Dr Yoon treated myself and my husband several years ago. I also, worked with him as a…read morecardiovascular technician. He IS the best.

Dr. Yoon has been my 95 year old Mother's cardiologist for 10 years since moving here to Fairfield…read more Mom had a slight stroke a few years ago, and did not have a big heart condition - but certainly Dr. Yoon has been amazing with her care. She had been over medicated previously with blood pressure control which made her faint. He has been able to provide less meds and change them as needed to keep her blood pressure normal and keep her feeling fine. He prescribed physical therapy after the stroke and keeps close watch over her condition with reports we provide periodically about daily vitals. He was terrific over the last two hospital visits and found a life threatening condition that was easily fixed and also after a recent visit that an ER doctor prescribed a drug that was too strong - he changed that right away and Mom is doing just great. We do not know what we would do without Dr. Yoon.

Having your Dr call you on a Sunday to check on you is pretty awesome. Dr Breneisen has continued…read moreto keep an eye on my boyfriend since he came home from the hospital. He has called in the afternoons, evenings and weekends. I can not recommend him enough to anyone needing a good, caring and compassionate cardiologist. Thank you Dr Breneisen for being the kind of doctor we all need.

Dr Chang is not only an exceptional Dr but truly cares about his patients!! My Mom and myself are…read moreboth his patients and he's been taking care of us 12 plus years. He listens and addresses all your concerns.

I went to him for a second opinion regarding a diagnosis given to me by my regular cardiologist of…read morewhich scared me. He confirmed the diagnosis. He also was able to reduce my stress with his explanations. Now I don't preoccupy over it. Al. Gomes

This Cardiologist is AMAZING!!! My Sister used TO work with him at The Queen of the Valley in Napa…read more He's now in Fairfield @North Bay Hospital. He put 2 stents in my heart, replaced 1, did 2 Angiograms. He told me we will go through this together. If you are looking for the Best Cardiologist, he's the one!!!

Everything went well. They were nice they were kind and they act concerned. I was very pleased with…read moreDr. Villalon. He was courteous always know and in a good spirit and kept him in a good spirit so it was touch and go for a minute it was close we're gonna let him stay here so we gotta keep pushing Bill along very very well recommended in my book.

I haven't had much experience with this office except with the woman who does the ultrasounds. I am…read moreso bummed that I didn't catch her name, but she is such a nice, bubbly and friendly person. She is obviously extremely skilled at her job, and goes through the ultrasound with nothing but professionalism and ease. This isn't the kind of thing you run into all the time or have a choice in, but if you do have a choice where to get your heart ultrasound done, this is it! I can also say that Dr. Argenal is an extremely thoughtful and well seasoned cardiologist as well. This is not the office we go to to see him, so a more detailed review about him will be at the Pleasant Hill page, but he is absolutely excellent! Usually has a long wait for appointments, but we'll worth it and you won't be disappointed!

This is only a review on the waiting area. This waiting room is so overcrowded that you practicly…read moreneed an air traffic controller to navigate it. Please take out the 5 extra chairs that no one can sit in any way. All they are doing is causing people discomfort and anxiety. And there are no public bathrooms in the entire building. Guests of patients must use the bathrooms in the doctors offices. Im writing this review whial I'm sitting in the overcrowded awful waiting room. There is no way this waiting room meets fire safty codes.

Dr. Chen is so next level!…read more In a world where docs are now often forced to conform to the corporate narrative of big pharma, big money, especially under hospital/IDN umbrellas, he does not practice cookie cutter cardiology. He was so thorough in explaining my calcium score test (even though it was a zero, he took the time to teach me what is looked for and the fact that only calcium, not soft tissue plaque shows up on this test). He shared images that no other doc in 4 yrs since took the time to explain. He went into great detail about how to monitor and optimize my heart health. I was so impressed by his down to earth and approachable personality, and even more so by his extensive and up to date knowledge; things have changed in cardiology, and he's young, and not stuck in old ways as other cardiologists can be. I would 150% recommend him to anyone, whether looking for a baseline on your heart health, or struggling with serious heart issues, he is a gem and such an asset to John Muir!

Dr. Christopher Chen was the cardiologist on call when I brought my dad in with unstable angina…read moreafter a NSTEMI. My dad is 91 and was terrified of having any procedure. Dr. Chen saw him promptly and went out of his way to recruit a skilled interventional cardiologist, Dr. Lim, who would go on to successfully stent and save my dad's life, rather than make him wait until the end of the day to see someone else who might not have performed any intervention on him. Dr. Chen also diagnosed my dad's new mitral valve regurgitation murmur caused by his MI and ordered additional echo images to assess this. We can't thank Dr. Chen enough for his excellent care! Don't let his youth and low-key manner fool you; he is an excellent diagnostician and attentive physician and we were so lucky to have him.

I have never in my life been to a doctor that has been so rude to…read more I originally called the Fairfield office (I'm assuming it was supposed to be his wife) and she was on vacation so the receptionist scheduled me for the next day at the Vacaville location. The only thing I needed was a referral for a dermatologist ASAP because my condition was getting worse. The day of the appointment I took off time from work, got there early, filled out the paper work, and ended up waiting about an hour. The nurse brought me back finally and started doing an EKG on me. I thought that was weird and asked her why and she said everyone gets one....... For a referral? Mind u I'm in my 20s and have never had a history of heart problems. After she took my reading the doctor came in and he was in an awful mood (but it wouldn't surprise me if he's like that all the time). He looked at me. Stared at my chart for a few minutes. Then asked me why I was there (in pretty sure my chart should have said why). I told him and he started to get angry towards me. He said I was wasting his time, and why was I there, etc etc etc. then he started yelling at his staff (I did feel bad for them) asking why I was there. At this point I wanted to get up and run out the front door!! How unprofessional and rude!! After his rants and ravings I finally got my referral and the worst experience at the doctors. About two weeks later I got the bill and it was over $400 with a lovely unnecessary $50 EKG charge. Wow. I filed a 3 page claim with my insurance provider about how traumatizing my visit was. I will never go back to any of the "Dassah" doctor locations and if you have half a mind you won't either!!!!!!

Do NOT waste your time with this guy. He's got a captive audience in Tricare Standard clients and…read moreseems to not care one iota about his business, practice, or his oath as a doctor. My experience: I arrived 20 minutes early, filled out the new patient intake, had my vitals taken, and the doctor wasn't in the building at my appointment time. He showed up 25 minutes late, and wanted me to do an EKG on their broken equipment. How does a cardiologist have a broken EKG machine? The mobile machine wasn't going to be there until 1.5 hours after my appointment. When I asked his staff what the EKG was for and why I was being asked to do it on a broken machine, I got blank stares and "What?" After repeating my concerns to the doctor, he was rude and dismissive and when I stated that I wasn't happy, he said "Let's move on" to his staff and walked away. I took my paperwork and left. This was the WORST experience I've ever had with a "doctor". Pathetic, really.