Long Qtc all of a sudden

Hello, thanks for taking my question. I am really concerned about the following: i am a fit, healthy 28 year old female, no history of heart problems other than severe anxiety/ moderate panic which cause me some palpitations, white coat syndrome blood presure (usually not much higher than 140/95.

I am on 100mg of zoloft and have been so for around 10 years. This works really well.

2 days ago, I got really stressed at work and had a moderate panic attack, I went to the GP and they did an ECG to reassure me. Everything was fine except the Qt/Qtc which was 446/488 (heart rate was 72). the doctor there said not to worry. Today I had another ECG with my local GP. The result for the Qt/Qtc was 404/484.

I guess now I am really worried, all previous ECGs have been perfect. My Dr says ECGs are inaccurate and has sent the reading to a cardiologist.  My questions are:

1. Why would I have suddenly developed a long qt? I have no family history of it, or history of fainting, cardiac disease etc?
2. Could the Zoloft have brought it and why now all of a sudden?
3. Two weeks ago I had general anaesthetic and flu shot, could this be causing it?
4. Am I in any dangee for torsades de pointes?
5. Can severe anxiety along cause the development of long qt in absence of family history etc?
Thanks so much
Rhia

[Koregol Prabhakar, MD]

Dear Rhia,

I would first like to start replying by reassuring you that  you don’t need to be too worried. Yes if two reports are showing corrected QT to be more than 470msec then its likely to be correct, though your doctor is right in getting the ECG visually reviewed by a physician or cardiologist.

As a group the SSRIs, the class of drugs to which zoloft belongs, are known to cause prolonged QT and that means potential to cause Torsades De Pointes, But again that falls into level four risk, which means the risk is extremely low. It is possible to have congenital QT prolongation but since you have had perfect normal ECGs in the past that is less likely.

As for the possibility of this being related to your general anesthetics or the adjunct medicines that they give, it is possible, but persistence is unusual. Still it would be worth rechecking the list of medicines.

Sometime QT prolongation due to drugs can occur in later phase of its use, and may be associated with stress and electrolyte abnormalities.

At this stage, at the current level of QT, I would suggest it is wise just stop zoloft for few days, let’s say a week, and recheck QT. If it normalizes, and especially if it gets prolonged on reintroduction, then it proves the causal hypothesis. You will need to stop and avoid zoloft and preferably all SSRIs if possible.

As of now you have very low risk of torsades de pointes and need not worry much unless you develop some symptoms.

Yes severe stress, electrolyte imbalance and other causes can produce QT prolongation especially on a background of drug induced or congenital QT abnormalities. If you persist to have prolongation after stopping the medicines, you might need further workup, but not get too worried.

Hope that this information helps and hope that you will get better soon.

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Best Regards.
Dr. Prabhakar Koregol

[saedsak]

There are 2 types of LQTS (inherent and acquired)…. If your QTc was OK and then become long it could be the medication you are taking or your blood potassium or magnesium level are low… check it out. Remember, I am not a doctor but I have seen this info somewhere in the net