Diagnostic and prognostic value of QRS duration and QTc interval in patients with suspected myocardial infarction (original) (raw)
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The American Journal of Cardiology, 2009
The purpose of this study was to evaluate the prognostic significance of QRS duration in patients with suspected coronary artery disease (CAD) referred for noninvasive evaluation of myocardial ischemia by dobutamine stress echocardiography. QRS duration is a prognostic marker in patients with previous myocardial infarction and/or heart failure. The relation between QRS duration and outcome of patients without known heart disease has not been evaluated. A total of 1,227 patients (707 men, mean age 61 ؎ 14 years) with suspected CAD underwent dobutamine stress echocardiography for evaluation of myocardial ischemia. Patients were followed to determine predictors of cardiac events and to assess the incremental significance of QRS duration compared to clinical and dobutamine stress echocardiographic data. During a mean follow-up of 4.2 ؎ 2.4 years, 280 patients (23%) died (129 cardiac deaths), and 60 (5%) had a nonfatal infarction. Annualized cardiac death rates were 2.0% in patients with QRS duration <120 ms and 4.4% in patients with QRS duration >120 ms, respectively (p <0.0001). Annualized event rates for cardiac death/nonfatal infarction were 2.8% in patients with QRS duration <120 ms and 4.8% in patients with QRS duration >120 ms (p ؍ 0.0001). Multivariate models identified age, male gender, smoking, QRS duration >120 ms, and an abnormal dobutamine stress echocardiogram as independent predictors of cardiac death and the combined end point cardiac death/nonfatal infarction. In conclusion, QRS duration is an independent predictor of cardiac death and cardiac death/nonfatal infarction in patients with suspected CAD. This risk is persistent after adjustment for clinical variables, left ventricular function, and myocardial ischemia.
Prognostic value of fragmented QRS on a 12-lead ECG in patients with acute myocardial infarction
Heart & Lung: The Journal of Acute and Critical Care, 2013
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 (1.00e2.74); p ¼ 0.047) was associated with an fQRS. During a mean follow-up of 846 AE 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 ¼ 0.019). However, the occurrence of heart failure symptoms and ventricular arrhythmia was not significantly different (p ¼ 0.162 and p ¼ 0.242, respectively). Survival analysis by the KaplaneMeier method showed a significant difference (log rank p ¼ 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 (0.95e2.60); p ¼ 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.
Circulation journal : official journal of the Japanese Circulation Society, 2017
In ST-segment elevation myocardial infarction (STEMI), QRS score at presentation ECG may reflect the progression of infarction and facilitate prediction of the degree of myocardial salvage achieved by reperfusion therapy.Methods and Results:Admission electrocardiogram (ECG) was studied in 2,607 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) within 24 h of symptom onset. Patients were classified into 3 groups according to QRS score: low (0-3, n=1,227), intermediate (4-7, n=810), and high (≥8, n=570). An increase of infarct size estimated by median peak creatine phosphokinase was observed as QRS score increased (low score, 1,836 IU/L; inter-quartile range (IQR), 979-3,190 IU/L; intermediate score, 2,488 IU/L; IQR, 1,126-4,640 IU/L; high score, 3,454 IU/L; IQR, 1,759-5,639 IU/L; P<0.001). Higher QRS score was associated with higher long-term mortality (low, intermediate, and high score, 15.6%, 19.7%, and 23.7% at 5 years, respectively; log-rank P<...
QRS prolongation in patients with acute coronary syndromes
American Heart Journal, 2010
Background QRS prolongation with or without bundle branch block (BBB) has been associated with adverse outcome in myocardial infarction; we examined the relationship between QRS duration and outcome in a broad spectrum of patients with acute coronary syndrome (ACS). Method and Results Core laboratory evaluation of the presenting electrocardiogram in Canadian ACS Registry patients (n = 5,003) showed 4,289 (85.7%) had QRS <120 milliseconds, 202 (4.0%) patients had QRS ≥120 milliseconds without BBB, 262 (5.2%) had left BBB (LBBB), and 250 (5.0%) had right BBB. Compared to patients with QRS <120 milliseconds, patients with QRS ≥120 milliseconds without BBB had higher in-hospital (3.5% vs 1.9%, odds ratio [OR]
International Journal of Advances in Medicine, 2019
Background: Arrhythmias are a common occurrence in acute myocardial infarction. Objectives of this study the hemodynamically significant arrhythmias and QTc interval in thrombolysed and non thrombolysed acute myocardial infarction patients.Methods: Two hundred patients of AMI were enrolled. ECG and cardiac parameters were examined. Arrhythmias and its various parameters like its incidence, type, frequency associated with site of infarction were recorded in thrombolysed and non thrombolysed patients of AMI.Results: AMI was more prevalent in the males (63.3%) and those with 41-50 years of age. Hypertension (35.7%), smoking (34.2%), and diabetes (23.1%) were the major risk factor. Incidence of AWMI (30.7%) is higher than IWMI (25.1%). Out of 200 subjects 130 were thrombolysed. Arrhythmias was observed in total 164 patients while 36 patients has no documentation of arrhythmias. Mean QTc was prolonged (546.88ms vs 404.33ms) in patients documented with arrhythmia compared with those who h...
The American Journal of Cardiology, 2009
Electrocardiographic signs of a non-ST elevation myocardial infarction (NSTEMI) are nonspecific, and therefore the diagnosis of NSTEMI during acute coronary syndromes (ACS) depends mainly on cardiac biomarker levels. Fragmented QRS (fQRS) represents myocardial conduction abnormalities due to myocardial infarction (MI) scars in patients with coronary artery disease. However, the time of appearance of fQRS during ACS has not been investigated. It was postulated that in patients with ACS, fQRS on 12-lead electrocardiography occurs within 48 hours of presentation with NSTEMI as well as ST elevation MI and that fQRS predicts mortality. Serial electrocardiograms from 896 patients with ACS (mean age 62 ؎ 11 years, 98% men) who underwent cardiac catheterization were studied. Four hundred forty-one patients had MIs, including 337 patients with NSTEMIs, and 455 patients had unstable angina (the control group). Serial electrocardiograms were obtained every 6 to 8 hours during the first 24 hours after the diagnosis of MI and the next day (<48 hours). Fragmented QRS on 12-lead electrocardiography was defined by the presence of single or multiple notches in the R or S wave, without a typical bundle branch block, in >2 contiguous leads in 1 of the major coronary artery territories. Fragmented QRS developed in 224 patients (51%) in the MI group and only 17 (3.7%) in the control group (p <0.001). New Q waves developed in 122 (28%), 76 (23%), and 2 (0.4%) patients in the MI, NSTEMI, and control groups, respectively. The sensitivity values of fQRS for ST elevation MI and NSTEMI were 55% and 50%, respectively. The specificity of fQRS was 96%. Kaplan-Meier survival analysis revealed that patients with fQRS had significantly decreased times to death compared to those without fQRS. Fragmented QRS, T-wave inversion, and ST depression were independent predictors of mortality during a mean follow-up period of 34 ؎ 16 months. In conclusion, fQRS on 12-lead electrocardiography is a moderately sensitive but highly specific sign for ST elevation MI and NSTEMI. Fragmented QRS is an independent predictor of mortality in patients with ACS. Published by Elsevier
Journal of the American College of Cardiology, 1989
A prospective study was undertaken of the prognostic significance of quantitative signal-averaged electrocardiographic (ECG) variables relative to clinical variables, site of myocardial infarction, left ventricular ejection fraction and characteristics of ventricular premature beats in 115 patients (mean age 62 2 12 years) studied 10 f 6 days after myocardial infarction. Signal-averaged variables included the root mean square voltage of the terminal 40 ms, the duration of the filtered signal-averaged QRS complex and low amplitude signals <40 PV determined at 25 and 40 Hz high pass filtering in all patients. Of the 115 patients, 51 (44%) had an abnormal signalaveraged ECG (one or more abnormal signal-averaged variables), 51 (44%) at 25 Hz and 48 (42%) at 40 Hz high pass filtering. A higher proportion of patients with an inferior wall infarction had an abnormal signal-averaged ECG as compared with patients with anterior wall infarction (58% versus 31%). Over a 14 + 8 month follow-up period 16 patients (14%) had an arrhythmic event. An abnormal signal-averaged ECG at 40 Hz high pass filtering had a higher sensitivity (81% versus 75%) and specificity (65% versus 61%) than at 25 Hz high pass filtering. The predictive value of the signal-averaged ECG was superior to that of the ejection Ventricular tachycardia and ventricular fibrillation are the major causes of sudden cardiac death after myocardial infarction. Although the ultimate factors that result in a From the Clinical Electrophysiology and Electrocardiography Section,
Specificity and sensitivity of QRS criteria for diagnosis of single and multiple myocardial infarcts
The American Journal of Cardiology, 1991
A subset of 3 criteria from the complete Selvester scoring system has been proposed earlier for electrocardiographic screening of healed myocardial infarcts. This subset yielded 95% specificity and high sensitivity for single anterior and inferior infarcts. In the present study, an automated version of these criteria was applied to 1,344 electrocardiograms from normal subjects (473 normal subjects as determined by cardiac catheterization and 871 apparently normal subjects by history and physical examination), to 706 from subjects with single myocardial infarction, and to 131 from subjects with combined anterior and inferior myocardial infarcts. Of the single infarcts, 366 had inferior, 277 anterior and 63 posterolateral locations. Presence and location of infarcts were judged from left ventriculograms and coronary angiograms. Overall specificity was only 86%, whereas overall sensitivity for the infarct population was 77%. Specificity was lower in men than in women; it was also lower in older than in younger subjects. One of the screening criteria (R 240 ms in Vi) may possibly be eliminated to augment specificity; this can be done with only minor loss of sensitivity. Differences in wave form measurements between the manual and computer methods account for a large part of the deterioration of specificity in this study compared with previously published results. Computer application of the screening criteria requires altered criteria limits in comparison with those used in manual application. Probably sex-and age-dependent criteria limits should be used.
Prognostic value of QT interval prolongation in post myocardial infarction patients
European Heart Journal, 1987
The QT interval recorded on the surface ECG represents the sum of uncancelled potential differences during depolarization and repolarization' 1 '. Clinically, the QT interval is a good index of the ventricular repolarization process. QT prolongation, caused by delayed ventricular repolarization, usually reflects an increase in the degree of temporal dispersion of refractory periods' 2 ', which could thus result in prolongation of the vulnerable period and may thereby enhance susceptibility to ventricular tachyarrhythmias' 3 '. Prolonged intervals have been found in congenital' 4 ', acquired and drug induced conditions and have been proven to predispose to the development of complex and often fatal arrhythmias' 5 '. Following the first report on the association between a prolonged QT interval and an increased risk for subsequent sudden death among postmyocardial infarction (MI) patients' 6 ', several studies have been performed to determine the predictive value of prolongation of the QT interval in the early as well as in the late phase after MI. Long-term prognostic value of post-MI QT prolongation In 1976, Schwartz and Wolf provided the first evidence on the predictive value of QT-interval prolongation after Ml' 6-7 '. This study included 55 patients with recent MI and 55 healthy controls matched for age, sex, race, weight, height, education and job. The study group was drawn from a consecutive series of patients seen at the University of Oklahoma between 1962 and 1965. ECG tracings were recorded at two-month