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BACKGROUND: The acuteness score (based on the modified Anderson-Wilkins score) estimates the acuteness of ischemia based on ST-segment, Q-wave and T-wave measurements obtained from the electrocardiogram (ECG) in patients with ST Elevation Myocardial Infarction (STEMI). The score (range 1 (least acute) to 4 (most acute)) identifies patients with substantial myocardial salvage potential regardless of patient reported symptom duration. However, due to the complexity of the score, it is not used in clinical practice. Therefore, we aimed to develop a reliable algorithm that automatically computes the acuteness score.METHODS: We scored 50 pre-hospital ECGs from STEMI patients, manually and by the automated algorithm. We assessed the reliability test between the manual and automated algorithm by interclass correlation coefficient (ICC) and Bland-Altman plot.RESULTS: The ICC was 0.84 (95% CI 0.72-0.91), P<0.0001. The mean difference between manual and automated acuteness score was 0.17±0.66. In only two cases, there was a major disagreement between the two scores. There was an excellent agreement between the scores for the remaining 48 ECGs, all within the upper (1.46) and lower (-1.12) limits of agreement.CONCLUSION: In conclusion, we have developed an automated algorithm for measurement of the modified Anderson-Wilkins ECG acuteness score from the pre-hospital ECG in STEMI patients. This automated algorithm is highly reliable, can be applied in daily practice for research purposes and may be implemented in commercial automated ECG analysis programs to achieve practical use for decision support in the acute phase of STEMI.

His Bundle pacing (HBP) restores electrical synchronization in left bundle branch block (LBBB); however, the underlying mechanisms are poorly understood. We examined the relation between native QRS axis in LBBB, a potential indicator of the site of block, and QRS normalization in patients with LBBB. Data from patients (n = 41) undergoing HBP at 3 sites were studied (68 ± 13 years, 13 women). Study criteria included strictly defined complete LBBB and successful implantation of a permanent HBP lead. Preprocedure and postprocedure electrocardiograms were reviewed independently by 2 blinded readers. QRS axis and duration were measured to the nearest 10° and 10 ms, respectively. QRS narrowing or normalization was the primary end point. Of 29 patients meeting study criteria, 9 had frontal plane QRS axes between -60° and -80°, 10 from -40° to 0°, and 10 from +1° to +90°. QRS narrowing occurred in 24 patients (83%, 44 ± 34 ms, p <0.05). Percent QRS narrowing by axis were 26 ± 19%, 29 ± 25%, and 28 ± 23%, respectively. No correlation between prepacing QRS axis and postpacing narrowing was identified (r(2) = 0.001, p = 0.9). In patients with or without QRS normalization after HBP, mean QRS duration was 155 ± 21 vs 171 ± 8 ms, respectively, p = 0.014. HBP induces significant QRS narrowing in most patients and normalization in patients with shorter baseline QRS duration. In conclusion, the lack of correlation between native QRS axis and narrowing suggests that proximal His-Purkinje block causes most cases of LBBB, or that additional mechanisms underlie HBP efficacy. Further studies are needed to better understand how to predict those patients in whom HBP will normalize LBBB.

Background: The Anderson-Wilkins score (AW-score) is based on quantitative 12-lead electrocardiogram (ECG) criteria to estimate acuteness of ischemia in patients with ST elevation myocardial infarction (STEMI). The score identifies patients with a substantial salvage potential after primary percutaneous coronary intervention regardless of patient reported symptom duration. However, due to the complexity of the score, its manual interpretation is time consuming and therefore has not been applied in clinical practice. Automation of this score could facilitate clinical application. Therefore, we aimed to develop and validate an automatic algorithm for the AW-score. Methods: The AW-score (obtained from presenting ECG), assesses changes in ST-T-segments, T-waves and Q-waves. Each lead is designated an acuteness phase (1A, 1B, 2A or 2B) and the overall score is calculated. AW-score ranges from 1 (late ischemia/least acute) to 4 (early ischemia/most acute) and is calculated from the formula: AW-score = [(4 × (#leads 1A) + 3 × (#leads 1B) + 2 × (#leads 2A) + 1 × (#leads 2B))/(∑#leads with 1A, 1B, 2A or 2B)]. We developed an algorithm to automatically determine AW-score. The algorithm was designed using 50 ECGs. Each ECG lead (except aVR) was manually scored according to AW-score by two independent experts (Exp1 and Exp2) and automatically by our designed algorithm (auto-score). An adjudicated manual score (Adj-score) was determined between Exp1 and Exp2. The inter-rater reliabilities (IRRs) between Exp1 vs Exp2, and Adj-score vs auto-score were assessed by interclass correlation coefficient (ICC). Results: The Adj-score and auto-score had median AW-score 2.7 (1.75–3.52) and 3.0 (2.32–3.80), respectively. The IRR for AW-score between Adj-score and auto-score was ICC = 0.64 (CI 0.36–0.80), p < 0.001). Substantial differences in AW-score between Adj-score and auto-score were due to difference in measures of Q-wave duration. The IRR for AW-score between Exp1 and Exp2 was ICC

Cdc42, a member of the Rho GTPase family, is a fundamental regulator of the actin cytoskeleton during cell migration. To generate a sensor for Cdc42 activation, we employed a multi-pronged approach, utilizing cysteine labeling and expressed protein ligation, to incorporate the environment sensitive fluorophore 4-N,N-dimethylamino-1,8-naphthalimide (4-DMN) into the GTPase binding domain of the WASP protein. These constructs bind only the active, GTP-bound conformation of Cdc42 to produce a fluorescence signal. Studies with a panel of five sensor analogs revealed a derivative that exhibits a 32-fold increase in fluorescence intensity in the presence of activated Cdc42 compared to incubation with the inactive GDP-bound form of the protein. We demonstrate that this sensor can be exploited to monitor Cdc42 nucleotide exchange and GTPase activity in a continuous, fluorescence assay., National Institutes of Health (U.S.) (Cell Migration Consortium GM064346), National Institute of General Medical Sciences (U.S.) (Biotechnology Training Grant T32-GM08334)

INTRODUCTION: Several studies have investigated the ability of the twelve-lead electrocardiogram (ECG) to reliably distinguish Takotsubo cardiomyopathy (TC) from an acute anterior ST-segment elevation myocardial infarction (STEMI). In these studies, only ECG changes were required - ST-segment deviation and/or T-wave inversion - in TC whereas in acute anterior STEMI, ECGs had to meet STEMI criteria. In the majority of these studies, patients of both genders were used even though TC predominantly occurs in women. The aim of this study is to see whether TC can be distinguished from acute anterior STEMI in a predominantly female study population where all patients meet STEMI-criteria.METHODS: Retrospective analysis of the ST-segment changes was done on the triage ECGs of 37 patients with TC (34 female) and was compared to the triage ECGs of 103 female patients with acute anterior STEMI. The latter group was divided into the following subgroups: 46 patients with proximal, 47 with mid and 10 with distal LAD occlusion. Three ST-segment based ECG features were investigated: (1) Existing criterion for differentiating anterior STEMI from TC: ST-segment depression >0.5mm in lead aVR+ST-segment elevation ≤1mm in lead V1, (2) frontal plane ST-vector and (3) mean amplitude of ST-segment deviation in each lead.RESULTS: The existing ECG criterion was less accurate (76%) than in the original study (95%), with a large difference in sensitivity (26% vs. 91%). Only a frontal plane ST-vector of 60° could significantly distinguish TC from all acute anterior STEMI subgroups (p<0.01) with an overall diagnostic accuracy of 81%. The mean amplitude in inferior leads II and aVF was significantly higher for patients with TC compared to all patients with acute anterior STEMI (p<0.01 and p<0.05 respectively) and the mean amplitude in the precordial leads V1 and V2 was significantly lower compared to proximal and mid LAD occlusion (p<0.01).CONCLUSIONS: Given

BACKGROUND AND AIM: The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR.METHOD AND RESULTS: In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53).CONCLUSION: The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.

BACKGROUND AND AIMS: The electrocardiogram (ECG) based Sclarovsky-Birnbaum Ischemia Grade may be used to determine the prognosis of patients with ST-elevation myocardial infarction (STEMI). However, application of the method is based on assumption of the baseline QRS morphology. Thus, the aims of this study were to determine if the baseline QRS morphology was correctly assumed based on an ECG recorded during induced ischemia, and if reference to the baseline ECG altered the designated Ischemia Grade.METHODS: Sixty-three patients with chronic ischemic heart disease that underwent elective percutaneous transluminal coronary angioplasty were included. Baseline ECG and ECG during the procedure were recorded. In the latter, Ischemia Grade was classified according to assumed baseline QRS morphology. Then the baseline ECG was used as reference and Ischemia Grade was determined based on change from the baseline ECG.RESULTS: In 66.6% (42/63) of patients the criteria for STEMI were fulfilled; the incidence was similar between left anterior descending (LAD) and right coronary artery (RCA) occlusion. In LAD patients who fulfilled STEMI criteria, assumption of baseline QRS morphology in involved leads was accurate in only 35% (7/20) and this altered the Ischemia Grade in 10% (2/20) of patients. In RCA patients who fulfilled STEMI criteria, assumption of baseline QRS morphology in involved leads was accurate in 77.3% (17/22) and this altered the Ischemia Grade in 9.1% (2/22) of patients.CONCLUSION: Application of the Sclarovsky-Birnbaum Ischemia Grade with reference to a baseline ECG altered Ischemia Grade in approximately 10% of patients. All patients that were reclassified were assigned a higher Ischemia Grade. Future research is needed to determine the impact of availability of the baseline ECG on the clinical diagnostic and prognostic performances of the Sclarovsky-Birnbaum Ischemia Grade.

BACKGROUND AND AIMS: The electrocardiogram (ECG) based Sclarovsky-Birnbaum Ischemia Grade may be used to determine the prognosis of patients with ST-elevation myocardial infarction (STEMI). However, application of the method is based on assumption of the baseline QRS morphology. Thus, the aims of this study were to determine if the baseline QRS morphology was correctly assumed based on an ECG recorded during induced ischemia, and if reference to the baseline ECG altered the designated Ischemia Grade.METHODS: Sixty-three patients with chronic ischemic heart disease that underwent elective percutaneous transluminal coronary angioplasty were included. Baseline ECG and ECG during the procedure were recorded. In the latter, Ischemia Grade was classified according to assumed baseline QRS morphology. Then the baseline ECG was used as reference and Ischemia Grade was determined based on change from the baseline ECG.RESULTS: In 66.6% (42/63) of patients the criteria for STEMI were fulfilled; the incidence was similar between left anterior descending (LAD) and right coronary artery (RCA) occlusion. In LAD patients who fulfilled STEMI criteria, assumption of baseline QRS morphology in involved leads was accurate in only 35% (7/20) and this altered the Ischemia Grade in 10% (2/20) of patients. In RCA patients who fulfilled STEMI criteria, assumption of baseline QRS morphology in involved leads was accurate in 77.3% (17/22) and this altered the Ischemia Grade in 9.1% (2/22) of patients.CONCLUSION: Application of the Sclarovsky-Birnbaum Ischemia Grade with reference to a baseline ECG altered Ischemia Grade in approximately 10% of patients. All patients that were reclassified were assigned a higher Ischemia Grade. Future research is needed to determine the impact of availability of the baseline ECG on the clinical diagnostic and prognostic performances of the Sclarovsky-Birnbaum Ischemia Grade.

BACKGROUND AND AIM: The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR.METHOD AND RESULTS: In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53).CONCLUSION: The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.

Many graphical methods for displaying ST-segment deviation in the ECG have been tried for enhancing decision-making in patients with suspected acute coronary syndromes. Computed electrocardiographic imaging (CEI), based on a mathematical inverse solution, has been recently applied to transform ST-J point measurements made in conventional 12-lead ECG into a display of epicardial potentials in bull's-eye format. The purpose of this study is to assess utility of CEI in the clinical setting.

The solvatochromic fluorophore 4-N,N-dimethylamino-1,8-naphthalimide (4-DMN) possesses extremely sensitive emission properties due largely to the low intrinsic fluorescence it exhibits in polar protic solvents such as water. This makes it well suited as a probe for the detection of a wide range of biomolecular interactions. Herein we report the development and evaluation of a new series of thiol-reactive agents derived from this fluorophore. The members of this series vary according to linker type and the electrophilic group required for the labeling of proteins and other biologically relevant molecules. Using the calcium-binding protein calmodulin as a model system, we compare the performance of the 4-DMN derivatives to that of several commercially available solvatochromic fluorophores identifying many key factors important to the successful application of such tools. This study also demonstrates the power of this new series of labeling agents by yielding a fluorescent calmodulin construct capable of producing a greater than 100-fold increase in emission intensity upon binding to calcium., National Institutes of Health (U.S.) (NIH Cell Migration Consortium (GM064346)), National Science Foundation (U.S.) (NSF CHE-0414243), National Institutes of Health (U.S.) (Interdepartmental Biotechnology Training Grant T32 GM08334), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF CHE-9808061)), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF DBI-9729592)), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF CHE-0234877)), Massachusetts Institute of Technology (Biophysical Instrumentation Facility for the Study of Complex Macromolecular Systems (NSF-0070319))

Solvatochromic fluorophores possess emission properties that are sensitive to the nature of the local microenvironment. These dyes have been exploited in applications ranging from the study of protein structural dynamics to the detection of protein-binding interactions. Although the solvatochromic indole fluorophore of tryptophan has been utilized extensively for in vitro studies to advance our understanding of basic protein biochemistry, the emergence of new extrinsic synthetic dyes with improved properties, in conjunction with recent developments in site-selective methods to incorporate these chemical tools into proteins, now open the way for studies in more complex systems. Herein, we discuss recent technological advancements and their application in the design of powerful reporters, which serve critical roles in modern cell biology and assay development., National Institutes of Health (U.S.) (NIH Cell Migration Consortium (GM064346)), National Science Foundation (U.S.) (CHE-0414243), National Institutes of Health (U.S.) (Interdepartmental Biotechnology Training Grant T32 GM08334), European Commission (Marie Curie Postdoctoral Fellowship Program)

Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates well with MI size determined by DE-MRI in reperfused STEMI.

Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates well with MI size determined by DE-MRI in reperfused STEMI.

Solvatochromic fluorophores possess emission properties that are sensitive to the nature of the local microenvironment. These dyes have been exploited in applications ranging from the study of protein structural dynamics to the detection of protein-binding interactions. Although the solvatochromic indole fluorophore of tryptophan has been utilized extensively for in vitro studies to advance our understanding of basic protein biochemistry, the emergence of new extrinsic synthetic dyes with improved properties, in conjunction with recent developments in site-selective methods to incorporate these chemical tools into proteins, now open the way for studies in more complex systems. Herein, we discuss recent technological advancements and their application in the design of powerful reporters, which serve critical roles in modern cell biology and assay development., National Institutes of Health (U.S.) (NIH Cell Migration Consortium (GM064346)), National Science Foundation (U.S.) (CHE-0414243), National Institutes of Health (U.S.) (Interdepartmental Biotechnology Training Grant T32 GM08334), European Commission (Marie Curie Postdoctoral Fellowship Program)

The solvatochromic fluorophore 4-N,N-dimethylamino-1,8-naphthalimide (4-DMN) possesses extremely sensitive emission properties due largely to the low intrinsic fluorescence it exhibits in polar protic solvents such as water. This makes it well suited as a probe for the detection of a wide range of biomolecular interactions. Herein we report the development and evaluation of a new series of thiol-reactive agents derived from this fluorophore. The members of this series vary according to linker type and the electrophilic group required for the labeling of proteins and other biologically relevant molecules. Using the calcium-binding protein calmodulin as a model system, we compare the performance of the 4-DMN derivatives to that of several commercially available solvatochromic fluorophores identifying many key factors important to the successful application of such tools. This study also demonstrates the power of this new series of labeling agents by yielding a fluorescent calmodulin construct capable of producing a greater than 100-fold increase in emission intensity upon binding to calcium., National Institutes of Health (U.S.) (NIH Cell Migration Consortium (GM064346)), National Science Foundation (U.S.) (NSF CHE-0414243), National Institutes of Health (U.S.) (Interdepartmental Biotechnology Training Grant T32 GM08334), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF CHE-9808061)), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF DBI-9729592)), Massachusetts Institute of Technology (Department of Chemistry Instrumentation Facility (NSF CHE-0234877)), Massachusetts Institute of Technology (Biophysical Instrumentation Facility for the Study of Complex Macromolecular Systems (NSF-0070319))

BACKGROUND: Resolution of ST-segment elevation in the electrocardiogram (ECG) is used as a reperfusion sign during thrombolytic therapy in acute myocardial infarction. Analysis of high-frequency QRS components (HF-QRS) might provide additional information. The study compares changes in HF-QRS (150-250 Hz) to ST-segment changes in the standard ECG during thrombolytic therapy. METHODS: Twelve patients receiving intravenous thrombolytic therapy were included. A continuous 12-lead ECG recording was acquired for 4 hours. RESULTS: After 1 hour of therapy, 3 patients showed ST-elevation resolution as well as an increase in HF-QRS. These changes in ST and HF-QRS occurred simultaneously. No other patient showed significant changes in ST or HF-QRS after 1 hour. After 2 and 4 hours, there was less concordance between the standard and high-frequency ECGs. CONCLUSIONS: In patients with early ST-elevation resolution, the standard and high-frequency ECGs show similar results. Later changes are more disparate and may provide different clinical information.

OBJECTIVE: This study evaluates depolarization changes in acute myocardial ischemia by analysis of QRS slopes. METHODS: In 38 patients undergoing elective percutaneous coronary intervention, changes in upward slope between Q and R waves and downward slope between R and S waves (DS) were analyzed. In leads V1 to V3, upward slope of the S wave was additionally analyzed. Ischemia was quantified by myocardial scintigraphy. Also, conventional QRS and ST measures were determined. RESULTS: QRS slope changes correlated significantly with ischemia (for DS: r = 0.71, P < .0001 for extent, and r = 0.73, P < .0001 for severity). Best corresponding correlation for conventional electrocardiogram parameters was the sum of R-wave amplitude change (r = 0.63, P < .0001; r = 0.60, P < .0001) and the sum of ST-segment elevation (r = 0.67, P < .0001; r = 0.73, P < .0001). Prediction of extent and severity of ischemia increased by 12.2% and 7.1% by adding DS to ST. CONCLUSIONS: The downward slope between R and S waves correlates with ischemia and could have potential value in risk stratification in acute ischemia in addition to ST-T analysis.

Acute ST-segment elevation myocardial infarction requires prompt restoration of myocardial perfusion to salvage myocardium at risk of ischemic necrosis and improve clinical outcome. Early resolution of ST-segment elevation during the time after reperfusion has been associated with both these end points. From the ASsessment of the Safety and Efficacy of a New Thrombolytic regimen (ASSENT) 3 trial, 3,425 patients were analyzed to investigate whether the amount of ST-segment resolution, divided into 3 groups (complete, >70%; partial, 30% to 70%; and no resolution, <30%), in the first hour after initiation of therapy was a predictor of final infarct size, estimated by peak creatine kinase and Selvester QRS score on the discharge electrocardiogram. Complete compared with partial and no ST resolution resulted in significantly (p<0.001) smaller infarct sizes of 10.5%, 13.2%, and 15.0% of the left ventricle and significantly (p=0.001) fewer patients with peak creatine >5 times the upper reference level at 50.3%, 71.8%, and 76.3%, respectively. In conclusion, our findings supported previous smaller studies suggesting that early resolution of ST elevation, as a sign of early myocardial reperfusion, resulted in less myocardial damage and preservation of left ventricular function.

BACKGROUND: The baseline sum of ST deviation (SigmaSTD) and ST segment resolution after fibrinolysis for ST-elevation myocardial infarction are prognostically useful. OBJECTIVES: To examine the prognostic impact of ST resolution after fibrinolysis and influence of baseline ST deviation in ASSENT-3. METHODS: ST resolution was determined in 4565 patients at 180 minutes after fibrinolysis. 30-Day and 1-year mortality was assessed in patients with complete (ie, > or =50%) versus incomplete ST resolution according to absolute baseline SigmaSTD. RESULTS: Patients with complete ST resolution had lower 30-day and 1-year mortality than those with incomplete ST resolution (3.7% vs 7.3%, p<0.001, and 6.1% vs 10.0%, p<0.001, respectively). After multivariable adjustment for key baseline risk factors, patients with anterior myocardial infarction (MI) in the highest quartile of SigmaSTD had a greater risk of 30-day and 1-year mortality than those in the lowest quartile in both complete (odds ratio (OR) = 2.34, 95% CI 1.14 to 4.80, and OR = 2.34, 95% CI 1.26 to 4.34, respectively) and incomplete ST resolution groups (OR = 4.97, 95% CI 1.82 to 13.61, and OR = 3.61, 95% CI 1.55 to 8.4, respectively). However, in patients with inferior MI this pattern only existed when ST resolution was incomplete (OR = 4.88, 95% CI 1.65 to 14.39, and OR = 4.34, 95% CI 1.66 to 11.37, respectively). CONCLUSION: These findings indicate that percentage ST resolution alone is an incomplete guide to 30-day and 1-year mortality. The integration of both the baseline and post-fibrinolysis ECG provides better risk assessment and can assist in the triage and treatment of such patients.

Udgivelsesdato: 2009-Feb-1, Guidelines recommend that patients with suggestive symptoms of myocardial ischemia and ST-segment elevation (STE) in > or =2 adjacent electrocardiographic leads should receive immediate reperfusion therapy. Novel strategies aimed to reduce door-to-balloon time, such as prehospital wireless electrocardiographic transmission, may be dependent on the interpretation accuracy of the electrocardiogram (ECG) readers. We assessed the ability of experienced electrocardiographers to differentiate among STE, acute STE myocardial infarction (STEMI), and nonischemic STE (NISTE). A total of 116 consecutive ECGs showing STE were studied. Fifteen experienced cardiologists were asked to decide, based on the ECG and assuming that the patient had compatible symptoms, whether they would send each patient for primary percutaneous coronary intervention (PPCI). If NISTE was chosen, the reader selected 1 or more 12 possible options to explain the choice. Of 116 patients, only 8 had STEMI. The percentage of ECGs for which PPCI was recommended for the patient by the individual readers varied widely (7.8% to 33%). There was no significant difference between the North American and Other Countries readers (p = 0.13). The sensitivity and specificity of the individual readers ranged from 50% to 100% (average 75%) and 73% to 97% (average 85%), respectively. There were broad inconsistencies among the readers in the chosen reasons used to classify NISTE. In conclusion, we found wide variations among experienced electrocardiographers in reading ECGs with STE and differentiating STEMI with need for PPCI from NISTE. There is a need to revise our current electrocardiographic criteria for differentiating STEMI from NISTE.

Udgivelsesdato: 2009-Feb-1, Guidelines recommend that patients with suggestive symptoms of myocardial ischemia and ST-segment elevation (STE) in > or =2 adjacent electrocardiographic leads should receive immediate reperfusion therapy. Novel strategies aimed to reduce door-to-balloon time, such as prehospital wireless electrocardiographic transmission, may be dependent on the interpretation accuracy of the electrocardiogram (ECG) readers. We assessed the ability of experienced electrocardiographers to differentiate among STE, acute STE myocardial infarction (STEMI), and nonischemic STE (NISTE). A total of 116 consecutive ECGs showing STE were studied. Fifteen experienced cardiologists were asked to decide, based on the ECG and assuming that the patient had compatible symptoms, whether they would send each patient for primary percutaneous coronary intervention (PPCI). If NISTE was chosen, the reader selected 1 or more 12 possible options to explain the choice. Of 116 patients, only 8 had STEMI. The percentage of ECGs for which PPCI was recommended for the patient by the individual readers varied widely (7.8% to 33%). There was no significant difference between the North American and Other Countries readers (p = 0.13). The sensitivity and specificity of the individual readers ranged from 50% to 100% (average 75%) and 73% to 97% (average 85%), respectively. There were broad inconsistencies among the readers in the chosen reasons used to classify NISTE. In conclusion, we found wide variations among experienced electrocardiographers in reading ECGs with STE and differentiating STEMI with need for PPCI from NISTE. There is a need to revise our current electrocardiographic criteria for differentiating STEMI from NISTE.

Background: The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads), or a subset hereof (e.g. 19-lead ECG), of the conventional 12-lead ECG or by using additional electrodes. The purpose of this study was to investigate the accuracy of the different ECG methods in diagnosing acute ST-elevation MI. Methods: The study population consisted of 479 patients admitted to Lund University Hospital with acute chest pain. One conventional ECG plus leads V4R, V5R, V8 and V9 were recorded for each patient within 24 h of admittance. Biochemical markers were used as the 'gold standard' for diagnosis of MI. We measured ST-segment elevations in the 12-, 16- and 24-lead postadmission ECGs as well as in the 12-, 19- and 24-lead admission ECGs. Results: The sensitivity for detecting acute MI was 28% for the postadmission 12-lead ECG, 33% for the 16-lead ECG and 37% for the 24-lead ECG. The specificities were 97%, 93% and 95%, respectively. For admission ECGs, the sensitivity was 33% for the 12-lead ECG, 45% for the 19-lead ECG and 49% for the 24-lead ECG, with specificities of 97%, 96% and 94%, respectively. Conclusion: The sensitivity for detecting acute MI was higher for the 16-, 19- and 24-lead ECGs than for the conventional 12-lead ECGs. Their specificity, however, was slightly lower. If increased sensitivity for detecting MI is desired, the 24-lead or 19-lead should be used as no additional electrodes are required.

BACKGROUND: Because patients with acute left circumflex occlusion are typically characterized primarily on the standard 12-lead electrocardiogram (ECG) by ST depression, they do not qualify to receive reperfusion therapy. Documentation of a relationship between the quantities of acute ST change and final QRS estimated acute myocardial infarction (AMI) size could form the basis for clinical trials to determine the value of reperfusion therapy. METHOD: The Fragmin and Fast Revascularization during Instability in Coronary artery disease trial included 3214 patients with unstable coronary artery disease. Two percent of the patients (n = 69) had maximum ST-segment depression in leads V 1 through V 3 and were selected for this study. Initial ECG changes were compared to final myocardial infarction size, using the Selvester QRS score as the end point. RESULTS: The quantity of initial ST-segment deviation correlated with the final AMI size (r = 0.43, P < .0005). The formula 3[0.22 (SigmaST downward arrow + SigmaST upward arrow) -0.02], where downward arrow indicates depression and upward arrow elevation, derived from measurements on the initial ECG, predicted the size of the AMI in percentage of the left ventricle as estimated on the final ECG. The study population had a large proportion of AMI (73%) indicated to be in or adjacent to the posterior left ventricular wall. CONCLUSION: The quantitative initial ST-segment deviation correlates linearly to the final AMI size in patients with maximum ST-segment depression in leads V 1 through V 3. The formula derived could be valuable for selecting patients who fail to meet strict ST-elevation AMI criteria for emergency intravenous or intracoronary reperfusion therapy.

Open-water disposal of dense suspensions of fluid mud with concentrations of 10 to 480 g/1 was studied at field sites in Mobile Bay, Alabama, and the James River, Virginia. The study aimed to determine the significance of fluid mud in dispersal of dredged material and in generation of turbidity. The bulk of the dredged material, more than 99 percent at the Mobile Bay site was dispersed in the form of fluid mud near the bottom, whereas less than 1 percent was dispersed through the water column. As suspended solids flocculate and settle, they contribute to the fluid mud. In turn, fluid mud resists resuspension and reduces turbidity. Disposal created a deposit that spread over an area 5 to 13 times the dredged area in the channel. Disposal raised the bed, forming dense layers in mounds 0.8 to 2.2 m high having slopes 1:125 to 1:2000. Broad spreading at the Mobile Bay site was associated with a high discharge rate over a short period, a low discharge angle, and muds with high plastic and liquid limits. Mounding at the James River site was associated with a moderate discharge rate over a long period, a vertically oriented discharge configuration, and muds with a moderate plastic limit and a relatively low liquid limit. After disposal, the fluid mud consolidated, bulk density increased, and slopes decreased. Height and volume of the James River mound decreased about 50 percent in a year. More field investigations of the movement of fluid mud are needed for a detailed understanding of its dynamics. (Author), Report on Dredged Material Research Program. Prepared in cooperation with Lafayette Coll., Easton, PA.

c - t ?£3> moi 01 1 - 1 - .......1 .J TECH NICA L REPORT D-78-40 A FIELD STUDY OF FLUID MUD DREDGED MATERIAL: ITS PHYSICAL NATURE AND DISPERSAL by Maynard M. Nichols, Galen S. Thompson Virginia Institute of Marine Science Gloucester Point, Va. 2 3 062 and Richard W. Faas Lafayette College Easton, Pa. 18042 July 1978 Final Report Approved For Public Release; Distribution Unlimited TA 7, W34t D-78-40 1978 Prepared for Office, Chief of Engineers, U. S. Army Washington, D. C. 2 0 3 14 Under Contract No. D A CW 3 9 -7 5 -C -0 I2 I (DM R P Work Unit No. 6 C 0 7 ) Monitored by Environmental Laboratory U. S. Army Engineer Waterways Experiment Station P. O. Box 6 3 1, Vicksburg, Miss. 39I80 L I BR AR Y NOV 61978 Bureau of Reclamation QgP. - Inracln Destroy this report when no longer needed. Do not return it to the originator. DEPARTMENT OF THE ARMY \ I BUREAU OF RECLAMATION DENVER LIBRARY TSDEbTfciD WATERWAYS EXPERIMENT STATION, CORPS OF ENGINEERS P. O. BOX 631 VICKSBURG, MISSISSIPPI 39180 IN R E P L Y R E F E R TO : WESEV 15 September 1978 SUBJECT: Transmittal of Technical Report D-78-40 TO: All Report Recipients 1. The technical report transmitted herewith represents the results of one research effort (work unit) initiated as part of Task 6C (Turbidity Prediction and Control) of the Corps of Engineers’ Dredged Material Research Program (DMRP). Task 6C, part of the Disposal Operations Project of the DMRP, was concerned with investigating the problem of sediment resuspension around dredging and disposal operations; developing methods to predict the nature, extent, and duration of the turbidity and fluid mud; and evaluating methods of controlling the generation and dispersion of turbidity and fluid mud. 2. Although there are still many questions about the direct and indirect effects of different levels of turbidity on aquatic organisms, fluid mud generated from open-water pipeline disposal has been shown to produce an adverse, although perhaps not long-term, environmental imp