very strong correlation with manual measurement for standard measures (r = 0.756-0.977, p ≤ 0.001). Concordance between human and software TpTe measurements varied between leads, with V5 showing a non-significant weak correlation (r = 0.197). CONCLUSION: CalECG software showed strong/very strong correlation with standard manual measures which affirms its use in ECG analysis. Advanced cardiology trainees showed greater variability in the identification and location of fQRS.