About 2 years ago I went to the ER with a fast heart rate. I was relaxed and not doing anything at the time. It went up to about 155. When I got there they did many tests (blood work, urine, and 2 EKGS). All normal. Vagel maneuvers did not correct the fast rate which was sustained around 150 for four hours or so. Finally I was given 40mg of propranolol and it went down to 80. My chest ached so much. I wore a 24 hour halter that night. And I had an echo 2 days later. The cardiologist said that I had SVT. For many years I had gone to the Dr and ER with similar symptoms and was told it was panic/anxiety. The Cardiologist said that it was likely always SVT. I was put on 120mg of propranolol a day and once I got used to it, I was fine. Actually felt so much better. Before the episode I had been having PVCs (I called them flutters at the time) A LOT. The med changed my life and I got pregnant soon after and continued on the drug. Everything turned out fine. However, something is bugging me. During that time I saw an EP cardiologist who had all my records of the tests I had taken. He said nothing to worry about. He saw nothing to be ablated and that it may even be IST. Well, why cant they tell for sure if it is SVT or IST? Both the EP and Cardiologist just said to stay on medication and no followup is necessary. Said I am fine. Well, all of a sudden developing a heart problem doesn’t seem fine to me. And it bothers me that I do not know FOR sure what I have. I mean, if they are not sure whether it is SVT or IST…how can I be assured it isn’t something dangerous?? Are they basing their ideas on the holter mainly? I was on the propranolol the day I had that on…wouldn’t that make a difference in diagnosing? How can they be so sure I am fine and in no danger if they are not even clear as to whether it is SVT or IST? Know what I mean??
This has defiantly caused much anxiety for me. Having these sx for so long and being misdiagnosed and basically ignored, created a health anxiety. I am working on it with therapy and medication (klonopin). But I feel that some answers here may help me. I have called both Cardiologist’s offices and they seem almost annoyed with my questions.
I have requested my medical records and all test results. I dont know if reading them will help me or not..but at least I will have them.
Neither SVT or IST are going to kill you. Since you are young and have no other heart problems, it is extremely unlikely that your episodes of tachycardia are anything dangerous. Your cardios aren't concerned because you aren't exhibiting any symptoms of anything dangerous, and you are young and healthy. My guess is that what you have is IST though, because if you've had an episode caught on an EKG, they could easily tell that if it was SVT. Normal EKG = IST as far as I know.
It must not have been clearly SVT when you were in the ER, because if it had been, they wouldn't have left you in tachy for so long before converting you. When I go to ER with SVT they always convert me immediately using Adenosine.
I have no doubt that you aren't in danger. I understand what you've gone through, though. Everyone also told me I was just having panic attacks for years even though I knew they were wrong. Finally I bit the bullet and went to the ER during an episode and it was caught on EKG, and they immediately identified that it was SVT. But in the years before I was diagnosed I developed a severe health anxiety, like you. The good news it that with meds and/or therapy, you absolutely have the opportunity to live a normal life again.
Timber,
Thank you so very much. It has been frustratng because the research I have done on SVT and IST makes it even harder to determine. I have SO many sx of IST but not all. And same with SVT...but less. Like what I read about SCT is that is usually doesnt last hours and it goes much higher than 150. I too thought it was more likely IST...but from what I read about IST it is a constant high rate. Where as I felt mine jump from normal to 150. I do think my resting rate was typically higher than normal, but I never checked my pulse before this. I think this is what caused so much anxiety and unhealthiness in my life. I am coming to terms with the fact that this will not likely kill me. But it is hard. I wonder if there is anyway to find out for sure it is IST.
Anyway, you response makes so much sense and was so helpful. Thank you very much!!
Haha, I know the frustration - I was told I had sinus tachycardia and put on Toprol for a week (with horrible side effects -- chest pain, arm pain, shortness of breath, just generally feeling baddddd) only to find out today that I don't have tachycardia at all.
However, during the time after I had been told I had tachycardia, I did a lot of research on it and I did learn some things ... what you're describing does sound like IST and not SVT ... if it was SVT, they'd have caught it, almost definitely since they did an EKG. People with IST (inappropriate sinus tachycardia) have normal EKGs/holters other than the fact that they are, well, faster than usual!
I know it's stressful though, and the added anxiety doesn't help at all ... still though, I truly believe your doctors would know if it was SVT.
Thanks for your response. That is why I cannot understand why my cardiologist seemed so sure it was SVT. She is one of the best cardios in the area. Then the EP was like "Yea..it may even be IST.." Like it could easily be either one. I dont get it!!!!!!!!
I'm so confused too. My Cardo told me at the end of Jan-05, that I had SVT.
I went to him because I have flutters. (a couple times a day). They also hooked me to the holter for 24 hours. They caught a lot of my flutters,but also that late night I developed the flu. So needless to say, my heart rate went faster. I did note that in my journal. So, I am also wondering if they said, I have SVT because they saw the rapid heart rate in the evening or because I was having flutters. When I do have flutters my heart rate is not fast. Good luck on your search, I hope someone here has an answer for you. If anyone else could respond. Does SVT have to have a fast heart rate along with flutters or can fluters alone be SVT. Thanks
SVT stands for Supraventricular Tachycardia, and tachycardia means fast heart rate. SVT is by definition a very fast heart rate that originates in the atria instead of in the sinus node where it's supposed to.
So the answer is that you must have a very fast heart rate to have SVT or it isn't SVT.
HI, I have IST. It was first diagnosed as SVT. The diff is where the tachy originates. From what I went thru it seems by just an ekg it may be hard or impossible to tell. They were able to tell during a TTT I had for my NCS diagnosis. The EP did a carotid massage and had me do vagal maneuvers and that is what led to the IST diagnosis. Again I am just going by what I experienced, it seems that since the maneuver didn't effect yours it might be IST. IST is not a continual high heart rate.
HI, I have IST. It was first diagnosed as SVT. The diff is where the tachy originates. From what I went thru it seems by just an ekg it may be hard or impossible to tell. They were able to tell during a TTT I had for my NCS diagnosis. The EP did a carotid massage and had me do vagal maneuvers and that is what led to the IST diagnosis. Again I am just going by what I experienced, it seems that since the maneuver didn't effect yours it might be IST. IST is not a continual high heart rate.
May I ask what do you do for your IST? What symptomsdid you experience and how often? How high would/does your HR go?
I didn't have any palpitations to clue me in, so my neuro was testing me for a year before deciding to rule out heart problems. My symptoms were fatigue, brain fog, and feeling like I would faint. That may have been a combo of the IST and NCS. The highest they caught my heart rate was 170 bpm. I am taking a beta blocker. At one pt. I was taking a calcium channel blocker too, because I could only take a sm. dose of bb before getting side effects. I don't think IST goes as high as SVT's. (I, also, have mild MVP, MR and TR.)
Sorry, Rayne and thank you , Timber. I am currently taken bisoprolol 5mg. I started on atenolol and couldn't manage more than 12.5mg and that is when I had to take a ccb to help with the tachy. I have taken another (I can't think of the name), too, that seemed ok but again with the ccb (verapamil ER). I stopped the ccb after getting out of the hospital a 3rd time this yr.(unrelated to heart), because ea. time in the hosp. they had to take me off both bb and ccb, because my bp would get dangerously low (I wasn't up and about). So, I decided to try just taking the bb and seeing how it goes. Unfortunately, I may be getting tachy and not knowing it, like in the beginning and times caught after. Hopefully it isn't for long periods if I am. If you watch my hr on a monitor for 2 or more mins. it's all over the place. I saw you posted on another forum and am interested to see the drs.' answer. Good luck
So basically the BBs made your BP too low and those are the effects you were speaking of? I worry about that sometimes. I dont have a monitor. But wonder if that could account for my lightheadness and extreme fatigue. At the Dr office I am usually 100/60 or around there. When I was in labor it kept going down to 60/30 and I was so scared. I think the epidural caused that along with the BBs. I was pretty out of it and asked the RN "What if it goes to 30/0?" She said bluntly, "Then youre dead." Nice, lady...thanks. LOL. I am assuming that the NCS causes the majority of your symptoms? Do you have any anxiety over these issues?
I don't have anxiety, fortunately. I did 1st finding out about the valvular disease, because I was ignorant then and my mother had just died 4 mos. prior due to chf and she had had a mitral valve replacement. I am told the tachy was causing me to be deprived of oxygen and so it was part of my symptoms. Also, my usually low bp came up a good bit, this they said was due to my heart beating more efficiently and with a real blood supply. I don't have trouble with my bp when I am well and up and about. It was after two surgeries and being laid up for post-op infections, all within 6 wks, that the bp got too low. I was in bed all that time and longer, so it's a natural response that was made worse with the bb. My EP had me on salt tabs at one time to keep my blood volume and bp up. BB's can make you fatigued and lightheaded, that is why they say get up slowly. But they were the symptoms I had from the tachy and NCS, and the beta blocker took care of that.
Re: Angry, Confused, Frustrated 
