Life-threatening ventricular arrhythmias remain the main cause of death among patients with cardiovascular diseases. Efforts have been spent on early detection of such fatal cardiac signs. We have previously reported a novel chaotic phase space differential (CPSD) algorithm in discriminating VPC, VT, and VF from normal sinus rhythm with both good sensitivity and specificity. In this article, we apply this algorithm on the rat model of calcium induced ventricular tachycardia. Peaked CPSD values can be observed along with the occurrence of ventricular tachycardia. In addition, minor ECG changes such as new onset S wave or sinus arrhythmia can also be noted on CPSD tracing. We believe that the CPSD algorithm not only is capable of detecting lethal ventricular arrhythmias, but also is potentially a good tool for long-term monitoring the change of ECG signals.