QRS Complex In Patients Research Articles

Prognostic implications of baseline and new-onset fragmented QRS complex in patients undergoing transcatheter aortic valve implantation

Prognostic implications of baseline and new-onset fragmented QRS complex in patients undergoing transcatheter aortic valve implantation

High predictive value of paced QRS frequency in verification of left bundle branch pacing.

Left bundle branch area pacing (LBBAP) is a newer technique to deliver more synchronous left ventricular activation. Several criteria have been proposed, but not fully validated, to confirm LBBAP during implantation of the pacing lead. Spectral analysis has been used to characterize the frequency components of the clinical QRS utilizing the Fourier transform algorithm. We hypothesized that higher frequency content of the paced QRS complex may show predictive value of successful LBBAP. We evaluated 84 patients with ejection fraction > 50%, who underwent LBB lead placement (n = 42) using ≥ 1 current criteria and right ventricular midseptal (RVsp) lead placement (n = 42) from 2000 to 2022. Time frequency analysis (Matlab) was used to determine the frequency content of the paced QRS complex. The centroid frequency (CF), which is the weighted average QRS frequency, was calculated. Patients in RVsp group had a longer paced QRS duration (155.6 ± 28.0 vs 127.1 ± 17.2, p < 0.002) compared to the LBBAP group. Of all standard ECG leads, the paced QRS in V2 gave the greatest difference of the CF of the LBBAP group at 8.8 ± 1.6 Hz versus 5.7 ± 0.7 Hz of the RVsp group. This difference was significant by both univariate (p < 0.003) and multivariate (p < 0.010) analysis. Predictive value of the CF for successful LBB pacing in lead V2 was highest with an AUC of 0.98. The sensitivity and specificity were 88.1% and 97.6%, respectively. Spectral analysis predicts successful LBBAP with higher frequency content when compared to RVsp pacing. Given the limitations to the current criteria to confirm LBBAP, intraprocedural use of frequency content analysis of the paced QRS complex in patients may prove useful at verifying LBB capture if verified by prospective clinical trials.

"Frequency Power Profile within the QRS Complex in Patients with Lethal Ventricular Arrhythmias: An Approach to a New Risk Marker for Sudden Cardiac Death"

"Frequency Power Profile within the QRS Complex in Patients with Lethal Ventricular Arrhythmias: An Approach to a New Risk Marker for Sudden Cardiac Death"

Abstract 13335: The Predictive Value of Paced Qrs Frequency Analysis in Achieving Left Bundle Branch Pacing

Introduction: Left bundle branch area pacing (LBp) is a newer technique to deliver more synchronous left ventricular activation. Several criteria have been proposed, but not fully validated, to confirm LBp during implantation of pacing lead. Hypothesis: We hypothesized that higher frequency content of the paced QRS complex may show predictive value of successful LBp. Methods: We evaluated 84 patients with ejection fraction &gt;50%, who underwent LBB lead placement (n=42) using ≥1 current criteria and right ventricular midseptal (RVsp) lead placement (n=42) from 2000-22. Time frequency analysis (Matlab) was used to determine frequency content of paced QRS complex. Centroid Frequency (CF), which is the weighted average QRS frequency, was calculated. Unpaired t-test and Chi Square test were used for continuous and categorical variables, respectively. Multivariate analysis using logistic regression was used for variables with univariate p&lt;0.20. Variables with significant multivariate comparison (p&lt;0.05) underwent receiver operator curve analysis. Sensitivity and specificity for a CF ≥7.0 Hz for LBp was determined. Results: Baseline clinical characteristics are listed in Table 1. Patients in RVsp group had longer paced QRS duration (155.6 ± 28.0 vs 127.1 ± 17.2, p&lt;0.002) compared to LBp group. Of all ECG leads, V2 gave greatest difference, with CF of LBp group at 8.8 ± 1.6 Hz vs 5.7 ± 0.7 Hz of RVsp group (fig 1). This difference was significant by both univariate (p&lt;0.003) and multivariate (p&lt;0.010) analysis. Predictive value of CF for successful LBB pacing in lead V2 was highest with an AUC of 0.98. Sensitivity and specificity were 88.1% and 97.6%, respectively. Conclusions: Spectral analysis predicts successful LBp with higher frequency content when compared to RVsp pacing. Given the limitations to the current criteria to confirm LBp, intraprocedural use of frequency content analysis of the paced QRS complex in patients may prove a useful means of identifying LBB capture

Association between wide QRS pulseless electrical activity and hyperkalemia in cardiac arrest patients.

We evaluated the relationship between hyperkalemia and wide QRS complex in patients with pulseless electrical activity (PEA) cardiac arrest. This was a single-center, retrospective observational study of patients over the age of 18 treated for cardiac arrest at a tertiary referral hospital whose initial electrocardiogram rhythm was PEA from February 2010 to December 2019. Wide QRS PEA was defined as a QRS interval of 120ms or more. Hyperkalemia was defined as serum potassium level>5.5mmol/L. The primary outcome was hyperkalemia. Multivariable logistic regression analysis was used to evaluate the relationship between wide QRS and hyperkalemia. Among 617 patients, we analyzed 111 episodes in the wide QRS group and 506 episodes in the narrow QRS group. The potassium level in the wide QRS group was significantly higher than in the narrow QRS group (5.4mmol/L, IQR 4.4-6.7 vs. 4.6mmol/L, IQR 4.0-5.6, P<0.001). Among all patients, 49.6% (n=55/111) in the wide QRS group had hyperkalemia, which was significantly higher than the 26.7% (n=135/506) in the narrow QRS group (P<0.001). In multivariable logistic regression analysis, wide QRS PEA was significantly associated with hyperkalemia (odds ratio=2.86, 95% confidence interval: 1.80-4.53, P<0.001). Wide QRS PEA as an initial cardiac rhythm was significantly associated with hyperkalemia in cardiac arrest patients.

Frequency of fragmented QRS in patients with acute Non ST elevation Myocardial Infarction (NSTEMI).

Objective: To determine the frequency of fragmented QRS complex in patients with acute non-ST elevation myocardial infarction (NSTEMI). Study Design: Cross-Sectional Study. Setting: Department of Cardiology, Faisalabad Institute of Cardiology, Faisalabad. Period: July 15, 2019 to January 15, 2020. Material &amp; Methods: One hundred and forty five diagnosed patients of NSTEMI on the basis of chest pain and positive troponin-I were included in this study. The electrocardiography (ECG) was performed to document the presence or absence of f QRS complex in these patients. A 12-lead ECG with paper speed of 25 or 50 mm per second and a voltage of 10 mm/mv was used. FQRS was labeled (as per operational definition). The collected data were entered and analyzed statistically by using SPSS v25.0. Data were stratified for age, gender, diabetes, smoking and hypertension. Post-stratification, f QRS complex was compared by Chi-Square test in stratified groups. A p-value ≤0.05 was taken as significant. Results: Total 145 patients presenting with NSTEMI were selected for this study. Mean age of the patients was 48.2±12.3 year. Among these patients, 90(62.1%) were males, while 55(37.9%) were females. Overall frequency of fQRS complex in patients with NSTEMI was 64(44.1%). Conclusion: There is an association of fQRS among patients with acute non-ST elevation myocardial infarction (NSTEMI). Further prospective studies are needed to determine the clinical significance of fQRS complex and identify its correlation with the incidence of possible complications.

Prognostic value of fragmented QRS complex in patients with acute myocardial infarction

Several factors and risk stratification tools have been studied to determine the prognosis of acute coronary syndrome. Fragmented QRS (fQRS) is amarker of myocardial scar and its prognostic role has recently been demonstrated. The present study aimed to investigate the association between the presence of fQRS in electrocardiogram and the prognosis of ST-segment elevation and non-ST-segment elevation myocardial infarction (STEMI and NSTEMI). Atotal of 661 patients with myocardial infarction (MI) were enrolled in aretrospective study. Based on the presence of fQRS in admission electrocardiogram, patients were divided into two groups. All patients were followed up for 6months, and all major adverse cardiovascular events (MACE) were recorded. The mean age of patients was 61.3 ± 1.2 years, and 71.7% were male. In the acute phase, the detection rates of regional wall motion abnormality and aortic valve insufficiency were higher in positive fQRS compared to negative fQRS group (p = 0.003). The incidence of total MACE was significantly higher in the positive fQRS compared to the negative fQRS group among all patients and in both STEMI and NSTEMI subgroups (p < 0.001). Based on multivariate analysis, the presence of fQRS and hypertension were the strongest predictors of total MACE at 6‑month follow-up (odds ratio [OR] = 5.929; 95% confidence interval [CI] = 3.620-9.709; p < 0.001 and OR = 2.220; 95% CI = 1.390-3.547; p < 0.001, respectively). Regardless of the type of MI, it was found that the presence of fQRS on admission electrocardiogram can be implemented in risk stratification tools in patients with acute MI.

Detection of arrhythmogenic substrate within QRS complex in patients with cardiac sarcoidosis using wavelet-transformed ECG.

Signal-averaged electrocardiography (SAECG) has been known to be useful for prediction of lethal ventricular arrhythmias (VA). However, this technique has limitations in patients with intraventricular conduction disturbance (IVCD), which is common in cardiac sarcoidosis (CS). Meanwhile, wavelet-transformed ECG (WTECG) has been reported to be useful for detecting arrhythmogenic substrate hidden within QRS complex. The objective of this study was to assess the utility of WTECG for detecting arrhythmogenic substrate in patients with CS. Forty-four CS patients including 18 patients with VA were retrospectively investigated. The parameters on the signal-averaged electrocardiography (SAECG) and the power of frequency components on WTECG were compared between VA group and non-VA group. Eighteen patients have VA (VT: n = 17, VF: n = 1). LP were detected in 17 in VA group and 24 in non-VA group. WTECG showed that high-frequency components (HFC; 80-150Hz) were developed in VA group. Peak power value at 150Hz (P150) was significantly higher in VA group than that in non-VA group (442.9 ± 160.2 vs 316.7 ± 100.8, p = 0.006). The receiver operating characteristic (ROC) curve analysis showed an optimal cutoff point of 336 of P150 for detecting patients with VA, with 82.4% sensitivity, 61.5% specificity, and area under the curve of 0.74 (95% confidence interval [CI] 0.59-0.89). WTECG may be useful for detecting CS patients who are prone to VA.

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

Cardiovascular disease is an important contributor to the mortality rate of patients with systemic lupus erythematosus (SLE), which is related to SLE disease activity. Fragmented QRS (fQRS) complexes, defined by additional spikes in the QRS complex, are useful for identifying myocardial scars on electrocardiography and can be an independent predictor of cardiac events. We aimed to assess the relationship between disease activity in patients with SLE and fQRS at the time of diagnosis. Forty-four patients with SLE were included. Patients with cardiac diseases, other rheumatic diseases, and prior treatment at the time of electrocardiography measurement were excluded. The appearance of fQRS represented exposure. The primary outcome was SLE Disease Activity Index 2000 (SLEDAI-2K). Multiple regression analysis was conducted to assess the association between fQRS and SLEDAI-2K adjusted for age, sex, and time from the estimated onset date to the date of diagnosis. Among patients with SLE at diagnosis, 26 (59.1%) had fQRS. The median SLEDAI-2K was 18 (interquartile range [IQR], 12-22) and 9 (IQR, 8-15) in the fQRS(+) and fQRS(-) groups, respectively. SLEDAI-2K was significantly higher in the fQRS(+) group than in the fQRS(-) group (regression coefficient, 2.69; 95% confidence interval, 0.76-4.61; p = 0.008). Our results suggested that fQRS(+) patients with SLE had high disease activity. fQRS could likely detect subclinical myocardial involvement in patients with SLE and predict long-term occurrence of cardiac events.

Investigation of short-term prognosis of fragmented QRS complexes in patients with acute myocardial infarction in two groups that received invasive and fibrinolytic therapy

BackgroundStudies have shown that the primary causes of death in patients with acute coronary syndrome are arrhythmias and heart failure. The aim of this study is to evaluate the short-term prognosis of fragmented QRS (f-QRS) in patients with acute myocardial infarction (MI). MethodsThis study was a prospective and longitudinal analytic study performed on all patients with acute MI admitted to Rasht Heshmat Hospital Emergency during 2018–2019. Serial Electrocardiography (ECG) was performed in the emergency room after patient admission and was repeated 24 h after percutaneous coronary intervention and fibrinolytic therapy, as well as at the time of patient discharge. Short-term prognosis of f-QRS in patients was evaluated by a cardiologist within admission, 40 days after hospitalization and three months later again. ResultsIn this study, 453 patients with MI were evaluated in two treatment methods of fibrinolytic and invasive with and without f-QRS. Based on the data of this study, the four study groups had no statistically significant difference in arrhythmia (p = 0.196). In addition, the effect of study groups on left ventricular ejection fraction index was not statistically significant (p = 0.597). The probability of adverse outcomes occurrence was not statistically significant among the four groups (p = 0.07). ConclusionThe final results of this study showed that there was no significant difference between the four study groups and arrhythmia status. Therefore, f-QRS was not introduced as an independent predictor of arrhythmia in patients with acute MI.

Immediate clinical outcomes of left bundle branch area pacing vs conventional right ventricular pacing.

BackgroundLeft bundle branch area pacing (LBBaP) is a new physiological pacing strategy that produces comparable clinical effects to His bundle pacing (HBP).ObjectiveThe purpose of this study was to investigate the immediate clinical outcomes of LBBaP vs RVP.Methods and ResultsFrom April 2018 to September 2018, we included 44 patients under continuous pacemaker implantation. Patients were randomly divided into the LBBaP group and conventional RVP group. Compared to the RVP group, the LBBaP group displayed significantly increased operative (90.10 ± 19.68 minutes vs 61.57 ± 6.62 minutes, P < .001) and X‐ray exposure times (15.55 ± 5.62 minutes vs 4.67 ± 2.06 minutes, P < .001). The lead threshold of the LBBaP group was increased (0.68 ± 0.20 mV vs 0.51 ± 0.0 mV, P = .001), while the R‐wave amplitude and ventricular impedance did not significantly differ between the two groups. The conventional RVP procedure significantly widened the QRS complex (93.62 ± 8.28 ms vs 135.19 ± 12.21 ms, P = .001), whereas the LBBaP had no effect on QRS complex (130.13 ± 43.30 ms vs 112.63 ± 12.14 ms, P = .904). Furthermore, the LBBaP procedure significantly narrowed the QRS complex in patients with left bundle branch block (LBBB) (168.43 ± 38.870 ms vs 119.86 ± 6.69 ms, P = .019).ConclusionLBBaP is a new physiological, safe and effective pacing procedure with a high overall success rate. Compared to conventional RVP, LBBaP can correct LBBB, thereby improving cardiac electrical dyssynchrony.

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.

Fragmented QRS complex in patients with implantable cardioverter defibrillator—Prevalence and predisposing factors

BackgroundIncidence of fragmented (fQRS) and predisposing factors in patients with implantable cardioverter-defibrillator (ICD) have not yet been established.AimTo examine incidence of fQRS, associated factors as well as predictive value in identifying site of coronary artery disease (CAD). MethodsConsecutive patients with ICD. Retrospective analysis of demographic, clinical and ECG data. ResultsOf 382 patients, 163 (43%) had fQRS. They had more frequently history of MI, Q wave, lower left ventricular ejection fraction and prolonged ECG repolarisation indices. The presence of fQRS in more than one ECG localisation was associated with higher number of MI and ICD for secondary prevention. By combining fQRS with Q wave location, site of CAD could be predicted (total accuracy 84–95%). ConclusionsThe fQRS is frequent in patients with ICD, especially those with CAD, more advanced cardiac disease and altered ECG repolarisation. The fQRS may improve ECG-based non-invasive identification of the site of CAD.

Influence of fragmented QRS complex in patients with paroxysmal atrial fibrillation

Influence of fragmented QRS complex in patients with paroxysmal atrial fibrillation

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

BackgroundThe diagnosis of coronary artery disease (CAD) in patients with LBBB represents a clinical challenge. The presence of fragmented QRS (fQRS) complex on surface ECG may be related to myocardial ischemia, scarring or fibrosis.ObjectivesTo investigate the relation between fQRS and the presence and severity of CAD in patients with LBBB.Patients and methods56 patients with symptoms suggesting CAD and complete LBBB were submitted to full history taking and clinical examination, complete 12-leads electrocardiography (ECG) to confirm the diagnosis of LBBB and to diagnose the fragmented wide QRS (f-wQRS) complex, echocardiography, and coronary angiography; lesions with ⩾70% narrowing in major epicardial artery or ⩾50% narrowing in the left main coronary artery were considered significant; and Gensini score was calculated. Patients were classified into two groups according to the presence or absence of f-wQRS.ResultsThere were significantly more patients with obstructive CAD among patients with f-wQRS (p = 0.000053). Gensini score was significantly higher in patients with than in patients without fwQRS (p < 0.00001). f-wQRS was the only significant independent predictor of obstructive CAD. Sensitivity of f-wQRS in predicting obstructive CAD was 80.1%, specificity was 73.3%, positive predictive value was 72.4%, negative predictive value was 81.5%, and overall accuracy was 76.8%, p = 0.0022.ConclusionSeeking for f-wQRS in patients with LBBB and suspected CAD is a simple, easy, available, method that may be helpful in noninvasive prediction of obstructive CAD.

Usefulness of Fragmented QRS Complexes in Patients With Congenital Heart Disease to Predict Ventricular Tachyarrhythmias

Fragmented QRS complexes (fQRS) on 12-lead electrocardiogram are known predictors of ventricular tachyarrhythmia (VTA) in patients with coronary artery disease. There is limited knowledge of the clinical implications of fQRS in patients with congenital heart defects (CHD). Aims of this study were to examine (1) the occurrence of fQRS in patients with various types of CHD and (2) whether fQRS is associated with development of VTA. This study was designed as retrospective case-control study. Patients with CHD with VTA were included and matched with control patients of the same age, gender, and CHD type. Clinical data and fQRS were analyzed and compared. The initial VTA episode developed in 139 patients with CHD at a mean age of 39 ± 14years. Compared with controls (n= 219, age 38 ± 13years), QRS duration was longer in patients with VTA (110 vs 100ms; p <0.01). Furthermore, fQRS was more frequently observed in patients with VTA in the last electrocardiogram before VTA (n= 73 [53%] vs n= 67 [31%]; p <0.001), especially in patients with sustained VTA (64%). Multiple conditional logistic regression demonstrated more fQRS (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.5 to 5.8; p= 0.002), nonsystemic ventricular dysfunction (OR 5.1, 95% CI 2.1 to 12.4; p <0.001), and more prolonged QRS complexes (OR 2.8, 95% CI 1.3 to 6.2; p= 0.011) in patients with VTA. Therefore, the presence of fQRS on electrocardiogram may be a useful tool in daily clinical practice to identify patients at risk for developing VTA in patients with CHD, in addition to known predictors of VTA.

The Prevalence of distorted terminal portion of QRS complex in patients of CKD with STEMI and its effect on their Outcome

Background: Distorted terminal portion of QRS complex on initial electrocardiogram ( ECG) in patients with ST segment elevation myocardial infarction ( STEMI) is a strong predictor of adverse outcome. Objectives: Our purpose of this study was to assess the relationship of distortion of QRS on initial ECG in STEMI with chronic kidney diseases (CKD). Methods: We evaluated 60 patients of STEMI admitted within 12 hours and receiving thrombolytic therapy. Patients having serum creatinine &lt; 1.5 mg/dl were group-I and ?1.5 mg/dl were group-II. We defined two ECG groups according to absence of distortion of terminal QRS and presence of distorted terminal QRS in two or more adjacent leads. Distorted QRS group further divided into pattern-A – J point originating at ?50% of height of R wave in leads with qR configuration and pattern B- S wave is absent in leads with RS configuration. Additionally study population was divided into two groups on the basis of serum creatinine level. Results: CKD patients had more QRS distortion (43.2% vs 68.8%, p=0.008) and worse inhospital outcome. Out of 60 patients 7(11.6%) death, 16(26.7%) heart failure and 37(61.7%) uneventful recovery. Hospital mortality and heart failure were significantly higher in STEMI with CKD group (4.5% vs 31%, p=0.004; 16% vs 56%, p=0.001; respectively), uneventful recovery was significantly higher in STEMI without CKD group(12.5% vs 80%, p=&lt;0.001). In multiple logistic regression analysis, CKD ( serum creatinine ?1.5) and Killip class ?II were independent predictors of QRS distortion (OR= 5.702, p=0.014; OR= 3.578,p=0.036; respectively). Conclusion: Among the CKD patients with STEMI the distorted terminal portion of QRS complex on initial ECG is more frequent and significantly related to adverse prognosis. Careful analysis of ECG which is simple, chief, universally available, bed side investigation may offer important information regarding prompt risk stratification and management in patients of CKD with STEMI.University Heart Journal Vol. 11, No. 1, January 2015; 7-12

Short-term Prognosis of Fragmented QRS Complex in Patients with Non-ST Elevated Acute Myocardial Infarction.

Background:There remains significant debate as to the relationship between fragmented QRS (fQRS) complexes on electrocardiogram (ECG) and acute myocardial infarction (AMI). Few studies have reported on this relationship in non-ST elevated AMI (NSTEMI), and thus, we attempt to assess this relationship and its potential short-term prognostic value.Methods:This was a single-center, observational, retrospective cohort study. A total of 513 consecutive patients (399 men, 114 women) with NSTEMI within 24 h who underwent coronary angiography at our department, between January 1, 2014, and December 31, 2014. Patients were divided into 2 groups according to the presence or absence of fQRS complex on the admission ECG. fQRS complexes were defined as the existence of an additional R’ or crochetage wave, notching in the nadir of the S wave, RS fragmentation, or QS complexes on 2 contiguous leads. All patients were followed up for 6 months, and all major adverse cardiac events (MACE) were recorded.Results:In this study, there were 285 patients with fQRS ECG in the 513 patients with NSTEMI. The number of patients with 0–2 coronary arteries narrowed by ≥50% in fQRS group were less while patients with 3 narrowed arteries were more than in the non-fQRS group (P = 0.042). There were fewer Killip Class I patients in the fQRS group (P = 0.019), while Killip Class II, III, and IV patients were more in the fQRS group than in the non-fQRS group (P = 0.019). Left ventricular ejection fraction levels were significantly lower in the fQRS group (P = 0.021). Baseline total cholesterol, low-density lipoprotein, creatinine, creatine kinase, homocysteine, high-sensitivity C-reactive protein (CRP), and red blood cells distribution width levels were significantly higher in the fQRS group. Total MACE (MACE, P = 0.028), revascularization (P = 0.005), and recurrent angina (P = 0.005) were also significantly greater in the fQRS group. On final logistic regression analysis, after adjusting for baseline variables, the following variables were independent predictors of fQRS: Coronary artery narrowing (P = 0.035), Killip classification (P = 0.026), and total cholesterol (P = 0.002). The following variables were found to be independent predictors of preoperative MACE: Hemoglobin (P = 0.000), gender (P = 0.026), fQRS (P = 0.016), and time from myocardial infarction to balloon or coronary artery bypasses grafting (P = 0.013).Conclusions:The fQRS complexes are commonly present in NSTEMI and the fQRS complexes are an independent predictor of MACE in NSTEMI patients. The number of narrowed coronary arteries, Killip classification, and total cholesterol are all independent predictors of the fQRS complexes.

Fragmentation of the QRS complex in patients with acute coronary syndrome treated invasively

Previous studies showed that the presence of fragmented QRS (f-QRS) in patients with acute coronary syndrome (ACS), who underwent complete revascularisation, is associated with worse prognosis and the possibility of arrhythmia occurrence. To assess the prognostic value of f-QRS in patients with ACS and complete revascularisation, in the context of cardiac ar-rhythmias. We analysed 124 consecutive patients (66.1% males; mean age 62.38 ± 11.0 years) with ACS (STEMI 49%) treated invasively. Based on electrocardiogram (ECG) record, performed during the admission to the clinic, after the complete revascularisation (TIMI = 3) and during discharging from hospital (4th-5th days after ACS), we classified QRS as f-QRS based on generally accepted criteria (QRS < 120 ms, which included an additional R wave [R']) or notching in the nadir of the S wave, or > 1 R' (fragmentation) in two contiguous leads, corresponding to a major coronary artery territory. 24-h Holter ECG recording was performed on the fifth day after ACS to assess the frequency of conduction disturbances and others arrhythmias. There were no statistically significant differences between patients with and without f-QRS during hospitalisation. In the patients with f-QRS there were no statistically significant conduction disturbances and other arrhythmias compared to patients without f-QRS at discharge. In the patients with ACS, who underwent successful revascularisation (TIMI = 3), the presence of f-QRS is not correlated with a higher incidence of arrhythmias compared to patients without f-QRS in short-term follow-up.

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.