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

The Relationship between Fragmented QRS and Myocardial Injury in Patients with Acute Carbon Monoxide Poisoning

Background and Objectives: Carbon monoxide (CO) intoxication is one of the most common causes of poisoning-related deaths and complications. Myocardial injury is an important complication of CO poisoning. In our study, we aimed to evaluate the relationship between the presence and prevalence of fragmented QRS (fQRS) and myocardial injury in patients with CO intoxication. Materials and Methods: We retrospectively evaluated patients who presented to the emergency department of our tertiary care center with CO intoxication between January 2020 and December 2023. In our study, we performed subgroup analyses according to the presence of myocardial injury and fQRS. We evaluated the parameters and risk factors associated with myocardial injury. Results: Myocardial injury was detected in 44 patients, and fQRS was detected in 38 patients. In the myocardial injury (+) group, the fQRS rate was 38.6%, and the median number of leads with fQRS was 3 (2-6) and was significantly higher than in the myocardial injury (-) group (p < 0.001). We found that carboxyhemoglobin had a significant positive correlation with troponin (p = 0.001) and pro-B-type natriuretic peptide (proBNP) (p = 0.009). As a result of multivariate analysis, we determined that age, creatinine, proBNP, fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury. Conclusions: Myocardial injury in CO intoxication patients is associated with proBNP, the presence of fQRS, and the number of leads with fQRS. Age, creatinine level, proBNP, the presence of fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury in patients with CO intoxication.

Why do we keep missing left circumflex artery myocardial infarctions?

BACKGROUND

Diagnosis of left circumflex artery (LCx) myocardial infarctions via 12‑lead electrocardiogram (ECG) has posed a challenge to healthcare professionals for many years.

METHODS AND RESULTS

A retrospective observational study was performed to analyze patients admitted with myocardial infarction. The study used electronic medical records and specific ICD-10 codes to identify eligible patients, resulting in 2032 encounters. After independent adjudication of cardiac biomarkers, coronary angiography, and electrocardiographic changes, a final patient population of 58 encounters with acute occlusion myocardial infarction (OMI) with a culprit LCx lesion was established. OMI was defined as a lesion with either thrombolysis in myocardial infarction flow (TIMI) 0-2 or TIMI 3 with Troponin I > 1 ng/mL (Reference range 0.00-0.03 ng/mL). ECGs of these patients were then independently evaluated and grouped into 8 different classifications based on the presence or absence of ST elevation and/or depression in corresponding leads. ECG patterns and anatomical characteristics (proximal or distal to the first obtuse marginal artery) of the LCx lesions were then correlated. The appropriateness of triage and delay in reperfusion therapy were also assessed. Those with a left dominant or codominant circulation, and with LCx lesions proximal to the first obtuse marginal artery, were more likely to present with no or subtle ST-segment changes that led to delays in reperfusion therapy.

CONCLUSIONS

Patients with left or codominant coronary artery circulation, with OMI proximal to the first obtuse marginal artery, may be less likely to have "classic" findings of ST-segment elevation on ECG due to cancellation forces in the limb leads.

The value of fragmented QRS in predicting the prognosis of chronic total occlusion patients with myocardial infarction history undergoing percutaneous coronary intervention: A 24-months follow-up study

BACKGROUND

Fragmented QRS (fQRS) is a marker of local myocardial scar. This study aimed to analyze the relationship between fQRS and coronary collateral circulation (CCC) and evaluate the predictive value of fQRS for long-term clinical outcomes among patients with chronic total occlusion (CTO) and prior myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI).

METHODS

A total of 862 patients with a definite history of MI who had one CTO coronary artery and underwent PCI between 2013 and 2018 were continuously analyzed. Patients were divided into group A (no Q wave and fQRS, n = 206), group B (fQRS, n = 265), group C (Q wave, n = 391). All patients were followed up for 2 years.

RESULTS

The incidence rate of major adverse cardiovascular events (MACE) in group B was significantly lower than in group C (group B vs. C: 7.2% vs. 11.3%, P = 0.043). The percentage of good CCC was 94.2%, 88.3%, and 82.9% in group A, B, and C (p < .001), respectively. The improvement of cardiac function in group B and A were more significant than in group C. Multivariate Cox regression analysis showed fQRS was an independent protective factor of MACE after PCI within 2 years in CTO patients with prior MI (RR = 0.668, 95% CI [0.422-0.917], p = .001).

CONCLUSION

fQRS is an independent protective factor of prognosis in patients with prior MI and one CTO vessel who underwent PCI, presenting with a higher rate of good CCC, less occurrence of MACE, and better heart function than in Q wave patients.

The Predictive Value of Fragmented QRS for Cardiovascular Events in Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Objective: Fragmented QRS (fQRS) have been reported as a predictor of major adverse cardiac events (MACE) and mortality in several studies on cardiovascular disease. However, most studies have yielded discrepant results. This study aimed to explore the correlation between fQRS and cardiovascular events in patients with acute myocardial infarction (AMI) during their hospital stay and follow-up period, and the predictive value of fQRS in the prognosis of AMI. Methods: We searched for relevant studies in four databases, Medline, Embase, PubMed, and the Cochrane Library from January 2010 to March 2020. Our initial search yielded 585 articles. Of these, we screened 19 studies, and finally included a total of 6,914 patients in this analysis, comparing death events or MACE in AMI patients with or without fQRS. Results: Fragmented QRS was significantly associated with a higher risk of in-hospital mortality (OR, 3.97; 95% CI, 2.45-6.44; p < 0.00001), long-term mortality (OR, 2.93; 95% CI, 1.76-4.88; p < 0.0001), in-hospital MACE (OR, 2.48; 95% CI, 1.62-3.80; p < 0.0001), and long-term MACE (OR, 3.81; 95% CI, 2.21-6.57; p < 0.00001). In particular, it demonstrated a higher predictive value for in-hospital cardiovascular mortality and long-term all-cause mortality in AMI patients and in-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI). Moreover, fQRS was also associated with an increased risk of ventricular arrhythmias (OR, 2.76; 95% CI, 1.72-4.43; p < 0.0001) and heart failure (OR, 1.65; 95% CI, 1.02-2.66; p = 0.04). Fragmented QRS was negatively associated with left ventricular ejection function (LVEF) (MD, -5.47; CI, [-7.03, -3.91]; p < 0.00001) and positively associated with a high incidence of coronary artery triple vessel lesions (OR, 2.14; 95% CI, 1.31-3.51; p = 0.002) in AMI patients. Conclusion: Fragmented QRS is significantly associated with in-hospital and long-term mortality and MACE in patients with AMI, as well as ventricular arrhythmias and heart failure. Furthermore, it may be a marker of mortality and MACE risk. Moreover, fQRS also indicates a reduced LVEF and a high incidence of coronary artery triple vessel lesions in AMI patients. Meta-analysis Registration: https://www.crd.york.ac.uk/prospero; ID: CRD42020171668.

Predictive value of fragmented QRS for ventricular tachyarrhythmias in patients with acute myocardial infarction: A meta-analysis

BACKGROUND

Recent studies indicated that fragmented QRS (fQRS) is associated with malignant cardiac arrhythmias in patients with acute myocardial infarction (AMI). However, a systematic review and meta-analysis on this issue still have not been conducted. Thus, we performed a systematic review and meta-analysis to access the predictive value of fQRS for ventricular tachyarrhythmias (VTAs) in patients with AMI.

MATERIALS AND METHODS

We searched the databases of PubMed, Embase and Cochrane Library for relevant studies until 8 June 2019. We included studies which compared VTAs in AMI patients with fQRS vs without fQRS.

RESULTS

Six studies enrolling 2218 ST-segment elevation myocardial infarction (STEMI) patients were included in this meta-analysis. The fQRS was significantly associated with greater risk of VTAs in STEMI patients (Odds ratio [OR] 2.81, 95% confidence interval (CI) 1.99-3.95, P < .00001; I²  = 30%). This association was still significant both in prospective (OR 3.25, 95% CI 1.94-5.46, P < .00001; I²  = 0%) and retrospective (OR 2.40, 95% CI 1.22-4.74, P = .01; I²  = 54%) studies. In particularly, fQRS in patients with low left ventricular ejection fraction (≤50%) (OR 2.97, 95% CI 1.88-4.70, P < .00001; I²  = 21%) or <60 years old (OR 3.07, 95% CI 2.02-4.66, P < .00001; I²  = 0%) tripled the risk of VTAs during AMI.

CONCLUSION

Our meta-analysis demonstrated that fQRS increases the risk of developing VTAs in patients with STEMI.

Fragmented QRS - Its significance

Fragment QRS (fQRS) complex is a myocardial conduction abnormality that indicates myocardial scar. It is defined as additional notches in the QRS complex. Though initially fQRS was defined in the setting of normal QRS duration (<120 m s), later it has been expanded to include conditions with wide QRS complexes as in bundle branch block, ventricular ectopy and paced rhythm, when more than 2 notches are present. It is an important, yet often overlooked marker of mortality and arrhythmic events in many cardiac diseases. The significance of fQRS lies in the fact that it just requires a surface ECG for its recording and the value of information about the condition of the heart it dispenses based on the clinical setting. We review the role of fQRS in predicting adverse cardiac events in various conditions.

Prognostic Value of QRS Fragmentation in Patients with Acute Myocardial Infarction: A Meta-Analysis

AIMS

Fragmented QRS has emerged as a novel electrocardiographic parameter associated with adverse clinical events in various diseases. The aim of this study was to investigate the association of fQRS with in-hospital and long-term cardiovascular events in patients with ST-segment elevation myocardial infarction (STEMI) and non-ST segment elevation myocardial infarction (NSTEMI).

METHODS AND RESULTS

We searched PubMed, Embase, Web of Science, and Cochrane Library up to October 2015 for eligible studies. We selected studies with fQRS defined with 12-lead ECG during the index hospitalization of STEMI/NSTEMI. Primary outcomes were in-hospital and long-term cardiovascular events. In-hospital mortality was significantly higher in fQRS (+) group (99/733; 13.5%) compared to fQRS (-) group (47/1293; 3.6%) (OR 4.03 95% CI 1.81-8.94; P = 0.0006). Long-term mortality rate was higher in fQRS (+) group (89/473; 18.8%) compared to fQRS (-) group (54/1009; 5.3%) (OR 3.93 95% CI 1.92-8.05; P = 0.0002). In addition the frequency of long-term MACE was higher in fQRS (+) group (46.9%) compared to fQRS (-) group (14.6%) (OR 5.13 95% CI 2.77-9.51; P < 0.00001) CONCLUSION: Presence of fQRS on admission ECG was found to be predictor of mortality, MACE, deterioration of LV function, and presence of multivessel disease in patients with STEMI and NSTEMI.

Fragmented QRS complexes have predictive value of imperfect ST-segment resolution in patients with STEMI after primary percutaneous coronary intervention

OBJECTIVES

To investigate the clinical characteristics of patients with the fragmented QRS complexes (fQRS) and the predictive value of fQRS in patients undergoing primary percutaneous coronary intervention (p-PCI).

METHODS

The study enrolled 227 consecutive patients with ST-elevation myocardial infarction who underwent p-PCI. Baseline clinical characteristics, the percentage of ST-segment resolution, and parameters of electrocardiography and coronary angiography were investigated. The relationship between fQRS on pre-PCI and post-PCI electrocardiogram and the percentage of ST-segment resolution after PCI were studied.

RESULTS

Patients with fQRS have higher troponin I, creatine kinase-MB levels, prolonged QRS duration, higher Gensini score, lower percentage of total ST-segment resolution, and left ventricular ejection fraction compared with patients without fQRS. Gensini score (odds ratio [OR], 1.013; 95% confidence interval [CI], 1.002-1.024; P < .006) and percentage of total ST-segment resolution (OR, 0.384; 95% CI, 0.186-0.795; P = .01) were independently associated with the presence of fQRS. A multivariate logistic regression analysis selected presence of fQRS pre-PCI (OR, 2.908; 95% CI, 1.095-7.723; P = .032) and the number of leads with fQRS before PCI (OR, 1.582; 95% CI, 1.250-2.002; P < .001) as independent predictors of imperfect ST-segment resolution.

CONCLUSIONS

The presence of fQRS is a predictor in ST-elevation myocardial infarction patients undergoing p-PCI. The occurrence of fQRS is beneficial to identify the patients with severe coronary lesion, left ventricular contraction dysfunction, and larger areas of ischemic injury.

Fragmented QRS on Admission Electrocardiography Predicts Long-Term Mortality in Patients with Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

Early diagnosis and identification of high-risk non-ST elevation myocardial infarction (NSTEMI) is an important issue. Fragmented QRS (fQRS) complexes are defined as various RSR' patterns on 12-lead resting electrocardiography (ECG). Previous studies revealed that fQRS is related with increased ventricular arrhythmias and cardiovascular mortality. The relation between fQRS and mortality in acute coronary syndromes, mitral valve disease severity and structural heart disease has been shown in different studies. The aim of this study was to investigate relation between fQRS and long-term cardiovascular mortality in NSTEMI patients.

METHODS

Patients who admitted to our emergency unit and diagnosed NSTEMI between 2012 and 2013, 433 patients were included prospectively. fQRS complexes determined in 85 patients. Patients were divided into two groups according to fQRS existence. All patients evaluated for their clinical, laboratory, electrocardiographic, and echocardiographic characteristics. Angiographic features of 315 patients who underwent coronary angiography was also recorded. In-hospital, 30-day and 12-month mortality was compared between these groups.

RESULTS

Demographic characteristics and cardiovascular risk factors were similar in both groups except hyperlipidemia. GRACE risk score was higher in patients with fQRS and positively correlated with existence of fQRS. In hospital and 30-days mortality were similar but late mortality was higher in fQRS group. Predictors of late mortality were found to be age, heart rate, male sex in addition to fQRS.

CONCLUSION

We found a relation between fQRS and late mortality. Fragmented QRS may be seen as a cautionary signal for extensive myocardial damage and thereby increased long-term mortality for patients with NSTEMI.

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.

Fragmented QRS on surface electrocardiogram is not a reliable predictor of myocardial scar, angiographic coronary disease or long term adverse outcomes

PURPOSE

Conflicting evidence remains regarding the value of fragmented QRS (fQRS) on surface electrocardiogram (EKG). We present the 5-year outcome of patients with fQRS on EKG and its correlation to SPECT and coronary angiography (CA).

METHODS

We retrospectively studied EKG's in 248 consecutive patients undergoing SPECT and CA with known or suspected coronary artery disease (CAD). The presence of fQRS or Q waves in two contiguous EKG leads was correlated with major coronary artery distributions on SPECT and cath. Patients with bundle-branch block, paced-rhythm or absence of EKG within one month of SPECT were excluded. The final EKG data for 238 patients were analyzed and compared with myocardial scar on SPECT and the presence of significant (>50%) coronary stenosis on CA. Predictors of MACE (death, MI, heart failure) were evaluated. Freedom from all-cause mortality was assessed by Kaplan-Meier analysis.

RESULTS

Of 238 patients, no significant difference was noted in the presence of scar on SPECT in fQRS (3/77; 3.8%) versus no fQRS (11/161; 6.8%) (P=0.56); or CA based CAD (55/77; 71% fQRS) and no fQRS (99/161, 61.4%) (P=0.20). EKG Q wave presence was similar in both groups: (12/77; 15.5% fQRS), (17/161; 10.5% no fQRS) (P=0.3). Patients with CA based significant LAD disease were 3.680 times more likely to have fQRS (P=0.04), however, fQRS was not significantly associated with MACE (P=0.92) or all-cause mortality (P=0.93).

CONCLUSIONS

This study does not support routine assessment of fQRS on surface EKG as a reliable predictor of SPECT myocardial scar, MACE or all-cause mortality over a long period of follow-up.

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.

Comparison of fragmented QRS and myocardial perfusion-gated SPECT findings

AIM

Fragmented QRS (fQRS) complex is an ECG parameter that has recently been introduced and investigated. It is assumed that fQRS occurs because of disruptions in ventricular conduction due to ventricular infarction and ischemia. Therefore, in this article, we aimed to investigate the relationship between the detection of infarction and ischemia on myocardial perfusion-gated single-photon emission computed tomography images and appearance of fQRS on ECG.

MATERIALS AND METHODS

We retrospectively reviewed the records of patients with a diagnosis of coronary artery disease who were referred to our institution for myocardial perfusion scintigraphy. In total, 261 patients (122 women and 139 men, with a mean age of 61±10.33 years) with and without fQRS (136 and 125, respectively) were included in the present study. The myocardial perfusion scintigraphy results were evaluated for the presence or absence of myocardial ischemia and infarction by visual and quantitative (summed stress score, summed rest, summed difference score, summed motion score, and summed thickening score) assessments. Statistical analysis was performed to determine the relationship between the presence of fQRS and myocardial ischemia and/or infarction. Student's t-test and the Mann-Whitney U-test were used for comparing the results. Pearson's χ2-test and Fisher's exact tests were also used to compare the distribution of variables between the two groups.

RESULTS

The prevalence of ischemia and infarction were found to be, respectively, 4.38-fold and 5.95-fold higher in patients with fQRS compared with the control group. Moreover, the prevalence of both ischemia and infarction was found to be 10.54-fold higher in patients with fQRS compared with the control group.

CONCLUSION

There is a highly statistically significant possibility of detecting ischemia and infarction in perfusion myocardial scintigrams of patients whose ECGs have fQRS.