Without her cooperation and support I wouldn't have accomplished this in my life. I am guilty of not spending enough time with my two year old daughter, Shivani, while pursuing cardiology fellowship and PhD simultaneously. Her cute words and beautiful smile provided lot of refreshment and ample energy to complete this task. I would like to thank my sister, Lyka, for her support and encouragement. She is always there and made me to stick to my goals and objectives. I would like to thank Dr. Neal Weintraub, Dr. Andrew Burger and Dr. Robin Vandivier for their support and encouragement. I would like to thank Ms. Tammi A. Thomas for her help and administrative support. I would like to thank Mr. Mark Evans, who assisted me for proof reading and formatting.