Qt Interval

[zasalamom]

Hi. Does anyone know the range for the QT interval. I have see "Prolonged QT Interval" on 3 out of 4 of my last EKGs as follows:
107BPM QT=300  QTc=400
79BPM QT=418  QTc=479
66BPM QT=420  QTc=440
68BPM QT=464  QTc=493

I had some chest tightness/ pressure in my throat/sustained tachycardia most recently after tennis [which I normally play without any problem]. Had a normal heart cath and echo. Only thing that worries me is that the tachycardia happened again today for about 7 hours it stayed at 110BPM or so and the QT interval thing is a worry.
Any shared experiences etc would be appreciated

[firemedic818]

QT interval,   QT interval is supposed to be between 0.33 and 0.42 any longer than that you are susceptible to certain ventricular arrythmias would discuss the EKG with the doctor definately!

[Sammie4258]

I agree with the earlier post.  You need to have this checked out.  There is a doctor in SLC, Utah who is one of the top ten specialists in the  world for her work on LQTS.. Several members of my family suffer from this.  The beta blockers work wonders and it is life saving.  some of their symptoms were palpitations, skipped beats, racing heart rate, and fainting spells.  I have these and seizures.  It is so treatable.  This is a very deadly syndrome and must be addressed if you have it.  also, if you are under 50 years old, you are especially at risk. This syndrome can  kill a 6 year old.  My 10 year neice has it also as well as her mother, and grandfather.  it will be very important for you to have your children and grandchildren checked.  Please notify your cousins, uncles etc.
If you make it past 50 years old, you may not need treatment.  The theory is that it is a young persons syndrome.  They did not put me on any treatment because I will be 50 years old in June.  They figure I am probably safe.  My dad is 81 years old and we just found out the he has it and is the carrier.  His dad died at 48, and his dads brother died at 42 along with my brother at 42.  Very dangerous.  It also needs to be monitored and genetic testing done to see how the gene is mutating.  They are acually doing a large study on my family alone because it is so prevelant and the gene is becoming very dangerous.   About 50 members of my family and relatives had to be check for this.  So please don't mess around with it.  Much to dangerous.  
Sammie  

[stevie_wonder]

Hi,
I have Long QT Syndrome and know a bit about it, but you are still best off to try and get a referal to an Electrophysiologist that is experienced with Long QTs. Visit the www.sads.org website and they will help you find a doctor in your area. While the machine can be wrong when it measures the QT interval, your last ECG with a heartrate of 68 and a QTc of 493 is way too high if it is correct. Most people with LQTS have normal Echos and have no major symptoms other than what you are describing and sometimes people have no symptoms at all. Is there any history of fainting or seizures in your family? Do you have any children., if so, they should be checked as well. But please find an experienced EP as regular cardiologists are notorious for not being able to diagnose LQTS. LQTS is a serious condition if left untreated, but is very treatable with Betablockers and in extreme cases or if a person has had a cardiac arrest, defibrillators are implanted. Most people live normal lives.
I don't mean to scare you but I just want to let you know that this needs to be checked out.
There is a support group at
http://health.groups.yahoo.com/group/longqt/
You just need to register a Yahoo account and you will find this group very helpful as many of them are very knowledgeable about LQTS.
I hope this info helps you.

[stevie_wonder]

That is good that you are under the care of a cardiologist, but remember that they are not always correct in their information about QT intervals. Even though your QTc has lowered, a Long QT is a Long QT. QT intervals can change very rapidly in people with LQTS. Just visit the SADS website and check it out for yourself.
Sorry to sound like a mother hen, but I feel compelled to share with others when it comes to this.

[zasalamom]

Thank you both. I am under the care of a cardiologist and the heart cath and ECHO are within the last two weeks, both normal. I do understand about the EP. The QTc at the top are the most recent. The one 493 is old, but those are the only 4 EKGS I have had. I will follow up for sure.

[maggiemag]

What did your doctor say about it?  I would tend to believe whatever s/he said, as we are not doctors.  Have you seen a cardiologist?  110 is just above what is considered tach, and some might not think it abnormal.  If it was recent, was the weather hotter than usual?  I think your rate can stay higher if you are dehydrated.