Electrocardiographic Signs of Remote Myocardial Infarction

doi:10.1016/j.pcad.2007.05.003

Progress in Cardiovascular Diseases

Volume 50, Issue 3, November–December 2007, Pages 198-208

https://doi.org/10.1016/j.pcad.2007.05.003 Get rights and content

Twelve-lead electrocardiogram is an integral part of the evaluation of an acute and a remote myocardial infarction (MI). Electrocardiographic signs of an acute ST-elevation MI are more precise than those of an acute non–ST-elevation MI. Recognition of a remote MI is more difficult because once the repolarization abnormalities (ST-segment and T-wave changes) stabilize after an acute MI resolves, then the Q wave remains as the only universally recognized sign of MI. In addition, there is no specific sign of a non–Q-wave MI or a non–ST-elevation MI, or in fact of an ST-elevation MI that did not result in Q waves. The fragmented QRS (fQRS) is another recently described sign of a remote MI. It is defined by the presence of an additional R wave (R′) or notching in the nadir of the S wave, or the presence of >1 R′ (fragmentation) in 2 contiguous leads corresponding to a major coronary artery territory. The specificity of fQRS is inferior to that of a Q wave for an MI scar (89% vs 99%). However, fQRS has a superior sensitivity and a negative predictive value compared with a Q wave. In addition, there is an incremental gain in the sensitivity up to 91.4% when these 2 signs (fQRS and Q wave) are combined. The repolarization abnormalities of MI may also persist indefinitely as a sign of a remote MI in few patients. These abnormalities include persistent ST elevation, ST depression, nonspecific ST-T wave changes, and T-wave inversion.

Section snippets

Acute Myocardial Ischemia and Acute MI

Acute myocardial ischemia occurs in the early phase of coronary artery occlusion or spasm; and if the coronary artery involved is not rapidly recanalized or revascularized, then myocardial necrosis occurs, resulting in acute MI. Initially, the T waves may become tall and peaked (hyperacute T wave).⁹ This is often accompanied by ST-segment changes. An acute MI is classified accordingly as STMI or NSTMI. The STMI is defined by ST-segment elevation in 2 or more contiguous leads. The J point should

Q Wave

Pathological Q waves are the major depolarization abnormalities encountered in conjunction with repolarization abnormalities (ST-T wave changes) in patients with acute MI. Pathological Q waves are defined as the appearance of Q waves in at least 2 contiguous inferior, lateral, or anterior leads. These represent MI of respective myocardial walls, whereas tall R waves in lead V₁ and/or lead V₂ are analogous to the negative Q waves, which represent a posterior wall MI.¹ A universal definition of a

fQRS Complexes

Recently, we defined fQRS on a resting 12-lead ECG.⁴² It was correlated with myocardial scar by myocardial single photon emission computed tomographic imaging in patients with known or suspected CAD. The fQRS was defined as various morphologies of the QRS (QRS duration <120 milliseconds), with or without the Q wave, on a 12-lead ECG (GE, Marquette, WI; model Mac 5000; filter range, 0.16-100 Hz; AC filter, 60 Hz, 25 mm/s, 10 mm/mV). It is defined by the presence of an additional R wave (R′) or

ST-Segment and T-Wave Abnormalities

ST-segment and T-wave abnormalities usually resolve within days or weeks after an acute MI. However, it may persist indefinitely as a sign of a remote MI in few patients. These abnormalities include persistent ST depression, nonspecific ST-T wave changes, and T-wave changes (biphasic T wave or T-wave inversion). However, none of these ECG signs is specific for a remote MI.

Conclusions

The 12-lead ECG still remains an inexpensive preliminary investigation for diagnosis of an acute MI. An acute MI needs to be confirmed by elevated biomarkers and, if needed, by various noninvasive tests. Similarly, ECG is helpful in diagnosing a remote MI. Although Q wave, fQRS, and persistent ST-segment elevation have a lower sensitivity for detecting a remote MI, these signs have a high specificity and therefore carry a high clinical significance. Persistent T waves in the presence of other

References (67)

K.A. Ammar et al.
Defining unrecognized myocardial infarction: a call for standardized electrocardiographic diagnostic criteria
Am Heart J
(2004)
C.G. Owens et al.
Electrocardiographic diagnosis of non–ST-segment elevation acute coronary syndromes: current concepts for the physician
J Electrocardiol
(2006)
W.C. Voon et al.
Q-wave regression after acute myocardial infarction assessed by T1-201 myocardial perfusion SPECT
J Nucl Cardiol
(2004)
M.P. Somers et al.
The prominant T wave: electrocardiographic differential diagnosis
Am J Emerg Med
(2002)
M.I. Furman et al.
Twenty-two-year (1975 to 1997) trends in the incidence, in-hospital and long-term case fatality rates from initial Q-wave and non–Q-wave myocardial infarction: a multi-hospital, community-wide perspective
J Am Coll Cardiol
(2001)
J. Candell-Riera et al.
Comparison of patients with anterior wall healed myocardial infarction with and without exercise-induced ST-segment elevation
Am J Cardiol
(1998)
A. Barbagelata et al.
Thrombolysis and Q wave versus non–Q wave first acute myocardial infarction: a GUSTO-I substudy. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries Investigators
J Am Coll Cardiol
(1997)
J.K. Jensen et al.
Redefinition of the Q wave—is there a clinical problem?
Am J Cardiol
(2006)
B. Phibbs
“Transmural” versus “subendocardial” myocardial infarction: an electrocardiographic myth
J Am Coll Cardiol
(1983)
D.H. Spodick
Q-wave infarction versus S-T infarction. Nonspecificity of electrocardiographic criteria for differentiating transmural and nontransmural lesions
Am J Cardiol
(1983)

Myocardial infarction redefined—a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction

Cited by (67)

Impact of Q wave in synthesized V7–9 lead on long-term outcomes after cardiac resynchronization therapy
2023, Journal of Cardiology
To investigate the relationship between the Q wave in synthesized V7–9 leads of a baseline electrocardiogram and clinical outcomes in patients with heart failure after cardiac resynchronization therapy (CRT) device implantation.
Consecutive patients with heart failure and a left ventricular (LV) ejection fraction <35 % were retrospectively analyzed. Patients with Q waves in the synthesized V7–9 lead were defined as the qV7–9 group and those without Q waves in the synthesized V7–9 lead were defined as the non-qV7–9 group. Multivariate analysis was performed to compare all-cause mortality and incidence of hospitalization for heart failure between the two groups.
We included 108 eligible patients. Twenty-nine patients were classified into the qV7–9 group and 79 patients were classified into the non-qV7–9 group. There were 22 patients (20 %) with ischemic etiology, 67 (62 %) with New York Heart Association functional class II or III heart failure, and 91 (84 %) with a defibrillator. The presence of Q waves in the synthesized V7–9 lead was significantly associated with worse outcomes, even with optimal medical treatment (adjusted hazard ratio, 2.1; 95 % confidence interval, 1.16–3.72; p = 0.03).
In patients with heart failure and an LV ejection fraction of <35 %, the presence of Q waves in the synthetic V7–9 lead was associated with increased all-cause mortality and incidence of hospitalization after CRT device implantation.
Regression of Q waves and clinical outcomes following primary PCI in anterior STEMI
2022, Journal of Electrocardiology
Pathological Q waves are correlated with infarct size, and Q-wave regression is associated with left ventricular ejection fraction improvement. There are limited data regarding the association of Q-wave regression and clinical outcomes. Our main objective was to assess the association of pathological Q wave evolution after reperfusion with clinical outcomes after anterior STEMI.
Standard 12-lead electrocardiograms (ECGs) were recorded in 780 anterior STEMI patients treated with primary percutaneous coronary intervention (PCI) from the CIRCUS trial. ECGs were recorded before and 90 min following PCI, as well as at hospitalization discharge and 12 months of follow-up. The number of classic ECG criteria Q waves was scored for each ECG. Patients were classified in the Q wave regression group if they had regression of at least one Q wave between the post-PCI, the discharge and/or one year ECGs. Patients were classified in the Q wave persistent group if they had the same number or greater between the post-PCI, the discharge and/or 1 and one year ECGs. All-cause death and heart failure events were assessed for all patients at one year.
There were 323(43%) patients with persistent Q waves (PQ group), 378(49%) patients with Q wave regression (RQ group) and 60(8%) patients with non-Q wave MI (NQ group). Infarct size as measured by the peak creatine kinase was significantly greater in the PQ group compared to the RQ and NQ groups (4633 ± 2784 IU/l vs. 3814 ± 2595 IU/l vs. 1733 ± 1583 IU/l respectively, p < 0.0001). At one year, there were 22 deaths (7%) in the PQ-group, 15 (4%) in the RQ-group and none in the NQ-group (p = 0.04). There was a 4-fold increase in the risk of death or heart failure in the PQ compared to the NQ group (HR 4.7 [1.1; 19.3]; p = 0.03), but there was no significant difference between NQ and RQ groups (HR 3.3 [0.8; 13.8]; p = 0.09).
In a population of anterior STEMI patients, persistent Q waves defined according to the classic ECG criteria after reperfusion was associated with a 4-fold increase in the risk of heart failure or death compared to non-Q-wave MI, while Q-wave regression was associated with significantly lower risk of events.
De-novo development of fragmented QRS during a six-month follow-up period in patients with COVID-19 disease and its cardiac effects
2022, Journal of Electrocardiology
Citation Excerpt :
As we know fQRS is an electrocardiographic sign of myocardial scar tissue, that explain the nonhomogeneous ventricular conduction delay [7]. In ischemic heard disease (IHD), the presence of fQRS was found to be an independent predictor of left ventricular (LV) dilatation, decreased ejection fraction and myocardial perfusion [16–18]. In patients with non-ischemic or ischemic cardiomyopathy fQRS was also able to predict arrhythmic events [19,20].
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.
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.
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.
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 on surface electrocardiography as a predictor of cardiac mortality in patients with SARS-CoV-2 infection
2021, Journal of Electrocardiology
Citation Excerpt :
Therefore, prediction of the negative effects of SARS-CoV-2 infection on cardiovascular system and early detection of myocardial damage is crucial. The presence of the fragmented QRS complex (fQRS) on the standard electrocardiogram (ECG) is an indicator of ventricular conduction disorder which was shown to be a marker of myocardial damage resulting from various diseases [4,5]. In several studies, the relationship between myocardial scar due to coronary artery disease (CAD) and the presence of fQRS has been shown [6].
Although severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is mainly a respiratory system disease, recent studies reported that cardiac injury is associated with poor outcomes in this population. There are few studies which assessed standard electrocardiogram (ECG) as a prognostic tool during the course of SARS-CoV-2 infection. The aim of this study is to identify the relationship between of ECG parameters and prognosis of patients infected with SARS-CoV-2.
A total of 114 consecutive patients with a confirmed diagnosis of SARS-CoV-2 infection between March 2020 and May 2020 were included in the study. Standard 12‑lead surface ECG was reviewed for presence of fragmented QRS (fQRS), abnormal Q wave, T wave inversion, and duration of QRS. fQRS was observed in 36.8% (n = 42) of the patients who had SARS-CoV-2. Patient groups with and without fQRS did not differ in terms of age, gender, the presence of comorbid diseases and medical treatment. Hospitalization duration, intensive care unit(ICU) requirement, all-cause mortality, and cardiac mortality were found to be higher in patients with fQRS (all p values <0.05). There was a positive correlation between QRS duration and duration of hospital stay (p < 0.001, r = 0.421). QRS duration was also found to be associated with intensive care need, all-cause mortality, and cardiac mortality.
Our data shows that QRS duration and the presence of fQRS on standard ECG can help to identify patients with worse clinical outcome admitted for SARS-CoV-2 infection.
Correlation of fragmented QRS complexes with the severity of CAD (using Syntax score) in patients with non-ST elevation acute coronary syndromes
2016, Egyptian Heart Journal
Citation Excerpt :
fQRS is defined as additional spikes within the QRS complex.4 Fragmented QRS complexes (f-QRS) on a 12-lead resting ECG include an additional R wave (R′), notching of the R wave, notching of the down stroke or upstroke of the S wave, or the presence of >1 R′ in 2 contiguous leads corresponding to a major coronary artery territory.5 In this study, we reviewed the ECG results in NSTE-ACS patients to evaluate the accuracy of f-QRS complexes to identify severity and complexity of CAD lesions assessed by SYNTAX score.
Fragmented QRS (f-QRS) complexes are novel electrocardiographic signals, which reflect myocardial conduction delays in patients with coronary artery disease (CAD). The significance of f-QRS complexes in non-ST elevation ACS patients for detection of the severity of CAD (correlation with Syntax score) was evaluated in this prospective study.
A total of 104 patients with non-ST-elevation ACS who underwent invasive coronary angiography for detection of coronary artery disease were recruited prospectively in this study, ECG was done to all patients, which showed f-QRS in 50 patients (f-QRS group) and inverted T wave or depressed ST in 54 patients (non f-QRS group). The significance of f-QRS complexes on 12-lead ECG for detection of the severity of the CAD (correlated with Syntax score) was assessed in this cohort of patients.
Among the patients studied, elderly patients (age ⩾ 65 years), males, diabetics, smokers and those with dyslipidemia had a significantly higher frequency of fQRS complexes (with P value = 0.02, 0.01, 0.019, 0.005, 0.02 respectively). Also, the present study found a higher frequency of f-QRS in patients with multi-vessel disease, in those with more severe degree of coronary artery stenosis, in those with positive Troponin I level and in those with high Syntax score (with P value = 0.009, 0.000, 0.000 respectively).
The frequency of f-QRS complexes was found to be higher in elderly, diabetic, dyslipidemic, and male patients with NSTE-ACS. The higher frequency of (f-QRS) was correlated with the extent and severity of coronary lesions in patients with NSTE-ACS.
Fragmented QRS complexes have predictive value of imperfect ST-segment resolution in patients with STEMI after primary percutaneous coronary intervention
2016, American Journal of Emergency Medicine
Citation Excerpt :
Regional myocardial scar and ischemia may lead to nonhomogeneous myocardial electrical activation, resulting in multiple spikes within the QRS complex, thus appearance of fQRS in the ECG record [15]. Recent studies demonstrated that fQRS represents not only prior occurrence and diagnosis of MI and silent MI [16] but also an independent predictor of cardiac events in patient with coronary artery disease [17,18]. However, the possible relation of fQRS and myocardial reperfusion has been still unclear until now.
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).
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.
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.
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.

View all citing articles on Scopus

View full text

Electrocardiographic Signs of Remote Myocardial Infarction

Section snippets

Acute Myocardial Ischemia and Acute MI

Q Wave

fQRS Complexes

ST-Segment and T-Wave Abnormalities

Conclusions

Am Heart J

J Electrocardiol

J Nucl Cardiol

Am J Emerg Med

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

Am J Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

Am J Cardiol

Am Heart J

Am Heart J

J Electrocardiol

Am J Cardiol

Am J Cardiol

J Electrocardiol

Am J Cardiol

Am Heart J

Ann Thorac Surg

Am J Cardiol

Myocardial infarction redefined—a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction

Eur Heart J

Unrecognized myocardial infarction

Ann Intern Med

Incidence of recognized and unrecognized myocardial infarction in men and women aged 55 and older: the Rotterdam Study

Eur Heart J

Prognostic value of a normal or nonspecific initial electrocardiogram in acute myocardial infarction

JAMA

Does the electrocardiographic presence of Q waves influence the survival of patients with acute myocardial infarction?

Eur J Heart

Fragmented QRS on 12-lead EKG is a sign of acute or recent myocardial infarction

Circulation