3D Heart: a new visual training method for electrocardiographic analysis.
ABSTRACT This new training method is based on developing a sound understanding of the sequence in which electrical excitation spreads through both the normal and the infarcted myocardium. The student is made aware of the cardiac electrical performance through a series of 3-dimensional pictures during the excitation process. The electrocardiogram 3D Heart 3-dimensional program contains a variety of different activation simulations. Currently, this program enables the user to view the activation simulation for all of the following pathology examples: normal activation; large, medium, and small anterior myocardial infarction (MI); large, medium, and small posterolateral MI; large, medium, and small inferior MI. Simulations relating to other cardiac abnormalities, such as bundle branch block and left ventricular hypertrophy fasicular block, are being developed as part of a National Institute of Health (NIH) Phase 1 Small Business Innovation Research (SBIR) program.
Journal of Electrocardiology 11/2001; 34(4):355-6. · 1.36 Impact Factor
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ABSTRACT: This study compares the effectiveness of teaching the calculation of frontal plane QRS axis with the use of the classical versus the orderly electrocardiographic limb lead display. Eighty-three students from two environments were randomized into two groups and were taught to determine frontal plane axis with one of the methods. The accuracy and time to determine the axis were tested on 10 electrocardiograms. In the United States the group using the classical display achieved 4.2 (+/-2.7) correct answers, whereas those using the orderly method achieved 6.8 (+/-3.0) (p = 0.0006). The classical group used 9.2 (+/-2.8) minutes to complete the test, whereas the orderly group needed 7.2 (+/-2.0) minutes (p = 0.015). The results achieved in Sweden were similar. The use of the orderly electrocardiographic limb lead display results in greater diagnostic accuracy in less time than the classical display when determining the frontal plane QRS axis.American Heart Journal 01/1998; 134(6):1014-8. DOI:10.1016/S0002-8703(97)70020-6 · 4.56 Impact Factor
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ABSTRACT: SUMMARY A digital computer model is presented for the simulation of the body surface electrocar- diogram (ECG) during ventricular activation and recovery. The ventricles of the heart are represented in detail by a three-dimensional array of approximately 4000 points which is subdivided into 23 regions. Excitation sequence and cellular action potential data taken from the literature are used to determine the spatial distribution of intracellular potentials at each instant of time during a simulated cardiac cycle. The moment of the single dipole representing each region is determined by summing the spatial gradient of the intracellular potential distribution throughout the region. The resulting set of 23 dipoles is then used to calculate the potentials on the surface of a bounded homogeneous volume conductor with the shape of an adult male torso. Simulated isopotential surface maps during both activation and recovery are in good agreement with data for humans reported in the literature. MAXIMAL use of the electrocardiogram (ECG) in diag- nosing and quantifying cardiac abnormalities is at present limited by an incomplete understanding of the relation- ships between body surface potentials and intracardiac electrical events. One technique for gaining insight into these relationships is through the use of mathematical models in simulation studies. The advantage of this ap- proach lies in the ease with which the computed surface potential distributions can be interpreted in terms of the electrical sources used in the simulation. The simulation sources should be related as closely as possible to electri- cal activity at the cellular level. Ventricular activation is generally considered to take place in a propagating layer approximately 1 mm in width, termed the wavefront of activation. 1 It has been noted that the resulting volume conductor currents are similar to those that would be generated by a sheet of current dipoles oriented in the mean direction of propa- gation of the wavefront. This concept has been used successfully in simulating the major features of torso surface potential distributions during ventricular activa- tion. 2 " 3 In such model studies, the heart is generally divided into a number of regions, each of which is repre- sented by a single current dipole. At a given instant during activation, each dipole is assigned a magnitude which is proportional to the surface area of the wavefront of activation in the corresponding region and is oriented in the mean direction of propagation of the wavefront in the segment. Surface potentials are then calculated using the discrete set of current dipoles as the simulation sources.