Presence Of Fragmented QRS Complexes Research Articles

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.

QRS-Fragmentation: Perspectives for Use in Clinical Practice

The current article provides a detail review of foreign publications, discussing the opportunities and the benefits of evaluation of the QRS-fragmentation (fQRS) a new electrocardiographic (ECG) parameter in patients with coronary artery disease (CAD). Diagnostic criteria for narrow and wide QRS-complexes are defined. Main results of the comparative and correlation analysis, evaluating fQRS and electrocardiographic (pathologic Q-waves), echocardiographic (left ventricular ejection fraction), angiographic settings are described. There is a discussion of the prognostic role of fQRS in stable CAD as well as in patients presented with acute myocardial infarction. fQRS is an available ECG-marker of local myocardial fibrosis. It seems to be a useful negative predictor in individuals with CAD, indicating an increased risk of life-threatening ventricular arrhythmias and recurrent cardiac events. The presence of fragmented QRS-complexes is associated with an increased in-hospital and long term (overall as well as cardiovascular) mortality. Routine evaluation of fQRS in standard ECG leads does not require additional resources, and will contribute to an improvement in diagnostics and risk stratification of stable CAD as well as myocardial infarction. Assessment of fQRS can be included in noninvasive diagnostic algorithm concerning CAD.

Use of Electrocardiographic Screening to Clear Athletes for Return to Sports Following COVID-19 Infection.

ObjectiveTo quantify the occurrence rate of abnormal electrocardiographic (ECG) findings and symptoms following coronavirus disease 2019 (COVID-19) infection.Patients and MethodsIn this retrospective analysis, we studied adult patients (>18 years old) who were participating in collegiate athletics and previously tested positive for COVID-19 between August 1, 2020, and December 30, 2020. The athletes underwent general examinations and ECG screening prior to being medically cleared for a return to sports following their COVID-19 diagnosis. Predetermined predictors were grouped into categorical variables including (1) sex, (2) symptom severity, and (3) body mass index (normal vs overweight [≥24 kg/m2]). These variables were used to examine differences of abnormal rates that occurred between different predictor categories.ResultsOf the 170 athletes screened, 6 (3.5%) presented with abnormal ECG findings and were referred to cardiologists. We found no evidence that sex, symptom severity, and body mass index category were associated with a higher rate of abnormal ECG findings (all P>.05). Greater severity of COVID-19 symptoms was associated with a higher percentage of ST depression, T-wave inversion, ST-T changes, and the presence of fragmented QRS complex. Loss of smell, loss of taste, headache, and fatigue were the most prevalent symptoms, with 38.8% (66), 36.5% (62), 32.9% (56), and 25.3% (43), respectively, of the 170 athletes reporting each symptom.ConclusionPreliminary findings indicate a low risk of myocardial injury secondary to COVID-19 infection, with less than 4% of the 170 patients in our study presenting with abnormal ECG findings and a total of 16 patients (9.4%) requiring referral to a cardiologist. Although viral myocarditis was not detected in any athlete referred for cardiological assessment, 2 patients experienced effusive viral pericarditis.

The Relationship between the Retinal Nerve Fiber Layer Thickness and the Presence of Fragmented QRS Complexes in Patients with Hypertension

Background: Fragmented QRS (fQRS) detected on electrocardiography (ECG) has been demonstrated to be a marker of myocardial fibrosis in hypertensive patients. Retinal microvascular abnormalities reflect cumulative microcirculatory damage resulting from hypertension and atherosclerosis. In this study, we aimed to evaluate the retinal nerve fiber layer (RNFL) thickness in hypertensive patients with and without fQRS complexes detected on ECG. Methods: Consecutive patients who were diagnosed with hypertension were included in the study. ECG and transthoracic echocardiography were performed to all patients. fQRS was defined as additional R’ wave or notching/splitting of S wave in two contiguous ECG leads. The RNFL thickness was measured by a spectral-domain optical coherence tomography device along a circle around the center of the optic disc. Results: This observational case-control study enrolled 62 (42 female, mean age: 54.3±9.9 years) hypertensive patients with fQRS and 42 (24 female, mean age: 53.1±11.8 years) hypertensive control patients without fQRS between April 2017 and October 2017. There was no significant difference between groups regarding demagraphic, laboratory and echocardiographic parameters. In all retinal quadrants, the mean RNFL thickness did not differ significantly between patients with fQRS(+) and fQRS(-) group. Conclusion: The presence of fQRS in the ECG had no significant effect on the RNFL thickness in hypertensive patients. Detection of fQRS may not be used as a useful non-invasive technique in the evaluation of atherosclerosis in hypertensive patients.

Body mass index is a predictor of presence of fragmented QRS complexes on electrocardiography independent of underlying cardiovascular status

BackgroundFragmented QRS (fQRS) as a sign of myocardial fibrosis indicates adverse outcomes in various cardiovascular diseases. However, there are no clear data regarding relationship between obesity and fQRS. We aimed to investigate whether high body mass index (BMI) predicts fQRS on electrocardiography (ECG) independent of underlying cardiovascular status. MethodsA total of 1530 patients were included into the study. Patients were divided into three groups according to BMI (normal, overweight and obese). Groups were compared regarding frequency of fQRS on ECG and we investigated the correlation between BMI and fQRS. ResultsAmong study population, 841 patients had normal BMI, 402 patients were overweight, and 287 patients were obese. Obese patients had significantly higher frequency of fQRS on ECG compared to non-obese patients (p < 0,001). Furthermore, multivariate logistic regression analysis revealed that BMI is an independent predictor of presence of fQRS on ECG (OR:1,220, 95% CI: 1,177–1,266, p < 0.0001). ConclusionBMI predicts fQRS independent of underlying cardiovascular status. Similar to cardiovascular diseases, BMI should be taken into consideration when using fQRS as a prognostic marker.

The effect of circadian blood pressure pattern on presence of fragmented QRS complexes in hypertensive subjects

The association of deteriorated circadian blood pressure (BP) variability with presence of fragmented QRS (fQRS) on electrocardiography (ECG) is not clear. The present study aims to evaluate the relationship of BP patterns with presence of fQRS on ECG. A total of 338 consecutive newly diagnosed and never treated hypertensive patients who are without left ventricular hypertrophy and underwent 24-hour ambulatory BP monitoring were enrolled. Patients were classified as dippers, nondippers, and reverse dippers according to ambulatory BP monitoring results. The groups were compared regarding frequency of fQRS on ECG. The frequency of fQRS was significantly higher in reverse dippers compared with dippers (37.7% vs. 20.6%, P = .013). In multivariate logistic regression analysis, nighttime systolic BP was found to be an independent predictor of fQRS on ECG (P < .001, 95% confidence interval = 0.901–0.955). Other predictors of fQRS were daytime diastolic BP and age. Furthermore, fQRS was found to be an independent predictor of reverse dipping BP pattern in hypertensive patients (P = .004, odds ratio: 2.416, 95% confidence interval = 1.327–4.396). In conclusion, as a marker of fibrosis and higher fibrotic burden within myocardium, fQRS may be useful to determine the high-risk hypertensive patients in the absence of left ventricular hypertrophy.

Comparison of the presence of fragmented QRS complexes in the inferior versus the anterior leads for predicting coronary artery disease severity

IntroductionFragmented QRS complexes (fQRS) are a sign of myocardial scar and are associated with adverse outcomes and mortality in patients with coronary artery disease (CAD). However, little is known about the significance of fQRS or of their localization on electrocardiography (ECG) in patients without known CAD. We aimed to investigate the association between localization of fQRS on ECG and CAD severity in patients undergoing a first diagnostic coronary angiography. MethodsWe enrolled 135 consecutive patients who had a narrow fQRS on ECG and underwent a first diagnostic coronary angiography. Patients were divided into two groups based on localization of fQRS on ECG (group 1: fQRS in the inferior leads, group 2: fQRS in the anterior leads). The groups were compared regarding the presence of significant CAD, multivessel disease (MVD) and SYNTAX score (SXscore). ResultsEighty-six (63.7%) patients had fQRS in the inferior leads and 49 (36.3%) had fQRS in the anterior leads. There was no statistically significant difference between the groups regarding presence of significant CAD (47.7% vs. 51%, p=0.708). However, the incidence of MVD was significantly higher in group 2 compared to group 1 (10.5% vs. 28.6%, p=0.007). The median SXscore (6 [3,12] vs. 8 [4,24], p=0.047), and incidence of patients with SXscore >22 were significantly higher in group 2 compared to group 1 (3.5% vs. 20.4%, p=0.009). ConclusionThe presence of fQRS in the anterior leads may indicate more severe CAD compared to fQRS in the inferior leads in patients undergoing a first diagnostic coronary angiography.

Comparison of the presence of fragmented QRS complexes in the inferior versus the anterior leads for predicting coronary artery disease severity

IntroductionFragmented QRS complexes (fQRS) are a sign of myocardial scar and are associated with adverse outcomes and mortality in patients with coronary artery disease (CAD). However, little is known about the significance of fQRS or of their localization on electrocardiography (ECG) in patients without known CAD. We aimed to investigate the association between localization of fQRS on ECG and CAD severity in patients undergoing a first diagnostic coronary angiography. MethodsWe enrolled 135 consecutive patients who had a narrow fQRS on ECG and underwent a first diagnostic coronary angiography. Patients were divided into two groups based on localization of fQRS on ECG (group 1: fQRS in the inferior leads, group 2: fQRS in the anterior leads). The groups were compared regarding the presence of significant CAD, multivessel disease (MVD) and SYNTAX score (SXscore). ResultsEighty-six (63.7%) patients had fQRS in the inferior leads and 49 (36.3%) had fQRS in the anterior leads. There was no statistically significant difference between the groups regarding presence of significant CAD (47.7% vs. 51%, p=0.708). However, the incidence of MVD was significantly higher in group 2 compared to group 1 (10.5% vs. 28.6%, p=0.007). The median SXscore (6 [3,12] vs. 8 [4,24], p=0.047), and incidence of patients with SXscore >22 were significantly higher in group 2 compared to group 1 (3.5% vs. 20.4%, p=0.009). ConclusionThe presence of fQRS in the anterior leads may indicate more severe CAD compared to fQRS in the inferior leads in patients undergoing a first diagnostic coronary angiography.

Quantitative Assessment of Vectorcardiographic Loop Morphology

Vectorcardiography (VCG), developed 100years ago, characterizes clinically important electrophysiological properties of the heart. In this study, VCG QRS loop roundness, planarity, thickness, rotational angle, and dihedral angle were measured in 81 healthy control subjects (39.0±14.2y; 51.8% male; 94% white), and 8 patients with infarct-cardiomyopathy and sustained monomorphic ventricular tachycardia (VT) (68.0±7.8y, 37.5% male). The angle between two consecutive QRS vectors was defined as the rotational angle, while dihedral angle quantified planar alteration over the QRS loop. In VT subjects, planarity index decreased (0.63±0.22 vs. 0.88±0.10; P=0.014), and dihedral angle was significantly more variable (variance of dihedral angle, median (IQR): 897(575–1450) vs. 542(343–773); P=0.029; rMSSD: 47.7±12.7 vs. 35.1±13.1; P=0.027). Abnormal electrophysiological substrate in VT patients is characterized by the appearance of QRS loop folding, likely due to local conduction block. The presence of fragmented QRS complexes on the 12-lead ECG had low sensitivity (31%) for detecting QRS loop folding on the VCG.

Risk stratification in Brugada syndrome: Clinical characteristics, electrocardiographic parameters, and auxiliary testing

Risk stratification in Brugada syndrome remains a clinical challenge because the event rate is low but the presenting symptom is often cardiac arrest (CA). We review the data on risk stratification. A history of CA or malignant syncope is a strong predictor of spontaneous ventricular fibrillation (VF), whereas the prognostic value of a history of familial sudden death and the presence of a SCN5A mutation are less well defined. On the electrocardiogram, the presence of spontaneous type I electrocardiogram increases the risk for VF in all studies, whereas the presence of fragmented QRS complexes and early repolarization correlates with increased risk in several studies. Signal-averaged techniques using late potentials and microscopic T-wave alternans show some promising results in small studies that need to be confirmed. The value of electrophysiologic studies for predicting spontaneous VF remains controversial, and this includes programmed stimulation protocols that avoid a third extrastimuli or stimulation from the right ventricular outflow. Risk prediction is particularly challenging in children and women.

Presence of Fragmented QRS Complexes in Patients with Obstructive Sleep Apnea Syndrome.

Background:Obstructive sleep apnea syndrome (OSAS) is a disease with increasing prevalence, which is mainly characterized by increased cardiopulmonary mortality and morbidity. It is well-known that OSAS patients have increased prevalence of cardiovascular diseases including coronary heart disease, heart failure, and arrhythmias. The aim of this study was to evaluate the presence of prolonged and fragmented QRS complexes, which have previously been associated with cardiovascular mortality, in OSAS patients.Methods:Our study included 51 patients (mean age 41.6 ± 10.1 years) who were recently diagnosed with OSAS (apnea-hypopnea index [AHI] ≥5 events/h) and never received therapy. The control group consisted of 34 volunteers (mean age 43.1 ± 11.6 years) in whom OSAS was excluded (AHI <5 events/h). The longest QRS complexes was measured in the 12-lead electrocardiogram (ECG) and the presence of fragmentation in QRS complexes was investigated.Results:Fragmented QRS frequency was significantly higher in patients with OSAS (n = 31 [61%] vs. n = 12 [35%], P = 0.021). QRS and QTc durations were also significantly longer in OSAS patients than controls (99.8 ± 13.9 ms vs. 84.7 ± 14.3 ms, P < 0.001; 411.4 ± 26.9 ms vs. 390.1 ± 32.2 ms, P = 0.001, respectively). Analysis of the patient and controls groups combined revealed a weak-moderate correlation between AHI and QRS duration (r = 0.292, P = 0.070). OSAS group had no correlation between AHI and QRS duration (r = −0.231, P = 0.203).Conclusions:In our study fragmented QRS frequency and QRS duration were found to increase in OSAS patients. Both parameters are related with increased cardiovascular mortality. Considering the prognostic importance of ECG parameters, it may be reasonable to recommend more detailed evaluation of OSAS patients with fragmented or prolonged QRS complexes with respect to presence of cardiovascular diseases.

The role of fQRS in coronary artery disease. A meta-analysis of observational studies.

Experimental and clinical studies have suggested that the presence of fragmented QRS complex (fQRS) is associated with various cardiovascular diseases. fQRS may predict major adverse cardiovascular events (MACE). The current meta-analysis was performed using clinical outcome studies to evaluate the role of fQRS in coronary artery disease (CAD). A systematic search of electronic databases (Cochrane, Medline, Embase and Pubmed) from their inception to April 2014 was performed. Data were extracted from applicable articles to evaluate the prognostic value of fQRS in CAD. A total of 16 observational studies about fQRS and CAD (n = 3,997 patients) were identified. Compared with the non-fQRS group, MACE and mortality were significantly higher in the fQRS group -odds ratios (OR) 3.19, 95 % confidence interval (95 % CI) [2.3, 4.42], p < 0.00001; OR 2.24, 95 % CI [1.71, 2.94], p < 0.0001. Patients developed Q waves, anterior-wall myocardial infarction (MI), and low left ventricular ejection fraction (LVEF) more frequently in the fQRS group than in the non-fQRS group-OR 2.59, 95 % CI [1.76, 3.81], p < 0.00001; OR 2.43, 95 % CI [1.07, 5.52], p = 0.03; OR - 6.43, 95 % CI [- 9.11, - 3.74], p < 0.00001. Based on current evidence, fQRS was associated with increased MACE, mortality, Q waves, anterior-wall MI, and decreased LVEF in CAD. These findings show that fQRS is a reliable marker in CAD.

The utility of fragmented QRS complexes to predict significant intraventricular dyssynchrony in nonischemic dilated cardiomyopathy patients with a narrow QRS interval

Fragmented QRS complexes in the electrocardiograms (ECGs) of patients with coronary artery disease are associated with adverse cardiac events. However, there are limited data on its predictive usefulness in patients with nonischemic dilated cardiomyopathy. Left ventricular dyssynchrony is common in heart failure patients who have wide QRS intervals, but its frequency in patients with narrow QRS intervals is uncertain. To investigate the relationship between fragmented QRS complexes and intraventricular dyssynchrony in patients with nonischemic dilated cardiomyopathy in sinus rhythm. Sixty nonischemic dilated cardiomyopathy patients with sinus rhythm and narrow QRS intervals were recruited. Forty patients had a fragmented QRS in their basal ECG, and 20 patients did not have a fragmented QRS. Patients were analyzed for correlation between fragmented QRS complexes and intraventricular dyssynchrony. The maximal difference in time to the peak myocardial systolic velocity between any two left ventricular segments (Max-ASE Sys), and maximal difference between Max-ASE Sys and the mean value of all segments (Max-ASE to Mean Sys) were significantly higher in patients with fragmented QRS complexes (P=0.001 and P=0.003, respectively). Seventy-two per cent of the patients with fragmented QRS complexes had significant left ventricular dyssynchrony; 15% of patients without fragmented QRS complexes had significant left ventricular dyssynchrony (P<0.0001). The presence of fragmented QRS complexes in leads corresponding to the specific ventricular segment in basal ECG was found to detect intraventricular dyssynchrony with 90.6% sensitivity (negative predictive value of 85%). Fragmentation in the resting ECG is associated with significant intraventricular dyssynchrony in patients with nonischemic cardiomyopathy, narrow QRS and sinus rhythm. Fragmentation in ECG might be useful in identifying patients who could benefit from cardiac resynchronization therapy.