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

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

OBJECTIVE

The aim of this study is to examine the probability of de-novo fQRS in patients with mild COVID-19 disease, as an indicator of cardiac injury.

METHODS

Data of 256 patients with normal admission electrocardiography and no comorbidities between 1.12.2020-31.12.2021, were examined retrospectively 6-month after mild COVID-19 disease. Patients were divided into two groups: fQRS+ group (n = 102) and non-fQRS group (n = 154). Relation between fQRS and other electrocardiography, echocardiographic and laboratory findings were investigated.

RESULTS

No significant difference was found between the groups among age and gender. Troponin-I and creatine kinase myocardial band values (retrospectively 9.10 ± 1.76 vs 0.74 ± 1.43, 34.05 ± 82.20 vs. 14.68 ± 4.42), COVID-19 IgG levels (45.78 ± 14.82 vs. 36.49 ± 17.68), diastolic dysfunction (39.21% vs. 15.07%), EF value (58.02 ± 1.95 vs. 64.27 ± 3.07), dyspnea (41.17% vs. 6.84%), post-COVID-19 tachycardia syndrome (19.6% vs. 2.74) were more frequent in fQRS+ group compared to non-fQRS group. The EF value was lower in the presence of fQRS in the high lateral leads (57.12 ± 1.99, 58.47 ± 1.79, p:0.018). There was a positive correlation between IgG value and endsystolic diameter, septum thickness and left atrium diameter. In multivariate analysis de-novo fQRS, dyspnea, high troponin and IgG values, diastolic dysfunction, low EF value and left atrial diameter were determined as independent risk factors for post-COVID-19 tachycardia syndrome in follow-up.

CONCLUSION

In COVID-19 disease de-novo fQRS, dyspnea, high IgG and troponin value, left atrial diameter, lower EF value, diastolic dysfunction were associated with post-COVID-19 tachycardia syndrome. The de-novo fQRS in SARS-COV-2 may be a predictor of future more important adverse cardiovascular outcomes and this should alert clinicians.

Fragmented QRS predicts reperfusion failure and in-hospital mortality in ST-Elevation myocardial infarction: a systematic review and meta-analysis

Objective: Recent studies have shown that fragmented QRS (fQRS) is associated with unfavourable outcomes in STEMI patients. However, there is controversy amongst studies. We performed a systematic review and meta-analysis to explore the effect of fQRS on reperfusion failure and in-hospital mortality among this population.Methods: We searched the databases of MEDLINE and EMBASE from inception to October 2018. Included studies were published cohort studies of STEMI patients that underwent primary percutaneous coronary intervention (pPCI) and thrombolysis. Data from each study were combined using the random-effects model.Results: Ten studies from January 2011 to October 2018 (2753 patients, 1075 patients with fQRS), were included. The fQRS was associated with higher risk of reperfusion failure in pPCI when defined by ST-segment resolution (OR = 3.08, 95% CI = 1.27-7.46, p-value = .013) but not when defined by TIMI flow grade (pooled OR = 1.45, 95% CI = 0.83-2.54, p-value = .192). In thrombolysis, fQRS was associated with higher risk of reperfusion failure when defined by both ST-segment resolution (pooled OR = 4.35, 95% CI = 1.80-10.49, p-value = .001) and TIMI flow grade (OR = 3.70, 95% CI = 2.10-6.53, p-value < .001). The fQRS was also associated with an increased risk of in-hospital mortality in both pPCI (pooled OR = 4.41, 95% CI = 1.60-12.16, p-value = .004) and thrombolysis (pooled OR = 2.38, 95% CI = 1.06-5.35, p-value = .036).Conclusions: Our meta-analysis demonstrated that fQRS in STEMI patients was associated with reperfusion failure as well as in-hospital mortality.

Electrocardiographic predictors of myocardial fibrosis and apical hypertrophic cardiomyopathy

BACKGROUND

Electrocardiography (ECG) may be an efficacious diagnostic and prognostic tool in hypertrophic cardiomyopathy (HCM). This study aimed to investigate association between deep T-wave inversion (TWI) and apical HCM, and between fragmented QRS (fQRS) complex and myocardial fibrosis in patients with HCM.

METHODS

Patients with documented HCM by cardiac magnetic resonance imaging (CMR) during 2005-2015 were studied. The 12-lead ECG and CMR were performed on the same day. All patients underwent CMR for the assessment of cardiac structure, function, and late gadolinium enhancement (LGE). LGE was used to detect myocardial fibrosis.

RESULTS

One hundred forty-four HCM (mean age 66 ± 15.8 years, 60.4% male) were included. Twenty-nine (20.14%) subjects had deep TWI, and apical HCM was found in 76 (52.78%). Deep TWI was associated with apical HCM with the Odds ratio (95%CI) of 5.82 (2.07, 16.04) and p < 0.001 in univariate analysis model. The association was still significant in multivariate analysis with adjusted Odds ratio (95%CI) of 9.86 (3.17, 30.66), p < 0.001. Forty-seven (32.64%) subjects had fQRS complex, and myocardial fibrosis was detected in 101 (70.14%). fQRS complex was found to be associated with myocardial fibrosis in univariate analysis with the Odds ratio (95%CI) = 2.75 (1.16, 6.54), p = 0.019. However, the association cannot be demonstrated in the multivariate analysis.

CONCLUSION

Deep TWI is independently associated with apical HCM, but the relationship between fQRS complex and myocardial fibrosis did not survive multivariate analysis.

Association between serum S100A1 level and Global Registry of Acute Coronary Events score in patients with non-ST-segment elevation acute coronary syndrome

Objective Acute coronary syndrome (ACS) is associated with several clinical syndromes, one of which is acute non-ST-segment ACS (NSTE-ACS). S100A1 is a calcium-dependent regulator of heart contraction and relaxation. We investigated the association between the serum S100A1 level and the Global Registry of Acute Coronary Events (GRACE) risk score in patients with NSTE-ACS and the potential of using the serum S100A1 level to predict the 30-day prognosis of NSTE-ACS. Methods The clinical characteristics of 162 patients with NSTE-ACS were analyzed to determine the GRACE score. The serum S100A1 concentration was determined using fasting antecubital venous blood. The patients were divided into different groups according to the serum S100A1 level, and the 30-day NSTE-ACS prognosis was evaluated using Kaplan-Meier analysis. Results The serum S100A1 levels differed significantly among the groups. Correlation analysis showed that the serum S100A1 level was positively correlated with the GRACE score. Kaplan-Meier analysis revealed that the number of 30-day cardiac events was significantly higher in patients with an S100A1 level of >3.41 ng/mL. Conclusions S100A1 is a potential biomarker that can predict the progression of NSTE-ACS and aid in its early risk stratification and prognosis.

Fragmented QRS complex as a predictor of coronary artery disease in patients with acute coronary syndrome (A study from Egypt)

Methods

Two groups according to the presence of fQRS in ECG.

Results

fQRS has higher sensitivity for LAD, LCX &RCA, more specific for LAD.

Conclusions

fQRS is a good, simple, applicable positive test to predict the presence of significant CAD in acute coronary syndrome (ACS), even without enzyme elevation.

Fragmented QRS and abnormal creatine kinase-MB are predictors of coronary artery disease in patients with angina and normal electrocardiographys

BACKGROUND/AIMS

Patients with symptoms of coronary artery disease (CAD) often display normal tracings or only nonspecific changes on electrocardiography (ECG). The aim of this study was to explore strategic elements of the ECG and other potential factors that are predictive of CAD in this scenario.

METHODS

This was an observational study of 142 patients with the chief complaint of chest pain, each of whom presented with a normal ECG and was subjected to emergency coronary angiography (CAG). Two population subsets were identified: those patients (n = 97) with no significant stenotic lesions and those (n = 45) with the significant stenotic lesions of CAD.

RESULTS

Those patients with normal or nonspecific ECGs and CAD (15.8%) were more likely to have left circumflex artery involvement (20% vs. 7%). In patients with normal ECGs and CAD (vs. normal CAG), male sex (86.7% vs. 68%, p = 0.023), creatine kinase-MB (CK-MB) levels > 10 U/L (13 vs. 10, p = 0.025), and fragmented QRS (fQRS) (38.6% vs. 21.6%, p = 0.042) occurred with greater frequency. In multivariable analysis, the following variables were significant predictors of CAD, given a normal ECG: male sex (odds ratio [OR], 2.593; 95% confidence interval [CI], 1.068 to 5.839); CK-MB (OR, 2.497; 95% CI, 0.955 to 7.039); and W- or M-shaped QRS complex (OR, 2.306; 95% CI 0.988 to 5.382).

CONCLUSIONS

In our view, male sex, elevated CK-MB (> 10 U/L), and fQRS complexes are suspects for CAD in patients with angina and unremarkable ECGs and should be considered screening tests.

Total Mortality, Major Adverse Cardiac Events, and Echocardiographic-Derived Cardiac Parameters with Fragmented QRS Complex

BACKGROUND

Fragmented QRS complex (fQRS), an easily evaluated noninvasive electrocardiographic parameter, is associated with worse outcomes in patients with several cardiovascular conditions. The presence of fQRS on ECG may be an indicator of myocardial damage in patients with coronary artery disease (CAD). In this article, we performed a meta-analysis in order to characterize the presence of fQRS on ECG in patients with CAD.

METHODS

We searched English-language randomized controlled trials involving fQRS on ECG in patients with CAD (n = 3279 patients, 12 trials). Two reviewers independently extracted data. Data on LVEF, LVESD, LVEDD, LVESV, LVEDV, total mortality, stroke, and MACE were collected. fQRS was performed a comparison with non-fQRS, calculating pooled relatives risk (RRs) and weighted mean difference (WMD), and associated 95% confidence intervals (CIs).

RESULTS

fQRS was associated with significant increased WMD of LVEDD (WMD, 2.26; 95%CI, 0.92 to 0.36, P = 0.0009), LVESD (WMD, 2.71; 95%CI, 1.23 to 4.19, P = 0.0003), LVEDV (WMD, 31.37; 95%CI, 24.82 to 37.92, P < 0.00001), and LVESV (WMD, 28.45; 95%CI, 22.92 to 33.98, P < 0.00001). As compared to non-fQRS, fQRS increased risk of total mortality (RR, 3.09; 95%CI, 1.76 to 5.44, P < 0.0001) and MACE (RR, 2.85; 95%CI, 1.98 to 4.09, P < 0.00001) in patients with CAD. However, a decreased trend was observed for LVEF (WMD, -3.59; 95%CI, -7.05 to -0.12, P = 0.04). For the incidence of stoke, there was no difference between fQRS and non-fQRS group.

CONCLUSIONS

Our findings indicate that fQRS is a valuable factor to predict total mortality and MACE in patients with CAD.

Fragmented QRS Is Associated with Improved Predictive Value of Exercise Treadmill Testing in Patients with Intermediate Pretest Likelihood of Significant Coronary Artery Disease

BACKGROUND

The predictive value of exercise treadmill testing (ETT) remains inadequate in diagnosing patients with suspected coronary artery disease (CAD) and needs to be improved.

OBJECTIVE

The aim of this study was to investigate whether the presence of FQRS on 12-lead ECG would increase the PPV of ETT in patients with an intermediate likelihood of CAD.

METHODS

fQRS, defined as the presence of notched R or S waves without accompanying typical bundle branch block or the existence of an additional wave-like RSR' pattern in the original QRS complex (with a duration of <120 ms), was assessed in 95 patients with positive ETT. Coronary angiogram (CA) was performed in all patients, divided into two groups as the significant CAD group and nonsignificant CAD group according to coronary artery lesions. The differences between the groups in terms of the presence of fQRS and clinical characteristics were investigated.

RESULTS

The mean age of patients was 51.3 ± 11.3 years, and 74 of them were males (77.9%). FQRS was present in 47 (49.5%) patients, and significant CAD was demonstrated in 51 subjects (53.7%) among the enrolled subjects. fQRS was more prevalent in the significant CAD group compared to nonsignificant CAD group (P < 0.001). The presence of FQRS increased the PPV of positive ETT from 53.7% to 85.1%. In addition, FQRS was associated with the increased risk of significant CAD in multivariate analysis (OR = 2.839, P < 0.001).

CONCLUSION

In clinical practice, the presence of fQRS in patients with positive ETT may support clinicians during the decision-making process with regard to the referral for a coronary angiography.

The Predictive Value of Admission Fragmented QRS Complex for In-Hospital Cardiovascular Mortality of Patients with Type 1 Acute Aortic Dissection

BACKGROUND

Fragmented QRS (fQRS) arises from impaired ventricular depolarization due to heterogeneous electrical activation of ischemic and/or infarcted ventricular myocardium. The short- and long-term prognostic values of fQRS have been reported for myocardial infarction, heart failure, fatal cardiac arrhythmias, and sudden cardiac death. The aim of this study was to investigate the predictive value of admission fQRS complex for in-hospital cardiovascular mortality of patients with type 1 acute aortic dissection (AAD).

METHODS

In this retrospective study, 203 consecutive patients with type 1 AAD who had been admitted to either of two large-volume tertiary hospitals between December 2008 and October 2013 were included. The patients were divided into two groups according to the presence or absence of the fQRS complex on admission.

RESULTS

In-hospital cardiovascular mortality (P < 0.001), major adverse cardiovascular events (P < 0.001), acute renal failure (P = 0.022), multiorgan dysfunction (P < 0.001), and acute decompensated heart failure (P < 0.001) were observed to be significantly more frequent in the fQRS-positive group than in the fQRS-negative group. fQRS (odds ratio [95% confidence interval]: 4.184 [1.927-9.082], P < 0.001), operation duration (4.184 [1.927-9.082], P = 0.001), and Killip class IV (3.900 [1.699-8.955], P = 0.001) were found to be significant independent predictors of in-hospital cardiovascular mortality after adjustment of other risk factors in the multivariate analysis.

CONCLUSIONS

fQRS is a simple, inexpensive, and readily available electrocardiographic entity that provides an additional risk stratification level beyond that provided by conventional risk parameters in predicting in-hospital cardiovascular mortality in type 1 AAD.

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

BACKGROUND

Experimental and clinical studies have suggested that the presence of fragmented QRS complex (fQRS) is associated with various cardiovascular diseases. fQRS may predict major adverse cardiovascular events (MACE). The current meta-analysis was performed using clinical outcome studies to evaluate the role of fQRS in coronary artery disease (CAD).

METHODS

A systematic search of electronic databases (Cochrane, Medline, Embase and Pubmed) from their inception to April 2014 was performed. Data were extracted from applicable articles to evaluate the prognostic value of fQRS in CAD.

RESULTS

A total of 16 observational studies about fQRS and CAD (n = 3,997 patients) were identified. Compared with the non-fQRS group, MACE and mortality were significantly higher in the fQRS group -odds ratios (OR) 3.19, 95 % confidence interval (95 % CI) [2.3, 4.42], p < 0.00001; OR 2.24, 95 % CI [1.71, 2.94], p < 0.0001. Patients developed Q waves, anterior-wall myocardial infarction (MI), and low left ventricular ejection fraction (LVEF) more frequently in the fQRS group than in the non-fQRS group-OR 2.59, 95 % CI [1.76, 3.81], p < 0.00001; OR 2.43, 95 % CI [1.07, 5.52], p = 0.03; OR - 6.43, 95 % CI [- 9.11, - 3.74], p < 0.00001.

CONCLUSION

Based on current evidence, fQRS was associated with increased MACE, mortality, Q waves, anterior-wall MI, and decreased LVEF in CAD. These findings show that fQRS is a reliable marker in CAD.

Significance of fragmented QRS complexes for identifying left ventricular hypertrophy in patients with hypertension

BACKGROUND

Fragmented QRS complexes (fQRS) were associated with left ventricular mass (LVM) in hypertensive patients. Our study aimed to investigate the association between fQRS and left ventricular hypertrophy (LVH) in hypertensive patients.

METHODS

Two hundred thirty-six hypertensive patients were divided into fQRS group and non-fQRS group. fQRS were defined as the presence of an additional R wave, notching in the R or S wave, or the presence of >1 R' in two contiguous leads. Echocardiography was used to detect LVH.

RESULTS

Patients with fQRS had higher levels of LVM than patients without fQRS (181.55 ± 65.64 g vs. 149.21 ± 35.08 g, P < 0.001). Receiver operating characteristic curves showed areas under the curve was 0.62 for fQRS (95% CI 0.54-0.69, P = 0.003). In univariate analyses, the presence of fQRS on ECG was positively associated with LVM. Multiple regression analyses found fQRS was associated with LVM, independently.

CONCLUSION

fQRS is a common electrocardiographic phenomenon in patients with hypertension. Although the diagnostic value for LVH is limited, the presence of fQRS on ECG is associated with a higher risk for worse LVH.

The assessment of relationship between fragmented QRS complex and left ventricular wall motion score index in patients with ST elevation myocardial infarction who underwent primary percutaneous coronary intervention

OBJECTIVES

Fragmented QRS (fQRS) has been found to be associated with high mortality and arrhythmic events in acute coronary syndromes. Regional systolic function using wall motion score index (WMSI) is an alternative to left ventricular ejection fraction (LVEF) for the assessment of left ventricular systolic function. The aim of this study was to investigate the relation between the presence of fQRS on admission electrocardiogram (ECG) and WMSI in ST elevation myocardial infarction (STEMI) underwent primary coronary intervention (PCI). The in-hospital and long-term prognostic significance of persistent fQRS was also evaluated.

METHODS

In this retrospective study, 542 patients with a diagnose of STEMI underwent primary PCI were included. Study patients were divided into two groups according to the presence (n = 153) or absence (n = 389) of a fQRS on admission ECG.

RESULTS

WMSI was found to be significantly higher in fQRS(+) group compared to the fQRS(-) group (P < 0.001). In multivariete analysis, WMSI was found to be an independent predictor of fQRS, and fQRS was inversely associated with LVEF. The in-hospital reinfarction (P = 0.003), MACE (P = 0.024), intraaortic balloon pump use (P = 0.014), and advanced heart failure (P < 0.001) were found to be significantly more frequent in the fQRS(+) group. The presence of fQRS on admission was found to be associated with an increase in long-term cardiovascular mortality (P = 0.028), and long-term all-cause mortality (P = 0.022).

CONCLUSION

WMSI was significantly related with the presence of the fQRS, which reflects the linking between impairment of regional left ventricular systolic function and the presence of severe myocardial injury in STEMI.

The basic social medical insurance is associated with clinical outcomes in the patients with ST-elevation myocardial infarction: a retrospective study from Shanghai, China

OBJECTIVE

Several social economic factors play important roles in treatments of ST-elevation myocardial infarction (STEMI) and finally influence the clinical outcomes. The basic social medical insurance (BSMI) is an important economic factor in China's medical system. However, the impact of BSMI on clinical outcomes in STEMI patients has not been explored yet. The aim of this study is to investigate whether BSMI is a predictor of clinical outcomes in the patients with STEMI in Shanghai, China.

MATERIAL AND METHODS

In this retrospective study, 681 STEMI patients from different areas in Shanghai were classified into four groups: new rural cooperative medical scheme (NCMS) group, urban resident basic medical insurance scheme (URBMI) group, urban employee basic medical insurance scheme (UEBMI) group and UNINSURED group, major adverse events (cardiac death, nonfatal reinfarction, clinically driven target lesion revascularization/target vessel revascularization, stroke, heart failure) were regarded as study endpoints to determine whether BSMI was a prognostic factor.

RESULTS

During a mean follow-up of 36 months, the incidence of major adverse events was significantly higher in NCMS patients (64; 38.8%) compared with the other groups: URBMI (47; 24.6%); UEBMI (28; 15.6%); UNISURED (40; 27.6%). Similarly, cardiac mortality was also higher in NCMS group (19; 11.5%). A Kaplan-Meier survival analysis revealed significantly lower event-free survival rate for major adverse events (p < 0.001) and cardiac mortality (p = 0.01) in NCMS group. Multivariate Cox regression analysis revealed that BSMI was an important prognostic factor in STEMI patients.

CONCLUSION

These results demonstrate that BSMI is closely associated with the major adverse events-free survival rate at 36-month follow-up in the STEMI patients under the current policies in Shanghai, China.

Effects of obstructive sleep apnea on cardiac function and clinical outcomes in Chinese patients with ST-elevation myocardial infarction

AIM

The objective of this study was to investigate the influence of OSA on cardiac function in Chinese patients with ST-elevation myocardial infarction (STEMI) and determine the prognostic impact of OSA among these patients.

METHODS

In this retrospective study, 198 STEMI patients were enrolled. Doppler echocardiography was performed to detect the effect of OSA on cardiac function. Major adverse cardiac events (MACE) and cardiac mortality were analyzed to determine whether OSA was a clinical prognostic factor; its prognostic impact was then assessed adjusting for other covariates.

RESULTS

The echocardiographic results showed that the myocardium of STEMI patients with OSA appeared to be more hypertrophic and with a poorer cardiac function compared with non-OSA STEMI patients. A Kaplan-Meier survival analysis revealed significantly higher cumulative incidence of MACE and cardiac mortality in the OSA group compared with that in the non-OSA group during a mean follow-up of 24 months. Multivariate Cox regression analysis revealed that OSA was an independent risk factor for MACE and cardiac mortality.

CONCLUSION

These results indicate that the OSA is a powerful predictor of decreased survival and exerts negative prognostic impact on cardiac function in STEMI patients.

Significance and usefulness of narrow fragmented QRS complex on 12-lead electrocardiogram in acute ST-segment elevation myocardial infarction for prediction of early mortality and morbidity

BACKGROUND

The presence of notched R or S waves without accompanying typical bundle branch blocks, or the existence of an additional wave like RSR' pattern in the original QRS complex (with a duration of <120 ms) has been defined as narrow QRS fragmentation. Persistence of the fQRS found on the admission electrocardiogram (ECG) in patients with acute ST segment elevation myocardial infarction (STEMI) will have prognostic significance in the short term.

METHODS

The study was carried out using retrospectively collected data of 296 consecutive patients diagnosed as acute STEMI .fQRS group had fQRS both in admission and latest ECGs (n = 80, 27%), and non-fQRS group had no fQRS in last ECG (n = 216, 73%). Primary end points were in-hospital cardiovascular mortality, hemodynamic instability, and electrical instability.

RESULTS

MI localization, symptom duration, reperfusion therapy (RPT) rate, RPT modality, rate of successful reperfusion did not differ. Mean ejection fraction was lower and all end points were more frequent in the fQRS group. Irrespective of the RPT modality and success of RPT, mortality rate was higher in patients with persistent fQRS. GRACE score >120 points (OR = 4.765), age >70 years (OR = 4.041), anterior MI localization (OR = 3.148), and presence of fQRS (OR = 2.484) were significant predictors of primary end points. fQRS increased the predictive ability of GRACE score >120 about two folds (OR = 7.305, P < 0.001).

CONCLUSION

Persistent fQRS on ECG is associated with poor prognosis and there is a lack of expected mortality benefit of RPT, particularly that of fibrinolytic therapy, in STEMI patients with fQRS.

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.

The prognostic significance of narrow fragmented QRS on admission electrocardiogram in patients hospitalized for decompensated systolic heart failure

BACKGROUND

Narrow fragmented QRS (fQRS) has recently been recognized as a significant predictor of prognosis in various cardiovascular diseases.

HYPOTHESIS

We hypothesized that the presence of narrow fQRS on admission electrocardiogram (ECG) in patients with decompensated systolic heart failure (HF) of any cause would be associated with long-term prognosis.

METHODS

Patients hospitalized for decompensated HF due to ischemic or nonischemic dilated cardiomyopathy (left ventricular ejection fraction <35%) were retrospectively analyzed. The primary clinical end points were cardiovascular mortality, sudden cardiac death, and rehospitalization for HF.

RESULTS

The mean duration of follow-up was 3.73 ± 1.41 years. Patients were classified as fQRS(+) group (n = 114; mean age, 63.49 ± 12.04 years) and fQRS(-) group (n = 113 patients; mean age, 65.04 ± 11.95 years). fQRS on ECG was significantly correlated with New York Heart Association (NYHA) functional class (P = 0.001). In multivariate Cox proportional hazard analysis, narrow fQRS (odds ratio [OR]: 3.130, 95% confidence interval [CI]: 1.560-2.848, P = 0.001), chronic renal failure (OR: 2.455, 95% CI: 1.120-5.381, P = 0.025), NYHA class (OR: 8.305, 95% CI: 2.568-26.855, P < 0.0001), and hypoalbuminemia (OR: 2.099, 95% CI: 1.122-3.926, P = 0.020) were independent predictors of cardiovascular mortality. In Kaplan-Meier survival analysis, narrow fQRS on admission ECG predicted worse survival rate at 84 months; survival probability significantly decreased in the fQRS(+) group compared with fQRS(-) group (P < 0.0001).

CONCLUSIONS

Presence of narrow fQRS is associated with worse NYHA functional class in patients hospitalized for decompensated HF. Narrow fQRS predicts cardiovascular mortality in a specific subgroup of systolic HF patients, namely those hospitalized for decompensated HF of both ischemic and nonischemic causes.