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.

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.

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.

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 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.

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.

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.

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.

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.

Predicting efficacy of combined assessment with fragmented QRS and severely depressed heart rate variability on outcome of patients with acute myocardial infarction.

The association between fragmented QRS (fQRS) and autonomic nervous dysfunction, and major adverse cardiovascular events (MACE) is not fully clear in patients with acute myocardial infarction (AMI). This study aimed to observe whether combined assessment with fQRS and cardiac autonomic nervous function could enhance the predicting efficacy on outcome in AMI patients. A total of 153 consecutive hospitalized AMI patients were included in this retrospective study. Patients were divided into non-fQRS (nfQRS) group and fQRS group according to 12-lead electrocardiogram, into sHRV [severely depressed heart rate variability (HRV): standard deviation of NN intervals (SDNN) < 100 ms and very low frequency (VLF) < 26.7 ms] group and nsHRV (non-severely depressed HRV) group according to 24 h Holter monitoring, and into non-MACE (nMACE) group and MACE group according to 12 months' follow-up results. The incidence of sHRV was significantly higher in the fQRS group than in the nfQRS group (71.9 vs. 39.3%, p < 0.05). The incidences of MACE were 7.4, 22.2, 25.7 and 56.5%, respectively, in nsHRV + nfQRS group, nsHRV + fQRS group, sHRV + nfQRS group and sHRV + fQRS group (p < 0.05). Multivariable Cox regression analysis showed that patients in the sHRV + fQRS group had a sixfold higher risk of MACE compared to patients in the nsHRV + nfQRS group (HR = 6.228, 95% CI 1.849-20.984, p = 0.003). The predicting sensitivity and specificity on MACE were 81.4 and 58.2% by sHRV, 69.8 and 69.1% by fQRS in these AMI patients. The specificity (81.8%) was the highest with the combination of sHRV and fQRS. Adding sHRV and fQRS to clinical data offered incremental prognostic value. Present results indicate that fQRS is closely related to sHRV, suggesting significant impairment of sympathetic nerve function in AMI patients with fQRS. Combined assessment with fQRS and sHRV enhances the predicting efficacy on outcome in AMI patients.

Fragmented QRS in the relatives of patients with coronary artery disease.

BACKGROUND: Coronary artery disease (CAD) is one of the important causes of mortality. It has been emphasized that the risk of CAD may be increased in the relatives of CAD patients. Fragmented QRS (fQRS) is an electrocardiography (ECG) marker showing myocardial damage. METHODS: A study group of 62 symptomatic individuals (31 males, mean age 38.5 ± 7.12 years) with first-degree relatives with coronary artery disease and 64 healthy volunteers (24 males, mean age 37.9 ± 11.6 years) were included in this study. The study did not include those with known cardiac disease, metabolic disease, or drug use that may cause a change in ECG parameters. RESULTS: There was no significant difference between the groups regarding gender, heart rate, QRS complex, QTc, frontal QRS-T angle, and left ventricle ejection fraction. Compared to the control group, the QT interval and fQRS count were significantly higher in the study group (p < .05 for both). Low-density lipoprotein cholesterol (LDL-C), hemoglobin, and neutrophil counts were significantly higher in the study group compared to the control group (p < .05 for all). CONCLUSIONS: Our study showed that fQRS was increased in individuals with symptomatic first-degree relatives with coronary artery disease compared to healthy volunteers.

Fragmented QRS as a risk marker for the occurrence of ventricular fibrillation in patients with variant angina.

BACKGROUND: Variant angina (VA) is caused by reversible coronary artery spasm, which is characterized by chest pain with ST-segment elevations on standard 12-lead electrocardiogram (ECG) at rest. Ventricular fibrillation (VF) is often caused by VA attack, but the risk stratification is not well understood. The purpose of this study was to evaluate the impact of fragmented QRS (fQRS) on VF occurrence in VA patients. METHODS: Ninety-four patients who showed ST elevation on 12-lead ECGs with total or nearly total occlusion in response to coronary spasm provocation test were enrolled. Among them, 16 patients had documented VF before hospital admission (n = 12) or experienced VF during provocation test (n = 4) (VF occurrence group). The fQRS was defined as the presence of spikes within the QRS complex of two or more consecutive leads. RESULTS: The prevalence of fQRS was more often observed in the VF occurrence group than in the non-VF occurrence group (63% [10/16] vs. 27% [21/78], p = 0.009). Univariate analyses revealed that age, history of syncope, QTc, and the presence of fQRS were associated with VF occurrence (p = 0.004, 0.005, 0.029, and 0.008, respectively). Furthermore, upon multivariate analyses using those risk factors, age, QTc, and fQRS predicted VF occurrence independently (p = 0.007, 0.041, and 0.014, respectively). CONCLUSIONS: The present study demonstrated that fQRS in VA patients is a risk factor for VF. The fQRS may be a useful factor for the risk stratification of VF occurrence in VA patients.

Fragmented QRS is associated with ventricular arrhythmias in heart failure patients: A systematic review and meta-analysis.

INTRODUCTION: Many primary prevention heart failure (HF) patients with an implantable cardiac defibrillator (ICD) rarely experience life-threatening ventricular arrhythmias (VA). New strategies are required to identify patients most at risk of VA and sudden cardiac death who would benefit from an ICD. One potential method is the detection of fragmented QRS (fQRS) on the electrocardiogram. The aim was to assess the predictive capacity of fQRS for VA and mortality in ischemic (ICM) and non-ischemic cardiomyopathy (NICM) primary prevention HF patients. METHODS AND RESULTS: A systematic review and meta-analysis of studies examining fQRS in HF patients with or without an ICD who met primary prevention indications with reduced ejection fraction ≤40%. Outcome measures were VA (or appropriate ICD therapy) and all-cause mortality. Ten studies involving 3885 patients were included for analysis. Most patients were male with non-fQRS patients being significantly younger (-1.5[-2.66, -0.42], p = .03). Diabetes was more likely in fQRS patients (1.12[1.01, 1.25], p = .03) while non-fQRS patients were 28% more likely to have a history of atrial fibrillation (0.82[0.67,1.00], p = .05). Ventricular arrhythmias were significantly 1.5 times more likely in patients with fQRS (1.51[1.02, 2.25], p = .04). HF patients were 1.7 times more likely to die of any cause if fQRS was present (1.68[1.13, 2.52], p = .01). NICM patients with fQRS have a significant 2.6-fold increased incidence of death compared with ICM patients (2.55[1.63, 3.98], p < .0001). CONCLUSION: fQRS is associated with VA and all-cause mortality and may be a novel marker in the risk stratification of primary prevention HF patients indicated for ICD implantation.

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.

De-novo development of fragmented QRS during a six-month follow-up period in patients with COVID-19 disease and its cardiac effects.

OBJECTIVE: The aim of this study is to examine the probability of de-novo fQRS in patients with mild COVID-19 disease, as an indicator of cardiac injury. METHODS: Data of 256 patients with normal admission electrocardiography and no comorbidities between 1.12.2020-31.12.2021, were examined retrospectively 6-month after mild COVID-19 disease. Patients were divided into two groups: fQRS+ group (n = 102) and non-fQRS group (n = 154). Relation between fQRS and other electrocardiography, echocardiographic and laboratory findings were investigated. RESULTS: No significant difference was found between the groups among age and gender. Troponin-I and creatine kinase myocardial band values (retrospectively 9.10 ± 1.76 vs 0.74 ± 1.43, 34.05 ± 82.20 vs. 14.68 ± 4.42), COVID-19 IgG levels (45.78 ± 14.82 vs. 36.49 ± 17.68), diastolic dysfunction (39.21% vs. 15.07%), EF value (58.02 ± 1.95 vs. 64.27 ± 3.07), dyspnea (41.17% vs. 6.84%), post-COVID-19 tachycardia syndrome (19.6% vs. 2.74) were more frequent in fQRS+ group compared to non-fQRS group. The EF value was lower in the presence of fQRS in the high lateral leads (57.12 ± 1.99, 58.47 ± 1.79, p:0.018). There was a positive correlation between IgG value and endsystolic diameter, septum thickness and left atrium diameter. In multivariate analysis de-novo fQRS, dyspnea, high troponin and IgG values, diastolic dysfunction, low EF value and left atrial diameter were determined as independent risk factors for post-COVID-19 tachycardia syndrome in follow-up. CONCLUSION: In COVID-19 disease de-novo fQRS, dyspnea, high IgG and troponin value, left atrial diameter, lower EF value, diastolic dysfunction were associated with post-COVID-19 tachycardia syndrome. The de-novo fQRS in SARS-COV-2 may be a predictor of future more important adverse cardiovascular outcomes and this should alert clinicians.

Electrocardiographic Changes Associated with Early Repolarization Pattern in Healthy Young Males.

Background and Objectives: Early repolarization pattern (ERP) has recently been shown to be related with an increased risk of ventricular arrhythmias in susceptible individuals. Materials and Methods: We studied the ERP-associated ECG changes, with potential clinical relevance, in 220 young (age 22.1 ± 1.6 years), healthy, male subjects using 12-lead ECG recordings. A total of 38 subjects (17.3%) fulfilled the diagnostic criteria for ERP, and a total of 90 ECG characteristics were compared between the groups of subjects with and without ERP. Results: None of the ECGs were pathological, and 22 ECG parameters differed significantly (p < 0.05) between the subjects with and without ERP. Among them, the P wave-related parameters (e.g., average P wave duration: 101.5 ± 9.2 ms vs. 106.8 ± 9.9 ms, p = 0.004) and the presence of fragmented QRS complexes (67.6% vs. 92.1%, p = 0.002) revealed a potential propensity for atrial and ventricular arrhythmogenesis. The time-domain parameters of repolarization, those not corrected for QRS duration, showed shorter values (e.g., Tpeak-Tend interval: 70.9 ± 8.1 ms vs. 67.8 ± 8.0 ms, p = 0.036), reflecting the accelerated repolarization. Conclusions: Certain ECG characteristics seem to be more associated with ERP. The clinical significance of this finding at the individual level needs further prospective investigations.

The Relationship Between fragmented QRS Complexes (fQRS) and the Severity of Coronary Artery Lesion in Coronary Artery Disease: A Cross-sectional Study.

BACKGROUND: The severity of coronary artery lesion is commonly used as a predictor of mortality, major adverse cardiovascular event, and revascularization in coronary artery disease (CAD). Fragmented QRS complex (fQRS) is used as a marker of myocardial ischemia in patients with CAD. The relationship between the two should be studied further. The objective of this study was to determine the relationship between fQRS and the severity of coronary lesion in patients with CAD. METHODS: A cross-sectional study was conducted at Cipto Mangunkusumo Hospital Jakarta. Secondary data were taken from 172 patients with CAD who underwent percutaneous coronary intervention (PCI) from January to June 2018 with total sampling. Patients were divided into two groups based on the existence of fQRS. Demographic, clinical, and corangiography characteristics (Gensini score, total vascular lesion, and vascular lesion significance) were studied. Data were analyzed using agreement test and chi-square. RESULTS: fQRS was present in 94 subjects (54.6%). Bivariate analysis showed a significant difference between fQRS with mild-moderate Gensini score as well as mild-severe Gensini score (kappa = 0.721 and 0.820; p<0.001), fQRS with significant CAD (kappa = 0.670; p<0.001), and fQRS with multivessel CAD (kappa = 0.787; p<0.001). CONCLUSION: There is a significant relationship between fQRS and the degree of severity of coronary lesion in CAD patients.

Prognostic impact of multiple fragmented QRS on cardiac events in idiopathic dilated cardiomyopathy.

AIMS: To evaluate the prognostic impact of fragmented QRS (fQRS) on idiopathic dilated cardiomyopathy (DCM). METHODS AND RESULTS: We conducted a prospective observational study of 290 consecutive patients with DCM (left ventricular ejection fraction ≤ 40%) and narrow QRS who underwent cardiac magnetic resonance. We defined fQRS as the presence of various RSR' patterns in ≥2 contiguous leads representing the anterior (V1-V5), inferior (II, III, and aVF), or lateral (I, aVL, and V6) myocardial segments. Multiple fQRS was defined as the presence of fQRS in ≥2 myocardial segments. Patients were divided into three groups: no fQRS, single fQRS, or multiple fQRS. The primary endpoint was a composite of hard cardiac events consisting of heart failure death, sudden cardiac death (SCD), or aborted SCD. The secondary endpoints were all-cause death and arrhythmic event. During a median follow-up of 3.8 years (interquartile range, 1.8-6.2), 31 (11%) patients experienced hard cardiac events. Kaplan-Meier analysis showed that the rates of hard cardiac events and all-cause death were similar in the single-fQRS and no-fQRS groups and higher in the multiple-fQRS group (P = 0.004 and P = 0.017, respectively). Multivariable Cox regression identified that multiple fQRS is a significant predictor of hard cardiac events (hazard ratio, 2.23; 95% confidence interval, 1.07-4.62; P = 0.032). The multiple-fQRS group had the highest prevalence of a diffuse late gadolinium enhancement pattern (no fQRS, 21%; single fQRS, 22%; multiple fQRS, 39%; P < 0.001). CONCLUSION: Multiple fQRS, but not single fQRS, is associated with future hard cardiac events in patients with DCM.