PCMA - Key Persons


Cristina Mercado

Job Titles:
  • Practice Manager
Cristina was born in Mexico, and raised in Southern California. She earned her Medical Assistant certificate from Watterson College in Pasadena, CA and then her Associates in Arts degree from Pierce Community College in Woodland Hills, CA. Cristina's love for medicine began at the age of 15 when she started volunteering at her local community hospital, and for the past 18 years she has been serving the San Fernando Valley community. Cristina currently resides in Chatsworth with her husband and two daughters. In her spare time Cristina returns to her first love, charity work. She shows her passion for helping others daily by taking care of her PCMA families.

David A. Ferry

Job Titles:
  • Associate Professor of Pediatrics at the UCLA David Geffen School of Medicine
Dr. David Ferry is a California native, being born in the Bay Area. He received his BA cum laude in biology from Claremont McKenna College and then his Doctorate of Medicine at Washington University School of Medicine in St. Louis, MO. He returned to southern California for his residency in pediatrics and fellowship in Pediatric Cardiology at Children's Hospital Los Angeles. Dr. Ferry has been a voluntary associate professor of Pediatrics at the UCLA David Geffen School of Medicine. He is a fellow of both the American Academy of Pediatrics as well as the American College of Cardiology, and past president of the California (now Western) Society of Pediatric Cardiology. He enjoys teaching of medical students and residents, and is the winner of the Francis Nunnally Winzer Prize in Pediatrics at CHLA as well as receiving four Golden Apple teaching awards from the pediatric housestaff at Cedars-Sinai Medical Center. There, Dr. Ferry was clinical chief of Pediatrics in 2000-2001, and director of pediatric cardiology from 2002 to 2011. He has helped organize over twenty volunteer trips to various countries in Latin America and Africa (Ethiopia) where he and his team members diagnose and treat children with congenital heart disease. He is board certified in Pediatrics and Pediatric Cardiology and speaks fluent Spanish. His interests include echocardiography and interventional cardiology. He is certified to perform transcatheter ASD and PDA closures. Dr. Ferry sees patients in our Encino, Lancaster and Santa Clarita locations.

Frederic Leong

Dr. Leong was born and raised in St. Louis, Missouri and earned his Bachelor of Arts in Biology and his Doctorate of Medicine at the University of Missouri. He then moved out to Los Angeles where he completed his Pediatric Residency, Chief Residency and Pediatric Cardiology Fellowship programs at UCLA Medical Center. He enjoys teaching and is an instructor of Pediatric Cardiology at the Ventura County Medical Center Family Practice Residency program. Each summer he enjoys volunteering​ with Camp Del Corazon, a Catalina Island summer camp for children with congenital heart disease. ​ Dr. Leong has over 20 years of pediatric cardiology clinical experience and he is certified by the American Board of Pediatrics and it's Sub-specialty Board of Pediatric Cardiology. His interests include echocardio​graphy, fetal echocardio​graphy and clinical cardiology.

Jeffrey A. Wong

Dr. Wong was born and raised in the San Francisco Bay Area and received his Bachelor of Science Degree in Physiology at UC Davis and his Doctorate of Medicine from the University of California Davis School of Medicine. He completed his Pediatric Residency at Oakland Children's Hospital. After serving as a medical missionary in Africa, he temporarily relocated to Ohio to complete his Pediatric Cardiology fellowship at the Children's Hospital Medical Center in Cincinnati. He then returned to California to join PCMA and to start a family. Dr. Wong is a Fellow of the American College of Cardiology and he is Board Certified in both Pediatric Cardiology and General Pediatrics by the American Board of Pediatrics. His interests include congenital heart disease and clinical pediatric cardiology and he speaks Spanish. He enjoys teaching and is a two-time winner of the Golden Apple Teaching Award given by the Pediatric residents at Cedars Sinai Medical Center. He has been a medical reviewer for the journal Catheterization and Cardiovascular Interventions, and has been published in numerous peer-reviewed medical journals, including the Journal of the American College of Cardiology, American Heart Journal, Circulation, Pediatric Cardiology, Annals of Thoracic Surgery, American Journal of Radiology and the American Journal of Medical Genetics. Dr Wong sees patients at our Encino, Lancaster, and Santa Clarita locations.

Nancy Kim

Dr. Kim is a southern California native and attended the University of California Berkeley where she graduated with a degree in Molecular and Cell Biology with an emphasis in Genetics and a minor in Music. She returned to Southern California to earn her medical degree and complete her Pediatrics residency at the University of California Irvine. She relocated to the Bay Area to complete a fellowship in Pediatric Cardiology at Lucile Packard Children's Hospital at Stanford University Medical Center. She is board certified in General Pediatrics and Pediatric Cardiology and is a fellow of the American College of Cardiology. She speaks Spanish and Korean. Her professional interests include fetal echocardiography and clinical cardiology. Personally, she is a happily married mother of two young kids.

Timothy W. Casarez

Dr. Casarez was born and raised in Southern California and earned his Bachelor of Arts in Economics from UCLA. He received his Doctorate of Medicine from the University of California San Francisco and completed his residency in Pediatrics at the UCSF Benioff Children's Hospital. He returned to UCLA to complete his fellowship in Pediatric Cardiology at the UCLA Mattel Children's Hospital. He has been recognized for his teaching abilities as the recipient of the Mead Johnson Teaching Award from the UCLA Residency Program and the Golden Apple Teaching Award from the Cedars Sinai Pediatric Residency Program. He is a Fellow of the American College of Cardiology and Member of the Western Society of Pediatric Cardiology. Dr. Casarez enjoys serving children and their families all over the world. He routinely travels on medical missions to Central America, South America, and Africa to diagnose and treat infants and children with congenital heart disease. His philanthropic efforts were recognized as the Medical Honoree at the Camp del Corazon Gala del Sol. He is board certified in Pediatric Cardiology and speaks Spanish. His interests include congenital heart disease of the newborn, interventional cardiology, echocardiography, and he is certified to perform ASD and PDA closure using transcatheter techniques.

Viviana Cabrera

Viviana has been part of the PCMA family for the past 23 years. She first started as our Medical Assistant, and then promoted to the authorizations department. She has now come full circle and returned to her love of working closely with families and helping them schedule their imaging appointments, Cardiac Catherization's and other Specialty Consultations. Viviana lives in North Hollywood with her son Anthony, and in her free time they enjoy outdoor activities, watching boxing matches and eating Thai food. Viviana works Monday- Friday 8:00am- 5pm her phone number is 818-784-6269 ext 218. Please feel free to reach out to Viviana for any of your scheduling needs. Her email is vcabrera@pcmasc.