PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Body Surface Potential Mapping”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1999

Low-frequency component of body surface potential maps identifies patients at risk for ventricular tachycardia.

AIMS: To investigate the ability of spectral features of signal-averaged body-surface potential maps in identifying post-infarction patients who are at risk of developing ventricular tachycardia. METHODS AND RESULTS: We recorded 120 lead body surface potential maps during sinus rhythm in 135 subjects (45 patients with healed myocardial infarction but no history of ventricular tachycardia, 45 patients with both healed myocardial infarction and at least one episode of sustained ventricular tachycardia, and 45 normal subjects) and analysed spectral features of body surface potential maps selected on the basis of isoharmonic maps for given bands of the frequency spectrum. We found that in the low-frequency band (1-11 Hertz), the group-mean power spectra of leads located at isoharmonic map maxima were significantly different (P<0.0001) between the two groups of myocardial infarction patients. We estimated that this single feature alone can prospectively identify myocardial infarction patients at risk for ventricular tachycardia with a predictive accuracy of 74+/-6%. CONCLUSION: Our results suggest that the bulk of diagnostic information associated with arrhythmogenicity resides in the low-frequency band of the power spectrum. This finding is at variance with the established notion that only the high-frequency component of signal-averaged electrocardiograms carries such information.

Adult↗
PubMed1981

Redundancy reduction for improved display and analysis of body surface potential maps. II. Temporal compression.

This paper describes use of the Karhunen-Loeve expansion to identify and reduce temporal redundancy in electrocardiographic body surface potential maps (192 body surface leads recorded simultaneously at 1 kHz/channel for approximately 600 msec). Temporal data compression of about 20 to 1 was obtained with accurate representation of the original data. Use of separate sets of orthonormal basis functions for QRS and ST-T provided a more accurate representation than the basis derived from QRST. Combined with the spatial compression described in the preceding paper, overall map data compression of about 320 to 1 was obtained without significant loss of accuracy of representation or map appearance. With both spatial and temporal compression the 100,000 numbers which typically comprise a single cardiac complex were accurately represented by 216 coefficients. Using basis functions derived from a single cardiac complex were accurately represented by 216 coefficients. Using basis functions derived from a training set of 221 maps, the estimated average rms error of representation was 60 microV during the ST-T. For 34 test maps which were not part of the training set, measured average errors were 64 microV during the QRS and 23 microV during the ST-T. This technique provides a basis for quantification of the diagnostic content of maps and automated classification of maps.

Adult↗
PubMed1995

[Usefulness of body surface potential maps to determine ablation site in patients with WPW syndrome].

We studied body surface potential maps (BSPM) in patients with WPW syndrome before surgical ablation. These BSPM were compared with computerized epicardial mapping using sock and snap electrode. In most patients the location of minima in the early delta wave was a simple and accurate index of the site of accessory pathway. In 4 patients BSPM was useful for the diagnosis of presence of bilateral accessory pathways. We conclude that BSPM may be also useful to determine ablation site of radiofrequency catheter ablation.

Body Surface Potential Mapping↗
PubMed1999

Spatial features in body surface potential maps of patients with ventricular tachyarrhythmias with or without coronary artery disease.

Body surface potential maps (BSPM) from patients with coronary artery disease or no structural heart disease were analyzed with respect to their spatial features and QT/QTc dispersion in order to determine whether BSPM allows identification of patients with ventricular fibrillation. QRST integral maps and QT/QTc dispersion were acquired from simultaneous recordings of 62 ECG leads during sinus rhythm in patients with idiopathic ventricular fibrillation (n=13), ventricular fibrillation and coronary artery disease (n=22), coronary artery disease without ventricular fibrillation (n=21) and healthy controls (n=18). The Karhunen-Loeve transformation was applied to reduce the dimensionality of the data matrix of the QRST map to eight coefficients. Linear discriminant analysis allowed discrimination between idiopathic ventricular fibrillation patients and controls with high sensitivity (85%) and specificity (89%). However, discrimination between coronary artery disease patients with or without ventricular fibrillation was poor (68% and 67%, respectively). QTc dispersion calculated from BSPM was longer in idiopathic ventricular fibrillation patients than in controls (99+/-30 ms vs 70+/-14 ms, P=0.009) in contrast to QTc dispersion taken from 12-lead ECG (53+/-21 ms vs. 47+/-12 ms, P=n.s.). No significant difference was noted for coronary artery disease patients with or without ventricular fibrillation. In conclusion, repolarization disturbances detected by BSPM allow identification of ventricular fibrillation patients without structural heart disease. However, our results do not suggest a major impact of QT/QTc dispersion or QRST integral mapping for identification of ventricular fibrillation patients with coronary artery disease.

Body Surface Potential Mapping↗
PubMed1981

Redundancy reduction for improved display and analysis of body surface potential maps. I. Spatial compression.

The Karhunen-Loeve technique of random process representation was investigated as a method of quantitatively characterizing body surface potential maps. One hundred ninety-two lead body surface potential maps from 124 normal subjects and 97 patients with independently documented heart disease were used in the study. Each map frame in QRS and ST-T of 34 maps in a test set was represented as a linear sum of orthonormal distributions derived from the covariance matrix estimated from all QRS frames in the 221 training maps. A 16:1 reduction in spatial data of the test set was achieved with rms errors of 45 and 21 microV in QRS and ST-T, respectively. Results suggest that 12 independent waveforms, derived from the 192 measured ECGs, may be used in place of those 192 ECGs. In addition to providing a convenient and familiar method of display for map data, the technique puts the data in an appropriate form for quantitative statistical analysis.

Cardiomegaly↗
PubMed2003

Body surface potential mapping--the application in men from the twenty years lasting epidemiological study.

Body surface potential mapping (BSPM) enables to obtain more information about local changes of the heart electrical field then classical electrocardiography makes it possible. We performed this non-invasive diagnostic method in the group of 108 men in the frame of the primary preventive study of the risk factors of atherosclerosis. The findings of BSPM were compared to the selective coronary angiography. The study was started in the years 1976-1979 in the district Prague 2. Out of 2370 invited middle-aged men, 1419 took part in the study. 937 men (66.0%) were affected by one or more risk factors of atherosclerosis. No statistical significance was found in regard to the number and the level of risk factors of atherosclerosis between the groups of patients with different findings on the coronary angiography. Nevertheless, the method of BSPM is a very useful in epidemiological studies of atherosclerosis, namely with coronary localization, in clinical practice, and in the biomedical research too.

Arteriosclerosis↗
PubMed1996

Body surface potential mapping of a patient with Wolff-Parkinson-White syndrome with two accessory pathways and two atrial pacemaker complexes.

As part of an ongoing research protocol, a patient with Wolff-Parkinson-White syndrome underwent body surface potential mapping and electrophysiologic studies before radiofrequency ablation therapy. Careful analysis of the body surface potential mapping data made it possible to distinguish four different map sequences representing four different cardiac complexes. Analysis of these maps is consistent with two accessory pathways, with the additional pathology of two distinct atrial pacemaker sites. A right anterosuperior pathway was found to conduct continuously. The second pathway is consistent with a right inferior pathway conducting intermittently. The analysis demonstrates the type of information that can be extracted from body surface potential maps, even in the presence of complex pathologies.

Adult↗
PubMed2000

Body surface distribution and response to drugs of ST segment elevation in Brugada syndrome: clinical implication of eighty-seven-lead body surface potential mapping and its application to twelve-lead electrocardiograms.

INTRODUCTION: Body surface distribution and magnitude of ST segment elevation and their reflection in 12-lead ECGs have not been clarified in Brugada syndrome. METHODS AND RESULTS: Eighty-seven-lead body surface potential mapping and 12-lead ECGs were recorded simultaneously in 25 patients with Brugada syndrome and 40 control patients. The amplitude of the ST segment 20 msec after the end of QRS (ST20) was measured from all 87 leads, and an ST isopotential map was constructed. The maximum ST elevation (maxST20) was distributed in an area of the right ventricular outflow tract in all Brugada patients, and it was larger than that in control patients (0.37 +/- 0.13 vs 0.12 +/- 0.04 mV; P < 0.0005). The maximum was observed on the level of the parasternal fourth intercostal space, on which the V1 and V2 leads of the standard 12-lead ECG were located, in 18 of the 25 Brugada patients in whom typical coved- or saddleback-type ST elevation was seen in leads V1 and V2. The maximum was located on the second intercostal space in the remaining seven Brugada patients in whom only a mild saddleback-type ST elevation was seen in leads V1 and V2 of the 12-lead ECG. Typical ST segment elevation was recognized in leads V1 and V2, which were recorded on the second or third intercostal space. ST elevation in Brugada patients was dramatically normalized by isoproterenol, a beta-adrenergic agonist (maxST20 = 0.17 +/- 0.08 mV; P < 0.0005 vs control conditions), and accentuated by disopyramide, an Na+ channel blocker (maxST20 = 0.50 +/- 0.15 mV; P < 0.0005 vs control conditions), without any change in the location of the maxST20. CONCLUSION: Our data indicate that recordings of leads V1-V3 of the 12-lead ECG on the parasternal second or third intercostal space would be helpful in diagnosing suspected patients with Brugada syndrome. The data suggest that Na+ channel blockers are capable of accentuating ST elevation in leads V1-V3.

Action Potentials↗
PubMed1998

Nonfluoroscopic localization of an amagnetic catheter in a realistic torso phantom by magnetocardiographic and body surface potential mapping.

This study was performed to evaluate the accuracy of multichannel magnetocardiographic (MCG) and body surface potential mapping (BSPM) in localizing three-dimensionally the tip of an amagnetic catheter for electrophysiology without fluoroscopy. An amagnetic catheter (AC), specially designed to produce dipolar sources of different geometry without magnetic disturbances, was placed inside a physical thorax phantom at two different depths, 38 mm and 88 mm below the frontal surface of the phantom. Sixty-seven MCG and 123 BSPM signals generated by the 10 mA current stimuli fed into the catheter were then recorded in a magnetically shielded room. Non-invasive localization of the tip of the catheter was computed from measured MCG and BSPM data using an equivalent current dipole source in a phantom-specific boundary element torso model. The mean 3-dimensional error of the MCG localization at the closer level was 2 +/- 1 mm. The corresponding error calculated from the BSPM measurements was 4 +/- 1 mm. At the deeper level, the mean localization errors of MCG and BSPM were 7 +/- 4 mm and 10 +/- 2 mm, respectively. The results showed that MCG and BSPM localization of the tip of the AC is accurate and reproducible provided that the signal-to-noise ratio is sufficiently high. In our study, the MCG method was found to be more accurate than BSPM. This suggests that both methods could be developed towards a useful clinical tool for nonfluoroscopic 3-dimensional electroanatomical imaging during electrophysiological studies, thus minimizing radiation exposure to patients and operators.

Body Surface Potential Mapping↗
PubMed2005

Body surface potential mapping investigating the ventricular activation patterns in the cardiac resynchronization of patients with left bundle-branch block and heart failure.

Body surface potential mapping assessed mean cardiac electrical activation times displayed by isochronal maps in the right ventricle (RV; right ventricle mean activation time [mRV]), anterior septal area (anterior septal area mean activation time [mAS]), and left ventricle (left ventricle mean activation time [mLV]) of 28 patients (mean, 61.07 years; congestive heart failure class III-IV; ejection fraction, < or =40%; left bundle-branch block [LBBB] QRS, 180.17 milliseconds), before and after biventricular pacemaker implantation, comparing them, using reference values from a control group of healthy individuals with normal hearts (GNL), in (1) baseline native LBBB, where mRV and mAS values were similar (40.99 vs 43.62 milliseconds), with mLV delayed (80.99 milliseconds, P < .01) and dyssynchronous with RV/anterior septal area; (2) single-site RV pacing, where mRV was greater than in GNL (86.82 milliseconds, P < .001), with greater mAS/mLV difference (63.41 vs 102.7 milliseconds; P < .001); and (3) biventricular pacing (BIV-PM), where mLV and mRV were similar (71.99 vs 71.58 milliseconds), mRV was greater than in GNL and native LBBB (71.58 vs 35.1 and 40.99 milliseconds; P < .001), and mAS approached values in GNL and native LBBB (51.28 vs 50.14 and 43.62 milliseconds). Body surface potential mapping showed that similar RV/left ventricle activation times during biventricular pacing, nearing mAS, indicate synchronized ventricular activation pattern in patients with congestive heart failure/LBBB.

Adult↗
PubMed1981

The determination of the human ventricular gradient from body surface potential map data.

We have analyzed the Wilson ventricular gradient in terms of body surface potential maps and of the reduction of such surface patterns to equivalent dipoles or vectors. While the ventricular gradient traditionally was treated as first a scalar, then a vector concept, we found that the three entities (QRS area, T area, QRST area) did not reduce to vectors with a common location. However, conventional vector addition (QRST area = QRS area + T area) did precisely apply. Further we found considerable more-than-vector or extra-dipolar information remaining for all three entities after removal of the dipole effect. This suggests that maps of these entities should be considered the boundaries of complex electrical fields rather than simple surface effects of vectors.

Adult↗
PubMed2004

Temporal analysis of the depolarization wave of healed myocardial infarction in body surface potential mapping.

BACKGROUND: We studied the ability of different time segments of the depolarization wave recorded with body surface potential mapping (BSPM) to detect and localize myocardial infarction (MI). METHODS: BSPM was recorded in 24 patients with remote MI and in 24 healthy controls. Cine and contrast-enhanced magnetic resonance imaging (MRI) was used as a reference method. Patients were grouped according to anatomical location of their MI. The QRS complex was divided into six temporally equal segments, for which time integrals were calculated. RESULTS: The time segments of the QRS complex showed different MI detection capability depending on MI location. For anterior infarction the second segment of the QRS complex was the best in MI detection and the optimal area was on the right inferior quadrant of the thorax (time integral average -1.5 +/- 1.8 mVms patients, 1.0 +/- 1.6 mVms controls, P = 0.002). For lateral infarction the first segment of the QRS complex performed best and the optimal area for MI detection was the left fourth intercostal area (time integral average 1.8 +/- 1.0 mVms patients, 0.7 +/- 0.5 mVms controls, P = 0.024). For inferior and posterior MI the mid-phases of the QRS complex were the best and the optimal area was the mid-inferior area of the thorax (time integral average -6.2 +/- 8.3 mVms patients, 3.3 +/- 4.3 mVms controls, P = 0.002; -9.1 +/- 6.1 mVms patients, 0.6 +/- 7.1 mVms controls, P = 0.001, respectively). CONCLUSIONS: Time segment analysis of the depolarization wave offers potential for improving the detection and localization of healed MI.

Aged↗
PubMed1998

The use of body surface potential map for identifying sites of accessory pathway in patients with Wolff-Parkinson-White syndrome.

The body surface potential map (BSPM) may reflect regional myocardial electrical activity. This technique can thus provide information regarding the excitation of ventricles. This study is an attempt to evaluate the usefulness of BSPM in determining the sites of the atrioventricular (AV) accessory pathway (AP) in patients with Wolff-Parkinson-White (W-P-W) syndrome. The BSPMs were obtained from 40 consecutive patients with W-P-W syndrome in a fasting state, using the heart potential map system designed by Toyama et al. Unipolar electrocardiograms were recorded simultaneously from 87 lead points on the chest surface, including 59 lead points on the anterior chest and 28 on the back. Wilson's central terminal was used as a voltage reference and BSPMs in an isopotential distribution pattern were made every millisecond throughout ventricular activation from these unipolar ECGs with the use of a microcomputer system. All patients underwent an electrophysiologic study (EPS) at cardiac catheterization. We analyzed the potential distribution during ventricular depolarization and compared the results between EPS and BSPM findings. The following results were obtained: (1) seven types of BSPM pattern were identified in accordance with the sites of the AV AP confirmed by EPS; (2) the location of the potential minimum of ventricular depolarization and the direction of the excitation wavefront during early ventricular depolarization, the reversal pattern of ventricular potential distribution, the epicardial right ventricular breakthrough and the dynamic change of ventricular potential distribution were useful for the detection of the ventricular pre-excitation site; (3) epicardial right ventricular breakthrough occurred in nearly all patients with left ventricular free wall accessory AV connections; (4) the abnormal early reversal pattern of ventricular potential distribution did not occur in patients with left ventricular AV connections but did appear in most patients with right ventricular free wall AV connections. Accordingly, BSPM is a reliable non-invasive procedure to determine the ventricular pre-excitation sites of patients with W-P-W syndrome.

Adolescent↗
PubMed2006

Selection of optimal recording sites for limited lead body surface potential mapping: a sequential selection based approach.

BACKGROUND: In this study we propose the development of a new algorithm for selecting optimal recording sites for limited lead body surface potential mapping. The proposed algorithm differs from previously reported methods in that it is based upon a simple and intuitive data driven technique that does not make any presumptions about deterministic characteristics of the data. It uses a forward selection based search technique to find the best combination of electrocardiographic leads. METHODS: The study was conducted using a dataset consisting of body surface potential maps (BSPM) recorded from 116 subjects which included 59 normals and 57 subjects exhibiting evidence of old Myocardial Infarction (MI). The performance of the algorithm was evaluated using spatial RMS voltage error and correlation coefficient to compare original and reconstructed map frames. RESULTS: In all, three configurations of the algorithm were evaluated and it was concluded that there was little difference in the performance of the various configurations. In addition to observing the performance of the selection algorithm, several lead subsets of 32 electrodes as chosen by the various configurations of the algorithm were evaluated. The rationale for choosing this number of recording sites was to allow comparison with a previous study that used a different algorithm, where 32 leads were deemed to provide an acceptable level of reconstruction performance. CONCLUSION: It was observed that although the lead configurations suggested in this study were not identical to that suggested in the previous work, the systems did bear similar characteristics in that recording sites were chosen with greatest density in the precordial region.

Algorithms↗
PubMed1998

Spatial resolution of body surface potential maps and magnetic field maps: a simulation study applied to the identification of ventricular pre-excitation sites.

The spatial resolution of body surface potential maps (BSPMs) and magnetic field maps (MFMs) is investigated by means of an anatomically accurate computer model of the human ventricular myocardium. BSPMs and MFMs are calculated for the simulated activation sequences initiated at 35 pre-excitation sites located along the atrioventricular (AV) ring of the epicardium. Changes in the BSPMs and MFMs corresponding to different pre-excitation sites are quantified in terms of the correlation coefficient r. The spatial resolution (selectivity) for a given pre-excitation site is defined as the half-distance between those neighbouring locations at which morphological features of maps, in terms of r, become distinct (r < 0.95). It is found that, at 28 ms after the onset of pre-excitation and with no noise added, this distance +/- SD, for all sites along the AV ring for the 117-lead BSPMs, is 0.83 +/- 0.32 cm, and for the 64-lead and 128-lead MFMs it is 1.54 +/- 0.84 cm and 1.15 +/- 0.43 cm, respectively. The findings suggest that, when features of non-invasively recorded electrocardiographic and magnetocardiographic map patterns are used for identifying accessory pathways in patients suffering from WPW syndrome, BSPMs are likely to provide more detailed information for guiding the ablative treatment than MFMs. For some sites MFMs provide more information. Both modalities may provide additional assistance to the cardiologist in locating the site of the accessory pathway.

Body Surface Potential Mapping↗
PubMed1986

Non-Q-wave acute myocardial infarction: body surface potential map and ventriculographic patterns.

Day 5 body surface map and radionuclide angiographic patterns were compared among 56 patients with first non-Q-wave or Q-wave acute myocardial infarction (AMI). Three radionuclide angiographic patterns were recognized in patients with non-Q infarction: no wall motion abnormalities (n = 8), single-segment wall motion abnormalities (n = 10) and multiple-segment wall motion abnormalities (n = 9). In contrast, only 2 radionuclide angiographic patterns were identified in patients with Q-wave infarction: multiple-segment wall motion abnormalities (n = 25) and single-segment wall motion abnormalities (n = 4). The Q-wave distributions of 14 of 18 patients with non-Q infarction with 0 or 1 wall motion abnormalities were normal; 2 patients had "missed" anterior; 1 patient had inferior; and 1 had posterior AMI patterns. Of 9 patients with non-Q infarction who had multiple-segment wall motion abnormalities, 8 had infarct Q waves on the posterior torso. Q-wave patterns in patients with anterior (n = 17) and inferior (n = 12) Q-wave infarctions were typical and homogeneous for each group. Quantitative analysis of minimum Q-zone integral, sigma Q-wave integrals, ST-integral maximum, wall motion abnormality score and ejection fraction revealed no differences between patients with non-Q-wave and those with inferior Q-wave infarction. In contrast, patients with anterior AMI had significantly more abnormal values of all variables than either of the other groups. Overall, the data support the concept of non-Q-wave AMI as a distinct, if heterogeneous, pathophysiologic entity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗