(713) 790-0841. In the ever-changing health care environment, Dr. Earl Mangin understands individualized, directed, and expert care is important to you. He is a board-certified cardiovascular physician who focuses on the diagnosis and treatment of diseases affecting the heart and stays up to date on latest advances in the field. The superior level of care that you receive is supported by a carefully chosen group of highly trained nurses, physician assistants, and technicians supplied with the latest technology to help assess, restore and/or maintain the health of your heart and circulatory system.