Fragmented Wide QRS on a 12-Lead ECG

The relationship between fragmentation on electrocardiography and in-hospital prognosis of patients with acute myocardial infarction

Background

In patients with acute ST elevation myocardial infarction (STEMI), QRS fragmentation was determined as one of the indicators of mortality and morbidity. The development of fragmented QRS (fQRS) is related to defects in the ventricular conduction system and is linked to myocardial scar and fibrosis.

Material/Methods

We prospectively enrolled 355 consecutive patients hospitalized in the coronary intensive care unit of our hospital with STEMI between the years 2010 and 2012 and their electrocardiographic features and the frequency of in-hospital cardiac events were evaluated.

Results

There were 217 cases in the fQRS group and 118 cases in the control group. QRS fragmentation was found to be a predictor for major cardiac events. In the fragmented QRS group, the frequency of in-hospital major cardiac events (MACE) and death were higher (MACE p<0.001; death p<0.003). In the fragmented QRS group, the cardiac enzymes (Troponin-I, CK-MB) were significantly higher than in the control group (p<0.001). In subgroup analyses, apart from the presence of fragmentation, the presence of more than 1 type of fragmentation and the number of fragmented deviations were also found to be related with MACE. A significant negative correlation was observed with the ejection fraction and, in particular, the number of fragmented deviations.

Conclusions

Fragmented QRS has emerged as a practical and easily identifiable diagnostic tool for predicting in-hospital cardiac events in acute coronary syndromes. Patients who present with a fragmented QRS demonstrate increased rates of major cardiac events, death risk, and low ejection fraction. In patients with STEMI, the presence of fQRS on the ECG and number of fQRS derivations are a significant predictor of in-hospital major cardiac events.

Usefulness of electrocardiographic parameters for risk prediction in arrhythmogenic right ventricular dysplasia

The value of electrocardiographic findings predicting adverse outcome in patients with arrhythmogenic right ventricular dysplasia (ARVD) is not well known. We hypothesized that ventricular depolarization and repolarization abnormalities on the 12-lead surface electrocardiogram (ECG) predict adverse outcome in patients with ARVD. ECGs of 111 patients screened for the 2010 ARVD Task Force Criteria from 3 Swiss tertiary care centers were digitized and analyzed with a digital caliper by 2 independent observers blinded to the outcome. ECGs were compared in 2 patient groups: (1) patients with major adverse cardiovascular events (MACE: a composite of cardiac death, heart transplantation, survived sudden cardiac death, ventricular fibrillation, sustained ventricular tachycardia, or arrhythmic syncope) and (2) all remaining patients. A total of 51 patients (46%) experienced MACE during a follow-up period with median of 4.6 years (interquartile range 1.8 to 10.0). Kaplan-Meier analysis revealed reduced times to MACE for patients with repolarization abnormalities according to Task Force Criteria (p = 0.009), a precordial QRS amplitude ratio (∑QRS mV V1 to V3/∑QRS mV V1 to V6) of ≤ 0.48 (p = 0.019), and QRS fragmentation (p = 0.045). In multivariable Cox regression, a precordial QRS amplitude ratio of ≤ 0.48 (hazard ratio [HR] 2.92, 95% confidence interval [CI] 1.39 to 6.15, p = 0.005), inferior leads T-wave inversions (HR 2.44, 95% CI 1.15 to 5.18, p = 0.020), and QRS fragmentation (HR 2.65, 95% CI 1.1 to 6.34, p = 0.029) remained as independent predictors of MACE. In conclusion, in this multicenter, observational, long-term study, electrocardiographic findings were useful for risk stratification in patients with ARVD, with repolarization criteria, inferior leads TWI, a precordial QRS amplitude ratio of ≤ 0.48, and QRS fragmentation constituting valuable variables to predict adverse outcome.

Fragmentation of the paced QRS complex: a marker of antitachycardia pacing effectiveness among ICD patients

INTRODUCTION

The presence of notches in the paced QRS complex (P-QRS) from the right ventricular apex (RVA) reflects delays in the activation of the left ventricle and may therefore be associated with longer times of stimulus conduction. Our objective was to determine prospectively the relationship between the duration of a notch ≥0.1 mV in the P-QRS (DN) and the effectiveness of antitachycardia pacing (ATP).

METHODS AND RESULTS

We followed 286 implantable cardioverter-defibrillator (ICD) patients with left ventricular dysfunction (pacing site: RVA) for 41 ± 27 months. ICD programming was standardized. P-QRS (100 bpm) was obtained at implant (50 mm/s). A total of 955 monomorphic ventricular tachycardias (VTs) with a cycle length of 335 ± 32 milliseconds occurred consecutively in 108 patients. ATP was successful in 84% of VTs. DN correlated with the probability of ineffective ATP (C = 0.67; P < 0.001), the cutoff point with the best sensitivity and specificity being 50 milliseconds. The adjusted mean ATP effectiveness per patient was 76% (95% CI: 72-85). Patients with a DN ≥ 50 milliseconds had a lower ATP efficiency: 67% (56-77) versus 92% (87-97) and a higher proportion of VTs terminated with shocks (SH): 31% (21-42) versus 8% (2-14); P < 0.001 for both. Although the occurrence of VT was similar (41% vs. 40%), the incidence of VT-related SH was higher in patients with a DN ≥ 50 (25% vs. 14%; P = 0.01) in the overall study population (n = 286).

CONCLUSIONS

When ATP is applied to the RVA, a DN ≥ 50 milliseconds is associated with a lower ATP effectiveness and a higher risk of SH due to VT.

Assessment of the relationship between red cell distribution width and fragmented QRS in patients with non-ST elevated acute coronary syndrome

Background

Red cell distribution width (RDW) and fragmented QRS (fQRS) complexes have also been reported to be predictors of cardiac events and all-cause mortality in coronary artery disease (CAD). We aimed to investigate the association of serum red cell distribution width (RDW) levels and fQRS in patients with non-ST elevated acute coronary syndrome (NST-ACS).

Material/Methods

We retrospectively evaluated a total of 251 patients (191 men and 60 women) with NST-ACS. The NST-ACS consisted of unstable angina (UA) and non-ST elevated myocardial infarction (NSTEMI). The fQRS pattern was defined as the presence of an additional R’ or crochetage wave, notching in the nadir of the S wave or fragmentation of the RS or QS complexes in 2 contiguous leads corresponding to a major coronary artery territory. The relationships between the RDW and fQRS were assessed.

Results

The patients in the fQRS group were older, left ventricular ejection fraction (LVEF) levels were significantly lower, and baseline RDW and troponin levels were significantly higher than in the group without fQRS. There were positive correlations between age, number of coronary arteries narrowed, and RDW, and negative correlations between triglyceride, LVEF, and RDW in study patients. There were positive correlations between number of fQRS leads, age, and RDW, and negative correlations between triglyceride, LVEF, and RDW in NSTEMI patients.

Conclusions

Our results indicate that an elevated RDW values is associated with fQRS in NST-ACS. Elevated RDW values and fQRS together may be useful for identifying NSTEMI patients in NST-ACS.

Myocardial tissue perfusion predicts the evolution of fragmented QRS in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions. However, alterations in fQRS in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and association of fQRS with myocardial blush grade (MBG) has not been investigated until now. In this study, we aimed to investigate the association of MBG after primary PCI with evolution of fQRS.

METHODS

Our study consisted of 401 consecutive patients with STEMI who underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2) at 48 hours after primary PCI. The evolution of fQRS on pre- and post-PCI ECG and their relation with myocardial reperfusion parameters were investigated.

RESULTS

Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with MBG (r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG <3, peak CK-MB level, pre-PCI fQRS at anterior localization and smoking.

CONCLUSION

Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

Increased frequency of fragmented QRS in patients with severe aortic valve stenosis

OBJECTIVE

To investigate the presence of myocardial fibrosis determined by fragmented QRS in patients with severe aortic valve stenosis.

SUBJECTS AND METHODS

Eighty-seven consecutive patients with severe aortic valve stenosis and 83 age- and gender-matched control subjects were enrolled into this study. Severe aortic valve stenosis was defined as an aortic valve area <1 cm(2), a Vmax >4 m/s, or a mean gradient ≥40 mm Hg. Fragmented QRS was assessed using a 12-lead electrocardiogram.

RESULTS

Fragmented QRS was detected in 40 (46%) patients in the aortic valve stenosis group and in 15 (18%) control subjects (p < 0.001). In multivariate binary logistic regression analysis, the presence of aortic valve stenosis was the only independent factor associated with fragmented QRS (OR = 3.69; 95% CI 1.81-7.55, p < 0.001).

CONCLUSION

A higher frequency of fragmented QRS was detected in patients with severe aortic valve stenosis compared to controls.

Fragmented QRS complex in adult patients with Ebstein anomaly and its association with arrhythmic risk and the severity of the anomaly

BACKGROUND

Fragmented QRS complex (fQRS) on 12-lead ECG, a marker of myocardial scar, is a predictor of arrhythmic events in patients with ischemic and nonischemic cardiomyopathy. We investigated whether the presence of fQRS is associated with the severity of the anomaly and with increased arrhythmic events in adult patients with Ebstein anomaly (EA).

METHODS AND RESULTS

In 51 consecutive adult patients with EA (median age, 37 years; 18 males), the severity index of EA calculated from echocardiographic data and clinical arrhythmic events were analyzed. The extent of fQRS in each patient was measured by counting the number of ECG leads showing fQRS. There were 35 (68.6%) patients with fQRS (fQRS group) and 16 (31.4%) patients without fQRS (non-fQRS group). fQRS was observed more frequently in the inferior (n=26) and precordial (n=25) leads versus the lateral leads (n=5). The patients in the fQRS group had a worse functional class, greater cardiothoracic ratios, more severe tricuspid regurgitation, larger atrialized right ventricular areas, higher EA severity scores, and more frequent arrhythmic events compared with those in the non-fQRS group. The atrialized right ventricular area showed a positive correlation with the fQRS extent (r=0.51; P<0.001). In multivariable Cox regression models, the presence of fQRS was independently associated with arrhythmic events (P=0.036).

CONCLUSIONS

Fragmented QRS on 12-lead ECG was associated with larger atrialized right ventricular area and an increased risk of arrhythmic events in adult patients with EA.

An automated algorithm for online detection of fragmented QRS and identification of its various morphologies

Fragmented QRS (f-QRS) has been proven to be an efficient biomarker for several diseases, including remote and acute myocardial infarction, cardiac sarcoidosis, non-ischaemic cardiomyopathy, etc. It has also been shown to have higher sensitivity and/or specificity values than the conventional markers (e.g. Q-wave, ST-elevation, etc.) which may even regress or disappear with time. Patients with such diseases have to undergo expensive and sometimes invasive tests for diagnosis. Automated detection of f-QRS followed by identification of its various morphologies in addition to the conventional ECG feature (e.g. P, QRS, T amplitude and duration, etc.) extraction will lead to a more reliable diagnosis, therapy and disease prognosis than the state-of-the-art approaches and thereby will be of significant clinical importance for both hospital-based and emerging remote health monitoring environments as well as for implanted ICD devices. An automated algorithm for detection of f-QRS from the ECG and identification of its various morphologies is proposed in this work which, to the best of our knowledge, is the first work of its kind. Using our recently proposed time-domain morphology and gradient-based ECG feature extraction algorithm, the QRS complex is extracted and discrete wavelet transform (DWT) with one level of decomposition, using the 'Haar' wavelet, is applied on it to detect the presence of fragmentation. Detailed DWT coefficients were observed to hypothesize the postulates of detection of all types of morphologies as reported in the literature. To model and verify the algorithm, PhysioNet's PTB database was used. Forty patients were randomly selected from the database and their ECG were examined by two experienced cardiologists and the results were compared with those obtained from the algorithm. Out of 40 patients, 31 were considered appropriate for comparison by two cardiologists, and it is shown that 334 out of 372 (89.8%) leads from the chosen 31 patients complied favourably with our proposed algorithm. The sensitivity and specificity values obtained for the detection of f-QRS were 0.897 and 0.899, respectively. Automation will speed up the detection of fragmentation, reducing the human error involved and will allow it to be implemented for hospital-based remote monitoring and ICD devices.

Fragmented surface ECG was a poor predictor of appropriate therapies in patients with Chagas' cardiomyopathy and ICD implantation (Fragmented ECG in CHAgas' Cardiomyopathy Study)

BACKGROUND

Main causes of death in chronic Chagas' cardiomyopathy (CChC) are progressive congestive heart failure and sudden cardiac death. Implantable cardioverter defibrillators (ICD) have been proved an effective therapy to prevent sudden death in patients with CChC. Identification of predictors of sudden death remains a challenge.

OBJECTIVE

To determine whether surface fragmented ECG (fQRS) helps identifying patients with CChC and ICDs at higher risk of presenting appropriate ICD therapies.

METHODS

Multicenter retrospective study. All patients with CChC and ICDs were analyzed. Clinical demographics, surface ECG, and ICD therapies were collected.

RESULTS

A total of 98 patients were analyzed. Another four cases were excluded due to pacing dependency. Mean age was 55.5 ± 10.4 years, male gender 65%, heart failure New York Heart Association class I 47% and II 38%. Mean left ventricular ejection fraction (LVEF) 39.6 ± 11.8%. The indication for ICD was secondary prevention in 70% of patients. fQRS was found in 56 patients (59.6%). Location of fragmentation was inferior (57.1%), lateral (35.7%), and anterior (44.6%). Rsr pattern was the more prevalent (57.1%). Predictors of appropriate therapy in the multivariate model were: increased age (P = 0.01), secondary prevention indication (P = 0.01), ventricular pacing >50% of the time (P = 0.004), and LVEF <30% (P = 0.01). The presence of fQRS did not identify patients at higher risk of presenting appropriate therapies delivered by the ICD (P = 0.87); regardless of QRS interval duration.

CONCLUSIONS

fQRS is highly prevalent among patients with CChC. It has been found a poor predictor of appropriate therapies delivered by the ICD in this population.

Fragmented QRS as a predictor of arrhythmic events in patients with hypertrophic obstructive cardiomyopathy

OBJECTIVES

This study aims to determine whether fragmented QRS (fQRS) in the surface electrocardiogram (ECG) at implantable cardioverter defibrillator (ICD) implant can predict arrhythmic events using appropriate therapy delivered by the ICD as a surrogate.

BACKGROUND

Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder associated with life-threatening arrhythmias frequently requiring an ICD. Seeking a noninvasive method of risk stratification remains a challenge.

METHODS

This paper is a retrospective, multicenter study of patients with HOCM and ICD. Surface 12-lead ECGs were analyzed. Appropriate therapy was validated by a blinded Core Lab. Univariate and multivariate analyses were performed. A p value of <0.05 was considered significant.

RESULTS

We included 102 patients from 13 centers. Mean age at implant was 41.16 ± 18.25 years, 52% were male. Mean left ventricular ejection fraction was 61.56 ± 9.46% and two thirds had heart failure according to the New York Heart Association class I. Secondary prophylaxis ICD implantation was the indication for implant in 40.2% of cases. About half received a single-chamber ICD. fQRS was present at the time of diagnosis in 21 and in 54% at ICD implant. At a mean follow-up of 47.8 ± 39.3 months, 41 patients (40.2%) presented with appropriate therapy. In a multivariate logistic regression, predictors of appropriate therapy included fQRS at implant (odds ratio [OR], 16.4; 95% confidence interval [CI], 3.6-74.0; p = 0.0003), history of combined ventricular tachycardia/fibrillation/sudden death (OR, 14.3; 95% CI, 3.2-69.3; p = 0.001) and history of syncope (OR, 5.5; 95% CI, 1.5-20.4; p = 0.009). Ten deaths (9.8%) occurred during the follow-up. fQRS in the lateral location increased the risk of appropriate therapy (p < 0.0001).

CONCLUSIONS

fQRS predicts arrhythmic events in patients with HOCM and should be considered in a model of risk stratification.

Prognostic value of fragmented QRS on a 12-lead ECG in patients with acute myocardial infarction

OBJECTIVE

To investigate the determinants and the prognostic value of fragmented QRS (fQRS) after AMI.

PATIENTS AND METHODS

Prospective cohort of 307 consecutive patients with AMI.

MAIN OUTCOMES MEASURED

MACE (death plus non-fatal recurrent MI), hospitalization for an episode of heart failure, ventricular arrhythmia (VT or VF) at two years follow-up.

RESULTS

On the serial 12-lead ECG recorded during the in-hospital stay, 162 (53%) had no fQRS (no fQRS group). 145 (47%) presented an fQRS, which was persistent in 108 (34%) patients (persistent fQRS group) and transient in 37 (12%) patients (transient fQRS group). Patients with a fragmented QRS (transient or persistent) were older, more likely to be hypertensive and less likely to be smokers than were patients without fQRS. By multivariate logistic regression analysis, only hypertension (OR (95% CI): 1.66 (1.00-2.74); p = 0.047) was associated with an fQRS. During a mean follow-up of 846 ± 297 days, there were 82 MACE recorded: 17 patients died from a CV cause (10% event rate) among patients without fQRS, 22 (20% event rate) among patients with persistent fQRS and 3 (8% event rate) among patients with transient fQRS. Similarly, non-fatal recurrent MI occurred more frequently in patients with fQRS (18 (16%) and 10 (27%)) for persistent and transient fQRS, respectively, vs. 16 (10%) in the no fQRS group (p = 0.019). However, the occurrence of heart failure symptoms and ventricular arrhythmia was not significantly different (p = 0.162 and p = 0.242, respectively). Survival analysis by the Kaplan-Meier method showed a significant difference (log rank p = 0.026) between groups, and only persistent fQRS was associated with decreased survival. In multivariate cox regression analysis, the GRACE score, blood glucose on admission, and B-blockers in the acute phase were independent predictors of MACE at two years. fQRS was not a significant independent predictor of MACE (HR (95% CI): 1.57 (0.95-2.60); p = 0.08). Moreover, fQRS was not a predictor of heart failure or ventricular arrhythmia in univariate analysis.

CONCLUSIONS

Persistent fQRS on a 12-lead ECG is a marker of decreased survival after AMI, whereas transient fQRS correlates with recurrent MI.

Fragmented QRS complex predicts the arrhythmic events in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia

BACKGROUND

Fragmented QRS (frQRS) complex, with various morphology, has been recently described as a diagnostic criterion of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). However, there are little data regarding the prognostic role of frQRS in these patients. Therefore, we aimed to investigate the association of frQRS with arrhythmic events in patients with ARVC/D.

METHODS

Seventy-eight patients (51 men, 65.4%; mean age: 31.25 ± 11.5 years) with the diagnosis of ARVC/D according to 2010 modified Task Force Criteria were analyzed retrospectively. Baseline ECG evaluation revealed frQRS complex in 46 patients (59%). Eleven patients with complete/incomplete right bundle branch block were excluded from the study. The phenomenon of frQRS was defined as deflections at the beginning of the QRS complex, on top of the R-wave, or in the nadir of the S-wave similar to the definition in CAD in either one right precordial lead or in more than one lead including all standard ECG leads.

RESULTS

During 38 ± 14 months follow-up period, 3 patients (3.8%) died suddenly, 36 patients (46.1%) experienced arrhythmic events (32 ventricular tachycardias [VTs] and 4 ventricular fibrillation [VF], 30 in the ICD group). The frQRS was significantly associated with arrhythmic events (P < 0.001). Also, the number of ECG leads with frQRS complex was higher in patients with arrhythmic events (5.08 ± 2.5 vs 1.14 ± 1.7, P < 0.001, respectively).

CONCLUSION

The frQRS complex on standard 12-lead ECG predicts fatal and nonfatal arrhythmic events in patients with ARVC/D. Therefore, large scale and prospective studies are needed to confirm those findings.

A new revised cardiac risk index incorporating fragmented QRS complex as a prognostic marker in patients undergoing noncardiac vascular surgery

The aim of this study was to investigate the value of a new Revised Cardiac Risk Index (RCRI) that includes consideration of QRS fragmentation (fQRS) as a predictor of cardiac events in patients undergoing noncardiac vascular surgery. Four hundred sixty-seven consecutive patients admitted for noncardiac vascular surgery were studied. Patients were allocated to RCRI 0, 1, 2, or ≥3 groups according to the sum of diabetes, renal insufficiency, and histories of ischemic heart disease, congestive heart failure, and cerebrovascular disease. They were then reallocated to fragmented RCRI (fRCRI) 0, 1, 2, or ≥3 groups after including a score of 1 or 0 corresponding to the presence or absence of fQRS. A major adverse cardiac event (MACE) was defined as a composite of death, myocardial infarction, congestive heart failure, and percutaneous coronary intervention before noncardiac vascular surgery. During index hospitalization, MACE developed in 38 patients (8.1%). fQRS was present in 169 (36.2%), and it was significantly greater in patients with MACE than in those without MACE (63.2% vs 34.3%, p <0.001). The proportions of RCRI 0, 1, 2, and ≥3 were 46.9% (n = 219), 35.3% (n = 165), 12.4% (n = 58), and 5.4% (n = 25), respectively. When fRCRI data were included, 28 patients (48.3%) in RCRI 2 were reclassified as fRCRI ≥3. By multivariate logistic regression analysis, fRCRI (odds ratio 1.529, 95% confidence interval 1.035 to 2.258, p = 0.033) and a left ventricular ejection fraction <50% independently predicted in-hospital MACE. In conclusion, fRCRI is an independent predictor of in-hospital MACE in patients undergoing noncardiac vascular surgery.

Predictive value of the fragmented QRS complex in 6-month mortality and morbidity following acute coronary syndrome

Background

Fragmented QRS encompasses different RSR’ patterns showing various morphologies of the QRS complexes with or without the Q wave on a resting 12-lead electrocardiogram. It has been shown possibly to cause adverse cardiac outcomes in patients with some heart diseases, including coronary artery disease. In view of the need for risk stratification of patients presenting with acute coronary syndrome in the most efficacious and cost-effective way, we conducted this study to clarify the value of developing fragmented QRS in a cohort of patients presenting with their first acute coronary syndrome in predicting 6-month mortality and morbidity.

Methods

One hundred consecutive patients admitted to the coronary care unit at Shahid Madani Heart Center in Tabriz from December 2008 to March 2009 with their first acute coronary syndrome were enrolled in this prospective study. Demographic and electrocardiographic data on admission, inhospital mortality, and need for revascularization were recorded. Electrocardiography performed 2 months after the index event was examined for development of fragmented QRS. Mortality and morbidity was evaluated at 6-month follow-up in all patients.

Results

The patients were of mean age 57.7 ± 12.8 years, and 84% were men. The primary diagnosis was unstable angina in 17 (17%) patients, non-ST elevation myocardial infarction (MI) in 11 (11%), anterior or inferior ST elevation MI in 66 (66%), and postero-inferior MI in six (6%). Fragmented QRS was present in 30 (30%) patients during the first admission, which increased to 44% at the 2-month follow-up and to 53% at the 6-month follow-up. The presence of various coronary risk factors and drug therapy given, including fibrinolytic agents, had no effect on development of fragmented QRS. Mortality was significantly higher (P = 0.032) and left ventricular ejection fraction was significantly lower (P = 0.001) in the fragmented QRS group at the 6-month follow-up.

Conclusion

This study strongly suggests that fragmented QRS on initial presentation with acute coronary syndrome is not predictive of subsequent events but, if present 6 months later, could be predictive of an adverse outcome.

Notched QRS complex in lateral leads as a novel predictor of response to cardiac resynchronization therapy

BACKGROUNDS

Notched QRS (nQRS) may be an indicator of ventricular delay. There are very few studies investigating the value of nQRS. The aim of the study was to identify the predictive value of nQRS for response to cardiac resynchronization therapy (CRT).

METHODS

Eighty-two patients with heart failure (HF) and widened QRS (≥120 ms) were implanted with a CRT device. nQRS was defined as presence of ≥2 R waves, or ≥1 notch in the R wave or S wave in ≥2 contiguous leads. Response to CRT was defined as percentage of left ventricular end-systolic volume (LVESV) reduction after 6 months CRT (ΔLVESV%) ≥15%.

RESULTS

nQRS was presented in 62 (76%) patients, 16 of whom had nQRS in anterior leads, 47 in inferior leads, and 42 in lateral leads. The rate of CRT response (65% vs 50%, P = 0.29) and ΔLVESV% (21.7 ± 31.7% vs 7.9 ± 25.4%, P = 0.09) were not different between patients with and without nQRS. But the rate of CRT response was higher in patients with nQRS in lateral leads (nQRS-L) than in those without nQRS-L (76% vs 45%, P = 0.006). ΔLVESV% was greater in patients with nQRS-L than in those without nQRS-L (25.2 ± 34.3% vs 10.1 ± 24.5%, P = 0.004). After adjusting for potential confounders including QRS duration, presence of nQRS-L still predicted positive CRT response (OR = 4.04, P = 0.009).

CONCLUSIONS

nQRS-L may be a novel predictor of response to CRT in patients with HF and widened QRS. Large-scale studies are needed to confirm this prognostic value of nQRS-L.

The delayed activation wave in non-ST-elevation myocardial infarction

BACKGROUND

Little is known about the relationship between the electrocardiographic characteristics and the infarct related artery (IRA) in non-ST-elevation myocardial infarction (NSTEMI). We found a curious phenomenon in electrocardiograms of patients with acute occlusion of left circumflex artery in NSTEM: A notch or deflection was often present in the terminal QRS complex in leads II,III and aVF or I,aVL . The objective of this study was to determine whether the previously unreported ECG phenomenon that we have found in NSTEMI could identify the culprit artery in non-ST-elevation myocardial infarction.

METHODS AND RESULTS

Our study included 218 NSTEMI patients who presented to our institution and underwent coronary angiography within 24 hours of admission. For convenience, 'N' wave was defined as a notch or deflection in the terminal QRS complex of the surface ECG. The duration of QRS with N wave before PCI was more prolonged than the duration of QRS without N wave (121 ± 12 ms vs 106 ± 11 ms, P<0.01). In the LCX group, 66(77%) patients had N wave in leads II, III and aVF, whereas only 5(6%) patients in the LAD group and 9(18%) patients in the RCA group had such ECG feature (P<0.001). A greater proportion of patients in the LCX group also had N waves in leads I and aVL (P<0.001). N wave in leads II, III and aVF was associated with 77% sensitivity and 89% specificity, respectively. N wave in leads I and aVL was associated with 64% sensitivity and 96% specificity, respectively.

CONCLUSION

The abnormal waveform in terminal QRS complex in NSTEMI ,which is described above, is the delayed activation wave of left ventricular basal region which the left circumflex artery supplies. It is associated with a higher specificity and higher sensitivity for culprit LCX in non-ST-elevation myocardial infarction. The delayed activation wave is a new pattern of ischemia in ECG.

High-risk electrocardiographic parameters are ubiquitous in patients with ischemic cardiomyopathy

BACKGROUND

The electrocardiogram (ECG) can be used to predict cardiovascular risk; however, like all risk factors with imperfect specificity, studies in low risk populations have been plagued by poor predictive accuracy. Although predictive accuracy might be improved among cohorts with a higher likelihood of cardiovascular events, this would also affect the prevalence of abnormal parameters and their exclusions.

METHOD

To determine the magnitude of these changes in a cohort with ischemic cardiomyopathy we analyzed 15 previously validated high-risk parameters from the resting and ambulatory ECG in subjects enrolled in the Prediction of Arrhythmic Events with Positron Emission Tomography (PAREPET) study (n = 198).

RESULTS

Using the published exclusion criteria from the validation studies (i.e., atrial fibrillation, persistent pacing, prolonged QRS), only 4 high-risk ECG parameters (27%) could be evaluated in all subjects and only 42% of subjects could have all 15 ECG parameters assessed. Nevertheless, almost every subject (97%) had at least one abnormal parameter. On average, there were 3.4 ± 1.8 (range, 0-8) high-risk ECG parameters per subject among the 11.7 ± 4.5 (range, 4-15) parameters that could be assessed.

CONCLUSIONS

Thus, 34% of all assessable parameters were abnormal. In conclusion, a significant proportion of ECG parameters cannot be assessed in patients with ischemic cardiomyopathy, but high-risk results are ubiquitous. The influence of these issues will be clarified when the results of the PAREPET study are available to actually determine the predictive value of these parameters on cause-specific mortality in a high-risk cohort.

Association of fragmented QRS complex with myocardial reperfusion in acute ST-elevated myocardial infarction

In this study, we aimed to evaluate the relationship between TIMI myocardial perfusion (TMP) grade, as an indicator of myocardial reperfusion, and fragmented QRS (fQRS) in standard 12-lead electrocardiogram. Also, we evaluate fQRS is an additional indicator of myocardial reperfusion. One hundred patients admitted with first STEMI to Coronary Intensive Care Unit and who were used thrombolytic therapy was included in this retrospective study. Standard 12-lead electrocardiogram records of patients simultaneous with coronary angiography (second day) were assessed and analysed for the presence of fQRS. Also, coronary angiography images were analyzed to identify the infarct related artery, TIMI grade of infarct related artery and TMP grade of infarct related artery. The patients with fQRS demonstrated a significantly lower TMP grade, TIMI grade and ejection fraction compared with the non-fQRS patients (P = 0.004, P = 0.003, P = 0.02 respectively). The patients with inadequate myocardial reperfusion demonstrated a significantly higher fQRS compared with the adequate myocardial reperfusion patients. (56.9% versus 23.5%, P = 0.002 respectively). On correlation analysis, there was a significant negative correlation between fQRS and left ventricular ejection fraction (r = -232, P = 0.02) TMP grade and adequate myocardial reperfusion (TMP 3) showed significant negative correlation with fQRS (r = -0.370, P = 0.000; r = -0.318, P = 0.001 respectively). Presence of fragmented QRS in STEMI patients was associated with inadequate myocardial reperfusion and it can be used as a simple, noninvasive parameter to evaluate myocardial reperfusion.

Absence and Resolution of Fragmented QRS Predict Reversible Myocardial Ischemia With Higher Probability of ST Segment Resolution in Patients With ST Segment Elevation Myocardial Infarction

BACKGROUND AND OBJECTIVES

Fragmented QRS complexes (fQRS) are associated with increased morbidity and mortality. The causative relationship between fQRS and cardiac fibrosis has been shown, but whether the presence and the number of fQRS on admission of electrocardiogram (ECG) predicts ST segment resolution in patients undergoing primary percutaneous coronary intervention (p-PCI) has not been investigated until now.

SUBJECTS AND METHODS

This study included one hundred and eighty-four consecutive patients with ST elevation myocardial infarction (STEMI) who underwent p-PCI. The presence or absence of fQRS on pre and post-PCI ECG and their relation with myocardial infarction and reperfusion parameters were investigated.

RESULTS

Patients with fQRS on admission of ECG or newly developed fQRS after p-PCI had increased inflammatory markers, higher cardiac enzyme levels, increased pain to balloon time, prolonged QRS time, more extended coronary involvement and more frequent Q waves on ECG in comparison to patients with absence or resolved fQRS. The presence and higher number of fQRS on admission or post-PCI ECGs were significantly related with low percent of ST resolution and myocardial reperfusion parameters. The area under the receiver operating characteristics curve values for the presence and number of fQRS to detect Thrombolysis in Myocardial Infarction Blush Grade 0 and 1, were 0.682 and 0.703.

CONCLUSION

In our study, fQRS was significantly related to infarction and myocardial reperfusion parameters before and after p-PCI. Successful myocardial reperfusion by p-PCI caused the reduction in number of fQRS and QRS time with higher ST resolution. fQRS may be useful in identifying the patients at higher cardiac risk with increased ischemic jeopardized or infarcted myocardium, and persistent or newly developed fQRS may predict low percent of ST segment resolution in patients undergoing p-PCI.

Number of leads with fragmented QRS predicts response to cardiac resynchronization therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) is an effective option in the treatment of patients with heart failure (HF) and wide QRS. Fragmented QRS (fQRS) on 12-lead electrocardiography has been shown to predict cardiac events in several patient populations. However, the relationship between the number of leads with fQRS and response to CRT has not been investigated.

HYPOTHESIS

The number of leads with fQRS may predict response to CRT.

METHODS

One hundred five patients with HF undergoing CRT were prospectively studied. The presence of fQRS was assessed using standardized criteria. Echocardiographic response to CRT was defined by a ≥15% reduction in left ventricular end-systolic volume at 6 months follow-up.

RESULTS

Seventy-four patients (71%) had CRT response after 6 months of follow-up. In multivariate analysis, significant associates of response to CRT were evaluated adjusting for gender, etiology of cardiomyopathy, QRS width, baseline left ventricular ejection fraction, and the number of leads with fQRS. The number of leads with fQRS was the only predictor of response to CRT (odds ratio: 0.61, 95% confidence interval: 0.48-0.77, P < 0.001).

CONCLUSIONS

The more leads with fQRS predicts nonresponse to CRT and may help in the selection of CRT candidates.

Fragmented QRS: What Is The Meaning?

Fragmented QRS (fQRS) is a convenient marker of myocardial scar evaluated by 12-lead electrocardiogram (ECG) recording. fQRS is defined as additional spikes within the QRS complex. In patients with CAD, fQRS was associated with myocardial scar detected by single photon emission tomography and was a predictor of cardiac events. fQRS was also a predictor of mortality and arrhythmic events in patients with reduced left ventricular function. The usefulness of fQRS for detecting myocardial scar and for identifying high-risk patients has been expanded to various cardiac diseases, such as cardiac sarcoidosis, arrhythmogenic right ventricular cardiomyopathy, acute coronary syndrome, Brugada syndrome, and acquired long QT syndrome. fQRS can be applied to patients with wide QRS complexes and is associated with myocardial scar and prognosis. Myocardial scar detected by fQRS is associated with subsequent ventricular dysfunction and heart failure and is a substrate for reentrant ventricular tachyarrhythmias.

Relationship between fragmented QRS and response to cardiac resynchronization therapy

PURPOSE

Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF) with a wide QRS. Fragmented QRS (fQRS) on a 12-lead electrocardiography (ECG) has been shown to predict cardiac events in several patient populations. We aimed to investigate the relationship between fragmented wide QRS (f-wQRS) and left ventricular dyssynchrony and response to CRT.

METHODS

Fifty-three patients with HF undergoing CRT were studied. The presence of fQRS was assessed using standardized criteria. Dyssynchrony was defined as interventricular mechanical delay (IVMD) ≥40 ms and tissue Doppler velocity opposing-wall delay ≥65 ms. Echocardiographic response to CRT was defined by a ≥15 % reduction in left ventricular end-systolic volume at 6 months follow-up.

RESULTS

Fragmented wide QRS was present in 17 (32 %) patients. Interventricular and intraventricular dyssynchrony were highly prevalent in both patient groups with f-wQRS and nonf-wQRS (64.7 % vs 75 %, p = 0.44; 70.6 % vs 72.2 %, p = 0.25). Ischemic HF was significantly higher in patients with f-wQRS than patients with nonf-wQRS (64 % vs 33 %, p = 0.03). Reverse remodeling was developed in 32 (89 %) and 6 (35 %) of patients with nonf-wQRS and f-wQRS, respectively (p = 0.001). In multivariate analysis, significant associates of response to CRT were evaluated adjusting for etiology of cardiomyopathy, QRS width, IVMD, intraventricular delay, and f-wQRS. Lack of f-wQRS was the only predictor of response to CRT (OR 1.556, 95 % CI, 0.016-0.806, p = 0.028).

CONCLUSIONS

Presence of dyssynchrony is necessary but not sufficient to select appropriate candidates for CRT. Presence of f-wQRS on baseline ECG may play a role in identifying patients who may not respond to CRT.

Idiopathic ventricular fibrillation with fragmented QRS complex and J wave in resting electrocardiogram

Objective

To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram.

Methods

We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups.

Results

The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ± 5.6 per-year in group I, 10.8 ± 3.9 per-year in group II, and 9.8 ± 4.2 per-year in group III. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1–7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity.

Conclusions

This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.

Sinus rhythm electrocardiogram identification of basal-lateral ischemic versus nonischemic substrate in patients with ventricular tachycardia

PURPOSE

Sinus rhythm (SR) electrocardiogram (ECG) features in patients with nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) have been described. ECG characteristics that distinguish nonischemic VT substrate from prior myocardial infarction (MI) have yet to be determined. We aimed to identify ECG differences between patients with basal-inferolateral scar due to NICM versus prior MI.

METHODS

SR/atrial-paced ECGs from patients who underwent VT ablation with endocardial/epicardial basal-inferolateral nonischemic scar (n = 25) were compared to patients with inferior/inferolateral MI (n = 30). Surface QRS complexes in each lead were analyzed. Patients with bundle branch block or ventricular pacing were excluded. The best diagnostic algorithm was determined by multivariate analysis then validated prospectively.

RESULTS

The NICM group had smaller R amplitude in leads I, II, and III (p ≤ 0.05 for all), greater S amplitude in leads II, III, and V6 (p ≤ 0.001 for all) and S/R ratio in lead V6 (p = 0.001). Inferior Q waves were uncommon in NICM (24 % vs. 87 %, p < 0.001). Lateral QRS fragmentation was uncommon (20 %) but only found in NICM. A three-step algorithm was derived with 100 % sensitivity and 77 % specificity for NICM. In the validation cohort (n = 51), ICM was appropriately excluded in 93 % of the cases of NICM (91 % interobserver agreement) by the algorithm.

CONCLUSIONS

Lateral lead QRS fragmentation, absence of inferior Q waves, and lead V6 S/R ratio ≥0.25 on the SR ECG distinguishes patients with basal-lateral scar due to NICM from those with prior MI. These findings demonstrate the value of the surface ECG in identifying unique scar-based VT substrate.

The J wave and fragmented QRS complexes in inferior leads associated with sudden cardiac death in patients with chronic heart failure

AIMS

To investigate the relationship between electrocardiogram (ECG) parameters [J wave, fragmented QRS (fQRS), QTc, the peak-to-end interval of T wave (Tp-Te)], and sudden cardiac death (SCD) in chronic heart failure (CHF).

METHODS AND RESULTS

The ECGs of 1570 CHF patients, 572 cases with dilated cardiomyopathy (DCM) and 998 cases with ischaemic cardiomyopathy (ICM) were analysed with the endpoint being an SCD or non-SCD (NSCD). During a median follow-up period of 36 months (0.40-65 months), 438 (27.89%) patients died, of which 158 (35.84%) were SCD. Overall, the occurrence of J wave, fQRS, and long Tp-Te were greater in SCD patients than that of NSCD patients (all P< 0.01). For DCM cases, more SCD patients had J waves observed in the inferior leads than that in the NSCD group (26.78 vs. 13.07%, P<0.001). However, ICM cases with SCD did have more fQRS in the inferior leads than that with NSCD (42.16 vs. 26.67%, P= 0.01). After adjusting for other risk factors, Cox regression analysis revealed that presence of J wave or fQRS in the inferior leads predicted a higher risk for SCD in DCM [hazard ratio (HR), 4.095; 95% confidence interval (CI), 2.132-7.863] and ICM (HR, 2.714; 95% CI, 1.809-4.072) patients. A left ventricular ejection fraction ≤ 30% also predicted SCD and NSCD in DCM and ICM patients. In contrast, the predictive value of QTc and Tp-Te for SCD was not significant.

CONCLUSIONS

Presence of J wave or fQRS in the inferior leads predicted higher risk of SCD in DCM and ICM patients and might serve as independent predictors for SCD in patients with CHF.

The independent relationship of systemic inflammation with fragmented QRS complexes in patients with acute coronary syndromes

Background and Objectives

QRS complex fragmentations are frequently seen on routine electrocardiograms with narrow or wide QRS complex. Fragmented QRS complex (fQRS) is associated with increased morbidity and mortality, sudden cardiac death and recurrent cardiovascular events. In this study, we aimed to interrogate the relationship of systemic inflammation with the presence of fQRS in patients with acute coronary syndromes (ACS).

Subjects and Methods

Two-hundred and twenty eligible patients with ACS that underwent coronary angiography were enrolled consecutively in this study. Patients with significant organic valve disease and those with any QRS morphology that had a QRS duration ≥120 ms as well as patients with permanent pacemakers were excluded from this study.

Results

Patients with fQRS were of a higher age (p=0.02), had increased C-reactive protein (CRP) levels (p<0.001), prolonged QRS time (p<0.001), extent of coronary artery disease (CAD) (p<0.001), creatine kinase-MB (CK-MB) levels (p=0.006) and Q wave on admission electrocardiography (p<0.001) in comparison to patients with non-fragmented QRS. When we performed multiple logistic regression analysis, fQRS was found to be related to increased CRP levels {odds ratio (OR): 1.2, 95% confidence interval (CI): 1.045-1.316, p=0.007}, QRS duration (OR: 1.1, 95% CI: 1.033-1.098, p<0.001), extent of CAD (OR: 1.5, 95% CI: 1.023-2.144, p=0.037), Q wave (OR: 2.2, 95% CI: 1.084-4.598, p=0.03) and CK-MB levels (OR: 1.0, 95% CI: 1.001-1.037, p=0.04) independently.

Conclusion

In our study, we found that fQRS was independently related to increased CRP. Fragmented QRS that may result as an end effect of inflammation at cellular level can represent increased cardiac risk by different causative mechanisms in patients with ACS.

QRS fragmentation and the risk of sudden cardiac death in MADIT II

BACKGROUND

QRS fragmentation (fQRS) has been reported as a useful ECG parameter in predicting mortality in high-risk postinfarction patients. Its prognostic value for sudden cardiac death (SCD) and ventricular arrhythmias in ischemic cardiomyopathy (ICM) remains unknown.

METHODS

MADIT II enrollment 12-lead ECGs were analyzed for fQRS defined as RSR' patterns (≥1 R' or notching of S or R wave) in patients with a normal QRS duration and >2 notches on the R or S wave in patients with abnormal QRS duration, present in 2 contiguous leads. Exclusion criteria included a paced rhythm and an uninterpretable or incomplete ECG. Study endpoints included SCD, SCD or appropriate implantable cardioverter defibrillator (ICD) shock, and total mortality (TM).

RESULTS

Of the 1,232 ECGs reviewed, 1,040 were of suitable quality for fQRS analysis. QRS fragmentation was found in 33% of patients in any leads, in 10% of patients in anterior leads, in 8% of patients in lateral leads and in 21% of patients in inferior leads. Anterior and lateral location of QRS fragmentation was not associated with follow-up events. Inferior location of fQRS was found to be predictive of SCD/ICD shock (hazard ratio [HR] 1.46, P = 0.032), SCD (HR 2.05, P = 0.007), and TM (HR 1.44, P = 0.036). This association was driven primarily by the increase in events found in LBBB patients: SCD/ICD shock (HR 2.05, P = 0.046), SCD (HR 4.24, P = 0.002), and TM (HR 2.82, P = 0.001).

CONCLUSIONS

Fragmented QRS, especially identified in inferior leads, is predictive of SCD, SCD or appropriate ICD shock, and all-cause mortality in patients with ICM. Identifying inferior fQRS in patients with LBBB is of particular prognostic significance and should reinforce the use of ICD therapy in this high-risk group.

Significance of fragmented QRS complexes for identifying culprit lesions in patients with non-ST-elevation myocardial infarction: a single-center, retrospective analysis of 183 cases

BACKGROUND

Fragmented QRS (fQRS) complexes are novel electrocardiographic signals, which reflect myocardial conduction delays in patients with coronary artery disease (CAD). The importance of fQRS complexes in identifying culprit vessels was evaluated in this retrospective study.

METHODS

A 12-lead surface electrocardiogram was obtained in 183 patients who had non-ST-elevation myocardial infarction (NSTEMI) and subsequently underwent coronary angiography (CAG). On the basis of the frequency of fQRS complexes, indices such as sensitivity, specificity, positive and negative predictive values, and likelihood ratio were evaluated to determine the ability of fQRS complexes to identify the culprit vessels.

RESULTS

Among the patients studied, elderly patients (age ≥ 65 years) and those with diabetes had a significantly higher frequency of fQRS complexes (p = 0.005, p = 0.003, respectively). The fQRS complexes recorded in the 4 precordial leads had the highest specificity (81.8%) for identifying the culprit vessel (left anterior descending artery). However, the specificity of fQRS complexes to identify lesions in the left circumflex and right coronary arteries was lower for the inferior and lateral leads than for the limb leads (65.5% versus 71.7%); however, the limb leads had higher sensitivity (92.3% versus 89.4%). And the total sensitivity and specificity of fQRS (77.1% and 71.5%) were higher than those values for ischemic T-waves.

CONCLUSIONS

The frequency of fQRS complexes was higher in elderly and diabetic patients with NSTEMI. The frequency of fQRS complexes recorded in each of the ECG leads can be used to identify culprit vessels in patients with NSTEMI.

Prognostic significance of fragmented QRS in patients with non-ST elevation myocardial infarction: results of a 1-year, single-center follow-up

OBJECTIVES

The aim of this study was to evaluate the predictive value of fragmented QRS (fQRS) among non-ST elevation acute coronary syndrome (ACS) patients.

DESIGN

The fQRS on standard 12-lead ECGs in 179 patients (63% males, mean age 60.9 ± 12.3 years) were analyzed. Cardiac events and cardiac mortality were regarded as two outcomes to determine whether fQRS was a clinical prognostic factor; its prognostic value was then assessed adjusting for other covariates.

RESULTS

Cardiac mortality (18 (17.0%) vs. 4 (5.5%)) and major cardiac event rate (46 (43.4%) vs. 22 (30.1%)) were higher in the fQRS group compared with the non-fQRS group during a mean follow-up of 12 months. A Kaplan-Meier survival analysis revealed significantly lower event-free survival for cardiac events (p = 0.030) and cardiac mortality (p = 0.020). Multivariate Cox regression analysis revealed that significant fQRS was an independent significant predictor for cardiac events and cardiac mortality.

CONCLUSION

These results indicate that the occurrence of fQRS in the ECG is a powerful predictor of decreased survival in NSTEMI. The prognostic importance of fQRS was incremental to clinical and conventional factors.

Fragmented QRS complexes predict right ventricular dysfunction and outflow tract aneurysms in patients with repaired tetralogy of Fallot

BACKGROUND

Fragmented QRS complexes (fQRS) correlate with myocardial scar, and may predict arrhythmias in patients with repaired tetralogy of Fallot (TOF). We investigated the relationship between fQRS in operated TOF patients with right ventricular (RV) dysfunction and RV outflow tract (RVOT) aneurysm.

METHODS

We studied 56 operated TOF patients with moderate/severe pulmonary regurgitation, referred for cardiac magnetic resonance imaging (MRI) over a 4.5 year period. The presence of fQRS (additional notches in the R/S wave in ≥ 2 contiguous leads on the ECG) was correlated with MRI findings.

RESULTS

fQRS was observed in 44 (78.6%) patients. Patients with fQRS had significantly larger RV end diastolic volume index (RVEDVi; 162 ml vs 141 ml, p=0.028) and RV end systolic volume index (RVESVi; 88 ml vs 70 ml, p=0.031). Increasing number of leads with fragmentation was independently associated with increasingly lower RV ejection fraction (adjusted co-efficient -0.97, 95%CI -1.83 to -0.12, p=0.026), greater pulmonary regurgitation fraction (1.65, 0.28 to 3.01, p=0.019), larger RVEDVi (6.78, 2.00 to 11.56, p=0.006) and RVESVi (5.41, 1.66 to 9.15, p=0.005). Anterior fragmentation correlated most significantly with RV dysfunction (p<0.05). fQRS had no significant association with LV dysfunction. Presence of any fQRS (OR 17.5, 95%CI 2.1-147.8, p=0.009) and inferior fQRS (OR 9.0, 95%CI 2.7-30.1, p<0.001) were found to be significant predictors for RVOT aneurysm.

CONCLUSIONS

The presence of fQRS on the ECG is significantly associated with RV dysfunction and RVOT aneurysms in repaired TOF patients. Increasing burden of fragmentation, especially in the anterior leads, is associated with increasing RV dysfunction.

Relationship of fragmented QRS complexes with inadequate coronary collaterals in patients with chronic total occlusion

BACKGROUND

Fragmented QRS (fQRS) complexes are defined as various RSR' patterns (≥1 R' or notching of S wave or R wave) in two contiguous leads corresponding to a major coronary artery territory. In previous studies, fQRS has been associated with increased morbidity and mortality, sudden cardiac death and recurrent cardiovascular events (CVEs). The causative relationship between fQRS and cardiac fibrosis has been shown in prior studies. The association between inadequate (poor) coronary collaterals and presence of fQRS has not comprehensively been studied in patients with chronic total occlusion (CTO) until now. We tested the hypothesis that the presence of fQRS is associated with inadequate coronary collateral growth.

METHODS

This study had a cross-sectional observational design. The study population consisted of patients who underwent coronary angiography with the suspicion of coronary artery disease at our institution in an outpatient manner. Patients who had CTO in at least one major epicardial coronary artery were included. Coronary angiograms of 148 eligible patients from our database were analyzed again. Ninety-three patients had good and 55 had poor collateral development according to the Cohen-Rentrop method.

RESULTS

Patients with poor collateral development had higher plasma glucose (130 ± 54 vs. 116 ± 33 mg/dl, P = 0.047) and an older age (65 ± 10 vs. 61 ± 10  years, P = 0.042) in comparison to patients with good collateral growth. The presence and number of fQRS were higher in the poor collateral group than the good collateral group (64 vs. 32%, P < 0.001 and 2.3 ± 2.4 vs. 1.2 ± 2.0, P = 0.002, respectively). Left ventricular ejection fraction was significantly lower in the poor collateral group than the good collateral group (45 ± 11 vs. 51 ± 13, P = 0.014). There was a significant correlation between number of fQRSs and the echocardiographic wall-motion abnormality score (r = 0.662, P < 0.001). In multivariate analysis, only the presence of fQRS was independently related to poor collateral development (odds ratio, 3.559; 95% confidence interval, 1.708-7.415, P = 0.001).

CONCLUSION

We found that fQRS was independently related to inadequate coronary collaterals in patients with CTO. fQRS, which may be derived from the effects of myocardial ischemia or scar on myocardial electricity at the cellular level, can represent inadequate coronary collateral development in patients with CTO.

The prognostic significance of fragmented QRS in patients with left ventricular noncompaction cardiomyopathy

BACKGROUND

Fragmented QRS complexes (fQRS) were proven to be associated with the prognosis of several heart diseases. However, no data is available regarding fQRS in left ventricular noncompaction cardiomyopathy (LVNC), in which the outcome varies greatly and a simple yet practicable prognostic predictor is needed. The purpose of this study was to determine the prognostic value of fQRS in LVNC patients.

METHODS

Sixty-four LVNC patients were evaluated. Fragmented narrow QRS (f-nQRS) included single or multiple notches in the R or S wave in at least 2 contiguous electrocardiogram (ECG) leads and QRS duration < 120 ms, fragmented wide QRS (f-wQRS) included more than 2 notches and QRS duration > 120 ms.

RESULTS

f-nQRS and f-wQRS was present in 24 (38%) and 7 (11%) patients respectively. During follow-up, 13 patients died and 7 patients underwent heart transplantation. Kaplan-Meier analysis revealed that compared with the non-f-nQRS group, the f-nQRS group associated with a significantly lower survival (P = 0.005). The f-wQRS group also demonstrated a substantially lower survival as compared with the non-f-wQRS group (P = 0.02). Multivariate analysis indicated f-nQRS was an independent predictor of all-cause mortality (HR: 5.33; P = 0.045).

CONCLUSIONS

In LVNC patients, the presence of f-nQRS has significant prognostic value and may provide a valid method of risk stratification.

Relationship of fragmented QRS with prognostic markers and in-hospital MACE in patients undergoing CABG

BACKGROUND

Fragmented QRS complex (fQRS) is associated with increased morbidity and mortality, sudden cardiac death and recurrent cardiovascular events. However, its prognostic role has not been studied comprehensively in patients undergoing coronary artery bypass graft (CABG) surgery. In this study, we investigated the relationship between the presence of fQRS, and the prognostic markers and in-hospital major adverse cardiovascular events (MACE).

METHODS

Two hundred and forty two eligible patients who underwent CABG surgery at our institution were enrolled consecutively. In analysis of fragmentations on electrocardiograms, presence of fQRS was defined as various RSR' patterns (≥ 1 R' or notching of S wave or R wave) with or without Q waves without a typical bundle-branch block in two contiguous leads corresponding to a major coronary artery territory. MACE was defined as cardiac death, recurrent myocardial infarction, heart failure, cerebrovascular event, sustained ventricular tachycardia or fibrillation.

RESULTS

Patients with fragmented QRS had older age (64 ± 10 vs. 61 ± 9 years, p = 0.03), prolonged QRS time (99 ± 11 vs. 87 ± 11 ms, p < 0.001), higher rate of Q wave on ECG (29% vs. 12%, p = 0.001), higher European system for cardiac operative risk evaluation (EUROSCORE) (4.0 ± 1.9 vs. 2.6 ± 1.6, p < 0.001) and lower left ventricular ejection fraction (LVEF)% (43 ± 12 vs. 60 ± 12, p < 0.001) in comparison to patients with non-fragmented QRS. In addition, the patients with fQRS had longer cross-clamp time (67 ± 23 vs. 55 ± 20 minutes, p = 0.001) and extracorporeal circulation (105 ± 31 vs. 91 ± 30 minutes, p = 0.003), increased inotropic usage (p < 0.001) and prolonged cardiac surgery intensive care unit (53 ± 25 vs. 35 ± 12 hours, p < 0.001) and in-hospital stay after CABG.

CONCLUSION

FQRS may have additional value in the assessment of cardiac function and in prediction of intra- and post-operative hemodynamic instability and adverse cardiovascular events. Fragmentations on admission ECG may be useful for identifying patients with higher risk who will need additional support after CABG surgery.

Relation of fragmented QRS complex to right ventricular fibrosis detected by late gadolinium enhancement cardiac magnetic resonance in adults with repaired tetralogy of fallot

Fragmented QRS (fQRS) on 12-lead electrocardiography reflects conduction delay caused by myocardial fibrosis and dysfunction. Ventricular fibrosis detected by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) is reportedly correlated with worse clinical outcomes in adults with repaired tetralogy of Fallot (TOF). The aim of this study was to assess whether the presence of fQRS is associated with right ventricular (RV) fibrosis or dysfunction in this patient group. In 37 consecutive patients (median age 30 years, median age at repair 6.6 years), the number of leads showing fQRS, defined as the presence of >2 notches on the R/S wave in ≥2 contiguous leads, was counted. RV systolic function, dilatation, and LGE score were measured using LGE CMR. Ventricular LGE was observed mainly at the previous surgical sites: the RV outflow tract (33 of 37), ventricular septal defect patch region (15 of 37), and RV anterior wall (11 of 37). Fragmented QRS was found mostly in the right and mid precordial leads. The fQRS group (n = 20) demonstrated higher RV LGE scores (p <0.001) and lower RV ejection fractions (p = 0.02) and a trend toward larger RV end-diastolic and end-systolic volumes (p = 0.12 and p = 0.06, respectively) compared to the non-fQRS group (n = 17). The number of electrocardiographic leads showing fQRS was positively correlated with RV LGE score (r = 0.75, p <0.001). The presence of fQRS remained independently associated with the presence of supramedian RV LGE score, even after adjusting for relevant parameters. In conclusion, fQRS was closely associated with more extensive RV fibrosis and dysfunction in adults with repaired tetralogy of Fallot.