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At least 163 records · Page 9Linked to original sources
PubMed1980

[Orthogonal ECG and a statistical system for computer diagnosis with ECG in chronic obstructive pneumopathy].

In 92 patients affected from chronic obstructive pulmonary disease (C.O.P.) undergoing spirometric evaluation, the ability of the Pipberger computer program for electrocardiographic interpretation to predict the presence of pulmonary disease with or without right ventricular hipertrophy was compared with that of the manually measured conventional and orthogonal (Frank system) electrocardiogram. The patients were classified as having mild, moderate and severe C.O.P. on the basis of spirometric data. Each system predicted the presence of C.O.P. with low sensitivity. P voltage in D2 greater than or equal to 2 mm (27,1%) and R/S voltage ratio in V5-V6 greater than or equal to 1 (22,8%) were the single conventional criteria more frequently satisfied. Results for 3 lead manual readings were only slightly lower: recognition rate of the R/S voltage ration in x lead less than or equal to 1,3 was 15,7%. The Pipberger program probabilistic answers were divided in "completely" and "partially" correct. Combined completely or partially correct diagnoses were made by the program 14,3% of patients with mild C.O.P., 17,2% of moderate and 48,8% of severe C.O.P. These results suggests that the Pipberger program has at least similar ability to predict C.O.P. compared with the 12 lead and orthogonal manually measured electrocardiogram.

Aged↗
PubMed1981

[Stress-ECG after myocardial infarct. Does myocardial infarct reduce the significance of stress ECG in the diagnosis of severe stenosis of the anterior interventricular ramus, the diagonal ramus and the marginal ramus of the coronary artery].

41 patients with inferior myocardial infarction underwent both exercise stress testing and coronary arteriography. Coronary arteriography of 15 patients showed high-degree stenosis as well as occlusions of the right coronary artery and/or of the R. circumflexus of the left coronary artery alone. In 14 of these 15 cases exercise stress testing showed a normal result, in one case results were abnormal. However, we detected additional high-degree stenosis of R. interventricularis anterior and/or of R. diagonalis and/or of R. marginalis in the other 26 patients. In 22 of these 26 cases exercise stress testing showed an abnormal result, in 4 cases it was normal. Because of a sensitivy of 84,6% and a specificity of 93,3% we can assume, that abnormal results of exercise stress testing suggest additional high-degree stenosis of the RIVA-vessel system in patient after inferior myocardial infarction. Considering an eventual bypass operation it is possible to narrow the indication for coronary arteriography.

Adult↗
PubMed2006

A prospective study on spontaneous fluctuations between diagnostic and non-diagnostic ECGs in Brugada syndrome: implications for correct phenotyping and risk stratification.

AIMS: Fluctuations between the diagnostic ECG pattern and non-diagnostic ECGs in patients with Brugada syndrome are known, but systematic studies are lacking. The purpose of this study was to prospectively evaluate the spontaneous ECG changes between diagnostic and non-diagnostic ECG patterns in patients diagnosed with Brugada syndrome. METHODS AND RESULTS: In 43 patients with Brugada syndrome (27 males; mean age 45+/-11 years), 310 resting ECGs were obtained during a median follow-up of 17.7 months. The ECGs were analysed for the presence of coved type, saddle-back type or no, respectively unspecific, changes. A coved-type ECG pattern with more than 2 mm ST-segment elevation in at least two right precordial leads was defined as diagnostic. The patients were compared for different clinical characteristics with respect to the pattern of fluctuations. Out of a total of 310 ECGs, 102 (33%) revealed a coved type, 91 (29%) a saddle-back type, and 117 (38%) a normal ECG. Fifteen patients (35%) initially presented with a diagnostic coved-type ECG. Fourteen patients (33%) with an initially coved-type ECG exhibited intermittently non-diagnostic ECGs during follow-up. Only one patient (2%) presented constantly with a coved-type ECG. Out of 28 patients (65%) with an initially non-diagnostic ECG, eight (19%) patients developed a diagnostic coved-type ECG during follow-up. Twenty patients (47%) revealed a coved-type ECG during ajmaline challenge, but never had a baseline coved-type ECG recorded. No significant differences were found in gender and clinical characteristics among patients with or without fluctuations between diagnostic and non-diagnostic basal ECGs. The rate of inducible ventricular fibrillation was significantly higher in patients with more than 50% coved-type ECGs than in patients with less than 50% diagnostic ECGs. CONCLUSION: The prevalence of fluctuations between diagnostic and non-diagnostic ECGs in patients with Brugada syndrome is high and may have an implication on the correct phenotyping and on the risk stratification in patients with Brugada syndrome without aborted sudden cardiac death. For correct phenotyping and risk stratification, repetitive ECG recordings seem to be mandatory.

Brugada Syndrome↗
PubMed1996

Use of the standard 12-lead ECG to simulate electrode displacements.

Placement of the precordial electrodes for recording a 12-lead electrocardiogram (ECG) is subject to variation. Previous research has shown that displacement, especially in the longitudinal direction, can lead to changes in diagnosis. In practice, both the displacement and the effects of displacement on an individual ECG are unknown. To assess this effect for a given ECG, the authors developed a method to simulate ECGs at different displacements using only the recorded ECG. The material consisted of 746 body surface potential maps (BSPMs) containing 232 cases without abnormalities, 277 with myocardial infarction (MI), and 237 with left ventricular hypertrophy. By interpolating BSPMs, ECGs from closely spaced electrode positions could be derived. Taking electrode positioning errors that may be encountered in practice, 40 ECGs at different electrode displacements (displaced ECGs) for each BSPM were derived. Using half of the BSPMs, for each displacement, a transformation matrix that transforms the ECG at the standard 12-lead electrode positions (standard ECG) to the displaced ECG was determined. Using the other half of the BSPMs, each displaced ECG was compared with the ECG yielded by the corresponding transformation matrix (transformed ECG). For each comparison, the differences were assessed between the two sets of ECG signals and between the diagnostic computer classifications of the two sets. Signal differences were expressed as mean absolute amplitude differences over the QRS. Computer interpretation of MI and left ventricular hypertrophy was graded in five levels of certainty (no, consider, possible, probable, definite). For instance, for the largest longitudinal displacement studied of about one intercostal space, the 96th percentile mean absolute amplitude difference over the test set was 204 microV. The percentage of cases showing a change in MI classification of more than two certainty levels was 2.7% for this displacement. When comparing the standard ECG with the displaced ECG, these figures were 434 microV and 8.3%, respectively. It is concluded that ECGs from displaced electrodes can be well simulated by transforming the standard ECG, both for the ECG signal and diagnostic classifications.

Body Surface Potential Mapping↗
PubMed1996

Analysis of interval measurements on CSE multilead reference ECGs.

As part of the International Electrotechnical Commission's (IEC) efforts to develop standards for interpretive electrocardiographs, electrocardiograms (ECGs) of the Common Standards of Electrocardiography (CSE) multilead measurement database were processed to (1) determine whether original ECG data would offer any advantage over cycle-repeated (artificial) ECGs and (2) compare the "clean" ECGs selected for interval measurement compliance testing (n = 100) with the remaining 25 "noisy" or nonsinus rhythm ECGs. Two sets of CSE measurement ECGs, namely, 125 original ECGs of the MO1 series and 125 artificial ECGs of the MA1 series were divided into 100 IEC-selected clean ECGs with good P and T waves and 25 noisy or nonsinus ECGs and processed for global wave duration and interval measurements (P duration, PR interval, QRS duration, and QT interval). The measured duration and interval values were compared against the CSE reference values (medians of referee values for 25 physician overread ECGs and medians of interpretive programs for the rest) to compute the measurement "differences". Also, the data of the median cardiac complex were evaluated for noise content. The original ECG data gave consistently smaller differences for all of the four measurements than the differences with the artificial ECG data. The noise levels in the median complexes formed from the original ECG data were significantly lower than the noise levels in the median complexes from the artificial ECG data. The noise levels in the medians of the 100 clean ECGs were lower than the noise levels in the medians of the 25 noisy ECGs for both the original and artificial ECG data.

Algorithms↗
PubMed2006

[Transmission and non-transmission portable ECG in home care medicine].

Portable electrocardiography is advantageous in that patients can record ECG by themselves at any time and place. Portable ECG can be classified into two kinds of devices, transmission type and non-transmission type. By using transmission-type portable ECG, patients can obtain an ECG diagnosis from the center by transmitting the recorded ECG. Transmission-type portable ECG is extremely useful for patients needing emergency treatment for such as an attack of ischemic heart disease or arrhythmic event. On the other hand, a patient has to go to a specialist to obtain an ECG diagnosis with the non-transmission-type portable ECG device after recording the ECG alone. As this model is slightly cheaper, and is easy to use, the non-transmission-type portable ECG is good in non-emergency use for early diagnosis and prevention of cardiac disease. Portable ECG is useful for ECG monitoring over time without seeing the patient, not only for symptomatic analysis of the patient. For example, silent myocardial ischemia and arrhythmic events developing during exercise will become clear in periodical portable ECG recording. In particularly, portable ECG is useful for noncontinual ECG monitoring of patients with Brugada syndrome and those administered with antiarrhythmic drugs. Portable ECG increases the opportunity to discover cardiac disease from the aspect of preventive medicine. When patients use a portable ECG during exercise, they can understand whether the exercise is suitable for their heart. Portable ECG is a useful measurement in preventive medicine as described above, not only for the home care of patients.

Electrocardiography↗
PubMed2003

A comparison of 2-lead, 6-lead, and 12-lead ECGs in patients with changing edematous states: implications for the employment of quantitative electrocardiography in research and clinical applications.

OBJECTIVE: Precordial ECGs reveal significant intrasubject variability due to the inexact employment of the recommended V(1)-V(6) chest landmarks. Also, as per the Einthoven law, the six limb leads can be derived from leads 1 and 2. The purpose of this study was to evaluate whether the 12-lead ECG could be substituted by ECG sets with a limited number of leads. MATERIALS AND METHODS: The performance of three ECG systems (ie, the 12-lead ECG, a 6-lead ECG comprising the limb leads, and a 2-lead ECG comprising exclusively leads 1 and 2) was evaluated in data from 28 patients with anasarca (AN), 28 control patients, 10 patients who had undergone hemodialysis, and 3 patients with idiopathic dilated cardiomyopathy. RESULTS: Linear regression analyses of changes in ECG data with the weight gain of patients with AN and the intercorrelations of the three ECG systems in the various patient subgroups were found to be statistically significant at p = 0.0005 and r values ranging from 0.61 to 0.99, which are suggestive of good/excellent correlations. However, regression analyses of peak weight (PW) gain with changes in the 2-lead ECG (r = 0.43; p = 0.02) and 6-lead ECG (r = 0.48; p = 0.01), and half of PW gain and 12-lead ECG (r = 0.41; p = 0.03), 6-lead ECG (r= 0.18; p = 0.35), and 2-lead ECG (r = 0.43; p = 0.02) revealed poor correlations. CONCLUSION: ECG systems, comprising 2 or 6 leads, can be substituted for the 12-lead ECG for certain clinical and research applications (pertaining to the amplitude of QRS complexes), attesting to the inherent redundancy of the information from the 12-lead ECG.

Cardiomyopathy, Dilated↗
PubMed2003

[Feasibility and reliability of a transtelephonic 12 leads ECG].

Feasibility and reliability of a 12 lead electrocardiogram (ECG), recorded by the patient himself and transmitted via telephone are mandatory for prehospital diagnosis of myocardial ischemia in patients with coronary heart disease. In this study, a 12-lead ECG recorded by patients and transmitted to the cardiology call center via telephone (Tele-ECG; model CG-7100; Card Guard) was compared with the conventional 12-lead ECG from the same patient recorded at the same time in 128 cases. The Tele-ECGs received by the call center were compared with conventional ECG by two cardiologists and one internist independently and blindly. In relation to the conventional ECG, reproducibility of PQ, QRS and QT-durations [ms] as measured in the Tele-ECG was 85%. Concordance between Tele-ECG and conventional ECG in the detection of negative T-waves was very high (Kappa value (kappa) 0.94, 0.96 and 0.97), respectively, depending on the physician. ST-segment changes were diagnosed correctly in most of the cases in Tele-ECG (kappa=0.98-0.99), as compared with the conventional ECG by all physicians. Concordance between Tele- and conventional ECG concerning the pattern of old myocardial infarction was very high (kappa=0.99) for all infarct localization. The limitations of Tele-ECG were of technical nature. In 14 cases, the peripheral electrodes were displaced; in 12 cases, there were baseline artifacts. These technical errors could be corrected in 126/128 patients (98.4%) by transtelephonic verbal communication. In conclusion, the reliability and feasibility of the 12-lead Tele-ECG-recorder used in this pilot study could be demonstrated. In an ongoing randomized controlled multicenter study, it is being investigated whether the strategy of prehospital diagnosis of acute coronary syndromes by Tele-ECG in combination with verbal communication is able to reduce pre- and in-hospital time delay, to avoid unnecessary hospital admissions and to reduce the economic burden of coronary heart disease.

Aged↗
PubMed2005

Accuracy of ECG interpretation in the pediatric emergency department.

STUDY OBJECTIVE: We assess accuracy of ECG interpretation and indications for obtaining ECGs and develop a clinical classification system of ECG abnormalities. METHODS: Prospectively acquired ECG data on patients 0 to 21 years of age and presenting to our pediatric emergency department (ED) were obtained. Clinical indications were documented. The initial ECG interpretation (pediatric ED attending physician) was compared with the criterion standard (pediatric cardiologist). A blinded cardiology panel reviewed discrepancies, and a final concordance rate was determined. An ECG abnormality classification system was developed and used to categorize these abnormal ECGs. RESULTS: One thousand six hundred fifty-three ECGs from 1,501 patients, aged 2 days to 21 years (median 10.0 years), were obtained during 3.5 years. Fifty-one percent were male patients. ECG indications included chest pain (21%), seizure or syncope (18%), arrhythmias (17%), apparent life-threatening event or respiratory symptoms (16%), ingestions (10%), cardiac abnormality (10%), and miscellaneous (8%). From 1,631 ECGs, 1,160 (71%) were normal (class 0), 259 (16%) were minimally abnormal (class I), 174 (11%) were moderately abnormal (class II), and 38 (2%) were severely abnormal (class III). Kendall's tau-b test showed concordance of 0.73 (95% confidence interval 0.70 to 0.77) between pediatric ED and cardiology interpretation. The sensitivity of pediatric ED interpretation was 75%, and the specificity was 98.5%. The positive predictive value of pediatric ED interpretation was 88.3%, and the negative predictive value was 96.3%. CONCLUSION: We conclude that, overall, a high rate of concordance exists between the pediatric emergency physician's and the cardiologist's ECG interpretation. The majority of discordant ECGs are not clinically significant. However, among the clinically significant ECGs, there is a higher rate of discordance. These data suggest that review of pediatric ECGs by pediatric cardiologists may significantly reduce underdetection of clinically important ECG findings in children.

Adolescent↗
PubMed1976

A system for computer-assisted ECG recording at rest and exercise.

Great investments have been made in computerized ECG interpretation but little attention has been paid to rationalization of such costly activities as recording, labelling and mounting ECGs, and still less to the presentation of ECGs. A system for such tasks is described. It includes a PDP8/E computer and modified ink jet ECG recorders, which write alphanumeric text and function as analogue input- and output-devices for the computer. On-line computer service is given independently to two laboratories for ECG at rest, VCG or exercise ECG. After averaging the ECG signal, the computer writes out a properly labelled ECG in an easily surveyable form. The visual interpretation of the ECG is entered and is then written on a new sheet together with the averaged 12-lead ECG and a rhythm strip. In exercise testing, the computer records and processes the ECG at predetermined intervals. The processing includes an automatic ST classification. A summarized presentationof the ECG before, during and after exercise allows easy visual identification of ECG changes. Experience of the system has mainly been obtained from 2 years of routine exercise ECG recording and to a limited extent from ECG and VCG recording at rest.

Cardiology↗