Changes In ST Segment Elevation Research Articles

Study of clinical outcomes of patients suffering from acute Myocardial Infarction in Pravara Rural Hospital, Loni

Study of clinical outcomes of patients suffering from acute Myocardial Infarction in Pravara Rural Hospital, Loni - IJCAAP- Print ISSN No: - 2581-5555 Online ISSN No:- 2456-9542 Article DOI No:- 10.18231/j.ijcaap.2019.005, IP International Journal of Comprehensive and Advanced Pharmacology-IP Int J Compr Adv Pharmacol

Coronary Artery Spasm After Cryo Maze III Procedure

The Cox Maze III procedure has been simplified with the availability of tissue ablation devices; however, complications related to their use are recognized. We report a case of 45-year-old woman who underwent mitral valve repair and concomitant Cryo-Maze procedure. She had reversible right coronary artery spasm develop after the procedure demonstrated by ST-segment elevation changes and coronary angiography, which was reversed with intracoronary nitroglycerin. The region of spasm suggested it as a consequence of proximity of the right coronary artery to the right atrial ablation lines.

Ocena skuteczności leczenia pierwotną angioplastyką wieńcową chorych z ostrym zawałem serca z przetrwałym uniesieniem odcinka ST na podstawie analizy krzywej EKG

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Madżitow H, Alimow D. Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej. 2011;7(4):292-296. doi:10.5114/pwki.2011.25787. APA Madżitow, H., & Alimow, D. (2011). Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, 7(4), 292-296. https://doi.org/10.5114/pwki.2011.25787 Chicago Madżitow, Hikmat H., and Donyor A. Alimow. 2011. "Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis". Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej 7 (4): 292-296. doi:10.5114/pwki.2011.25787. Harvard Madżitow, H., and Alimow, D. (2011). Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, 7(4), pp.292-296. https://doi.org/10.5114/pwki.2011.25787 MLA Madżitow, Hikmat H. et al. "Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis." Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, vol. 7, no. 4, 2011, pp. 292-296. doi:10.5114/pwki.2011.25787. Vancouver Madżitow H, Alimow D. Original paperAssessment of the efficacy of primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction based on the ECG analysis. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej. 2011;7(4):292-296. doi:10.5114/pwki.2011.25787.

E0236 A reperfusion model in AMI rabbits

ObjectiveTo Explore the feasibility of establishing the reperfusion model on AMI rabbit by the method of obstructing and releasing the Left Anterior Ventricular Branch (LAVB) of left circumflex coronary artery...

Cardiomyocyte sulfonylurea receptor 2-KATP channel mediates cardioprotection and ST segment elevation.

Sulfonylurea receptor-containing ATP-sensitive potassium (K(ATP)) channels have been implicated in cardioprotection, but the cell type and constitution of channels responsible for this protection have not been clear. Mice deleted for the first nucleotide binding region of sulfonylurea receptor 2 (SUR2) are referred to as SUR2 null since they lack full-length SUR2 and glibenclamide-responsive K(ATP) channels in cardiac, skeletal, and smooth muscle. As previously reported, SUR2 null mice develop electrocardiographic changes of ST segment elevation that were shown to correlate with coronary artery vasospasm. Here we restored expression of the cardiomyocyte SUR2-K(ATP) channel in SUR2 null mice by generating transgenic mice with ventricular cardiomyocyte-restricted expression of SUR2A. Introduction of the cardiomyocyte SUR2A transgene into the SUR2 null background restored functional cardiac K(ATP) channels. Hearts isolated from rescued mice, referred to as MLC2A, had significantly reduced infarct size (27 ± 3% of area at risk) compared with SUR2 null mice (36 ± 3% of area at risk). Compared with SUR2 null hearts, MLC2A hearts exhibited significantly improved cardiac function during the postischemia reperfusion period primarily because of preservation of low diastolic pressures. Additionally, restoration of cardiac SUR2-K(ATP) channels significantly reduced the degree and frequency of ST segment elevation episodes in MLC2A mice. Therefore, cardioprotective mechanisms both dependent and independent of SUR2-K(ATP) channels contribute to cardiac function.

Electrocardiographic changes and clinical outcomes after transapical aortic valve implantation

Transapical aortic valve implantation (TAVI) for the treatment of severe aortic stenosis requires the insertion of a large catheter through the left ventricular apex. However, the electrocardiographic (ECG) changes associated with the incision and repair of the left ventricular apex and the potential damage to the conduction system caused by implanting a balloon-expandable valve in aortic position are not known. The objective of our study was to determine the incidence, type, and timing of ECG changes associated with TAVI. The standard 12-lead ECGs of 33 consecutive patients (mean age 81 +/- 9 years, 13 men) diagnosed with symptomatic severe aortic stenosis (valve area 0.62 +/- 0.16 cm(2)) who underwent TAVI with an Edwards-SAPIEN valve were analyzed at baseline (within 24 hours before the procedure), immediately (within 6 hours) after the procedure, at hospital discharge, and at 1-month follow-up. There were no procedural deaths, and 30-day mortality was 6%. The incidence of complete left ventricular branch block (LBBB) and left anterior hemiblock (LAHB) increased from 9% and 3% at baseline to 27% and 36% after the procedure, respectively (P < .03 for both). A lower (ventricular) position of the valve relative to the hinge point of the anterior mitral leaflet was associated with a higher incidence of new LBBB (35% vs 0%, P = .029); and a greater valve size-aortic annulus ratio, with the occurrence of new LAHB (1.20 +/- 0.07 vs 1.14 +/- 0.06, P = .021). At 1-month follow-up, the rate of LBBB and LAHB decreased to 13% and 10%, respectively (P = not significant compared with baseline). There were no cases of new atrioventricular block, and no patient needed pacemaker implantation. Transient (<48 hours) ST-elevation changes, mostly in the anterior and/or lateral leads, occurred in 6 patients (18%) immediately after the procedure; but only 1 of these patients presented new Q waves at 1-month follow-up. Transapical aortic valve implantation was associated with a significant but transient (<1 month) increase in LBBB and LAHB, with no patient requiring pacemaker implantation. These changes were partially related to both lower (more ventricular) valve positioning and greater valve oversizing. Transient (<48 hours) ST-segment elevation changes occurred in about one fifth of the patients after the procedure, but only a minority developed new Q waves in the ECG.

Perioperative Management of a 7-Year-Old Child With Brugada Syndrome

Brugada syndrome results from abnormalities in the myocardial transmembrane conduction of sodium, resulting in the characteristic electrocardiographic changes of ST segment elevation in the precordial leads and incomplete right bundle branch block in an otherwise structurally normal heart. Affected patients are frequently asymptomatic until their presentation with potentially lethal arrhythmias including ventricular fibrillation. The youngest reported patient with Brugada syndrome to undergo anesthetic management is presented in this article; the pathophysiology of the syndrome is reviewed, and its perioperative implications are discussed.

Clinical Implications of Serial Changes in ST-Segment Elevation After Reperfusion in Patients With Anterior Acute Myocardial Infarction

In patients with acute myocardial infarction (AMI), the relationship of serial changes in ST-segment elevation after reperfusion to left ventricular (LV) function remains unclear. The study group comprised 164 patients with reperfused anterior AMI within 6 h of symptom onset. The sum of ST-segment deviation was calculated on admission (SigmaST-admission), and 1 h (SigmaST-1 h) and 24 h (SigmaST-24 h) after reperfusion. ST resolution was defined as a reduction in SigmaST-1 h of > or =50% as compared with SigmaST-admission. Patients were classified into 3 groups: group A, 82 patients with ST resolution in whom SigmaST-1 h > or = SigmaST-24 h; group B, 37 patients with ST resolution in whom SigmaST-1 h < SigmaST-24 h; group C, 45 patients without ST resolution. Peak creatine kinase were higher in groups B and C than in group A (4,578+/-2,176, 4,236+/-2,638, 2,222+/-1,926 mU/ml, p<0.01). At 6 months follow-up, the LV ejection fraction were lower in groups B and C than in group A (53+/-8, 54+/-12, 62+/-9%, p<0.01). An increase in ST-segment elevation 1-24 h after reperfusion, despite ST resolution, is associated with a larger infarction and poorer LV function in patients with reperfused anterior AMI.

Influence of Meals on Variations of ST Segment Elevation in Patients with Brugada Syndrome

Glucose-induced insulin secretion is one of the contributing factors to fluctuation of ST segment elevation in Brugada syndrome. The purpose of this study was to explore the influence of meals on variations of ST elevation in Brugada syndrome. We assessed changes of ST segment elevation in lead V1-3 on ECG before and after taking meals, at midnight, and at 3:00 a.m. in 20 patients with Brugada syndrome. Plasma glucose, insulin, and K(+) concentrations were measured. Variations of ST elevation were defined as morphological changes and/or augmentation of ST segment level by >1.0 mm. Variations of ST segment morphology or elevation level after meals were observed in 15 of 20 patients (75%). ST elevation was augmented most markedly after dinner (3.3 +/- 1.7 mm) and decreased both at midnight (2.6 +/- 1.3 mm: P < 0.01 vs after dinner) and at 3:00 a.m. (2.4 +/- 1.2 mm: P < 0.01 vs after dinner). Morphologic changes and elevation levels of ST segment were associated with changes in glucose-induced insulin levels after meals, being highest after dinner (47 +/- 33 microU/mL) and decreasing significantly at midnight (7 +/- 4 microU/mL) and at 3:00 a.m. (5 +/- 2 microU/mL). There were no correlations between ST elevation and changes in serum K(+) level or heart rate. The present findings suggest that variations of ST elevation are frequently associated with meals. Aggravation of ST elevation is most prominent in the evening to night after dinner rather than the period between midnight and early morning. This information may help to predict event times at high risk for life-threatening arrhythmias in Brugada syndrome.

Takotsubo Cardiomyopathy—Transient Left Ventricular Apical Ballooning Mimicking Acute Myocardial Infarction

Takotsubo cardiomyopathy is characterized by transient left ventricular dysfunction with clinical symptoms of chest pain, electrocardiographic changes of ST-segment elevation or T wave inversion, which mimics acute myocardial infarction in patients without angiographically significant coronary artery stenosis. We report a 75-year-old woman with a history of chest tightness who presented with typical pictures of takotsubo cardiomyopathy. Acute myocardial infarction was initially diagnosed based on the electrocardiographic changes and elevated troponin. Apical akinesis and ballooning with basal hyperkinesis were noted during left ventriculography. Coronary angiography, however, did not show significant coronary artery stenosis. Electrocardiography was normal 3 months later. Follow-up echocardiography did not show any wall motion abnormality. This patient remained well without chest pain or dyspnea over 24 months of follow-up. Optimal medical management of takotsubo cardiomyopathy remains unclear. This patient received diltiazem to prevent possible coronary artery spasm. The prognosis of this syndrome seems to be favorable except for occasional mortality due to left ventricular rupture or ventricular arrhythmia. Recurrence of this syndrome is rare.

Circadian changes of ST-segment elevation on 12 lead ECG in the Brugada syndrome

Circadian changes of ST-segment elevation on 12 lead ECG in the Brugada syndrome

ST segment elevation at 72 hours in patients with a first anterior myocardial infarction best correlates with pre-discharge and 1-year regional contractility and ventricular dilatation.

To analyse the relationship between the in-hospital course of ST segment elevation (STE) and negative T wave (NTW) with ejection fraction, regional contractility and left ventricular end-diastolic volume at pre-discharge and at 1 year in patients with a first anterior STE acute myocardial infarction (AMI). ECG changes were measured during hospitalization and at 1 year whereas ejection fraction, regional contractility score and end-diastolic volume index were measured by isotopic ventriculography at pre-discharge and at 1 year. At 72h but not earlier patients with SigmaSTE >0.6mV (group A, n: 35) had a lower ejection fraction (P<0.001), a higher regional contractility score (P<0.001) and a larger end-diastolic volume index (P<0.001) at discharge than those with <0.6mV (group B, n: 26). Negative T wave did not provide additional information. At 1 year, group A continued to show a more impaired ejection fraction and regional contractility than group B and a larger end-diastolic volume. Although reportedly changes in STE within the first hours correlate with coronary reperfusion our findings indicate that additional assessment of STE as early as at 72h correlates with wall motion, ejection fraction and ventricular dilatation at discharge and at 1 year.

Isosorbide-2-mononitrate reduces the consequences of myocardial ischaemia, including arrhythmia severity: implications for preconditioning.

The effects of the intracoronary administration of isosorbide-2-mononitrate (ISMN; 3 microg kg(-1) min(-1)), a major metabolite of isosorbide dinitrate, were examined in chloralose-urethane anaesthetized dogs before and during a 25 min, acute occlusion of the left anterior descending coronary artery. The only significant haemodynamic effects of ISMN administration were a slight (-11 +/- 2 mmHg) decrease in arterial blood pressure and a decrease (< 12%) in diastolic coronary vascular resistance. Coronary occlusion in the presence of ISMN led to a markedly reduced incidence and severity of ventricular arrhythmias compared to those in control, saline-infused dogs. There were fewer ectopic beats (62 +/- 35 versus 202 +/- 72; p < 0.05), a lower incidence (25% versus 75%; p < 0.05) and number of episodes (0.7 +/- 0.4 versus 4.3 +/- 2.1; p < 0.05) of ventricular tachycardia and fewer dogs fibrillated during the ischaemic period (17% versus 82%; p < 0.05). More dogs given ISMN survived the combined ischaemia-reperfusion insult (50% versus 0%; p < 0.05). Changes in ST-segment elevation (recorded by epicardial electrodes) and in the degree of inhomogeneity of electrical activation within the ischaemic area were much less pronounced throughout the occlusion period in dogs given ISMN. These results add weight to the hypothesis that the previously reported antiarrhythmic effects of ischaemic preconditioning, and of the intracoronary administration of nicorandil, involve nitric oxide.

Repeated Cardiac Pacing Extends the Time During Which Canine Hearts are Protected Against Ischaemia-induced Arrhythmias: Role of Nitric Oxide

Right ventricular pacing in lightly anaesthetized dogs (4×5 min periods at a pacing rate of 220 beats/min) protects against the consequences of coronary artery occlusion when this is initiated 24 h after the pacing stimulus. The main purpose of the present experiments was to determine whether repeating the pacing stimulus, at a time when protection from the initial stimulus had faded (48 h), prolonged the protection afforded against ischaemia-induced ventricular arrhythmias and other ischaemic changes (epicardial ST-segment mapping; changes in the degree of electrical inhomogeneity in the ischaemic region). Dogs were paced on two occasions, with a 48 h period between and, at different times (48, 72 and 96 h) after the second pacing stimulus, were re-anaesthetized and subjected to occlusion of the left anterior descending coronary artery. There was a marked reduction in the severity of ischaemia-induced arrhythmias 48 and 72 h after the second pacing stimulus (reduction in occlusion-induced and reperfusion-induced ventricular fibrillation, e.g. at 72 h 0/11 during occlusion and only 3/11 following reperfusion, compared to 7/21 and 10/21 respectively in the controls P<0.05). The protection had disappeared 96 h following the second pacing stimulus. Changes in ST-segment elevation and in the degree of inhomogeneity largely followed these changes in the severity of ventricular arrhythmias. The results suggest the possibility of maintaining protection against life-threatening arrhythmias following coronary occlusion by repeating a preconditioning pacing stimulus. We also demonstrate that this prolonged protection afforded by repeated cardiac pacing is mediated by nitric oxide, since the marked antiarrhythmic effect observed, e.g. 72 h after the second pacing stimulus, was abolished when S-(2-aminoethyl)-isothiourea (AEST), a particularly selective inhibitor of iNOS, had been administered before coronary artery occlusion.

Is the development of myocardial tolerance to repeated ischemia in humans due to preconditioning or to collateral recruitment?

OBJECTIVESThe purpose of this study in patients with quantitatively determined, poorly developed coronary collaterals was to assess the contribution of ischemic as well as adenosine-induced preconditioning and of collateral recruitment to the development of tolerance against repetitive myocardial ischemia.BACKGROUNDThe development of myocardial tolerance to repeated ischemia is nowadays interpreted to be due to biochemical adaptation (i.e., ischemic preconditioning).METHODSIn 30 patients undergoing percutaneous transluminal coronary angioplasty, myocardial adaptation to ischemia was measured using intracoronary (i.c.) electrocardiographic (ECG) ST segment elevation changes obtained from a 0.014-in. (0.036 cm) pressure guidewire positioned distal to the stenosis during three subsequent 2-min balloon occlusions. Simultaneously, an i.c. pressure-derived collateral flow index (CFI, no unit) was determined as the ratio between distal occlusive minus central venous pressure divided by the mean aortic minus central venous pressure. The study patients were divided into two groups according to the pretreatment with i.c. adenosine (2.4 mg/min for 10 min starting 20 min before the first occlusion, n = 15) or with normal saline (control group, n = 15).RESULTSCollateral flow index at the first occlusion was not different between the groups (0.15 ± 0.10 in the adenosine group and 0.13 ± 0.11 in the control group, p = NS), and it increased significantly and similarly to 0.20 ± 0.14 and to 0.19 ± 0.10, respectively (p < 0.01) during the third occlusion. The i.c. ECG ST elevation (normalized for the QRS amplitude) was not different between the two groups at the first occlusion (0.25 ± 0.13 in the adenosine group, 0.25 ± 0.19 in the control group). It decreased significantly during subsequent coronary occlusions to 0.20 ± 0.15 and to 0.17 ± 0.13, respectively. There was a correlation between the change in CFI (first to third occlusion; ΔCFI) and the respective ST elevation shift (ΔST): ΔST=−0.02 to 0.78×ΔCFI;r=0.54,p=0.02.CONCLUSIONSEven in patients with few coronary collaterals, the myocardial adaptation to repetitive ischemia is closely related to collateral recruitment. Pharmacologic preconditioning using a treatment with i.c. adenosine before angioplasty does not occur. The variable responses of ECG signs of ischemic adaptation to collateral channel opening suggest that ischemic preconditioning is a relevant factor in the development of ischemic tolerance.

Utility of the prehospital electrocardiogram in diagnosing acute coronary syndromes: the Myocardial Infarction Triage and Intervention (MITI) project

Objectives. We sought to determine whether the prehospital electrocardiogram (ECG) improves the diagnosis of an acute coronary syndrome.Background. The ECG is the most widely used screening test for evaluating patients with chest pain.Methods. Prehospital and in-hospital ECGs were obtained in 3,027 consecutive patients with symptoms of suspected acute myocardial infarction, 362 of whom were randomized to prehospital versus hospital thrombolysis and 2,665 of whom did not participate in the randomized trial. Prehospital and hospital records were abstracted for clinical characteristics and diagnostic outcome.Results. ST segment and T and Q wave abnormalities suggestive of myocardial ischemia or infarction were more common on both the prehospital and hospital ECGs of patients with as compared with those without acute coronary syndromes (p ≤ 0.00001). Those with prehospital thrombolysis were more likely to show resolution of ST segment elevation by the time of hospital admission (14% vs. 5% in patients treated in the hospital, p = 0.004). In patients not considered for prehospital thrombolysis, both persistent and transient ST segment and T or Q wave abnormalities discriminated those with from those without acute coronary ischemia or infarction. Compared with ST segment elevation on a single ECG, added consideration of dynamic changes in ST segment elevation between serial ECGs improved the sensitivity for an acute coronary syndrome from 34% to 46% and reduced specificity from 96% to 93% (both p < 0.00004). Overall, compared with abnormalities observed on a single ECG, consideration of serial evolution in ST segment, T or Q wave or left bundle branch block (LBBB) abnormalities between the prehospital and initial hospital ECG improved the diagnostic sensitivity for an acute coronary syndrome from 80% to 87%, with a fall in specificity from 60% to 50% (both p < 0.000006).Conclusions. ECG abnormalities are an early manifestation of acute coronary syndromes and can be identified by the prehospital ECG. Compared with a single ECG, the additional effect of evolving ST segment, T or Q waves or LBBB between serially obtained prehospital and hospital ECGs enhanced the diagnosis of acute coronary syndromes, but with a fall in specificity.

Acute Epicardial ECG Parameters as Quantitative Predictors of Infarct Size at 1 Week in the Baboon

We describe an experimental baboon model that allows quantitative prediction of myocardial necrosis measured at 1 week from acute epicardial ECG parameters recorded from a high-resolution matrix of fixed epicardial electrodes. The electrode grid overlies a circumscribed area of ultimate necrosis, produced by the occlusion of a selected diagonal branch of the left anterior descending coronary artery (LAD). This grid allowed examination of the pattern of changes in ST segment elevation (ST↑) throughout their return to control levels, and profiled changes in the distribution of electrodes recording TQ-ST segment deflections. Those points more centrally located within the area of ST↑ consistently showed greater absolute values of ST↑ and remained elevated longer than the more peripheral electrodes. Areas of the electrode matrix corresponding to those electrode points showing significant ST↑ (2 mV above control) at each recording interval through 8 hr were fitted to the area of necrosis underlying this electrode grid. While the maximum area of ST↑ (maxAst) uniformly overestimated infarct size between animals on the order of 25%, regression analysis allowed prediction of the extent of infarct from maxAst with an error of only 5%. Correlation of maxAst with the epicardial extent of infarct, total weight, and volume yielded coefficients of 0.95, 0.85, and 0.91 respectively, while mean ST↑ (ST↑) showed a poorer correlation with respective coefficients of 0.49, 0.55, and 0.39. MaxAst proved to be the single best predictor of infarct size assessed at 1 week.

Use of changes in ST segment elevation for prediction of infarct artery recanalization in acute myocardial infarction

The role of the ECG in evaluating reperfusion status after thrombolytic treatment in acute myocardial infarction is not clear. Dramatic ST segment changes have been observed during recanalization of an infarct-related artery, but ST criteria have not been definitively established for prediction of coronary artery patency. Differences in ST segment changes in relation to infarct localization have not been evaluated, and further investigation is required into reciprocal ST depression, which provides information independent from ST elevation. Therefore, the aim of this study was to evaluate how early changes in ST segment elevations and depressions predict vessel patency after fibrinolysis for patients with anterior and inferior/lateral infarcts. Two hundred patients with a Pardee wave in the ECG and chest pain of less than 6 h duration were given thrombolytic treatment. The result of the therapy was assessed simultaneously with coronary angiography. Patients were divided into two groups: I (50 patients) without recanalization (TIMI grade 0, 1 or 2), and II (150 patients) with successful recanalization (TIMI grade 3). Before and after therapy, analysis of the 12 lead ECG included maximum ST elevation measurement (H1, H2 respectively), the sum of ST elevations (sigma H1, sigma H2), the sum of ST segment depressions (sigma h1, sigma h2), and the ratios of ST segment changes (R1 = H2:H1, R2 = sigma H2:sigma H1, R3 = sigma h2:sigma h1). The mean interval from the first to the second ECG was 3.5 +/- 1 h. Successive values of R1 and R2 were examined to find that which best distinguished between the two groups. The best values for prediction of reperfusion were: (1) For anterior wall infarct [table: see text] (2) For inferior and lateral infarct [table: see text] In 13 patients with a complete right or left bundle branch block in the first or second ECG, the result of treatment was predicted in 11 patients using criteria for factor R1 and in 12 patients using criteria for R2. Analysis of ST segment depressions revealed a significant correlation between normalization of ST segment depressions and elevations (R3 vs R1: r = 0.60, P < 0.05; R3 vs R2 r = 0.59, P < 0.05). Multivariate discriminant analysis showed an independent value of R3 for discrimination between the two groups, but only in patients with inferior/lateral infarcts. The overall accuracy of the common algorithm in predicting reperfusion was significantly better in patients with inferior/lateral infarcts (Chi2 test, P = 0.0078). When separate algorithms were used, there was no significant difference between patients with anterior or inferior/lateral infarcts because of the significant improvement in prediction of reperfusion in patients with anterior infarcts (McNemar's test: P = 0.041). We conclude that analysis of ST segments on the standard 12-lead ECG offers valuable help in the early identification of successful recanalization of infarct-related arteries after thrombolytic therapy in patients with acute myocardial infarction. Use of the ratio of ST segment normalization according to the separate criteria for anterior and inferior/lateral infarcts gives the test a high sensitivity and specificity, even in the presence of interventricular conduction disturbances.

Changes in standard electrocardiographic ST-segment elevation predictive of successful reperfusion in acute myocardial infarction

The ability of the electrocardiographic ST segment to predict successful reperfusion after thrombolytic therapy remains controversial. To evaluate whether angiographically determined reperfusion could be predicted from changes in ST-segment elevation, the sum of ST-segment elevation in affected leads of the electrocardiogram was compared before and after thrombolytic therapy in 53 patients with acute myocardial infarction (AMI). Reperfusion status of the infarct-related artery was determined angiographically < 8 hours from onset of symptoms. According to the Thrombolysis in Myocardial Infarction trial (TIMI) criteria, 33 patients had successful reperfusion (TIMI grade 2 to 3 flow) after thrombolytic therapy and 20 patients did not (TIMI grade 0 to 1 flow). Logistic multiple regression analysis showed that the proportional value for the shift in the sum of ST elevation, termed the “% ST change”, was more strongly associated with reperfusion than the absolute measured difference in millimeters (chi-square = 11.34 vs 9.22). The entire spectra of sensitivities and specificities were determined to identify a level of the percent ST change with simultaneous high sensitivity and specificity. A 20% decrease in ST elevation provided such a level (88% sensitivity, 80% specificity). The positive and negative predictive values of a 20% decrease in ST elevation were 88 and 80%, respectively. These results suggest that a decrease of only 20% in the sum of ST elevation in the standard electrocardiogram after thrombolytic therapy is a useful noninvasive predictor of reperfusion status in patients with evolving AMI.

The relationship of ST elevation to eventual QRS loss in acute inferior myocardial infarction

The electrocardiographic changes of ST-segment elevation in acute myocardial infarction are related to the region of infarction. The authors examined body surface map data in 70 patients with acute inferior infarction to determine the exact relationship of the initial ST elevation to the eventual loss of QRS. The patients had no evidence of previous myocardial infarction and no subsequent infarction and did not receive thrombolytic therapy or other acute interventions, such as surgery. Maps were recorded on admission to the hospital, during the hospital admission and again at follow-up examination 6–48 months after infarction. The region of ST elevation of the initial body surface map was compared to a QRS loss region derived by subtracting the follow-up map, integrated over the 80 msec after the onset of the QRS, from a “QRS loss region” derived from 381 normal patients using the same interval. In 76% of patients there was a direct relationship between the position of the ST elevation and the QRS loss region (mean correlation coefficient, 0.49). In a further 15% of patients there was a general relationship without specific features, and in the remaining 8% the difference maps were not related to the position of ST elevation. The region of ST elevation predicts the eventual QRS loss in the majority of patients and may be useful for monitoring interventions in acute myocardial infarction.