After obtaining PhD, Man Si started postdoc work in Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport. In this new lab she established Langendorff system for isolation cardiac myocytes and patch clamp system for electrophysiology recording. She studied to define the contribution of Kv1.1 potassium channels in mouse heart and arrhythmogenesis as the principal investigator in Malcolm Feist Cardiovascular Research Fellowship, LSU Health Sciences Center Institute for Cardiovascular Disease and Imaging 2014. She moved to Department of Biological Sciences, Southern Methodist University 2019. To further research, she plan to study electrophysiological dysfunction in mouse sinoatrial node lacking Kv1.1 Channels. Therefore, finding an intrinsic cardiac role for Kv1.1 channels would identify them as a new type of cardiac potassium channel and would suggest an alternate mechanism for arrhythmia susceptibility due to Kv1.1-deficiency apart from brain-mediated dysfunction.