The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Tsutomu Imaizumi - One of the best experts on this subject based on the ideXlab platform.

  • portable type Signal Averaged Electrocardiography with dipyridamole to detect patients with coronary artery disease
    Circulation, 2006
    Co-Authors: Hitoshi Otsubo, Teruhisa Yoshida, Tatsuro Hiraki, Tomohito Inage, Manabu Matsumoto, Tsutomu Imaizumi
    Abstract:

    Background In a retrospective study portable-type Signal-Averaged Electrocardiography (SAECG) with dipyridamole stress was found to identify patients with coronary artery disease (CAD) at their bedside with high sensitivity and specificity, so the utility of this method was prospectively investigated in the present study. Methods and Results Standard 12-lead QRS wave SAECG was performed before and after dipyridamole stress at the bedside in 71 patients with chest pain (43 males, mean age 63 ±9 years). The filtered QRS duration (fQRSd) before and after dipyridamole stress was determined by multiphasic oscillation method for each of the standard 12 leads, and the maximal value of changes in fQRSd (MAX ΔfQRSd) among the 12 leads was determined. The positive test was defined as MAX ΔfQRSd ≥5 ms, and negative as MAX ΔfQRSd <5 ms based on the previous study. Selective coronary arteriography was performed next. In the positive group (n=31), 25 patients had significant stenosis of the coronary artery and 6 did not. In the negative group (n=40), 5 patients had significant stenosis and 35 did not. The sensitivity, specificity, positive predictive accuracy and negative predictive accuracy for CAD detection by SAECG was 83%, 85%, 81% and 88%, respectively. Conclusions Dipyridamole-stress portable SAECG is useful for detecting CAD at the patient's bedside with high sensitivity and specificity. (Circ J 2006; 70: 1568 - 1573)

  • portable type Signal Averaged Electrocardiography with dipyridamole a new and convenient method to detect patients with coronary artery disease and ischemia
    Japanese Circulation Journal-english Edition, 2005
    Co-Authors: Manabu Matsumoto, Teruhisa Yoshida, Tatsuro Hiraki, Takashi Hamada, Masanobu Ohga, Hisao Ikeda, Tsutomu Imaizumi
    Abstract:

    Background Whether or not patients with coronary artery disease (CAD) could be easily detected at the bedside using dipyridamole stress was investigated using a portable type Signal-Averaged Electrocardiography (portable SAECG). Methods and Results The standard 12-lead QRS wave SAECG was performed at the bedside before and after dipyridamole stress in 30 patients with angiographically significant stenotic lesions, who had positive myocardial ischemia in the dipyridamole-thallium myocardial perfusion imaging (CAD group), and 33 patients with no significant stenotic lesions, who had negative imaging (control group). The filtered QRS duration (fQRSd) before and after dipyridamole stress was determined by the vector magnitude method and the difference (ΔfQRSd) was obtained. Furthermore, the ΔfQRSd was obtained using the multiphasic oscillation method, as well at the same standard 12-lead, and the maximal value of changes in fQRSd (MAX ΔfQRSd) between the 12 leads was determined. The ΔfQRSd was similar between 2 groups (p=0.11). The MAX ΔfQRSd associated was significantly greater in the CAD group (p<0.0001). When a cut-off value of MAX ΔfQRSd ≥ 5 ms was used for the detection of CAD, the sensitivity and specificity were 97 and 94%, respectively. Conclusion The portable dipyridamole-stress SAECG easily detect CAD and myocardial ischemia at the bedside. (Circ J 2005; 69: 659 - 665)

  • p wave Signal Averaged Electrocardiography predicts recurrence of paroxysmal atrial fibrillation in patients with wolff parkinson white syndrome who underwent successful catheter ablation a prospective study
    Journal of Cardiovascular Electrophysiology, 2002
    Co-Authors: Tatsuro Hiraki, Teruhisa Yoshida, Tomohito Inage, Manabu Matsumoto, Takashi Hamada, Hisao Ikeda, Masatsugu Ohe, Hitoshi Ohtsubo, Ichiro Kubara, Tsutomu Imaizumi
    Abstract:

    P-SAECG Predicts Recurrence of PAF After Ablation.Introduction: Paroxysmal atrial fibrillation (PAF) frequently occurs in patients with Wolff-Parkinson-White (WPW) syndrome. Catheter ablation of the accessory pathway eliminates PAF in some patients, but PAF frequently recurs in other patients. The present study was designed to determine prospectively whether P wave Signal-Averaged Electrocardiography (P-SAECG) predicts the recurrence of PAF after successful ablation in patients with WPW syndrome. Methods and Results: Forty-six patients with WPW syndrome who had episodes of PAF were prospectively followed. SAECG recording was performed on day 7 after successful ablation of the accessory pathway at study entry. Abnormal P-SAECG for the prediction of recurrence of PAF was defined as a filtered P wave duration > 130 msec. Eleven patients had an abnormal P-SAECG (group 1), whereas 35 patients (group 2) did not. The two groups did not differ in terms of gender, age, left atrial dimension, and atrial vulnerability as determined by electrophysiologic study. During follow-up (40 ± 19 months), the recurrence of PAF was noted in 10 (91%) of 11 patients in group 1, whereas it was observed in only 2 (6%) of 35 patients in group 2. Kaplan-Meier analysis revealed that the recurrence of PAF was significantly more frequent in group 1 than in group 2 (log rank test, P 130 msec was an independent predictor of recurrence of PAF after ablation (Chi-square = 21.5, P < 0.0001). Conclusion: The results of this study indicate that P-SAECG may be useful for identifying patients at risk for recurrence of PAF after successful ablation of WPW syndrome.

Jean Lekieffre - One of the best experts on this subject based on the ideXlab platform.

  • determination of left ventricular mass in systemic hypertension comparison of standard and Signal Averaged Electrocardiography
    Heart, 1995
    Co-Authors: D Lacroix, M A Nader, Christine Savoye, Didier Klug, R Logier, S Kacet, Jean Lekieffre
    Abstract:

    OBJECTIVE--To investigate the quantitative relationship, if any, between Signal Averaged electrocardiographic variables and echocardiographically determined left ventricular mass in hypertensive subjects. DESIGN--Cohort analytic prospective study. SETTING--University hospital. SUBJECTS--50 hypertensive subjects selected consecutively from inpatients. Patients older than 75 years, with underlying cardiac disease, with inconclusive echocardiograms with bundle branch block, or in atrial fibrillation were excluded. INTERVENTIONS--Antihypertensive therapy involving 41 patients was continued. MAIN OUTCOME MEASURES--Left ventricular mass calculated in accordance with the standards of the Penn convention. Thirteen criteria derived from combinations of Signal Averaged electrocardiographic X, Y, and Z Frank orthogonal leads, including voltage criteria, duration, and time-voltage integrals of the QRS complex. Four widely used standard electrocardiographic criteria for detection of left ventricular hypertrophy. RESULTS--There was no difference in the values for any of the electrocardiographic variables between patients with (n = 29) and without left ventricular hypertrophy (n = 21). The time-voltage integral of QRS in the horizontal plane was the best Signal Averaged variable related to left ventricular mass (r = 0.33, P = 0.019); however, the correlation with Rodstein voltage was stronger (r = 0.46, P = 0.0009). A positive correlation was also found between left ventricular indexed mass and Rodstein voltage (r = 0.43, P = 0.0019). Stepwise regression analysis revealed Rodstein voltage as the only predictor of indexed mass (P = 0.0019), and Rodstein voltage (P = 0.0022) and body weight (P = 0.011) as the only independent correlates of left ventricular mass. CONCLUSIONS--The relation between electrocardiographic variables and left ventricular mass or indexed mass is of limited value; Signal Averaged orthogonal leads do not improve this assessment compared with standard electrocardiographic leads.

  • Signal Averaged Electrocardiography and detection of heart transplant rejection comparison of time and frequency domain analyses
    Journal of the American College of Cardiology, 1992
    Co-Authors: Dominique Lacroix, Salem Kacet, Pierre Savard, Franck Molin, Jean Dagano, Annie Pol, Jean Lekieffre
    Abstract:

    To evaluate the role of the Signal-Averaged electrocardiogram (ECG) in the detection of heart transplant rejection, findings on 277 ECGs were compared with those in 218 endomyocardial biopsy specimens in 25 patients followed up for a median duration of 5.2 months (range 7 days to 17.5 months). Signal-Averaged ECGs obtained at intervals of 16.4 ± 22.3 days were analyzed in the time domain before and after high pass filtering at 25 and 70 Hz. Frequency domain analysis was performed with use of a fast Fourier transform algorithm. Sixteen severe rejection episodes requiring treatment were observed. These episodes induced significant decreases in peak and root-mean-square voltages of both filtered and unfiltered QRS complexes, as well as in the total spectral area. Conversely, QRS duration and 50- to 250-Hz or 70- to 110-Hz spectral areas were not significantly altered. In 14 cases mild rejection episodes were observed that did not significantly alter any of the variables studied. The root-mean-square voltage of the 70-Hz high pass filtered QRS complex was found to be the most accurate variable in detecting rejection. Moreover, this variable was also the most reproducible in 10 healthy control subjects. The optimal rejection criterion was defined as an 11% decrease in voltage between two consecutive recordings. It provided 87.5% sensitivity with 78.4% specificity. In conclusion, the Signal-Averaged ECG is helpful in the management of heart transplant rejection. Frequency domain analysis of the QRS complex does not increase the accuracy of the technique compared with the time domain approach.

Nabil Elsherif - One of the best experts on this subject based on the ideXlab platform.

  • a comparison of t wave alternans Signal Averaged Electrocardiography and programmed ventricular stimulation for arrhythmia risk stratification
    Journal of the American College of Cardiology, 2000
    Co-Authors: Michael R Gold, Nabil Elsherif, Daniel M Bloomfield, Kelley P Anderson, David J Wilber, William J Groh, N Mark A Estes, Elizabeth S Kaufman, Mark L Greenberg, David S Rosenbaum
    Abstract:

    OBJECTIVES The goal of this study was to compare T-wave alternans (TWA), Signal-Averaged Electrocardiography (SAECG) and programmed ventricular stimulation (EPS) for arrhythmia risk stratification in patients undergoing electrophysiology study. BACKGROUND Accurate identification of patients at increased risk for sustained ventricular arrhythmias is critical to prevent sudden cardiac death. T-wave alternans is a heart rate dependent measure of repolarization that correlates with arrhythmia vulnerability in animal and human studies. Signal-Averaged Electrocardiography and EPS are more established tests used for risk stratification. METHODS This was a prospective, multicenter trial of 313 patients in sinus rhythm who were undergoing electrophysiologic study. T-wave alternans, assessed with bicycle ergometry, and SAECG were measured before EPS. The primary end point was sudden cardiac death, sustained ventricular tachycardia, ventricular fibrillation or appropriate implantable defibrillator (ICD) therapy, and the secondary end point was any of these arrhythmias or all-cause mortality. RESULTS Kaplan-Meier survival analysis of the primary end point showed that TWA predicted events with a relative risk of 10.9, EPS had a relative risk of 7.1 and SAECG had a relative risk of 4.5. The relative risks for the secondary end point were 13.9, 4.7 and 3.3, respectively (p < 0.05). Multivariate analysis of 11 clinical parameters identified only TWA and EPS as independent predictors of events. In the prespecified subgroup with known or suspected ventricular arrhythmias, TWA predicted primary end points with a relative risk of 6.1 and secondary end points with a relative risk of 8.0. CONCLUSIONS T-wave alternans is a strong independent predictor of spontaneous ventricular arrhythmias or death. It performed as well as programmed stimulation and better than SAECG in risk stratifying patients for life-threatening arrhythmias.

  • a comparative analysis of commercial software for Signal Averaged Electrocardiography
    Annals of Noninvasive Electrocardiology, 1996
    Co-Authors: Gioia Turitto, Shahid Mansoor, Srisha Rao, Nabil Elsherif
    Abstract:

    Background: Lack of standardization of software algorithms to identify the end of QRS for time-domain analysis of the Signal-Averaged electrocardiogram may limit the comparison of results obtained with different machines. Methods: To study this problem, 50 normal volunteers underwent Signal-Averaged electrocardiogram with ART 1200 EPX and Corazonix Predictor units in random sequence, collecting an equal number of beats. Data were analyzed with five different commercial softwares by ART and Corazonix. Results: Comparison of QRS duration, duration of low amplitude Signals, and root mean square voltage of last 40 ms of QRS at two high-pass filter settings (25 and 40 Hz) showed significant differences among softwares. Conclusions: Standardization of software for time-domain analysis of the Signal Averaged electrocardiogram is warranted; until then, normal values for Signal Averaged electrocardiogram parameters will have to be appropriately selected for each study, according to the software utilized.

  • risk stratification for arrhythmic events in patients with nonischemic dilated cardiomyopathy and nonsustained ventricular tachycardia role of programmed ventricular stimulation and the Signal Averaged electrocardiogram
    Journal of the American College of Cardiology, 1994
    Co-Authors: Gioia Turitto, Edward B. Caref, Ratan K Ahuja, Nabil Elsherif
    Abstract:

    Abstract Objectives . This study investigated prediction of arrhythmic events by the Signal-Averaged electrocardiogram (ECG) and programmed stimulation in patients with nonischemic dilated cardiomyopathy. Background . Risk stratification in patients with nonischemic dilated cardiomyopathy remains controversial. Methods . Eighty patients with nonischemic dilated cardiomyopathy and spontaneous nonsustained ventricular tachycardia underwent Signal-Averaged Electrocardiography (both time-domain and spectral turbulence analysis) and programmed stimulation. All patients were followed up for a mean of 22 ± 26 months. Results . Sustained monomorphic ventricular tachycardia was induced in 10 patients (13%), who all received amiodarone. The remaining 70 patients were followed up without antiarrhythmic therapy. Of the 80 patients, 15% had abnormal findings on the time-domain Signal-Averaged ECG, and 39% had abnormal findings on spectral turbulence analysis. Time-domain Signal-Averaged Electrocardiography had a better predictive accuracy for induced ventricular tachycardia than spectral turbulence analysis (88% vs. 66%, p Conclusions . In patients with nonischemic dilated cardiomyopathy, 1) there is a strong correlation between abnormal findings on the time-domain Signal-Averaged ECG and induced ventricular tachycardia, but both findings are uncommon; and 2) normal findings on the Signal-Averaged ECG, as well as failure to induce ventricular tachycardia, do not imply a benign outcome.

  • standards for analysis of ventricular late potentials using high resolution or Signal Averaged Electrocardiography a statement by a task force committee of the european society of cardiology the american heart association and the american college of
    Journal of the American College of Cardiology, 1991
    Co-Authors: G Breithardt, Nabil Elsherif, M E Cain, Vinzenz Hombach, Michiel J Janse, Michael B Simson, Nancy C Flowers, Gerhard Steinbeck
    Abstract:

    Sufficient data are available to recommend the use of the high-resolution or Signal-Averaged electrocardiogram in patients recovering from myocardial infarction without bundle branch block to help determine their risk for developing sustained ventricular tachyarrhythmias. However, no data are available about the extent to which pharmacological or nonpharmacological interventions in patients with late potentials have an impact on the incidence of sudden cardiac death. Therefore, controlled, prospective studies are required before this issue can be resolved. As refinements in techniques evolve, it is anticipated that the clinical value of high-resolution or Signal-Averaged Electrocardiography will continue to increase.

David S Rosenbaum - One of the best experts on this subject based on the ideXlab platform.

  • a comparison of t wave alternans Signal Averaged Electrocardiography and programmed ventricular stimulation for arrhythmia risk stratification
    Journal of the American College of Cardiology, 2000
    Co-Authors: Michael R Gold, Nabil Elsherif, Daniel M Bloomfield, Kelley P Anderson, David J Wilber, William J Groh, N Mark A Estes, Elizabeth S Kaufman, Mark L Greenberg, David S Rosenbaum
    Abstract:

    OBJECTIVES The goal of this study was to compare T-wave alternans (TWA), Signal-Averaged Electrocardiography (SAECG) and programmed ventricular stimulation (EPS) for arrhythmia risk stratification in patients undergoing electrophysiology study. BACKGROUND Accurate identification of patients at increased risk for sustained ventricular arrhythmias is critical to prevent sudden cardiac death. T-wave alternans is a heart rate dependent measure of repolarization that correlates with arrhythmia vulnerability in animal and human studies. Signal-Averaged Electrocardiography and EPS are more established tests used for risk stratification. METHODS This was a prospective, multicenter trial of 313 patients in sinus rhythm who were undergoing electrophysiologic study. T-wave alternans, assessed with bicycle ergometry, and SAECG were measured before EPS. The primary end point was sudden cardiac death, sustained ventricular tachycardia, ventricular fibrillation or appropriate implantable defibrillator (ICD) therapy, and the secondary end point was any of these arrhythmias or all-cause mortality. RESULTS Kaplan-Meier survival analysis of the primary end point showed that TWA predicted events with a relative risk of 10.9, EPS had a relative risk of 7.1 and SAECG had a relative risk of 4.5. The relative risks for the secondary end point were 13.9, 4.7 and 3.3, respectively (p < 0.05). Multivariate analysis of 11 clinical parameters identified only TWA and EPS as independent predictors of events. In the prespecified subgroup with known or suspected ventricular arrhythmias, TWA predicted primary end points with a relative risk of 6.1 and secondary end points with a relative risk of 8.0. CONCLUSIONS T-wave alternans is a strong independent predictor of spontaneous ventricular arrhythmias or death. It performed as well as programmed stimulation and better than SAECG in risk stratifying patients for life-threatening arrhythmias.

  • prognostic significance of electrical alternans versus Signal Averaged Electrocardiography in predicting the outcome of electrophysiological testing and arrhythmia free survival
    Heart, 1998
    Co-Authors: Antonis A Armoundas, David S Rosenbaum, Jeremy N Ruskin, Hasan Garan, Richard J Cohen
    Abstract:

    Objective To investigate the accuracy of Signal Averaged Electrocardiography (SAECG) and measurement of microvolt level T wave alternans as predictors of susceptibility to ventricular arrhythmias. Design Analysis of new data from a previously published prospective investigation. Setting Electrophysiology laboratory of a major referral hospital. Patients and interventions 43 patients, not on class I or class III antiarrhythmic drug treatment, undergoing invasive electrophysiological testing had SAECG and T wave alternans measurements. The SAECG was considered positive in the presence of one (SAECG-I) or two (SAECG-II) of three standard criteria. T wave alternans was considered positive if the alternans ratio exceeded 3.0. Main outcome measures Inducibility of sustained ventricular tachycardia or fibrillation during electrophysiological testing, and 20 month arrhythmia-free survival. Results The accuracy of T wave alternans in predicting the outcome of electrophysiological testing was 84% (p Conclusions —T wave alternans was a highly significant predictor of the outcome of electrophysiological testing and arrhythmia-free survival, while SAECG was not a statistically significant predictor. Although these results need to be confirmed in prospective clinical studies, they suggest that T wave alternans may serve as a non-invasive probe for screening high risk populations for malignant ventricular arrhythmias.

  • 926 26 electrophysiologic testing electrical alternans and Signal Averaged Electrocardiography as predictors of arrhythmia free survival
    Journal of the American College of Cardiology, 1995
    Co-Authors: Antonis A Armoundas, David S Rosenbaum, Jeremy N Ruskin, Hasan Garan, Richard J Cohen
    Abstract:

    Arrhythmia-free survival was analyzed retrospectively in 47 patients who underwent programmed electrophysiologic (EP) testing as well as electrical alternans (EA) and Signal Averaged Electrocardiography (SAECG) measurements. We compared the accuracy of (i) electrophysiologic testing (inducible ventricular tachycardia or fibrillation), (ii) electrical alternans (alternans ratio g 3), (iii) Signal Averaged ECG (QRS duration g 114 msec or LAS g 38 msec or RMS 40 l 20 μV) and (iv) the combined use of EA and SAECG (a patient was classified positive if EA was positive and SAECG was positive or indeterminate) to predict the arrhythmia-free survival of these patients. SAECG was deemed indeterminate if the QRS duration of any of the unfiltered Frank leads was greater than 120 msec (n = 11). The accuracy of predicting arrhythmia-free survival was estimated by computing actuarial arrhythmia free-survival at 20 months and comparing 20 month survival rates with EP, EA and SAECG testing. The results are: Sensitivity Specificity PV+ PV- RR Accuracy P EP 71% 78% 36% 94% 5.89 77% 0.0090 EA 89% 82% 53% 97% 17.06 83% l0.0001 SAECG 50% 72% 18% 92% 2.27 69% 0.3706 EA & SAECG 88% 91% 68% 97% 24.61 90% l0.0001 PV+: positive predictive value, PV-: negative predictive value, RR: relative risk Conclusions EP, EA and EA & SAECG were significant predictors of arrhythmia free survival; SAECG alone was not a significant predictor. In this patient population, EA or EA combined with SAECG provided a powerful measure of risk comparable or superior to ER.

Marek Malik - One of the best experts on this subject based on the ideXlab platform.

  • usefulness of Signal Averaged Electrocardiography in evaluation of idiopathic dilated cardiomyopathy in families
    American Journal of Cardiology, 1997
    Co-Authors: Philip J Keeling, Marek Malik, Katerina Hnatkova, Jonathan H Goldman, William J Mckenna
    Abstract:

    Family studies have confirmed that familial dilated cardiomyopathy is common and that a large proportion of relatives have mild left ventricular enlargement and therefore potentially early disease. Previous studies have shown that patients with idiopathic dilated cardiomyopathy have abnormalities of the Signal-Averaged electrocardiogram (ECG). We assessed the usefulness of analysis of the Signal-Averaged ECG in the evaluation of familial dilated cardiomyopathy. Signal-Averaged electrocardiographic recordings were obtained from 58 patients with idiopathic dilated cardiomyopathy, from 161 of their relatives (35 of whom had left ventricular enlargement), and from 59 healthy subjects. Signal-Averaged ECGs were analyzed using both time domain and spectral turbulence analysis techniques. The time domain and spectral turbulence analysis variables were markedly abnormal in patients with idiopathic dilated cardiomyopathy compared with relatives considered normal and healthy controls (p <0.05). Late potentials were more common in patients with idiopathic dilated cardiomyopathy (17%) and in relatives with left ventricular enlargement (20%) than in normal relatives (5%) or healthy controls (5%) (p = 0.003). Spectral turbulence analysis was abnormal in 24% of patients with idiopathic dilated cardiomyopathy, 14% of relatives with left ventricular enlargement, 6% of normal relatives, and 5% of healthy controls (p = 0.0006). The sensitivity, specificity, and positive predictive accuracy for identification of relatives with left ventricular enlargement were 20%, 95%, and 54% for time domain analysis and 14%, 94%, and 42% for spectral turbulence analysis. Similar positive predictive accuracy was achievable with spectral turbulence analysis and with time domain analysis. In conclusion, the Signal-Averaged ECG is frequently abnormal in patients with idiopathic dilated cardiomyopathy and relatives with left ventricular enlargement.

  • 961 81 time domain and spectral turbulence analysis of Signal Averaged Electrocardiography as prognostic determinants in idiopathic dilated cardiomyopathy
    Journal of the American College of Cardiology, 1995
    Co-Authors: Yi Gang, William J Mckenna, Philip J Keeling, Katerina Hnatkova, Jonathan H Goldman, S Bent, Marek Malik
    Abstract:

    Identification of patients with idiopathic dilated cardiomyopathy (IDC) with poor prognosis [sudden death (SD) or progressive heart failure (PHF)] represents a major management problem. The Signal Averaged electrocardiogram (SAECG) is potentially a non-invasive marker of clinical outcome in IDC. This study compared the ability of time domain (Td) and spectral turbulence analysis (STA) of the SAECG to predict SD/PHF in IDC patients. SAECG were recorded in 58 consecutive patients with IDC (WHO criteria; age 41 ± 14 years) presenting to our hospital and followed over 26 ± 19 months. During the follow up 17 patients had SD/PHF and 41 remained symptomatically and echocardiographically stable. In this population, 27 patients with left bundle branch block or who took anti-arrhythmic drugs had been excluded. Conventiona Td (40 Hz, Butterworth filter) and STA analysis were performed using Del Mar 183 software. Result There were significant differences in all STA parameters (low slice correlation ratio, interslice correlation mean. interslice correlation standard deviation and spectral entropy) between SD/PHF and stable patients (p l 0.01), but in none of the Td parameters (tQRS, LAD40, RMS40). SD/PHF was more likely in patients with an abnormal ( ≥ 3 abnormal STA parameters) compared to a normal STA result (56% vs 19%; p = 0.005). There was a significant difference in event free survival at 1 year between patients with abnormal and normal STA (61% vs 88%; P = 0.03), but the presence of late potentials was not discriminatory (72% vs 82%; P = 0.4). The sensitivity, specificity and total predictive accuracy for predicting SD/PHF were 29%, 85% and 69% (p = 0.2) for Td and 53%, 83% and 74% (p = 0.005) for STA analysis. The positive predictive characteristics curves showed that higher positive predictive accuracies were achieved by STA compared to those of Td analysis. The differences were significant at different sensitivity levels (at 50%, 60%, 70%. p = 0.05; 80%. p = 0.01). The relative risk (95% Cl) of SD/PHF was 2.1 (0.7-6.0) for presence of late potentials and 3.5 (1.4-9.2) for abnormal STA result. Conclusion STA analysis of SAECG is a more sensitive and specific predictor of SD/PHF than Td analysis for IDC patients and has an important role in clinical management.

  • effect of thrombolytic therapy on the predictive value of Signal Averaged Electrocardiography after acute myocardial infarction
    American Journal of Cardiology, 1992
    Co-Authors: Marek Malik, Piotr Kulakowski, O Odemuyiwa, Jan Poloniecki, Anne Staunton, T Millane, T Farrell, John A Camm
    Abstract:

    Standard time domain variables from Signal-Averaged Electrocardiography were examined in a population of 331 survivors of acute myocardial infarction. Of these subjects, 130 received early (less than 24 hours) thrombolytic therapy. During a follow-up of greater than or equal to 10 months, there were 17 arrhythmic events (8.5%) (sudden death or sustained symptomatic ventricular tachycardia) in the group without thrombolysis and 8 (6.2%) in those with thrombolysis. Statistically, highly significant differences between the Signal-Averaged electrocardiographic variables of patients with and without arrhythmic events were found in the group without thrombolysis, whereas only root-mean-square voltage of the terminal 40 ms of the Signal-Averaged QRS complex was statistically associated with outcome (the differences in the other 2 indexes being not significant) in patients with thrombolysis. When using 2 previously published categoric criteria for the diagnosis of abnormal Signal-Averaged Electrocardiography, the performance of these criteria in predicting arrhythmic events was substantially better in the group without thrombolysis than in those with thrombolysis (positive predictive accuracy greater than 3 times lower). Retrospectively adjusted receiver-operator characteristics showed that for a sensitivity of 30%, the maximum achievable positive predictive accuracy of Signal-Averaged Electrocardiography for arrhythmic events was 100% in the group without thrombolysis, but only 27% in those with thrombolysis. It is concluded that standard Signal-Averaged Electrocardiography after acute myocardial infarction is less informative in patients who receive thrombolytic treatment.