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Dr. James Ong, MD

Dr. James Ong, MD

Clinical Cardiac Electrophysiology*
35+ years of experience

Dr. James Ong, MD is a clinical cardiac electrophysiologist in Tarzana, CA and has over 35 years of experience in the medical field. He graduated from University of California in 1989. He is affiliated with medical facilities Los Robles Regional Medical Center and West Hills Hospital and Medical Center. He is accepting new patients and telehealth appointments.

4.9 Star Rating
Based on 216 reviews 4.9 Star Rating (216 reviews)

Practice

18372 Clark St Ste 218 Tarzana, CA 91356
Telehealth available

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Dr. Ong's Reviews

Likelihood to recommend Dr. Ong

4.9
216 ratings, 39 with a written review
5 star
97%
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3 star
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One of the best offices around!
My husband has been seeing Dr Ong in the Tarzana office for the past six years and I have recently become a patient as well after seeing the excellent care my husband has received. Dr Ong has treated my husband for Afib with ablation and has inserted a pacemaker and defibrillator. All procedures have been successful with no complications. Dr Ong is extremely knowledgeable and kind and is highly regarded by the other cardiologists we have seen. I also can not say enough about his office staff. You can always get through to someone but if you have to leave a message your call is always promptly returned. Kindness and skill mean the world to a cardiac patient and we have found these attributes in Dr Ong and his staff. I would not hesitate to refer anyone to Dr Ong
What went well
  • I felt respected
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
Helpful
Apr 24, 2025
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In year 2022 while replaceing the pacemaker Dr Ong disconnect one of the wires and left it hanging loose and replaced other wire in a totally wrong place. his explanation for loose wire was hard to remove . Ever since that I hav3e complications and I had to see another cardiologist to fix the damages and to relocate the wire .He also increase the dosage of my medication for my heart arrhythmia wich was not necessary .I do nor recommend him to anyone .As a mather of fact his name shouil be remove from list of specialist.
What went well
  • I felt respected
  • Appointment scheduling
  • Listened & answered questions
  • Staff friendliness
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
Helpful
Jan 02, 2025
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Outstanding Electrophysiologist!
Dr. Ong and his surgical team were highly competent, professional, and caring during my surgery. I was apprehensive before the operation, but Dr. Ong put me at ease with his confidence and reassurance. Given his extensive experience, I truly feel that I was in the best hands. The procedure was a success and I am so grateful to be his patient. Thank you, Dr. Ong!
What went well
  • I felt respected
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
Helpful
Yolanda S. – Nov 24, 2024
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Patient, linked together wish patient,
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
Helpful
Joyce Lederer – Nov 14, 2024
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Patient for over 10 years
I was referred to him by another cardiologist who also misdiagnosed my condition. Immediately Dr Ong correctly diagnosed me and recommended ablation surgery. Despite suggesting to do it soon, he put me at ease with his thorough explanation and comforting demeanor. He made sure to take the time I needed to fully understand the differences between the conditions, and the surgical recommendation. I see him every year for followups and look forward to seeing and catching up every time :)
What went well
  • I felt respected
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
Helpful
T Tholke – Oct 08, 2024
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OUTSTANDING CARDIOLOGIST; WITHOUT PEER
I found Dr. Ong after a very poor experience with another Cardiologist, ( Dr.B-Z) on Ventura Blvd. in Tarzana's unprofessional care. I am tremendously impressed with Dr. Ong's knowledge & readiness to explain my cardiac needs issues articulately with me. He always takes whatever time is needed to make certain my questions are answered and is very thorough, empathic, & friendly. I checked out quite a few Cardiologists after unfortunate experince with BZ, even visiting a few Cardiologists for consultations. Dr. Ong is a dedicated professional & a truly outstanding Cardiologist.
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
2 others found this helpful
Helpful
Apr 04, 2023
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Exceptional!
I have been a patient of Dr. Ong's for nearly 2 years. I found him through this website when searching for a electrophysiologist for my wife a couple of years prior. I was impressed with his rating and reviews. I recently had a cardiac ablation procedure to treat AFib and I am VERY pleased with the outcome. Although I live >40 miles from Dr. Ong's office, he is worth and I would (and have) recommended him to others.
What went well
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Trusted the provider's decisions
What could be improved
No results
Helpful
Eric B. – Sep 02, 2022
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I flew from Malaysia to seek experienced EP for my SVT condition in November 2021. Dr Ong acted quickly to squeeze me into his packed schedule at short notice. Catheter ablation was accomplished within a week of evaluation/consultation. Another of my concern was my high calcium score (2000+). Dr. Ong recommended a nuclear cardiac stress test instead of proceeding directly to invasive angiogram. I achieved the twin objectives of treating SVT and determining the functionality of my coronary arteries about 10 days, a wonderful journey of healing!
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
Helpful
Richard Tiong – Nov 22, 2021
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I had a very bad and dangerous case of Afib. It took two ablations to find all of the bad nerve sites, but he did it! (More than one ablation is common about 40% of the time.) No Afib for 2 1/2 years and perfectly normal nuclear stress tests and EKGs. Lucky a friend told me about Dr. Ong! It could have ended much differently.
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
4 others found this helpful
Helpful
Kathy P. – Jun 17, 2020
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Everyone in the office is very friendly and courteous . I like coming here.
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
5 others found this helpful
Helpful
Jan 30, 2020
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Zoe is great to work with
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
4 others found this helpful
Helpful
Oct 24, 2019
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Experienced Dr we can trust and always recommend to all my relatives. He has a magic hand since I came to his office I feel younger and healthier
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
5 others found this helpful
Helpful
Oct 24, 2019
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I have trust in Dr. Ong's skills
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
4 others found this helpful
Helpful
Oct 24, 2019
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I have the utmost confidence and trust in Dr. Ong. I wouldn't see anyone else.
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
2 others found this helpful
Helpful
Oct 19, 2019
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Dr.Ong is a miracle worker. His level of expertise is awesome. He s wonderfully caring, dedicated, and talented. I owe my improved health and vitality to Dr. Ong. He saved my life. Thank you again Dr. Ong
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
What could be improved
No results
3 others found this helpful
Helpful
Oct 19, 2019
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WONDERFUL DOCTOR, I FEEL WELL CARED FOR.
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
1 other person found this helpful
Helpful
Apr 24, 2019
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THE OFFICE STAFF IS KIND, PERSONABLE, PLEASANT AND FRIENDLY AT ALL TIMES
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
2 others found this helpful
Helpful
Feb 07, 2019
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GREAT DOCTOR & HUMAN BEING!
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
4 others found this helpful
Helpful
Jan 31, 2019
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FEEL GREAT AFTER PROCEDURE THANK YOU!!
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
2 others found this helpful
Helpful
Jan 22, 2019
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Dr James Ong IS the Doctor you want to go to if you have A Fib! Hands down the BEST! He took an extra 2 hours to make sure he hit every area of my heart that was causing issues with Rhythm, I have complete confidence in Dr Ong and his team at West Hills Hospital was truly amazing! I feel like I have a second chance at life after having a 6 hour ablation. Dr Ong takes the time to explain and answers your questions in a manner that is comforting and concise. I highly recommend Dr Ong. CA IN WH
What went well
  • Office environment
  • Appointment scheduling
  • Listened & answered questions
  • Explained conditions well
  • Staff friendliness
  • Appointment wasn't rushed
  • Trusted the provider's decisions
  • Wait times
What could be improved
No results
9 others found this helpful
Helpful
Dec 11, 2018
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Know Before You Go

About Me

Watch Dr. Ong's Video

care philosophy

Education, education, education - Patients' understanding of their conditions is the most critical first step in their healing process. We emphasize patient teaching in every aspect of our encounters with our patients.

biography

Dr. James Ong, board certified in cardiology and electrophysiology, received his medical education from the University of California San Diego School of Medicine. His residencies were completed at UCLA Medical Center and UCLA Wadsworth VA Medical...read more

  • Clinical Cardiac Electrophysiology

*Healthgrades does not verify qualifications for medical specialties. Please verify your provider's specialty and qualifications directly with your provider and applicable medical board.

  • University Of California

    Internship Hospital

  • Cedars Sinai Medical Center

    Fellowship Hospital, 1995

  • University Of California

    Residency Hospital, 1992

  • University Of California

    Medical School, 1989
For detailed information about any of the below board actions, please search for the provider's records on the linked state licensing board or the Federation of State Medical Boards. To learn more about the difference between these sources, please refer to our FAQs.
Healthgrades has not received any data indicating a board action exists for this provider.

Healthgrades receives board action history for physicians and physician assistants. The information displayed here is sourced from independent information providers, such as state board websites, and may not be the most up-to-date information. Healthgrades makes no representations with respect to the accuracy of any information provided here and assumes no responsibility or liability for such information.

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  • English

  • Chinese

  • French

  • Mandarin

  • Mandarin

  • Spanish

  • Relation between ligament of Marshall and adrenergic atrial tachyarrhythmia. Circulation. 1999 Aug 24;100(8):876-83., 1999

  • Website, 2004

  • Pulmonary veins and ligament of Marshall as sources of rapid activations in a canine model of sustained atrial fibrillation. Circulation. 2001 Feb 27;103(8):1157-63., 2001

  • Atrial fibrillation ablation, 2009

  • Focal source hypothesis of atrial fibrillation. J Electrocardiol. 1998;31 Suppl:32-4., 1998

  • End Afib

  • Prevalence of Retrograde Accessory Pathway Conduction During Atrial Fibrillation. Journal of Cardiovascular Electrophysiology 1997;8(4);377-387., 1997

  • The Relation Between Atrial Fibrillation Wavefront Characteristics and Accessory Pathway Conduction. Journal of Clinical Investigation 1995;96:2284-96., 1995

  • Arrhythmias Following Cardioverter-Defibrillator Implantation: Comparison of Epicardial and Transvenous Systems. American Journal of Cardiology 1995;75:137-40., 1995

  • Merck Fellowship, 1995

  • National Institute of Health Research Grant, 1996

  • Solomon Scholar, 1992

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Locations

Practice

Unavail18372 Clark St Ste 218 Tarzana, CA 91356
1
(818) 345-5580

Practice

Unavail32144 Agoura Rd Ste 218 Westlake Village, CA 91361
2
(818) 342-5377
See all Clinical Cardiac Electrophysiologists in Tarzana, CA