John J. Hollowed, MD

Dr. Happy D. Thakkar is a board-certified cardiologist who practices in UCLA Health's Simi Valley office. He has expertise in treating patients with all types of cardiovascular diseases, such as hypertension, lipid disorders, heart failure, valvular heart disease, abnormal heart rhythms, coronary artery disease, and peripheral vascular disease. He has specific interests in preventive cardiology, including cardiovascular nutrition, exercise, and lifestyle, as well as critical care cardiology. Dr…

Dr. Jeffrey Harrell is an interventional cardiologist who practices in Simi Valley and performs procedures at Ronald Reagan UCLA Medical Center and Adventist Health Simi Valley Hospital. He specializes in cardiovascular medicine and interventional cardiology, the catheter-based treatment of heart disease. He performs nonsurgical procedures, such as percutaneous coronary intervention (PCI), to treat people with coronary artery blockages and improve blood flow to the heart. Dr. Harrell’s clinical…

Dr. Helen Huang is a non-invasive cardiologist who practices in Porter Ranch and Simi Valley. She is board-certified in internal medicine, cardiovascular medicine, echocardiography, and nuclear medicine. She specializes in cardiovascular medicine with an interest in furthering women's health. She is fluent in Cantonese. Dr. Huang received her undergraduate and medical degrees in a combined program at Sophie Davis School of Biomedical Education (City College of New York) and Albany Medical…