Correlation between fragmented QRS and the short-term prognosis of patients with acute myocardial infarction

Correlation between fragmented QRS and the short-term prognosis of patients with acute myocardial infarction 碎裂QRS波对急性心肌梗死患者的短期预后评估 corresp first-author ‡Corresponding Authors ‡Corresponding Authors †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn shengqinhui@medmail.com.cn †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn shengqinhui@medmail.com.cn corresp ‡Corresponding Authors ‡Corresponding Authors †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn †E-mail:shengqinhui@medmail.com.cnmandy.c.hsu@gmail.comlijianping@medmail.com.cn shengqinhui@medmail.com.cn Department of Cardiology, Peking University First Hospital, Beijing 100034, China Department of Cardiology, Peking University First Hospital, Beijing 100034, China This study is aimed to investigate the clinical significance and the short-term prognostic value of fragmented QRS (fQRS) for patients with acute myocardial infarction (AMI). Three hundred patients with AMI were tested with retrospective analysis on the patients’ clinical information, hospitalized treatment, fQRS onset time, location of lesions, and other relevant data, in order to assess the relationship between the presence of fQRS and its prognosis. The rates of malignant cardiac arrhythmia, left ventricular systolic dysfunction (LVSD), and mortality in the positive fQRS group were 13.6%, 29.2%, and 23.7%, respectively, with all showing a p value < 0.05. For the ST segment elevation myocardial infarction (STEMI) subgroup, all the rates showed significant differences with a p value < 0.01, while for the non-STEMI (NSTEMI) subgroup showed no significant differences. In patients with a positive fQRS, there were no differences in malignant cardiac arrhythmia between patients with and without percutaneous coronary intervention (PCI) ( p > 0.05). As for the LVSD and mortality, the p values between patients with and without PCI were 0.031 and 0.000, respectively, suggesting statistical significance. The results imply that AMI patients with positive fQRS especially for the patients with STEMI had higher rates of malignant cardiac arrhythmia, LVSD, and mortality than the non-fQRS group. Patients of AMI with positive fQRS, who underwent early revascularization, could lower the incidence of the cardiovascular event. In addition, the presence of fQRS could be used as an indication of early intervention treatment for patients. 研究目的 2 探讨碎裂QRS波对急性心肌梗死患者的短期预后评估的价值，及其对ST段抬高和非ST段抬高型心肌梗死（STEMI和NSTEMI）患者不同的预测价值。 创新方法 2 证实了碎裂QRS波对急性心肌梗死尤其是ST段抬高型心肌梗死的短期预后价值，对早期再灌注治疗有指导意义。 研究手段 2 通过对碎裂QRS波发生及持续时间的详细记录（见图1、2），评价出现碎裂QRS波的STEMI及NSTEMI患者住院期间发生恶性心律失常、泵功能衰竭及住院死亡的风险（见图3；表3–5），并观察早期经皮冠状动脉介入治疗（PCI）对预后的不同影响（见表6）。 重要结论 2 1. 急性心肌梗死（尤其是STEMI）患者心电图出现碎裂QRS波短期内易发生恶性心律失常、左心室功能不全及死亡；2. 对出现碎裂QRS波的急性心肌梗死患者，早期PCI再灌注治疗可改善患者短期预后。 Fragmented QRS Acute myocardial infarction Short-term prognosis 碎裂QRS波 急性心肌梗死 短期预后 Introduction 1 Acute myocardial infarction (AMI) is due to the onset of stenosis or occlusion in the coronary artery that can cause severe ischemia and necrosis of myocardium and consequently result in a high mortality rate and poor prognosis. It has been shown that the primary causes of death are arrhythmia and heart failure. Malignant arrhythmia (mainly ventricular fibrillation) is usually the primary manifestation and accounts for 50% of the mortality (Wang and Zhao, 2011 2011 ) while heart failure is commonly seen in patients with a large area of myocardial infarction ( > 40%) and sometimes results in cardiogenic shock. As a new electrocardiographic index, fragmented QRS (fQRS) has been proved to be a valuable tool for detecting myocardial infarction (France et al., 1990 1990 ; Michael et al., 2007 2007 ; Xu and Qi, 2009 2009 ), as well as predicting the incidence of malignant cardiac arrhythmia and left ventricular systolic dysfunction (LVSD) (Guo, 2008 2008 ; Cheema et al., 2010 2010 ). However, the correlation between incidence of malignant cardiac arrhythmia, LVSD, or mortality and factors such as fQRS onset and duration, fQRS distribution in electrocardiography (ECG) leads, coronary lesion, ST segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and percutaneous coronary intervention (PCI), is still poorly understood as there are only a few studies available on these subjects. This study focuses on the investigation of the clinical significance and the short-term prognostic value of fQRS for patients with AMI. Materials and methods 1 General information 2 ST-segment and T-wave abnormalities and Q waves were defined per standard definitions recommended by consensus documents of the Guideline for Diagnosis and Treatment of Patients with Acute Myocardial Infarction (Gao, 2001 2001 ) and the universal definition of myocardial infarction (MI) based on patients’ symptoms, analysis of the standard 12-lead electrocardiogram, biomarkers, cardiac catheterization results as well as clinical data. Three hundred patients with AMI under continuous treatment in the coronary care unit and the general wards of the Peking University First Hospital during January 2010 to September 2011 were selected for the study. Patients with the following conditions would be excluded: (1) severe valvular disease, congenital heart disease, or pacemaker implantation; (2) other severe organ disease or dysfunction such as cancer, liver or kidney failure, neurological or mental disease. Experiment procedure 2 Routine ECG 3 All admitted patients would receive 12-lead ECG as a part of a routine examination (filter range, 0.5–100 Hz; AC filter, 25 mm/s, 10 mm/mV). ECG monitoring was required for every patient upon admission to the hospital. Serial ECG was performed right after the patients were administered in the hospital. To minimize the omission of fQRS, patients would have their ECG rechecked after administered in 1, 3, 6, 12, and 24 h segments. Every patient would have an ECG performed every day and additional ECG would be performed when presented with any related discomfort until they were discharged or died. All the patients would have an ECG rechecked after a PCI. Every patient would have their Holter ECG and echocardiogram on the third day of admission as well. Diagnostic standard for fQRS (Das et al., 2006 2006 ; 2007 2007 ) 3 Narrow fQRS: fQRS includes various RSR’ patterns with different morphologies of the QRS complexes except the bundle branch block, with or without the Q wave on the regular 12-lead ECG shown in at least two contiguous leads, corresponding to a myocardial territory. Fragmented wide QRS (f-wQRS): For a wide QRS wave of bundle branch block (QRS>120 ms), R wave or S wave with more than two notches is observed in two sequential leads (f-LBBB QRS, f-RBBB QRS); for a wide QRS complex of premature ventricular contractions (PVCs), R waves will show two notches and it is required to show time intervals of greater than 40 ms between two notches of the QRS waves in two or more sequential leads (f-PVCs). Electrocardiograms were compared with previous electrocardiograms if available to confirm fQRS or that pathologic Q waves were of a new onset. Follow-up and observation endpoint 2 An echocardiogram was performed for all the patients. A patient with a left ventricular ejection fraction (LVEF), which evaluated the heart function, shown to be < 40% had LVSD (Paulus et al., 2007 2007 ). Malignant cardiac arrhythmia included polymorphic ventricular extrasystoles, ventricular tachycardia, and ventricular fibrillation. The patients testing would end with either a discharge after recovery or an all-cause death. Statistical analysis 2 All quantitative data would be shown as mean±standard deviation (SD). The t -test was for comparison of averages. The Chi-square test was for the comparison of rates. The 95% confidence interval (CI) of relative risk (RR) suggested the presence of clinically significant risk factor. A p value < 0.05 indicated statistical significance. The Kaplan-Meier method was used to estimate survival functions of all-cause mortality and a Cox regression model was used to estimate the hazard ratios of variables of interest while controlling for other covariates. All statistical analyses would be completed using the SPSS 16.0 software. Results 1 Basic information of selected patients 2 The mean follow-up period of the patients studied was (15.09±0.813) d and the average age of the 300 patients was (68.48±0.71) years. The study included 204 male patients and 96 female patients, 99 STEMI patients and 201 NSTEMI patients, and 184 patients received PCI treatment during hospitalization. We found 169 patients with fQRS and the other 131 patients without fQRS, and there was no statistical significance in comparison of age, sex, and location of the infarct between the groups with or without fQRS. Information of fQRS 2 Onset time of fQRS 3 The average fQRS onset time was (2.91±0.35) d after AMI. Sixty-eight percent of the patients had fQRS within 24 h after AMI (115/169), 9.5% patients showed fQRS in 2 d (16/169), and 4.1% on the third day (7/169) ( p < 0.01). Approximately 88.2% of all patients had fQRS by the first week of testing after AMI (149/169) (Fig. 1 1 ). Onset time of fQRS of 68.05% patients was within 2 d after AMI Duration of fQRS 3 The average duration of fQRS was (4.34±0.45) d. Most of all patients, 43.8% had persistence of fQRS for 1 d (74/169), 13.0% showed fQRS for 2 d (22/169), and 4.1% showed fQRS for 3 d (7/169) ( p < 0.01). Approximately 4.7% of the patients had fQRS for as long as a period of 7 d (8/169). For a duration of fQRS longer than two weeks, 4.7% of patients fell into this category (8/169) (Fig. 2 2 ). Duration of fQRS over 50% patients was 2 d Short-term prognostic outcome for AMI patients with fQRS 2 fQRS and malignant cardiac arrhythmia 3 Retrospective analysis on ECGs for the 300 hospitalized AMI patients showed that 30 patients developed malignant cardiac arrhythmia. Based on the presence of fQRS, 300 patients were put into different groups and the correlation between fQRS and malignant cardiac arrhythmia would then be observed and analyzed. From Table 1 1 , it was seen that in 30 patients, who later developed malignant cardiac arrhythmia, 76.7% had positive fQRS (23/30) and 23.3% showed a negative result for fQRS (7/30). In the positive fQRS group, including 169 patients, 13.6% of the patients developed malignant cardiac arrhythmia (23/169); in 131 cases for the non-fQRS group, only 5.3% showed this condition (7/131) ( p < 0.05). Univariate electrocardiographic predictors of mortality on the basis of the Cox regression model were fQRS and Q waves. After controlling for age, diabetes, hypertension, hypercholesterolemia, family history of coronary artery disease, and history of smoking, fQRS was shown to be a significant predictor of malignant cardiac arrhythmia, whereas Q waves did not predict malignant cardiac arrhythmia (Table 2 2 ). 2 Group 3 Number 2 p Total Positive fQRS Negative fQRS With malignant cardiac arrhythmia 30 23 7 2 0.018 Without malignant cardiac arrhythmia 270 146 124 Derived after controlling for age, diabetes, hypertension, hypercholesterolemia, family history of coronary artery disease, and smoking Electrocardiographic sign p Hazard ratio * * (95% CI)  fQRS 0.024 0.393 (0.174–0.887)  Q wave 0.419 0.720 (0.324–1.597) fQRS and LVSD 3 In the hospitalized AMI patients, 283 of them completed echocardiography and were grouped according to LVEF. There were 219 patients with LVEF≥40% and 64 patients with LVEF < 40% suggesting LVSD. As shown in Table 3 3 , there were a total of 64 patients with LVSD, in which 73.4% also had a positive fQRS (47/64) and 26.6% had a negative result of fQRS (17/64). In the positive fQRS group including 161 patients, 29.2% of the patients developed LVSD (47/161), and in 122 cases of the non-fQRS group, only 13.9% showed this condition (17/122) ( p < 0.05). 2 Group 3 Number 2 p Total Positive fQRS Negative fQRS  LVSD 64 47 17 2 0.013  Non-LVSD 219 114 105 fQRS and mortality 3 During a mean follow-up period of (15.09±0.813) d, 19.7% of the patients died. Mortality was significantly higher in the fQRS group than in the non-fQRS group. By observing the prognoses of patients in relation to the presence of fQRS, it was found that in 169 cases of positive fQRS, the mortality rate was 23.7% (40/169); the 131 patients of the non-fQRS group showed a 14.5% mortality rate (19/131) (odd ratio (OR) 1.828, 95% CI 1.001–3.337, p =0.048). Kaplan-Meier survival analysis revealed significantly decreased survival for the fQRS group compared to the non-fQRS group ( p =0.013) (Fig. 3 3 ). Correlation between fQRS and the short-term prognosis for patients with STEMI 2 There were 99 STEMI patients (33.0%) and 201 NSTEMI patients (67.0%). For the two groups, an analysis on the correlation between fQRS and a condition of malignant cardiac arrhythmia, LVSD, or prognosis was conducted. As shown in Table 4 4 , the STEMI patients of positive fQRS had four times the incidence of malignant cardiac arrhythmia in comparison to the non-fQRS group ( p < 0.01). The rate of LVSD of fQRS group was 7.5 times higher than that of the non-fQRS group ( p < 0.01). The mortality rate of fQRS group was 2.4 times greater than that of the non-fQRS group (OR 2.44, 95% CI 1.044–5.702, p =0.006). 2 Prognosis 2 Number (percentage) 2 p fQRS Non-fQRS Malignant cardiac arrhythmia 16 (31.4%) 4 (8.3%) 0.004 LVSD 25 (53.2%) 3 (7.1%) 0.000 Death 24 (47.1%) 10 (20.8%) 0.006 Correlation between fQRS and the short-term prognosis for patients with NSTEMI 2 Between the subgroups of fQRS and non-fQRS in the NSTEMI patients, there was no statistical significance in malignant cardiac arrhythmia, LVSD, and mortality (Table 5 5 ). 2 Prognosis 2 Number (percentage) 2 p fQRS Non-fQRS Malignant cardiac arrhythmia 7 (5.9%) 3 (3.6%) 0.457 LVSD 22 (19.3%) 14 (17.5%) 0.842 Death 16 (13.6%) 9 (10.8%) 0.566 Correlation between PCI and the short-term prognosis for patients with positive fQRS 2 Out of 169 cases with positive fQRS, 101 patients had coronary angiography, including 10 patients for the coronary bypass surgery, and 90 patients for PCI treatment. A total of 68 patients did not receive a coronary angiography because of the patients’ health conditions, economics, etc. The correlation analysis between PCI treatment and the development of malignant cardiac arrhythmia, LVSD, or mortality in patients with positive fQRS is shown in Table 6 6 . In comparison to the PCI group, there was no difference in development of malignant cardiac arrhythmia in the non-PCI group, but as for the LVSD and mortality rate, the non-PCI group had significantly higher incidences ( p < 0.05). 2 Prognosis 2 Number 2 p PCI Non-PCI Malignant cardiac arrhythmia 11 12 0.209 LVSD 23 24 0.031 Death 14 26 0.000 Discussion 1 AMI is a high-risk disease whose primary cause of death is malignant cardiac arrhythmia, accounting for 50% of all deaths. Heart failure is commonly found in patients with a large area of myocardial infarction. Therefore, the objective of risk evaluation immediately after admission is to provide early risk stratification of patients with AMI and to identify high-risk patients and predict complications. Thus, it plays an important role to assess the short-term and long-term prognostic outcomes, as well as preventing adverse events and improving prognosis for patients (Das et al., 2006 2006 ; 2009 2009 ). More researchers are now focusing on clinical application of fQRS (Carey et al., 2010 2010 ). Currently, there are many theories on the mechanism of fQRS (Flowers et al., 1969 1969 ; Frustaci et al., 2005 2005 ; Zhang et al., 2011 2011 ). In our study, the frequent onset time of fQRS of approximately 77.5% of the patients was 24 to 48 h after AMI, and the fQRS duration of 56.8% of the patients who developed fQRS was 24 to 48 h. It takes approximately two to four weeks for cardiac muscle remodeling after infarction and the replacement of tissues by fibroblasts is completed by the 6th and the 8th weeks. The myocardial scarring becomes the basis of the ventricular remodeling process. It was thus postulated that the formation of fQRS in early myocardial ischemia might be due to the asynchronous conduction during infarction (Wang and Zhao, 2011 2011 ). Most of the studies related to fQRS spent more time to evaluate the outcomes of the MI patients after more than 30 d. Many early validation studies had shown that fQRS was a remote surrogate marker of the myocardial scar (Gardner et al., 1985 1985 ; Das et al., 2008 2008 ). In our study, a large portion of the patients developed fQRS in the acute phase. This phenomenon showed that fQRS might be a remark for the electrocardiographic predictors in the acute phase of MI. Can fQRS be induced for the same reasons that cause electrical storm in the early phase of AMI patients? This may require further study to investigate the etiology of fQRS. This study also showed that there was an 81.1% incidence rate of fQRS in the inferior lead (137/169), which was significantly higher than the rates observed at the anterior and the lateral chest wall. However, the analysis on fQRS in correspondence with coronary lesions found no statistical significance between the two. The attempt to link fQRS of a lead to the number of coronary lesions showed that there were variations in the number of coronary lesions (either single or multiple) when fQRS occurred in the inferior lead ( p < 0.05). On the other hand, there was no statistical significance between the incidence of fQRS in the anterior or the lateral leads and the number of coronary lesions. Yao et al. ( 2011 2011 ) studied the relationship between fQRS in the inferior lead and the coronary lesion in 128 patients with coronary heart disease. They arrived at the same conclusion as this study that the incidence rate of fQRS was significantly higher in the inferior lead than in the other two leads (anterior and lateral). Furthermore, they pointed out that fQRS in the II, III and the aVF-lead could not be used to determine the number of coronary lesions (either to be single or multiple). Apoptosis appears to play a more important role in causing arrhythmogenic right ventricular cardiomyopathy (ARVC). Coincidently, the apoptosis usually occurs in the right ventricular segments adjacent to the diaphragm, as well as the apical (known as the triangle of dysplasia). Therefore, this might in some aspect explain the high incidence rate of fQRS located in the inferior lead. However, it is still unclear why the incidence rate of fQRS is notably higher in the inferior lead and further investigation is required to understand if it is related to the anatomical uniqueness where blood supplies from both directions of coronary arteries overlap or is simply due to the average level of cardiac electric axis. It is well known that fQRS can be the indicator of the upcoming malignant arrhythmia, which is consistent with our results. However, in our study, Q waves were significant predictors of mortality (OR 1.934, 95% CI 1.121‒3.335, p =0.018) compared to fQRS (OR 1.687, 95% CI 0.978‒2.910, p =0.060). This indicates that Q wave still can be a valuable predictor of mortality while fQRS can assist physicians to evaluate the condition of their AMI patients with its high predict value of malignant arrhythmia or when there is no evidence of Q waves existing. This study also showed that the positive fQRS group had higher rates in malignant cardiac arrhythmia, LVSD, and mortality than the non-fQRS group ( p < 0.05). The STEMI patients of positive fQRS had four times the incidence of malignant cardiac arrhythmia in comparison to the non-fQRS group ( p < 0.01). The rate of LVSD of the fQRS group was 7.5 times higher than that of the non-fQRS group ( p < 0.01). The mortality rate of the fQRS group was 2.4 times greater than that of the non-fQRS group (OR 2.44, 95% CI 1.044‒5.702, p =0.006). Between the subgroups of fQRS and non-fQRS in the NSTEMI patients, there was no statistical significance in malignant cardiac arrhythmia, LVSD, or mortality. It suggests that the presence of fQRS in STEMI patients might be strongly correlated to a higher incidence of cardiovascular events. Statistical analysis showed no significant variation in the incidence rates of fQRS between the STEMI and the NSTEMI patients ( p > 0.05), implying that fQRS was not correlated to the type of myocardial infarction. The result was probably due to the small sample size and further research with a larger population of subjects might be required to prove it. To understand if PCI was capable of reducing rates of malignant cardiac arrhythmia, LVSD, and mortality in patients with positive fQRS, the experimental results showed no difference in the number of malignant cardiac arrhythmia between the groups with and without PCI treatment ( p =0.209). As for the LVSD and mortality, the p -values between the patients with and without PCI were 0.031 and 0.000, respectively. There were many reports using fQRS as an index to detect various cardiac structural abnormalities such as the arrhythmogenic right ventricular dysplasia (ARVD) (Peters et al., 2008 2008 ; Das and El Masry, 2010 2010 ; Zhou et al., 2011 2011 ). And, many researchers have already proven a strong correlation between fQRS and malignant cardiac arrhythmia (Morita et al., 2008 2008 ; Sha et al., 2011 2011 ). In the study, results suggested that the incidence rate of malignant cardiac arrhythmia in the positive fQRS group was not related to revascularization (Erdoğan et al., 2012 2012 ). It was postulated that the sample size with malignant cardiac arrhythmia was too small and further investigation with more subjects might be required. For patients with positive fQRS, early revascularization treatment can greatly reduce the incidence rates of LVSD and mortality. Liu et al. ( 2010 2010 ) studied the effect of revascularization treatment at different periods for AMI patients and pointed out that early therapy could indeed reduce the fQRS rate and even improve the LVEF for patients. Therefore, by identifying fQRS, it can guide physicians in prescribing early revascularization treatment for patients and can improve their life quality, as well as the survival rate of AMI. Conclusions 1 In summary, fQRS plays an important role in cardiovascular disease. To demonstrate the relation between fQRS and short-term prognosis of patients with AMI, we compared malignant cardiac arrhythmia, LVSD, and mortality rates between STEMI and NSTEMI patients. Early revascularization in patients with positive fQRS could lower the incidence of the cardiovascular events. Further studies are needed to clarify these interrelations. References MG Carey , Jr AJ Luisi , S Baldwa , 等 . The Selvester QRS Score is more accurate than Q waves and fragmented QRS complexes using the Mason-Likar configuration in estimating infarct volume in patients with ischemic cardiomyopathy . J Electrocardiol , 2010 . 43 ( 4 ): 318 - 325 . 20381066 DOI: 10.1016/j.jelectrocard.2010.02.011 http://doi.org/10.1016/j.jelectrocard.2010.02.011 . The Selvester QRS Score is more accurate than Q waves and fragmented QRS complexes using the Mason-Likar configuration in estimating infarct volume in patients with ischemic cardiomyopathy A Cheema , A Khalid , A Wimmer , 等 . Fragmented QRS and mortality risk in patients with left ventricular dysfunction . Circ Arrhythm Electrophysiol , 2010 . 3 ( 4 ): 339 - 344 . 20511537 DOI: 10.1161/CIRCEP.110.940478 http://doi.org/10.1161/CIRCEP.110.940478 . Fragmented QRS and mortality risk in patients with left ventricular dysfunction MK Das , H El Masry . Fragmented QRS and other depolarization abnormalities as a predictor of mortality and sudden cardiac death . Curr Opin Cardiol , 2010 . 25 ( 1 ): 59 - 64 . 19881337 DOI: 10.1097/HCO.0b013e328333d35d http://doi.org/10.1097/HCO.0b013e328333d35d . Fragmented QRS and other depolarization abnormalities as a predictor of mortality and sudden cardiac death MK Das , B Khan , S Jacob , 等 . Significance of a fragmented QRS complex versus a Q wave in patients with coronary artery disease . Circulation , 2006 . 113 ( 21 ): 2495 - 2501 . 16717150 DOI: 10.1161/CIRCULATIONAHA.105.595892 http://doi.org/10.1161/CIRCULATIONAHA.105.595892 . Significance of a fragmented QRS complex versus a Q wave in patients with coronary artery disease MK Das , C Saha , H El Masry , 等 . Fragmented QRS on a 12-lead ECG: a predictor of mortality and cardiac events in patients with coronary artery disease . Heart Rhythm , 2007 . 4 ( 11 ): 1385 - 1392 . 17954396 DOI: 10.1016/j.hrthm.2007.06.024 http://doi.org/10.1016/j.hrthm.2007.06.024 . Fragmented QRS on a 12-lead ECG: a predictor of mortality and cardiac events in patients with coronary artery disease MK Das , H Suradi , W Maskoun , 等 . Fragmented wide QRS on a 12-lead ECG: a sign of myocardial scar and poor prognosis . Circ Arrhythm Electrophysiol , 2008 . 1 ( 4 ): 258 - 268 . 19808417 DOI: 10.1161/CIRCEP.107.763284 http://doi.org/10.1161/CIRCEP.107.763284 . Fragmented wide QRS on a 12-lead ECG: a sign of myocardial scar and poor prognosis MK Das , MA Michael , H Suradi , 等 . Usefulness of fragmented QRS on a 12-lead electrocardiogram in acute coronary syndrome for predicting mortality . Am J Cardiol , 2009 . 104 ( 12 ): 1631 - 1637 . 19962466 DOI: 10.1016/j.amjcard.2009.07.046 http://doi.org/10.1016/j.amjcard.2009.07.046 . Usefulness of fragmented QRS on a 12-lead electrocardiogram in acute coronary syndrome for predicting mortality T Erdoğan , SA Kocaman , M Çetin , 等 . Relationship of fragmented QRS complexes with inadequate coronary collaterals in patients with chronic total occlusion . J Cardiovasc Med (Hagerstown) , 2012 . 13 ( 8 ): 499 - 504 . 22498998 DOI: 10.2459/JCM.0b013e328353683c http://doi.org/10.2459/JCM.0b013e328353683c . Relationship of fragmented QRS complexes with inadequate coronary collaterals in patients with chronic total occlusion NC Flowers , LG Horan , JR Thomas , 等 . The anatomic basis for high-frequency components in the electrocardiogram . Circulation , 1969 . 39 ( 4 ): 531 - 539 . 5778254 DOI: 10.1161/01.CIR.39.4.531 http://doi.org/10.1161/01.CIR.39.4.531 . The anatomic basis for high-frequency components in the electrocardiogram RJ France , JM Formolo , DG Penney . Value of notching and slurring of the resting QRS complex in the detection of ischemic heart disease . Clin Cardiol , 1990 . 13 ( 3 ): 190 - 196 . 2323119 DOI: 10.1002/clc.4960130309 http://doi.org/10.1002/clc.4960130309 . Value of notching and slurring of the resting QRS complex in the detection of ischemic heart disease A Frustaci , SG Priori , M Pieroni , 等 . Cardiac histological substrate in patients with clinical phenotype of Brugada syndrome . Circulation , 2005 . 112 ( 24 ): 3680 - 3687 . 16344400 DOI: 10.1161/CIRCULATIONAHA.105.520999 http://doi.org/10.1161/CIRCULATIONAHA.105.520999 . Cardiac histological substrate in patients with clinical phenotype of Brugada syndrome RL Gao . Guideline for the management of acute myocardial infarction . Chin Circ J , 2001 . 16 ( 6 ): 407 - 422 . (in Chinese) . Guideline for the management of acute myocardial infarction PI Gardner , PC Ursell , Jr JJ Fenoglio , 等 . Electrophysiologic and anatomic basis for fractionated electrograms recorded from healed myocardial infarcts . Circulation , 1985 . 72 ( 3 ): 596 - 611 . 4017211 DOI: 10.1161/01.CIR.72.3.596 http://doi.org/10.1161/01.CIR.72.3.596 . Electrophysiologic and anatomic basis for fractionated electrograms recorded from healed myocardial infarcts JH Guo . Fragmented QRS . J Clin Electrocardiol , 2008 . 17 ( 1 ): 60 - 68 . (in Chinese) . Fragmented QRS JC Liu , LY Zhang , LY Kou , 等 . Influence of emergency PCI in different time windows to cardiac scar and cardiac function after myocardial infarction . Clin Med Chin , 2010 . 26 ( 12 ): 1277 - 1279 . (in Chinese) DOI: 10.3760/cma.j.issn.1008-6315.2010.12.017 http://doi.org/10.3760/cma.j.issn.1008-6315.2010.12.017 . Influence of emergency PCI in different time windows to cardiac scar and cardiac function after myocardial infarction MA Michael , H El Masry , BR Khan , 等 . Electrocardiographic signs of remote myocardial infarction . Prog Cardiovasc Dis , 2007 . 50 ( 3 ): 198 - 208 . 17976504 DOI: 10.1016/j.pcad.2007.05.003 http://doi.org/10.1016/j.pcad.2007.05.003 . Electrocardiographic signs of remote myocardial infarction H Morita , KF Kusano , D Miura , 等 . Fragmented QRS as a marker of conduction abnormality and a predictor of prognosis of Brugada syndrome . Circulation , 2008 . 118 ( 17 ): 1697 - 1704 . 18838563 DOI: 10.1161/CIRCULATIONAHA.108.770917 http://doi.org/10.1161/CIRCULATIONAHA.108.770917 . Fragmented QRS as a marker of conduction abnormality and a predictor of prognosis of Brugada syndrome WJ Paulus , C Tschöpe , JE Sanderson , 等 . How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology . Eur Heart J , 2007 . 28 ( 20 ): 2539 - 2550 . 17428822 DOI: 10.1093/eurheartj/ehm037 http://doi.org/10.1093/eurheartj/ehm037 . How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology S Peters , M Trümmel , B Koehler . QRS fragmentation in standard ECG as a diagnostic marker of arrhythmogenic right ventricular dysplasia-cardiomyopathy . Heart Rhythm , 2008 . 5 ( 10 ): 1417 - 1421 . 18783995 DOI: 10.1016/j.hrthm.2008.07.012 http://doi.org/10.1016/j.hrthm.2008.07.012 . QRS fragmentation in standard ECG as a diagnostic marker of arrhythmogenic right ventricular dysplasia-cardiomyopathy J Sha , S Zhang , M Tang , 等 . Fragmented QRS is associated with all-cause mortality and ventricular arrhythmias in patient with idiopathic dilated cardiomyopathy . Ann Noninvasive Electrocardiol , 2011 . 16 ( 3 ): 270 - 275 . 21762255 DOI: 10.1111/j.1542-474X.2011.00442.x http://doi.org/10.1111/j.1542-474X.2011.00442.x . Fragmented QRS is associated with all-cause mortality and ventricular arrhythmias in patient with idiopathic dilated cardiomyopathy Y Wang , HN Zhao . Investigation of changing and significance of connexin43, [Ca 2+ ] i and apoptosis in early phase of acute myocardial ischemia . Chin J Cardiac Pacing Electrophysiol , 2011 . 4 ( 25 ): 349 - 352 . (in Chinese) . Investigation of changing and significance of connexin43, [Ca2+]i and apoptosis in early phase of acute myocardial ischemia AG Xu , XQ Qi . The contrast analysis on the prognostic values of fragmented QRS and pathologic Q-wave for old myocardial infarction . Shandong Med J , 2009 . 49 ( 9 ): 50 - 51 . (in Chinese) . The contrast analysis on the prognostic values of fragmented QRS and pathologic Q-wave for old myocardial infarction JD Yao , B Shen , CX Lu , 等 . Clinical significance of fragmented QRS complex in II, III, aVF leads with coronary artery disease . Clin J Med Officer , 2011 . 39 ( 2 ): 214 - 216 . (in Chinese) . Clinical significance of fragmented QRS complex in II, III, aVF leads with coronary artery disease Y Zhang , XP Liu , Q Yan , 等 . QRS complexes in healthy adults: prevalence and implications . J Clin Cardiol , 2011 . 27 ( 4 ): 299 - 302 . (in Chinese) . QRS complexes in healthy adults: prevalence and implications XJ Zhou , B Yang , J Wang , 等 . Diagnostic value of fragmented QRS complex in patients with arrhythmogenic right ventricular cardiomyopathy . Chin J Cardiac Arrhyth , 2011 . 15 ( 1 ): 23 - 26 . (in Chinese) DOI: 10.3760/cma.j.issn.1007-6638.2011.01.004 http://doi.org/10.3760/cma.j.issn.1007-6638.2011.01.004 . Diagnostic value of fragmented QRS complex in patients with arrhythmogenic right ventricular cardiomyopathy Compliance with ethics guidelines Qin-hui SHENG, Chih-Chi HSU, Jian-ping LI, Tao HONG, and Yong HUO declare that they have no conflict of interest. All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5). Informed consent was obtained from all patients for being included in the study. Additional informed consent was obtained from all patients for which identifying information is included in this article. 10.1631/jzus.B1300091 Project supported by the National Science & Technology Pillar Program during the 12th Five-Year Plan Period (No. 2011BAI11B06), China 2013-03-27 2013-12-20 2013-11-12 2022-01-05 Copyright © Zhejiang University and Springer-Verlag Berlin Heidelberg 2014 2014 Journal of Zhejiang University-SCIENCE B (Biomedicine and Biotechnology) 01 15