Body Surface Potential Research Articles

ECG-Based Detection of Early Myocardial Ischemia in a Computational Model: Impact of Additional Electrodes, Optimal Placement, and a New Feature for ST Deviation

In case of chest pain, immediate diagnosis of myocardial ischemia is required to respond with an appropriate treatment. The diagnostic capability of the electrocardiogram (ECG), however, is strongly limited for ischemic events that do not lead to ST elevation. This computational study investigates the potential of different electrode setups in detecting early ischemia at 10 minutes after onset: standard 3-channel and 12-lead ECG as well as body surface potential maps (BSPMs). Further, it was assessed if an additional ECG electrode with optimized position or the right-sided Wilson leads can improve sensitivity of the standard 12-lead ECG. To this end, a simulation study was performed for 765 different locations and sizes of ischemia in the left ventricle. Improvements by adding a single, subject specifically optimized electrode were similar to those of the BSPM: 2–11% increased detection rate depending on the desired specificity. Adding right-sided Wilson leads had negligible effect. Absence of ST deviation could not be related to specific locations of the ischemic region or its transmurality. As alternative to the ST time integral as a feature of ST deviation, the K point deviation was introduced: the baseline deviation at the minimum of the ST-segment envelope signal, which increased 12-lead detection rate by 7% for a reasonable threshold.

P.6.f.006 Different temperaments are linked to craving between patients with internet gaming disorder and patients with alcohol dependence

A necessary but not sufficient prerequisite of malignant arrhythmias is the existence of elevated static or dynamic repolarization dispersion (RD) of the ventricular myocardium. The early detection of this type of spatiotemporal impairment might have a clinical importance. Body surface potential mapping, using high resolution QRST integral maps, provides a unique noninvasive method for the beat-to-beat exploration of spatial RD. The sound theoretically proven relationship of ventricular RD and QRST integral maps has been known for many years, offering a novel electrocardiological imaging possibility. However, a “yes or no” type risk assessment can be achieved even without solving the ill-posed electrocardiological inverse problem by computing the body surface potential QRST integral map non-dipolarity index (NDI). In this study a multi-element numerical heart and a piecewise homogeneous chest model was used to estimate the sensitivity of the NDIs on pathological ventricular RD patterns. The tests included the physiological RD pattern as a reference and additional 83 pathological ones classified into 3 major types. All the local action potential (AP) modulation types were systematically swept through the anterior, lateral, posterior, septal and apical segments of the left ventricle. Additionally the impact of impaired conduction system and the involvement of the right ventricle were tested as well. It was concluded that the source level origin of the extreme NDIs was located in the apical part of the heart, due to permanent myocardial necrosis, temporally refracter regions or reversed transmural AP patterns.

Computing volume potentials for noninvasive imaging of cardiac excitation.

In noninvasive imaging of cardiac excitation, the use of body surface potentials (BSP) rather than body volume potentials (BVP) has been favored due to enhanced computational efficiency and reduced modeling effort. Nowadays, increased computational power and the availability of open source software enable the calculation of BVP for clinical purposes. In order to illustrate the possible advantages of this approach, the explanatory power of BVP is investigated using a rectangular tank filled with an electrolytic conductor and a patient specific three dimensional model. MRI images of the tank and of a patient were obtained in three orthogonal directions using a turbo spin echo MRI sequence. MRI images were segmented in three dimensional using custom written software. Gmsh software was used for mesh generation. BVP were computed using a transfer matrix and FEniCS software. The solution for 240,000 nodes, corresponding to a resolution of 5 mm throughout the thorax volume, was computed in 3 minutes. The tank experiment revealed that an increased electrode surface renders the position of the 4 V equipotential plane insensitive to mesh cell size and reduces simulated deviations. In the patient-specific model, the impact of assigning a different conductivity to lung tissue on the distribution of volume potentials could be visualized. Generation of high quality volume meshes and computation of BVP with a resolution of 5 mm is feasible using generally available software and hardware. Estimation of BVP may lead to an improved understanding of the genesis of BSP and sources of local inaccuracies.

Binary optimization for source localization in the inverse problem of ECG.

The goal of ECG-imaging (ECGI) is to reconstruct heart electrical activity from body surface potential maps. The problem is ill-posed, which means that it is extremely sensitive to measurement and modeling errors. The most commonly used method to tackle this obstacle is Tikhonov regularization, which consists in converting the original problem into a well-posed one by adding a penalty term. The method, despite all its practical advantages, has however a serious drawback: The obtained solution is often over-smoothed, which can hinder precise clinical diagnosis and treatment planning. In this paper, we apply a binary optimization approach to the transmembrane voltage (TMV)-based problem. For this, we assume the TMV to take two possible values according to a heart abnormality under consideration. In this work, we investigate the localization of simulated ischemic areas and ectopic foci and one clinical infarction case. This affects only the choice of the binary values, while the core of the algorithms remains the same, making the approximation easily adjustable to the application needs. Two methods, a hybrid metaheuristic approach and the difference of convex functions (DC), algorithm were tested. For this purpose, we performed realistic heart simulations for a complex thorax model and applied the proposed techniques to the obtained ECG signals. Both methods enabled localization of the areas of interest, hence showing their potential for application in ECGI. For the metaheuristic algorithm, it was necessary to subdivide the heart into regions in order to obtain a stable solution unsusceptible to the errors, while the analytical DC scheme can be efficiently applied for higher dimensional problems. With the DC method, we also successfully reconstructed the activation pattern and origin of a simulated extrasystole. In addition, the DC algorithm enables iterative adjustment of binary values ensuring robust performance.

A Method to Noninvasively Identify Cardiac Bioelectrical Sources

We have introduced a method to guide radiofrequency catheter ablation (RCA) procedures that estimates the location of a catheter tip used to pace the ventricles and the target site for ablation using the single equivalent moving dipole (SEMD). To investigate the accuracy of this method in resolving epicardial and endocardial electrical sources. Two electrode arrays, each of nine pacing electrodes at known distances from each other, sutured on the left- and right-ventricular (LV and RV) epicardial surfaces of swine, were used to pace the heart at multiple rates, while body surface potentials from 64 sites were recorded and used to estimate the SEMD location. A similar approach was followed for pacing from catheters in the LV and RV. The overall (RV & LV) error in estimating the interelectrode distance of adjacent epicardial electrodes was 0.38 ± 0.45 cm. The overall endocardial (RV & LV) interelectrode distance error, was 0.44 ± 0.26 cm. Heart rate did not significantly affect the error of the estimated SEMD location (P > 0.05). The guiding process error became progressively smaller as the SEMD approached an epicardial target site and close to the target, the overall absolute error was ∼ 0.28 cm. The estimated epicardial SEMD locations preserved their topology in image space with respect to their corresponding physical location of the epicardial electrodes. The proposed algorithm suggests one can efficiently and accurately resolve epicardial electrical sources without the need of an imaging modality. In addition, the error in resolving these sources is sufficient to guide RCA procedures.

Using Transmural Regularization and Dynamic Modeling for Noninvasive Cardiac Potential Imaging of Endocardial Pacing With Imprecise Thoracic Geometry

Cardiac electrical imaging from body surface potential measurements is increasingly being seen as a technology with the potential for use in the clinic, for example for pre-procedure planning or during-treatment guidance for ventricular arrhythmia ablation procedures. However several important impediments to widespread adoption of this technology remain to be effectively overcome. Here we address two of these impediments: the difficulty of reconstructing electric potentials on the inner (endocardial) as well as outer (epicardial) surfaces of the ventricles, and the need for full anatomical imaging of the subject's thorax to build an accurate subject-specific geometry. We introduce two new features in our reconstruction algorithm: a nonlinear low-order dynamic parameterization derived from the measured body surface signals, and a technique to jointly regularize both surfaces. With these methodological innovations in combination, it is possible to reconstruct endocardial activation from clinically acquired measurements with an imprecise thorax geometry. In particular we test the method using body surface potentials acquired from three subjects during clinical procedures where the subjects' hearts were paced on their endocardia using a catheter device. Our geometric models were constructed using a set of CT scans limited in axial extent to the immediate region near the heart. The catheter system provides a reference location to which we compare our results. We compare our estimates of pacing site localization, in terms of both accuracy and stability, to those reported in a recent clinical publication , where a full set of CT scans were available and only epicardial potentials were reconstructed.

PM209 Correlation Of The Ecg Changes (St Segment Depression With Or Without T Wave Inversion In Lateral Leads 1, Avl.V4-V6) With Coronary Angiographic Findings In Acs Patients

Despite being the mainstay for the initial noninvasive assessment of patients with symptomatic coronary artery disease, the 12‑lead ECG remains a suboptimal diagnostic tool for myocardial ischemia detection with only acceptable sensitivity and specificity scores. Although myocardial ischemia affects the configuration of the QRS complex and the STT waveform, current guidelines primarily focus on ST segment amplitude, which constitutes a missed opportunity and may explain the suboptimal diagnostic performance of the ECG. This possible opportunity and the low cost and ease of use of the ECG provide compelling motivation to enhance the diagnostic accuracy of the ECG to ischemia detection. This paper describes numerous computational ECG methods and approaches that have been shown to dramatically increase ECG sensitivity to ischemia detection. Briefly, these emerging approaches can be conceptually grouped into one of the following four approaches: (1) leveraging novel ECG waveform features and signatures indicative of ischemic injury other than the classical ST-T amplitude measures; (2) applying body surface potentials mapping (BSPM)-based approaches to enhance the spatial coverage of the surface ECG to detecting ischemia; (3) developing an inverse ECG solution to reconstruct anatomical models of activation and recovery pathways to detect and localize injury currents; and (4) exploring artificial intelligence (AI)-based techniques to harvest ECG waveform signatures of ischemia. We present recent advances, shortcomings, and future opportunities for each of these emerging ECG methods. Future research should focus on the prospective clinical testing of these approaches to establish clinical utility and to expedite potential translation into clinical practice.

The Single Equivalent Moving Dipole Model Does Not Require Spatial Anatomical Information to Determine Cardiac Sources of Activation

Radio-frequency catheter ablation (RCA) is an established treatment for ventricular tachycardia (VT). A key feature of the RCA procedure is the need for a mapping approach that facilitates the identification of the target ablation site. In this study, we investigate the effect of the location of the reference potential and spatial anatomical constraints on the accuracy of an algorithm to identify the target site for ablation therapy of VT. This algorithm involves processing body surface potentials using the single equivalent moving dipole (SEMD) model embedded in an infinite homogeneous volume conductor to model cardiac electrical activity. We employed a swine animal model and an electrode array of nine electrodes that was sutured on the epicardial surface of the right ventricle. We identified two potential reference electrode locations: at an electrode most far away from the heart (R1) and at the average of all 64 body surface electrode potentials (R2). Also, we developed three spatial "constraining" schemes of the algorithm used to obtain the SEMD location: one that does not impose any constraint on the inverse solution (S1), one that constrains the solution into a volume that corresponds to the heart (S2), and one that constrains the solution into a volume that corresponds to the body surface (S3). We have found that R2S1 is the most accurate approach (p < 0.05 versus R1S1 at earliest activation time-EAT) for localizing epicardial electrical sources of known locations in vivo. Although the homogeneous volume conductor introduces systematic error in the estimated compared to the true dipole location, we have observed that the overall error of the estimated interelectrode distance compared to the true one was 0.4 ± 0.4cm and 0.4 ± 0.1cm for the R1S1 and R2S1 combinations, respectively, at the EAT (p = N.S.) and 1.0 ± 0.6 and 0.5 ± 0.4cm, respectively, at the pacing spike time (PST, ). In conclusion, our algorithm to estimate the SEMD parameters from body surface potentials can potentially be a useful method to rapidly and accurately guide the catheter tip to the target site during a RCA procedure without the need for spatial anatomical information obtained by conventional imaging modalities.

ST-segment changes in high-resolution body surface potential maps measured during exercise to assess myocardial ischemia: a pilot study.

IntroductionThe aim of the study was to assess myocardial ischemia by analysis of ST-segment changes in high-resolution body surface potential maps (HR-BSPM) measured at rest and during an exercise stress test.Material and methodsThe study was carried out on a group of 28 patients with stable coronary artery disease and 15 healthy volunteers. The HR-BSPM were measured at rest and during the exercise stress test on a supine ergometer. The workload was increased in stages by 25 W every 2 min, beginning at 50 W. The maps of ST-segment depression (ST60) were calculated from time averaged recordings at rest and at maximal workload.ResultsThe efficiency in detection of myocardial ischemia was higher for HR-BSPM than for standard 12-lead electrocardiography (ECG) when both methods were evaluated by outcomes of coronarography. The sensitivity of HR-BSPM was 82.4% while for the standard 12-lead ECG exercise stress test it was 58.8%. For some patients significant changes in the ST segment were observed at stress HR-BSPM but were not visible in standard 12-lead ECG recorded under the same conditions.ConclusionsObtained high values of sensitivity and specificity in myocardial ischemia detection suggest that maps of ST60 calculated from HR-BSPM can improve detection of patients with ischemic heart disease in comparison to the standard electrocardiographic exercise stress test examinations.

Cardiac Arrythmias: Multimodal Assessment Integrating Body Surface ECG Mapping into Cardiac Imaging

To demonstrate the feasibility of comprehensive assessment of cardiac arrhythmias by combining body surface electrocardiographic (ECG) mapping (BSM) and imaging. This study was approved by the institutional review board, and all patients gave written informed consent. Twenty-seven patients referred for electrophysiologic procedures in the context of ventricular tachycardia (VT) (n = 9), Wolff-Parkinson-White (WPW) syndrome (n = 2), atrial fibrillation (AF) (n = 13), or scar-related ventricular fibrillation (VF) (n = 3) were examined. Patients underwent BSM and imaging with multidetector computed tomography (CT) (n = 12) and/or delayed enhanced magnetic resonance (MR) imaging (n = 23). BSM was performed by using a 252-electrode vest that enabled the computation of epicardial electrograms from body surface potentials. The epicardial geometry used for BSM was registered to the epicardial geometry segmented from imaging data by using an automatic algorithm. The output was a three-dimensional cardiac model that integrated cardiac anatomy, myocardial substrate, and epicardial activation. Acquisition, segmentation, and registration were feasible in all patients. In VT, this enabled a noninvasive assessment of the arrhythmia mechanism and its location with respect to the myocardial substrate, coronary vessels, and phrenic nerve. In WPW syndrome, this enabled understanding of complex accessory pathways resistant to previous ablation. In AF and VF, this enabled the noninvasive assessment of arrhythmia mechanisms and the analysis of rotor trajectories with respect to the myocardial substrate. In all patients, models were successfully integrated in navigation systems and used to guide mapping and ablation. By combining information on anatomy, substrate, and electrical activation, the fusion of BSM and imaging enables comprehensive noninvasive assessment of cardiac arrhythmias, with potential applications for diagnosis, prognosis, and ablation targeting. Online supplemental material is available for this article.

An analysis of the U-wave and its relation to the T-wave in body surface potential maps for healthy subjects and MI patients.

The aim of this study was to analyze the U-wave morphology and its relation to the T-wave in one group of healthy subjects and in two groups of myocardial infarction (MI) patients-with and without ventricular tachycardia (VT) episodes. The context of the U-wave origin was also discussed and the U-wave as a potential marker of VT was investigated. The study was carried out on three groups of subjects: 20 healthy subjects, 14 MI patients not at risk of VT, and 22 MI patients at risk of VT. The morphology of the repolarization phase was examined in the high-resolution body surface potential maps recorded from 64 surface ECG leads. The temporal and spatial distributions of several ECG parameters were studied. The U-wave was present in almost all the studied subjects. The spatial heterogeneity and smooth change in both the T- and U-wave shapes on the entire torso were observed in all the studied groups. The statistical significance of discrimination between the MI patients without VT and MI patients with VT was observed for QRS interval, QT interval, U-wave integral, and normalized U-wave integral. High-resolution measurement of body surface potentials and an advanced data analysis allow for a detailed description of U-wave morphology and its relation to the T-wave. This might be of value in discriminating intracardiac repolarization effects, mechano-electrical feedback, and arrhythmia risk stratification.

Pseudo Body Surface Potential Mapping on Heart using 3D Wavelet Transform

surface potential mapping (BSPM) is used to detect real diagnostic information about the myocardium state more than the standard 12-lead electrocardiogram (ECG). The present research introduces a practical solution for recording body surface potential maps using the standard 12-lead ECG with different positions. It is called pseudo BSPM where all channels were not read out simultaneously. It is based on the assumption that heart beat body surface potential mapping (BSPM) is used to detect real diagnostic information about the myocardium state more than standard 12-lead electrocardiography (ECG). Pseudo BSPM pattern is not changed considerably during the whole measurement session. Body surface potential mapping was applied to normal and abnormal persons suffering from coronary heart diseases (CHD). We detect QRS complexes using filter banks and consequently build up a cardiac map using 3D wavelet transform. Our results for the cardiac map demonstrate the changes that occur for the cardiac electrical activity which represents the patient case in color degradation patterns.

The combination of self-organizing feature maps and support vector regression for solving the inverse ECG problem

Noninvasive electrical imaging of the heart aims to quantitatively reconstruct transmembrane potentials (TMPs) from body surface potentials (BSPs), which is a typical inverse problem. Classically, electrocardiography (ECG) inverse problem is solved by regularization techniques. In this study, it is treated as a regression problem with multi-inputs (BSPs) and multi-outputs (TMPs). Then the resultant regression problem is solved by a hybrid method, which combines the support vector regression (SVR) method with self-organizing feature map (SOFM) techniques. The hybrid SOFM–SVR method conducts a two-step process: SOFM algorithm is used to cluster the training samples and the individual SVR method is employed to construct the regression model. For each testing sample, the cluster operation can effectively improve the efficiency of the regression algorithm, and also helps the setup of the corresponding SVR model for the TMPs reconstruction. The performance of the developed SOFM–SVR model is tested using our previously developed realistic heart-torso model. The experiment results show that, compared with traditional single SVR method in solving the inverse ECG problem, the proposed method can reduce the cost of training time and improve the reconstruction accuracy in solving the inverse ECG problem.

Model interpretation of body surface potential QRST integral map variability in arrhythmia patients

A necessary but not sufficient prerequisite of malignant arrhythmias is the existence of elevated static or dynamic repolarization dispersion (RD) of the ventricular myocardium. The early detection of this type of spatiotemporal impairment might have a clinical importance. Body surface potential mapping, using high resolution QRST integral maps, provides a unique noninvasive method for the beat-to-beat exploration of spatial RD. The sound theoretically proven relationship of ventricular RD and QRST integral maps has been known for many years, offering a novel electrocardiological imaging possibility. However, a “yes or no” type risk assessment can be achieved even without solving the ill-posed electrocardiological inverse problem by computing the body surface potential QRST integral map non-dipolarity index (NDI). In this study a multi-element numerical heart and a piecewise homogeneous chest model was used to estimate the sensitivity of the NDIs on pathological ventricular RD patterns. The tests included the physiological RD pattern as a reference and additional 83 pathological ones classified into 3 major types. All the local action potential (AP) modulation types were systematically swept through the anterior, lateral, posterior, septal and apical segments of the left ventricle. Additionally the impact of impaired conduction system and the involvement of the right ventricle were tested as well. It was concluded that the source level origin of the extreme NDIs was located in the apical part of the heart, due to permanent myocardial necrosis, temporally refracter regions or reversed transmural AP patterns.

Noninvasive reconstruction of potentials on endocardial surface from body surface potentials and CT imaging of partial torso

Noninvasive reconstruction of potentials on endocardial surface from body surface potentials and CT imaging of partial torso

Determination of local activation time in bipolar endocardial electrograms: a comparison of clinical criteria and a new method based on the non-linear energy operator

liver. A boundary element method is used to compute the electrical activity from the surface of the atria to the surface of the torso. Elements of the torso mesh corresponding to the locations of the electrode placement are selected to simulate 12 and 64 lead ECG. PWM morphology associated with ectopic and rotor wave activity from a variety of regions throughout the atria and in the PV is analysed. Results: During sinus rhythm conditions, the simulated P-waves and body surface potentials dipole direction show strong agreement with experimental data. Marked changes in PWM are observed in both 12 and 64 lead ECG associated with ectopic atrial activity and the presence of rotor waves. Conclusion: Our simulation data suggested that ectopic activity originating from the PV can be identified based on changes of PWM. The correlation between PWM and rapid ectopic activity or the presence of rotor waves in the PV requires more detailed analysis and validation.

The effect of AF-induced electrical remodelling on regional electrical heterogeneity and tissue vulnerability to atrial fibrillation—insights from modelling

liver. A boundary element method is used to compute the electrical activity from the surface of the atria to the surface of the torso. Elements of the torso mesh corresponding to the locations of the electrode placement are selected to simulate 12 and 64 lead ECG. PWM morphology associated with ectopic and rotor wave activity from a variety of regions throughout the atria and in the PV is analysed. Results: During sinus rhythm conditions, the simulated P-waves and body surface potentials dipole direction show strong agreement with experimental data. Marked changes in PWM are observed in both 12 and 64 lead ECG associated with ectopic atrial activity and the presence of rotor waves. Conclusion: Our simulation data suggested that ectopic activity originating from the PV can be identified based on changes of PWM. The correlation between PWM and rapid ectopic activity or the presence of rotor waves in the PV requires more detailed analysis and validation.

Noninvasive cardiac activation imaging of ventricular arrhythmias during drug-induced QT prolongation in the rabbit heart

Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis.

Usefulness of ventricular endocardial electric reconstruction from body surface potential maps to noninvasively localize ventricular ectopic activity in patients

As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23–77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.

042 EPICARDIAL POTENTIALS DERIVED FROM THE BODY SURFACE POTENTIAL MAP USING INVERSE ELECTROCARDIOGRAPHY IMPROVE DIAGNOSIS OF ACUTE MYOCARDIAL INFARCTION: A PROSPECTIVE STUDY

Background Epicardial potentials (EP) derived from body surface potentials using a thoracic volume conductor model (TVCM) improve acute myocardial infarction (AMI) diagnosis. In this study, we compared EP derived from the 80-lead body surface potential map (BSPM) using a TVCM developed from CT imaging with other electrocardiographic techniques in AMI diagnosis. Methods In this prospective study, consecutive patients presenting to both the ED and pre-hospital coronary care unit between August 2009 and August 2011 with acute ischaemic-type chest pain at rest were enrolled. At first medical contact a 12-lead electrocardiogram (ECG) and BSPM were recorded. Cardiac troponin-T (cTnT) was sampled 12 h after symptom onset. AMI was diagnosed when cTnT ≥0.1 µg/l. Patients were excluded from analysis if they had bundle branch block, permanent pacemaker, left ventricular hypertrophy by voltage criteria or concomitant digitalis therapy. A cardiologist assessed the 12-lead ECG for STEMI by Minnesota criteria and the BSPM. BSPM ST-elevation (STE) was ≥0.2 mV in anterior, ≥0.1 mV in lateral, inferior, right ventricular (RV) or high right anterior and ≥0.05 mV in posterior territories indicating AMI. To derive EP, the 80-lead BSPM data were interpolated (Laplacian method) to yield values at 352-nodes of a Dalhouse torso. Using an inverse solution based on the boundary element method employing Tikhonov regularisation, EP at 98 cardiac nodes positioned within a standard TVCM were estimated. EP ≥0.3 mV defined STE. A cardiologist blinded to both the 12-lead ECG and BSPM interpreted the EP map. Results Enrolled were 400 patients (age 62±13 years; 57% male): 80 patients had exclusion criteria. Of the remaining 320 patients, 180 (56%) had AMI. Of these 180 patients, 117 had STEMI by Minnesota criteria (sensitivity 65%, specificity 89%) and 146 had BSPM STE (sensitivity 81%, specificity 90%). EP STE occurred in 158 patients (sensitivity 88%, specificity 95%, p Conclusions Among those with an initial non-diagnostic 12-lead ECG, EP derived from BSPM using a TVCM significantly improves AMI diagnosis.