Simulated ECG waveforms in long QT syndrome based on a model of human ventricular tissue

The electrocardiogram (ECG) is an important index of clinical diagnosis of cardiac arrhythmias. Simulations of ECG had revealed the causative relationship between waveforms of ECG and action potentials (APs). However, those studies were mainly based on the Luo-Rudy (LRd) model or the Priebe-Beuckelman (PB) model. In this study, we developed a ID model of transmural ventricular strand based on the Tusscher et al. (TNNP) model of human ventricular myocytes. Using the model, the computed QT interval is 335 ms under the control condition. The value fits well with the clinical diagnosis (320∼440 ms) and is about 100 ms longer than that from the LRd model. We studied the ECG waveforms under the LQT condition due to various ionic channel gene mutations. The morphology of simulated ECG resembles the main features of clinical recorded ECG of LQT syndrome, which include prolongation of the QT interval, widening of T wave, and increasing of the amplitude of T wave. This study provides an important insight to understand the causative link between LQT syndrome and underlying genetic mutations.