A mathematical model of the electrocardiographicQT-RR relationship

A mathematical model of the electrocardiographicQT-RR relationship is presented. Numerical estimates produced a curve that fits reasonably well the empirical approximation made with Bazett's formula. The model is general and would agree in principle with previous membrane theories; this fact should encourage experiments in the mammalian heart and in single cells. The ‘activation’ constant A was found to be 3·88×10^?2 1/s. The critical periodT _k =x ₀ estimated from the experimental data was 0·5 s with a corresponding critical frequencyf _k of 120 beats/min. These values are valid for the whole ventricle of the snakeConstrictor constrictor; beyondf _k fibrillation would be expected to occur.