A simulator for clinical models of supraventricular
    arrhythmias

Alexandru Dan Corlan; Radu Corlan; Mircea Cinteză; Serban Bălănescu; Ileana Vasilescu; Dragos Vinereanu; Leonida Gherasim

A simulator for clinical models of supraventricular arrhythmias

Alexandru Dan Corlan, Radu Corlan, Mircea Cinteză, Serban Bălănescu, Ileana Vasilescu, Dragos Vinereanu, Leonida Gherasim,

Eur Heart J 16 (suppl):242-242, 1995

ABSTRACT

BACKGROUND: The explanation of a rhythm disturbance is given by proposing an activation sequence of the myocardium along the assumed underlying pathologic changes of the heart tissue. We call this explanation 'the clinical model of the arrhythmia'. It is usually built in qualitative or semi-quantitative terms. The fact that, with realistic anatomic and electrophysiologic parameters, the assumed activation process would actually result, is not always clear--especially when a sequence of events trigger each other. PURPOSE: We wrote a program which constructs a computer representation of the clinical model of supraventricular arrhythmias, so that the activation sequence implied by the model can be calculated in detail. METHOD: The program was developed in the programming language Ada and runs on 386 or 486 PC's under either Unix (Linux) or MS-DOS. The supraventricular structures are decomposed in a three-dimensional network of 'simulation cells'--which represent syncitial regions assumed to be electrophysiologically solidary. Typically, they have a size of 0.1--10 mm³. Only the anatomical connections of the simulation cells are represented. The user may specify continuous blocks of cells and assign to them various electrophysiological properties (action potential type and parameters, conduction speed, dyastolic depolarization presence and parameters, etc). Intervals of variation of any parameter can be entered---leading to random generation of the values of that parameter in the given interval. Drug and hormonal influence can be specified if their effect on the action potential of various structures is known. RESULTS: The program computes every cell activation and repolarization, and also an approximation of the ECG on 3 bipolar leads. The activation sequence of selected sections through the heart is displayed on the screen during the process, using a color code to indicate the current action potential phase of each simulation cell. A recording of the 3D activation sequence is stored on disk and any section of it can be later replayed. The recording can also be annotated by the user. CONCLUSION: The program is useful for finding the extent of pathologic changes necessary for events (such as circus movement or concealed conduction) to actually take place and for making a detailed demonstration of clinical explanations.