A simple model for demonstration of STT-changes in ECG

This study is based on the idea that the STT part of the electrocardiogram in a small segment of the heart wall can be accurately constructed by calculating the difference between one subendocardial and one epicardial action potential. The following simulations were performed on computer and graphically presented. Endocardial ischaemia producing depression of the ST segment, downward sloping of the ST segment and negative T waves. Epicardial injury causing either a real or a pseudo ST elevation. Abnormal conduction between endocardium and epicardium (Increased delay between endocardial and epicardial excitation or reversed excitation path) producing discordant R and T waves. Analysis of STT changes are discussed on the background of these simulations. The proposed model for a segmental ECG was extrapolated to the whole heart by considering the contribution from each of 8 segments to a resultant heart vector.