Gan-Xin Yan, MD, PhD

Research Summary:

Our laboratory focuses on exploring the mechanisms responsible for sudden cardiac death under various clinical conditions, including life-threatening rapid and irregular heart beats, myocardial infarction (“heart attack”), enlarged and weakened heart. These cardiovascular studies, from the organ to a single isolated cardiac cell, have contributed a great deal to our understanding of normal electrophysiology as well as electrical disturbances in heart disease. Recently, the lab has started a new project to inject bone marrow cells into heart for repairing weakened heart muscles.

An animal ventricular wedge preparation which I developed has received a great deal of attention and has been adopted by many universities and pharmaceutical companies worldwide. This wedge preparation possesses many advantages over traditional methods to study electrical signals traveling within the heart. From the wedge preparation, three separate floating microelectrodes are used to record the signals in the outer, mid and inner regions of the heart. The experimental findings based on the ventricular wedge model have led to several fundamental changes in our thinking as to the origin and maintenance of normal as well as abnormal heart rhythms.

Selected Publications:

1. Patel C, Burke J, Patel H, Kowey PR, Antzelevitch C, Yan CX: Cellular Basis of the T Wave: A Century of Controversy. Circulation (Electrophysiology and Arrhythmias) 2009; 2: 80-88 
2. Zhu,T.G.; Patel,C.; Martin,S.; Quan,X.; Wu,Y.; Burke,J.F.; Chernick,M.; Kowey,P.R.; Yan,G.X. Ventricular transmural repolarization sequence: its relationship with ventricular relaxation and role in ventricular diastolic function. Eur.Heart J. 2009;30: 372-380 
3. Guo D, Young L, Patel C, Jiao Z, Wu Y, Liu T, Kowey PR, Yan GX: Calcium-activated Chloride Current Contributes to Action Potential Alternations in Left Ventricular Hypertrophy Rabbit. Am. J. Physiol 2008; 295:H97-H104 
4. Guo D, Zhao X, Wu Y, Liu T, Kowey PR, Yan GX: L-type calcium current reactivation contributes to arrhythmogenesis associated with action potential triangulation. Journal of Cardiovascular Electrophysiology 2007;18: 196-203
5. Liu T, Brown B, Wu Y, Kowey PR, Yan GX: Blinded Validation of the Isolated Arterially Perfused Rabbit Ventricular Wedge in Preclinical Assessment of Drug-Induced Proarrhythmias. Heart Rhythm 2006; 3:948-956 
6. Yan GX, Joshi A, Guo D, Hlaing T, Martin J, Xu, X, Kowey PR: Phase 2 reentry as a trigger to initiate ventricular fibrillation during early acute myocardial ischemia. Circulation 2004, 110: 1036-1041 
7. Yan GX, Lankipalli R, Burke J, Musco S and Kowey PR: Ventricular Repolarization Components on the Electrocardiography: Cellular Basis and Clinical Significance. Journal of American College of Cardiology 2003; 42:402-409 
8. Medina-Ravell VA, Lankipalli RS, Yan GX, Antzelevitch C, Medina-Malpica NA, Medina-Malpica, OA, Droogan C, Kowey PR: Effect of epicardial or biventricular pacing to prolong QT interval and increase transmural dispersion of repolarization: does resynchronization therapy pose a risk for patients predisposed to long QT or torsade de pointes? Circulation 2003;107:740-746