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Eric Castleman, MD, is a board-certified cardiologist and internist at COR Healthcare Medical Associates in Los Angeles. He currently sees patients at the practice’s locations in Torrance and Redondo Beach, California, where he brings more than 35 years of experience specializing in general cardiology, and adult congenital heart disease.

Dr. Castleman earned his medical degree at Mount Sinai School of Medicine in New York City before moving to California for his medical training. He completed his internal medicine residency at the University of California, Los Angeles (UCLA) Medical Center and a cardiology fellowship from UC Irvine Medical Center in Orange, California.

Dr. Castleman has many interests outside of work. He loves spending time with his wife, who is a nurse, and their four children. He loves gardening, traveling, and tinkering in the garage repairing things.

A triple diplomate of the American Board of Internal Medicine, Matthew Ostrom, MD, is board-certified in clinical cardiac electrophysiology, cardiovascular disease, nuclear cardiology, and internal medicine. Dr. Ostrom, who has more than 15 years of experience, serves the Los Angeles communities of Torrance and Redondo Beach, California, at COR Healthcare Medical Associates.

Born and raised in Seattle, Dr. Ostrom received his Bachelor of Science in microbiology from the University of Washington in 1999. Throughout his undergraduate studies, Dr. Ostrom was actively involved in cardiovascular research at the university and at the local biotechnology company ZymoGenetics, Inc.

Shortly after graduating, Dr. Ostrom began his medical studies at Loyola University Chicago Stritch School of Medicine. He completed an internal medicine internship and residency through the University of California, Los Angeles (UCLA) system. In addition, Dr. Ostrom pursued cardiology and electrophysiology fellowships at Harbor-UCLA Medical Center in West Carson, California, and at Kaiser Permanente Los Angeles Medical Center in Los Angeles. He is a fellow of the American College of Cardiology and the Heart Rhythm Society. 

Today, Dr. Ostrom is a practicing electrophysiologist, specializing in catheter and device-based therapies in the treatment of complex arrhythmias, syncope, sudden cardiac death, and heart failure.

His research interests include the ablation of complex arrhythmias and device-based treatments for sudden cardiac death and congestive heart failure. Dr. Ostrom has authored or co-authored numerous articles in peer-reviewed cardiology and electrophysiology journals.

In addition to his work at COR Healthcare Medical Associates, Dr. Ostrom is on staff at Providence Little Company of Mary Medical Center and Torrance Memorial Medical Center.

Away from work, Dr. Ostrom loves spending time outdoors with his wife and children.

Sang Yong Ji, MD, is a board-certified adult cardiologist and cardiac electrophysiologist at COR Healthcare in Torrance, California. His board certification also includes internal medicine, nuclear cardiology, and echocardiography.

Dr. Ji was born in South Korea and moved to Paraguay during his junior high school year. He earned his medical degree from Asunción National University, Paraguay. He then moved to New York City to complete internal medicine residency and cardiology fellowship at Albert Einstein College of Medicine before completing a cardiac electrophysiology fellowship at Johns Hopkins Hospital in Baltimore, Maryland. He graduated as the Best Resident of the year and with Program director's award & Chief of Division award from internal medicine residency program and cardiology fellowship program respectively. He also served as chief fellow at both Montefiore cardiology fellowship program and Johns Hopkins University cardiac electrophysiology fellowship program. He provides state of the art care including complex ablations for different arrhythmias and implantation of cardiac electronic devices. He shares his expertise by authoring numerous publications in highly respected scientific and medical journals. He continues to stay active as current Principal Investigator in several clinical research projects at Torrance Memorial Medical Center as well.

Dr. Ji is fluent in English, Spanish, and Korean. When he’s not treating patients, Dr. Ji enjoys spending time with his wife, who is an internal medicine physician and their four children.

Ray Wyman, MD, is a board-certified cardiologist specializing in general cardiology, internal medicine, interventional cardiology, and adult congenital heart disease. An experienced cardiologist with more than 20 years in his field, Dr. Wyman serves the community of Los Angeles at COR Healthcare Medical Associates in Torrance, California.

Dr. Wyman earned his medical doctorate from Johns Hopkins University School of Medicine in Baltimore before completing his internal medicine residency at Johns Hopkins Hospital in the same city. Dr. Wyman developed an interest in cardiology early in his career and later completed dual cardiology fellowships through Boston’s Beth Israel Hospital and Harvard Medical School in Cambridge, Massachusetts.

In addition to heart disease and heart attack treatment, anticoagulation management, and high blood pressure treatment, Dr. Wyman performs ongoing research in coronary artery stenting.

Dr. Wyman has many interests and hobbies outside of work. When he isn’t spending time with his wife and four children, he loves playing outdoor sports and cooking gourmet meals at home.

As a triple diplomate with the American Board, Erol Kosar, MD, holds board certifications in clinical cardiac electrophysiology, cardiovascular diseases, and internal medicine. At COR Healthcare Medical Associates in Los Angeles, Dr. Kosar proudly brings his 30 years of experience to patients of all ages at the practice’s location in Torrance, California.

He is also certified by the International Board of Heart Rhythm Examiners (IBHRE). 

After earning his medical doctorate at Sidney Kimmel Medical College, Thomas Jefferson University, in Philadelphia in 1989, Dr. Kosar completed an internal medicine internship and residency at the University of Pittsburgh in 1992. He later received additional training through a cardiology and electrophysiology fellowship at the University of Southern California (USC) in Los Angeles. After completing his fellowship, Dr. Kosar served as a full-time assistant professor of medicine at USC.

Continuing education is a top priority for Dr. Kosar, who is a Western regional trainer for excimer laser lead extraction — developed by Spectranetics® — which uses laser technology to remove permanent pacemaker lead.

Dr. Kosar is highly trained in all aspects of cardiology and cardiac electrophysiology, but his special research interests include cardiac resynchronization, sudden cardiac arrest, lead extraction, and atrial fibrillation.

As a leader in his field, Dr. Kosar has authored numerous publications in Circulation, Journal of the American College of Cardiology, and Cardiac Electrophysiology Review.

Not only does Dr. Kosar work with patients at COR Healthcare Medical Associates in San Pedro, CA, but he is also on staff at Providence Little Company of Mary Medical Center in Torrance, and Torrance Memorial Medical Center

Bruce Jackson, MD, is a board-certified cardiologist and internist at COR Healthcare Medical Associates in Los Angeles. At the practice’s location in Redondo Beach, California, he specializes in diagnosing and treating cardiovascular disease and has almost 50 years of experience. 

In addition to treating patients at COR Healthcare Medical Associates, Dr. Jackson is affiliated with several area hospitals, including Harbor-UCLA Medical Center in West Carson, California, and Providence Little Company of Mary Medical Center in Torrance, California. Dr. Jackson was also an Associate Clinical Professor of Medicine/Cardiology at Harbor UCLA for 20 years and an Assistant Clinical Professor of Nursing at UCLA for 8 years

Dr. Jackson earned his medical degree from the University of California, Los Angeles (UCLA) School of Medicine. He completed an internal medicine residency at the University of California, San Diego, and a cardiology fellowship at Harbor-UCLA Medical Center. Dr. Jackson speaks English and Spanish.

When’s he’s not treating patients, Dr. Jackson is a ham radio operator with an interest in near space balloon communications. He enjoys relaxing with his wife, Susan, and spending time with their 11 grandchildren.

Brenton Bauer, MD, is a board-certified internist and cardiologist at COR Healthcare in Los Angeles. He sees patients at the Torrance, Redondo Beach and El Segundo offices in addition to the cardiology department at Torrance Memorial Medical Center.  He specializes in general cardiology, cardio-oncology, and advanced cardiac imaging.

Dr. Bauer completed his medical education and advanced training at the University of California, Los Angeles (UCLA). In addition to earning his Doctor of Medicine with honors, Dr. Bauer completed an internal medicine internship and residency, serving as chief resident, and a cardiovascular disease fellowship serving as chief fellow. He has been certified by the American Board of Internal Medicine in addition to subspecialty boards of Echocardiography, Cardiovascular CT, and Nuclear Cardiology. Dr. Bauer has written extensively for medical journals and other publications.

An award-winning physician, Dr. Bauer has been named to the American College of Cardiology’s (ACC) national conference program faculty, as an ACC National FIT (Fellows in Training) Jeopardy Competition finalist, as a finalist for the UCLA Most Outstanding Fellow Teaching Award, and won the best poster presentation in congenital heart disease at the American College of Cardiology’s 2015 conference, among others.

In his leisure time, Dr. Bauer loves traveling the world with his wife and junior high sweetheart.  They particularly enjoy experiencing different cultures, trying amazing food, and learning different languages (to which he is fluent in English and Spanish and working on others including Italian).