Relation between evolutionary ST segment and T-wave direction and electrocardiographic prediction of mycardial infarct size and left ventricular function among patients with anterior wall Q-wave acute myocardial infarction who received reperfusion therapy

Prognostic Implications of Newly Developed T-Wave Inversion After Primary Percutaneous Coronary Intervention in Patients With ST-Segment Elevation Myocardial Infarction

We investigated the prognostic value of newly developed T-wave inversion after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction. New T-wave inversion was defined as new onset of T-wave inversion after the primary PCI, without negative T waves on the presenting electrocardiogram. The primary end point was the occurrence of major adverse cardiac events (MACE), which consisted of cardiovascular mortality, nonfatal myocardial infarction, and rehospitalization for heart failure. A total of 271 patients were analyzed and followed up for 24 months in this study. New T-wave inversion was observed in 194 patients (72%), whereas the remaining 77 patients (28%) did not show T-wave inversion after the index PCI. Post-PCI Thrombolysis In Myocardial Infarction flow grade 2 or 3 was observed more frequently in patients with new T-wave inversion (97% vs 90%; p = 0.011). The cumulative MACE rate was significantly lower in patients with new T-wave inversion than in those without new T-wave inversion (8% vs 30%; odds ratio 0.197, 95% confidential interval 0.096 to 0.403; p <0.001). In multivariate Cox regression analysis, new T-wave inversion was an independent prognostic factor for MACE (hazard ratio 0.297, 95% confidential interval 0.144 to 0.611; p = 0.001). In conclusion, newly developed T-wave inversion after primary PCI was associated with favorable long-term outcome.

The Predictive Value of Fragmented QRS and QRS Distortion for High-Risk Patients with STEMI and for the Reperfusion Success

BACKGROUND

QRS fragmentation (fQRS) and QRS distortion were separately shown to be related to increased cardiovascular mortality and morbidity. To our knowledge, no study so far evaluated both parameters together in ST segment elevation myocardial infarction (STEMI). The main goal of our study is to find out if fQRS and QRS distortion can help us to determine high-risk STEMI patients, and the success of reperfusion.

METHODS

Two hundred forty-eight eligible patients with acute STEMI that underwent coronary angiography consecutively between January 1, 2009, and July 1, 2011, were enrolled in this study. Twelve-lead electrocardiography (ECG) of the patients taken in the first 48 hours were analyzed. Patients with fQRS formed group 1, without fQRS formed group 2; with QRS distortion formed group 3, and without QRS distortion formed group 4.

RESULTS

Group 1 have lower left ventricular ejection fraction (LVEF; P < 0.001), higher maximum troponin levels (P < 0.001), lower ST segment resolution (P < 0.001), more frequent proximal lesions (P < 0.001) when compared to group 2. Similar findings were observed in group 3 in comparison to group 4. Group 1 had also more frequent three vessels disease (P < 0.001), and higher rates of failed thrombolysis (P < 0.001). In-hospital mortality was found to be higher in group 1 and group 3.

CONCLUSION

fQRS and QRS distortion may be useful for identifying patients at higher cardiac risk. fQRS can foresee thrombolytic therapy failure and three vessels disease whereas QRS distortion does not possess such quality. These findings may guide the physician deciding initial treatment modality in STEMI.

Significance of T-wave amplitude and dynamics at the time of reperfusion in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Peri-interventional T-wave changes may reflect the microvascular reperfusion status and potentially carry early independent, prognostic information in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

The first available electrocardiogram (ECG) (index ECG) and the ECG recorded immediately post-PCI were analyzed for T-wave morphology in 207 patients with STEMI. Absolute T-wave amplitude was recorded and any change in T-wave amplitude from index ECG to post-PCI ECG was calculated. Continuous ST monitoring was performed from hospital arrival until 90 minutes after PCI. Maximum troponin level and left ventricular ejection fraction were evaluated before discharge. Final infarct size was assessed by myocardial perfusion imaging after 1 month.

RESULTS

Large, positive T-wave amplitude in the index ECG and the post-PCI ECG was associated with delayed ST resolution after PCI. In the post-PCI ECG, T-wave amplitude was positively associated with troponin-T value (P < .001) and final infarct size (P = .036), and inversely associated with left ventricular ejection fraction (P < .001). However, T-wave amplitude in the post-PCI ECG was also associated with procedural increase in ST elevation (P < .001) and inversely associated with spontaneous ST resolution (P < .017). A net decrease in T-wave amplitude during reperfusion therapy was associated with faster microvascular reperfusion as evaluated by time to ST resolution.

CONCLUSION

Large T-wave amplitudes in static pre- and post-PCI ECGs are associated with delayed microvascular reperfusion, whereas the dynamic development of more negative T waves during PCI is associated with earlier microvascular reperfusion. However, in the acute setting, T waves provide little incremental information when compared to ST parameters available in the per-interventional phase.

Prediction of improvement in left ventricular function during a 1-year follow-up after acute myocardial infarction by the degree of acute resolution of electrocardiographic changes

BACKGROUND AND PURPOSE

Reperfusion therapy results in better left ventricle (LV) function in cases of successful myocardial reperfusion; however, insufficient reperfusion or reocclusion of the infarct-related artery is associated with LV dysfunction. This study was proposed to determine whether the rate of ECG stage dynamics, after mechanical, thrombolytic, or spontaneous recanalization, is a predictor of improvement in LV function.

METHODS

Twenty-seven consecutive patients, observed for 1 year, were divided into group A (11, change rate of > or =2 ECG stages per 2 days), group B (13, no rapid change), and cases with reocclusion (3).

RESULTS

Clinical and radiographic signs of heart failure tended to decrease in group A but tended to increase in other cases. Echocardiographic dyssynergic score decreased, and LV ejection fraction increased only in group A: 4.3 +/- 1.2 vs 2.7 +/- 1.5, P = .04, and 42.0 +/- 4.8 vs 46.0 +/- 8.3, P = .049, respectively; in group B, the values were 3.4 +/- 2.4 vs 3.4 +/- 2.2 and 44.0 +/- 6.9 vs 43.8 +/- 9.3, respectively.

CONCLUSIONS

Rapid ECG stage changes predict follow-up improvement in LV function.

Electrocardiographic Markers of Reperfusion in ST-elevation Myocardial Infarction

The outcome of patients who fail to reperfuse with thrombolytic therapy or percutaneous coronary intervention (PCI) for ST-elevation acute myocardial infarction (STEMI) may be improved with additional pharmacologic and mechanical interventions such as rescue PCI or intravenous glycoprotein IIb/IIIa infusion. The standard 12-lead ECG is the most commonly available and suitable tool for routine bedside evaluation of the success of reperfusion therapy for STEMI. This article reviews and discusses the current data on the four ECG markers for prediction of the perfusion status of the ischemic myocardium: ST-segment deviation, T-wave configuration, QRS changes, and reperfusion arrhythmias.

Ischemia-induced ST-segment elevation: classification, prognosis, and therapy

The standard 12-lead electrocardiogram (ECG) remains the most useful tool for the diagnosis, early risk stratification, triage, and guidance of therapy in patients with acute coronary syndromes. However, the initial and the terminal part of the QRS complex, the ST segments, and the T waves are influenced by anatomical and metabolic factors such as the "myocardium at risk" and "severity" and "duration" of ischemia. Moreover, there are complex interactions between all these factors. The ECG can identify potential candidates for reperfusion therapy as well as the completeness and success of reperfusion, whereas it can also identify those patients who will have no benefit from reperfusion because of either late arrival or nonischemic etiologies of ECG changes. These patients may have a "pseudo" ST-elevation acute myocardial infarction (STEAMI) or "pseudo-pseudo" STEAMI. The presence of Q waves and additional ST-segment depression and T-wave inversion on the admission ECG in patients with STEAMI may provide us information regarding the potential myocardial reserves, and various ECG scoring systems are in current use for that purpose. The pattern and timing of changes in Q waves, ST segment, and T waves may all be markers of the patency status of the infarct-related artery. We review and discuss each of the dynamic ECG variables during ischemia and reperfusion: the initial QRS (Q and R waves), the terminal QRS (Sclarovsky-Birnbaum score), the ST segment, and the T waves.

Electrocardiogram of acute ST-elevation myocardial infarction: the significance of the various "scores"

The Electrocardiogram has extensively been used for evaluation and triage of patients with acute chest pain. The clinician admitting a patient with ST elevation acute myocardial infarction should be able to estimate the size and location of the ischemic area at risk, how much of the ischemic myocardium has already undergone irreversible necrosis by the time of presentation, and the "severity of ischemia" (or what is the rate of progression of necrosis as long as ischemia continues). The electrocardiographic variables that are used to make these estimates are the initial portion of the QRS (Q and R waves), the terminal portion of the QRS (the S waves and the J-point), the ST segment, and the configuration of the T waves. This editorial discuss the ability to predict each of the "physiological" parameters using the above mentioned electrocardiographic variables.

Relation of T-wave inversion in Q-wave acute myocardial infarction to myocardial viability on resting rubidium-82 and 18-fluoro-deoxyglucose positron emission tomography imaging

T-wave inversion in areas of Q-wave myocardial infarction has been advocated as a predictor of myocardial viability. However, the predictive value of this electrocardiographic finding in distinguishing viable from nonviable muscle is not fully defined. Thus, we correlated electrocardiographic Q waves and a measure of T-wave inversion with the results of rubidium-82 (Rb-82) and 18-fluoro-deoxyglucose-positron emission tomography (FDG-PET) imaging at rest. We analyzed 35 Q-wave myocardial infarct regions in 25 patients. Nineteen of the 35 (54%) were judged viable by Rb-82/FDG-PET. Using the Novacode T-wave score, T-wave inversion was present in 11 of 19 regions (58%) with viability and 5 of 16 regions (31%) without viability. Thus, neither Q waves nor T-wave inversion can accurately predict myocardial viability in patients with Q-wave myocardial infarction.

Prediction of decrease in myocardial perfusion defect size and severity during a 3-month follow-up by the degree of acute resolution of electrocardiographic changes

Myocardial perfusion in infarct-related artery (IRA) distribution improves progressively until a few months after successful reperfusion therapy. We assessed the rate of electrocardiographic (ECG) stage dynamics to predict perfusion improvement after mechanical, thrombolytic, or spontaneous recanalization of IRA. Thirteen patients were divided into group A (n = 8, with > or = 2 ECG stages per 2-day change rate) and group B (n = 5, no rapid change of ECG stages). There were no significant technetium Tc 99m sestamibi scintigraphic differences between the groups 3 days after recanalization; however, after 3 months, perfusion deficit size (2.8 +/- 1.8 vs 4.8 +/- 1.2, P < or = .03) and severity (1.8 +/- 0.9 vs 3.0 +/- 0, P < or = .03) were smaller in group A vs group B. The prediction sensitivity of the method was 87.5% for decrease in size and 100% for decrease in severity of perfusion defect; the specificity was 80% and 100%, respectively. A change rate of 2 or more ECG stages per 2 days predicts follow-up improvement of myocardial perfusion after IRA recanalization.

Correlation between ST elevation and Q waves on the predischarge electrocardiogram and the extent and location of MIBI perfusion defects in anterior myocardial infarction

BACKGROUND

The common electrocardiographic subclassification of anterior acute myocardial infarction (AMI) is not reliable in presenting the exact location of the infarct. We investigated the relationship between predischarge electrocardiographic patterns and the extent and location of perfusion defects in 55 patients with first anterior AMI.

METHODS

Predischarge electrocardiogram was examined for residual ST elevations and Q waves which were correlated with technetium-99m-sestamibi function and perfusion scans.

RESULTS

Patients with ST elevations in V2-V4 and Q waves in leads V3-V5 had worse global perfusion scores. Perfusion defects in the apex inferior segment were significantly less frequent in patients with Q waves in leads I and aVL (11% vs 54%, P = 0.027; and 22% vs 60%, P = 0.011, respectively). Patients with Q wave in aVF had more frequently involvement of the apex inferior segment (80% vs 40%; P = 0.035). Patients with Q wave in lead II had significantly more frequent perfusion defects in the inferior wall. ST elevation in V3 and V4 was associated with perfusion abnormalities of the infero-septal segments. ST elevation in V5 and V6 and Q wave in V5 were associated with regional perfusion defects in apical inferior segment (73% vs 30%, P = 0.002), extending into the mid inferior segment (55% vs 18%, P = 0.005 for Q wave in V5). Q wave in lead aVL is associated with less apical and inferior involvement. Q waves in leads II and aVF are a sign of inferior extension of the infarction.

CONCLUSIONS

Residual ST elevation in leads V3 and V4 are more frequently associated with involvement of the apical-inferoseptal segment rather than the anterior wall. Residual ST elevation and Q waves in V5 are related to a more inferior rather than a lateral involvement.

Prognostic value of predischarge electrocardiographic measurement of infarct size after thrombolysis: insights from GUSTO I Economics and Quality of Life substudy

BACKGROUND

Current methods for risk stratification after acute myocardial infarction (MI) include several noninvasive studies. In this cost-containment era, the development of low-cost means should be encouraged. We assessed the ability of an electrocardiogram (ECG) MI-sizing score to predict outcomes in patients enrolled in the Economics and Quality of Life (EQOL) sub study of the Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries -I (GUSTO-I) trial.

METHODS

We classified patients by electrocardiographic Selvester QRS score at hospital discharge: those with a score 0-9 versus > or =10. Endpoints were 30-day and 1-year mortality, resource use, and quality-of-life measures.

RESULTS

Patients with a QRS score <10 were well-matched with those with QRS score > or =10 with the exception of a trend to more anterior MI in the higher scored group. Patients with QRS score > or =10 had increased risk of death at 30-days (8.9% vs. 2.9% P < .001), and this difference persisted at 1 year (12.6% vs. 5.4%, P = .001). Recurrent chest pain, use of angiography, and angioplasty were similar during follow-up. However, there was a trend toward less coronary bypass surgery in patients with a QRS score > or =10. Readmission rates were higher at 30 days but similar at 1 year.

CONCLUSIONS

Stratification of patients after acute MI by a simple measure of MI size identifies populations with different long-term prognoses; patients with a QRS score > or =10 (approximately 30% of the left ventricle infarcted) at discharge have poorer outcomes in both the short- and long-term. The standard 12-lead ECG provides a simple, economical means of risk stratification at discharge.

Diagnostic value of routine clinical parameters in acute myocardial infarction: a comparison to delayed contrast enhanced magnetic resonance imaging. Delayed enhancement and routine clinical parameters after myocardial infarction

AIMS

Contrast enhanced magnetic resonance imaging (ceMRI) has been shown to reliably identify irreversible myocardial injury. The aim of this study was to compare the findings on ceMRI with routine clinical markers of myocardial injury in patients with acute myocardial infarction (MI).

METHODS AND RESULTS

Twenty-four patients with acute MI were investigated at 1.5 T. The global myocardial function was analysed with a standard cine MR protocol and a stack of short axis slices encompassing the entire left ventricle. Corresponding short axis slices were acquired for delayed ceMRI 15-20 min after the administration of 0.2 mmol gadolinium-DTPA/kg body weight. Mass of hyperenhancement and peak creatine kinase release (peak CK) was determined for each patient. The presenting 12-lead ECG was analysed for ST-elevation on admission and later development of Q-waves. Mass of hyperenhancement correlated moderately well to peak CK (r = 0.65, p < 0.01) and endsystolic volume index (r = 0.55, p < 0.01). Mass of hyperenhancement was inversely correlated to ejection fraction (r = -0.50, p = 0.02). Neither the presence of ST elevation on the admission ECG nor the later development of Q-waves did relate to the transmural extent of hyperenhancement and to the mass of hyperenhancement.

CONCLUSION

Mass of hyperenhancement significantly correlates to global myocardial function and to peak CK. However, there is no relationship between the findings in ceMRI and 12-lead ECG abnormalities on admission suggesting an advantage of ceMRI in defining transmural extent and depicting small areas of necrosis.

Relationship between myocardial viability and the predischarge electrocardiographic pattern in patients with first anterior wall acute myocardial infarction

BACKGROUND

The assessment of residual viability in the infarcted area after an acute myocardial infarction is relevant to subsequent management and prognosis.

OBJECTIVE

The aim of this study was to investigate the correlation between myocardial viability after an acute anterior myocardial infarction (AMI) as assessed by low dose dobutamine stress echocardiography (LDDSE) and the electrocardiographic patterns of ST segment and T wave abnormalities at the end of the first week of the acute event.

METHODS

Sixty-nine consecutive patients (51 men, 18 women, mean age+/-standard deviation=57+/-11 years) who admitted to our clinic due to a first episode of transmural AMI were included in this study. Two-dimensional echocardiography was performed to all patients during rest and low dose dobutamine administration at the end of the first week of admission (7+/-2 days). Patients were classified into four groups according to ST segment and T wave morphology: group A, ST elevation < or =0.1 mV and negative T waves; group B, ST elevation < or =0.1 mV and positive T waves; group C, ST elevation > or =0.1 mV and negative T waves and group D, ST elevation > or =0.1 mV and positive T waves.

RESULTS

Myocardial viability was detected more often in patients with isoelectric ST segments (22/24, 92%) than those with elevated ST segments (21/45, 47%) (P<0.001). Similarly patients with negative T waves had myocardial viability more frequently compared to those with positive T waves (32/45, 71% vs. 11/24, 46%, P<0.01). Seventeen (94%) of 18 patients in group A and 5 (83%) of six patients in group B had viable myocardium (P>0.05). Myocardial viability was found in 15 (56%) of 27 patients in group C and six (33%) of 18 patients in group D (P<0.01). As a marker of viable myocardium, isoelectricity of ST segment was specific (92%) but only moderately sensitive (51%), with a 92% positive predictive accuracy and a poor (53%) negative predictive value. T wave negativity was less specific but more sensitive than isoelectricity of ST segment for myocardial viability.

CONCLUSION

The presence of isoelectric ST segment and negative T wave indicates a high probability of myocardial viability. However, absence of these electrocardiographic patterns does not exclude the presence of viable myocardium.

The predischarge electrocardiographic pattern in anterior acute myocardial infarction: relation between evolutionary ST segment and T-wave configuration and prediction of myocardial infarct size and left ventricular systolic function by the QRS Selvester score

Left ventricular systolic function, determined mainly by final infarct size, has a major influence on prognosis after acute myocardial infarction (MI). It was found that infarct size and left ventricular ejection fraction can be predicted using the Selvester QRS-score in patients not receiving reperfusion therapy. We assessed whether the predischarge QRS-score can be used for estimating infarct size and left ventricular ejection fraction in 51 patients with a first anterior MI who had received reperfusion therapy and whether considering the configuration of the ST-segments and T-waves will increase the accuracy of these predictions. All patients had received reperfusion therapy and had predischarge resting 99mTc-sestamibi scan. We determined the Selvester QRS score using the electrocardiograms performed on the same day of the scan. In addition, we divided the patients into 3 groups: A: isoelectric ST and negative T-waves (n = 12); B: ST elevation (> or =0.1 mV) and negative T-waves (n = 23); and C: ST elevation (> or =0.1 mV) and positive T-waves (n = 16). The myocardial perfusion defect extent increased from group A to C (28.5+/-16.4%, 39.4+/-14.8%, and 45.3+/-15.8% in groups A, B, and C. respectively; P = .022). Similarly, the left ventricular ejection fraction decreased (41.7+/-11.6%, 38.4+/-8.1%, and 32.0+/-9.7%, respectively; P = .042) from group A to C. Overall, the correlation between the QRS-score and the myocardial perfusion defect extent (Rho = 0.249; P = .08), and ejection fraction (Rho = -0.229; P = .11) was not good. A statistically significant correlation between the myocardial perfusion defect size and the QRS-score was found only in group A (Rho = 0.599, P = .04). In patients with a first anterior myocardial infarction who underwent reperfusion therapy, the predischarge QRS-score is predictive of infarct size only in those in whom ST elevation resolved completely. In patients with residual ST elevation the Selvester QRS-score is inaccurate in predicting infarct size and left ventricular ejection fraction upon discharge.

Myocardial damage and left ventricular dysfunction in patients with and without persistent negative T waves after Q-wave anterior myocardial infarction

Persistent T-wave inversions during the chronic stage of Q-wave myocardial infarction (MI) indicate the presence of a transmural infarction with a fibrotic layer pathologically. The aim of the present study was to examine the relation between left ventricular (LV) damage and changes in polarity of the T waves from the acute to chronic phase in patients with Q-wave anterior wall MI. We studied 140 patients with persistent T-wave inversions in leads with Q waves (negative T-wave group) and 158 patients with positive T waves (positive T-wave group) at 12 months after anterior MI. In the positive T-wave group, the precordial T waves reverted from a negative to a positive morphology < 3 months after MI in 21 patients (3 M-positive T-wave subgroup), 3 to 6 months in 52 patients (6 M-positive T-wave subgroup), and 6 to 12 months in 75 patients (12 M-positive T-wave subgroup). Ten patients had persistent positive T waves without initial T-wave inversion (persistent positive T-wave group). Wall motion index and LV dimension were higher and the wall thickness for the infarct area and LV ejection fraction were lower in the negative T-wave than in the positive T-wave groups, except the persistent positive T-wave group in the chronic stage (p < 0.0001). Wall motion in the infarcted area improved over the course of 1 year in the 3 M-, 6 M-, and 12 M-positive T-wave subgroups (p < 0.0001), but not in the persistent positive T-wave group. Among the patients with T-wave inversions after admission, those who had persistent negative T waves after 12 months had worse LV function. In patients with initial T-wave inversion, earlier normalization of the precordial T waves was associated with greater improvement in LV function. Patients with persistent positive T waves without initial negative T waves had poorer recovery of LV function than patients with persistent negative T waves. We conclude that the presence of inverted T waves in leads with abnormal Q waves 12 months after MI and the time required for T-wave normalization can be used to assess the degree of LV dysfunction.

The use of the electrocardiogram to identify epicardial coronary and tissue reperfusion in acute myocardial infarction

The standard 12-lead electrocardiogram (ECG) gives us crucial information concerning myocardial perfusion and the success of reperfusion therapy for ST elevation acute myocardial infarction. Continuous monitoring has advantages over repeated snapshot recordings. There are four electrocardiographic markers for prediction of the perfusion status of the ischemic myocardium: (1) ST-segment measurements, (2) T-wave configuration, (3) QRS changes, and (4) reperfusion arrhythmias. Complete and stable (> or = 70%) resolution of ST-segment elevation is associated with better outcome and preservation of left ventricular function than partial (30 to 70%) or no (<30%) ST-segment resolution. Early inversion of the T waves after initiation of reperfusion therapy is another marker of myocardial reperfusion and a good prognostic sign. Using standard 12-lead ECG, dynamic changes in Q-wave number, amplitude, and width; R-wave amplitude; and S-wave appearance are detected during reperfusion therapy. However, the significance of these changes has not been clarified. Reperfusion arrhythmias, especially bradycardia and accelerated idioventricular rhythm, are detected occasionally during reperfusion therapy, but the value of reperfusion arrhythmias as a marker of coronary artery patency is still debatable. Dynamic changes in the QRS complexes, ST segments and T waves occur during reperfusion therapy and the days after. Whereas changes in ST-segment amplitude have been extensively studied, the significance of QRS-complex and T-wave changes is less clear, and especially whether changes in the QRS complex and T wave may be complementary and additive to ST-segment monitoring. It has remained unclear whether electrocardiographic signs of reperfusion and reischemia should be used for therapeutic decision making in the clinical setting.

The use of the electrocardiogram to identify epicardial coronary and tissue reperfusion in acute myocardial infarction

The standard 12-lead ECG gives us crucial information concerning myocardial perfusion and the success of reperfusion therapy for ST-elevation acute myocardial infarction. Continuous monitoring has advantages over repeated snapshot recordings. There are four electrocardiographic markers for prediction of the perfusion status of the ischemic myocardium: 1) ST-segment measurements; 2) T-wave configuration; 3) QRS changes; and 4) reperfusion arrhythmias. Complete and stable (> or = 70%) resolution of ST-segment elevation is associated with better outcome and preservation of left ventricular function than partial (30% to 70%) or no (< 30%) ST-segment resolution. Early inversion of the T-waves after initiation of reperfusion therapy is another marker of myocardial reperfusion and a good prognostic sign. Using standard 12-lead ECG, dynamic changes in Q-wave number, amplitude and width, R-wave amplitude and S-wave appearance are detected during reperfusion therapy. However, the significance of these changes have not been clarified. Reperfusion arrhythmias, especially bradycardia and accelerated idioventricular rhythm are detected occasionally during reperfusion therapy, but the value of reperfusion arrhythmias as a marker of coronary artery patency is still debatable. Dynamic changes in the QRS complexes, ST-segments and T-waves occur during reperfusion therapy and the days after. While changes in ST-segment amplitude have been extensively studied, the significance of QRS-complex and T-wave changes are less clear, and especially whether changes in the QRS-complex and T-wave may be complementary and additive to ST-segment monitoring. It has remained unclear whether electrocardiographic signs of reperfusion and re-ischemia should be used for therapeutic decision-making in the clinical setting.