I can't thank these two doctors enough! Dr. Tony Ngoc Nguyen in So. El Monte, and Dr. John McKenzieIII in Glendale. Upon several tests, it was apparent that my daughter would be in need of having a Pacemaker inserted. Thank God there was an option that is a fairly new procedure called a "Leadless Pacemaker". We opted for the new procedure which was performed by Dr. McKenzieIII. Almost instantly, the very next day, my daughter started feeling better, her color came back, and her fatigue went away and best of all, no wires or chest scar! She was back to being herself within the first week after recovery. It was simply amazing! May God continue to bless these two doctors and guide their hands when working with heart patients. Additionally, the office staff of both doctors were very kind and helpful. I would highly recommend either of these two doctors if you have any heart concerns. read more

No respect for people's time. What is the point of setting an appointment if we're going to just rot in the waiting room for 90 minutes plus? read more

Their Office Manager, Sonia does not send referrals for Dr McKenzie to approve. She is very feisty, aggressive and rude. Yet, Dr McKenzie and the administration don't take any action. I am thinking seriously of contacting a Counselor to resolve my issues. I get no feedback, only aggression. read more

I'm indebted to Dr. McKensie and his staff. I needed a procedure to prevent a more serious issue with my heart and he took care of it in very short order. His office is busy but that's a tribute to his expertise. The front office staff and the technicians are all very professional. My hat's off to Sonia for her diligence and attentiveness to my needs. I would recommend Dr. McKensie to anyone of my family and friends. read more

I had atrial fibrillation for over 6 years but no more feelings of a fast fluttering or pounding heartbeat, chest pain, dizziness, fatigue. Lightheadedness, reduced ability to walk and exercise, shortness of breath, weakness thanks to Dr. John P Mckenzie III, M. D. I feel like I did when I was in High School ready to conquer the world. I have to tell you I got my life back. read more

Dr. John was referring by Dr. Tony Ngọc Nguyen from El Monte office to follow up for my Dad the removal of pace maker that left wires ( since 20 some years ago). Few months ago it started popping to skin . I will update soon. Thanks to both Dr. read more

My cardiologist recommended Dr McKenzie to proceed with laser Ablation. I I'm so glad I went with him and agreed for ablation. He is one of the best electrophysiologist in the area , very detailed, particular, and professional in his job. Everything went smooth and successful. I am very surprised by people giving 3 stars because he deserves a 100. Thank you very much Dr McKenzie for all you do. I will recommend him with no hesitation. read more

This place sucks . Apt time 4:45 , received a call at 4:40 when we arrived if we wanted to re schedule apt because dr was running late . Didn't get seen until 8pm , yes 8pm . What a joke read more

I have only positive things to say about Dr. McKenzie EXCEPT he's perhaps too busy! The waiting room is generally standing room only but this was easily solved by showing up on time for my appointment, checking in with the receptionist and inquiring how long to expect to wait. They called me withing 5 minutes of when the doctor was able to see me and then took me in right away. Problem solved. read more

(I am writing this for a friend of mine who has a hard time setting this up) The cardiologist is the best. I had a great experience to help my mother during a hard time with her surgery. They made us feel amazing. We had peace in our hearts and communicated with us through out the whole process. Professional attention and the receptionist made us feel at home. Great results and I would recommend them. Thank you read more

Dr. Mckenzie is the best. He performed a procedure on my mom and dad and they both feel great. Thank you Dr. read more

The doctor's doctor. Like speaking to a family member. Wonderful ability, exceptional attitude. Simply the best heart doctor for me since 1998. read more

If we could Dr. McKenzie 10 stars we would! He performed my moms heart procedure yesterday and we are extremely pleased. My mom who is scared of every little thing was freaking out, but Dr. McKenzie took great care of her. He was very gentle with her and my mom and I are extremely grateful. Thank you Dr. McKenzie for saving my moms life. You are God sent. read more

I recently called to get information and was "helped" but what I can assume was the world's rudest receptionist. She was not helpful, who gives attitude to some one who is seeing if they want their service, and she clearly sounded and spoke like she didn't have much training on how to talk to people. In my complete disbelief that some one would respond to someone like that I didn't clearly catch her name, Adlyn, Adele something like that. I've heard ok things about this office but to avoid further communication with such person I will be looking else where. read more

I had atrial fibrillation and was referred to Dr. McKenzie by another cardiologist. My wife and I were favorably impressed with his manner, explanations, and responses to questions during our first visit where we decided to pursue the ablation procedure. We took great pains to choose a Doctor and a Hospital that was in our insurance network. Prior to the procedure, I tried to gather information about billing and costs. His scheduler referred me to the billing department who said they couldn't tell me anything because they knew nothing about my case, even though I had told them my name, my condition, and the scheduled date and place of my procedure. They said they had to talk to Sonia (the scheduler) and would call me back. They never did. In the hospital, Dr. McKenzie did not see me before or after the procedure. The hospital( Glendale Memorial) left me alone most of the night with the nurse-call buttons turned off. I was very uncomfortable and dehydrated. After the procedure I received a $3,300 bill from the "non-participating" anesthesiologist, whom I would have never permitted to touch me had I known they weren't in my network. For my next appointment, I waited for over an hour and a half while Dr. McKenzie chatted with another patient across the hall, who had come in after me. Most of the conversation was non-medical. When he finally came in to see me he explained that the other patient was his pastor. At 90 days after the procedure, I went in for an EKG, after which his scheduler left me an urgent message to schedule a cardioversion. I told her I'd like the Doctor to call me first to discuss what he saw in the EKG before schedulnig anything. I found an email address on Dr. McKenzie's business card and wrote a lengthy email spelling out my concerns and frustrations. He responded with a thorough and thoughtful reply, addressing my concerns, and explaining in more detail my condition and his recommended course of action. From what I've learned from the internet and my other cardiologist, these are the right procedures to treat my condition. I also believe Dr. McKenzie is very, very good at the procedures he performs. The process, however, has been a bit frustrating - and I appreciate Dr. McKenzie's efforts to address my concerns. read more

The worst unprofessional, uncaring Doctor I have ever come across. Don't expect him to return a call or answer any questions unless you pay for a visit. Never would I trust him or want him to be in charge of my life. The good reviews are only of patient with whom he successes letting them live. He is nothing special. Keep looking for a doctor who can fulfill what is needed for a heart specialist. This is the most important decision you can make. read more

Doctor Mckenzie is amazing. He diagnosed and treated my heart problem. He is very busy and you will wait to be seen so be prepared. The wait is worth it when you are being treated by the best! Sonia is the office manager and is also amazing. Everyone is very caring. read more

Dr. McKenzie is a very good doctor. He found out what was wrong with my heart and successfully treated it within a year of the symptoms flaring up. He does a good job of explaining the situations and the solutions. I also like the fact that whoever went with me to my appointments were also allowed to go with me into the waiting rooms. The treatment itself was somewhat painful but that was expected of such a procedure. The only con about having him as my cardiologist is that he is late most of the time to things but makes up for it by being so caring and patient. read more

After suffering from a cardiac arrest while playing soccer, I was assigned to Dr. Mckenzie at Glendale Adventist. It was then that he implanted my ICD and misdiagnosed me with long qt syndrome, and said to get back on the soccer field and go back to my normal life. I saw him for check ups for over a year and a half and during these checkups he never even took my blood pressure or weight. I, being naive and optimistic, thought everything must be fine. Well it wasn't. A year and a half later I had a couple of dizzy spells and decided to take myself back to Glendale Adventist...something was wrong. At the hospital, Dr. Mckenzie ordered an echo cardiogram. Thank God the technician who administered it, told me what was going on. She said I had a dilated cardiomyopathy, an enlarged heart, and an ejection fraction of 30%. As soon as she left the room, I looked up what all that meant online, and it meant that I had HEART FAILURE. Dr. Mckenzie never came back to the hospital room to explain what was going on. Instead, he told me to make an appointment with him in a couple of weeks! All of this time, Dr. Mckenzie had failed to monitor me properly. He was not giving me the right medication, nor should I ever be playing soccer again. I should have been in cardiac rehab, etc. And not only that, but when I gathered my records from my original hospital visit, he even noted that I had a dilated cardiomyopathy and that I should be monitored after discharge and he never told me! Another strange thing is that when I went to gather my records from Dr. Mckenzie's office, they said that they don't have any! They have no records on any of my visits. Sounds illegal right?! After extensive research to find an amazing doctor, I've discovered that Dr. Mckenzie has quite a bad reputation among other doctors in the area. He's an egomaniac, and just does what he needs to to get by. If you're a patient of his, which I hope you aren't because it could be fatal, but if you are, you will notice he's SO busy... Well it's a numbers game to him. He has no passion for the job. He's a slacker... But he's a great actor...very charismatic. Advocate for yourself and always ask to see your records. Now, by the time I leave my new doctors office, he has delivered all of my office visit notes via an app. Also, my ejection fraction is now up, I feel much better and my heart is getting stronger. I have an amazing doctor now whose put me on the right track and he genuinely cares about my wellbeing. Stay away from Dr. Mckenzie. read more

Dr. John Mckenzie preformed heart surgery on me last year and about a month afterwards during my first visit following surgery he had no clue who I was and even after I explaining who I was he still asked me "Did I do heart surgery on you?" My response was "Yes John, you were In the middle of my heart for three hours!" Since then every single office visit I've had with John he's been on his cell phone conversing with his daughters and with his wife. Literally more than half of my short and rushed 5 minute visits he's on his phone speaking and texting his family. My last visit was the kicker. About a month ago I was in his office waiting in one of the rooms and all four doors were left open so I could see and hear John and the other patients. Just across from where I was sitting John was sitting in the room across and he was again taking to his family on his cell phone. Normally it's at lease an hour total wait from the time I sign in so now I'm sitting waiting watching him take his time even longer while he's on his phone. Listening to his words it's clear this is not an emergency phone call nor have any other of his personal phone calls he's made been emergencies. So now his next patient is brought into the room where he is sitting and he doesn't even pause his conversation, stop it nor even apologies to this patient. Finally John gets up while still on his phone conversation and comes into my room. I wait while he wraps up his phone call then he starts to ask me how I'm feeling. I begin to tell him how I'm feeling and while I am speaking he gets back on his phone again and completely cuts me off. I wait for many minutes until he has finished talking to his family AGAIN. I ask "Should I start over or...?" so I start over and during the remainder of this visit he gets back on his phone at least three more times. I have never in my life had any experience with any other doctor even closely to this nor been treated with such lack of interest, preoccupied, uncaring, unconcerned attention to my health and well being as John has proven time and time again. No wonder why he didn't recall preforming heart surgery on me, didn't know my name nor my symptoms. Perhaps if I were one of his daughters or his wife he would pay closer attention. I think John should learn to keep his personal life separate from his profession. Thank you for reading and hopefully you won't have the same experiences as I have. If you still choose to trust John with the engine of your body, your heart, good luck. read more

I went in to see Dr. McKenzie to get refills for my heart medication that I have been on for 11 years, and he proceeded to tell me that he didn't believe I actually had a heart problem (which is the opposite of what my last 6 cardiologists told me since I was a child) and he wanted me to pay for a genetics test (are you kidding me?) to prove that I ACTUALLY had what I have been repeatedly diagnosed with since I was 13. I said sure, just wanting to leave, then got my 6 month medication refill from him. WELL, I just went to the pharmacist to fill my 5th month of refills, and they tell me that it has been called in by Dr. McKenzie to cancel it. SO, even though I'm completely out of heart meds (thinking I had two more months before I had to go to a DIFFERENT cardiologist for my refills) it doesn't matter, because he is trying to force me, out of desperation for my HEART MEDS, into coming back to his office. Avoid this place! PLUS the receptionist is a nightmare. read more