A Cardiac Arrhythmogenesis Model: Spiraling Out of Control

Arrhythmic Sudden Cardiac death accounts for up to 5 million cases per year across the world. Cardiac arrhythmia is an abnormal activity in the heart that can lead to sudden cardiac death resulting from ventricular fibrillation. The electrocardiogram (ECG) reading during an arrhythmia indicates rapid contractions of the heart. This phenomenon is due to the development of a re-entrant circuit of electrical activity that repetitively stimulates the heart. The heart presents a spatio-temporal complex system, where the tissue biophysics and structure leads to reaction diffusion type models. These models portray the re-entrant wave patterns observed during arrhythmia. Fibrillation is characterized by the break up of a single spiral wave formed during tachycardia into multiple waves of electrical activity. We will use our model to better understand the mechanisms that lead to fibrillation and can halt fibrillation. Moreover, various factors such as sexual hormones may facilitate arrhythmogenesis. Female sex hormones may lead to a prolonged Action Potential Duration (APD). This prolongation of APD allows for L-Type calcium channels to recover their excitability while the membrane remains in the depolarized state. The resulting current may lead to an extrasystole, which yields a re-entrant pattern that triggers the arrhythmogenesis. Thus, we will also consider the role of female sex hormones in the model