The effect of ischaemic region shape on epicardial potential distributions in transient models of cardiac tissue

Abstract

Cardiac ischaemia is a restriction of blood supply to tissues in the heart. It is often diagnosed via an electrocardiograph by looking at the segment of the electrocardiograph between the QRS complex and the t wave, which is known as the ST segment. Previous work on ischaemia during the ST segment has shown that the shape of the ischaemic region can significantly affect the epicardial potential distribution at the surface of the heart. This numerical study compares the results from the steady state simulations with a more realistic transient model. The model consists of a slab of ventricular tissue with an ischaemic region at the centre resting on a blood bath. The transient bidomain equations were solved using a finite volume method for the spatial discretisation and a semi-implicit method for the time integration. Ischaemia is included by taking into account three of the main physiological consequences which include hyperkalaemia, acidosis and anoxia. Results are obtained for three different ischaemic region geometries (rectangular, cylindrical and semi-ellipsoidal). References

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