Can a routine EKG diagnose long QT syndrome?

Question

Hello doctor,

I have been having random bouts of waking up with a high heart rate. My heart rate was 167 bpm, which was sustained for 10 minutes, and the same thing happened two other times. I have had a decent cardio workup, but curious if common tests would pick up LQTS 3. I have a low heart rate at rest, typically in the high 40s.

I have done a stress test, cardiac event monitor, and heart echo for newfound palpitations while exercising. Currently, I am also taking Losartan, Prozac, and Xanax. How is LQTS 3 diagnosed if that is typically only a problem at night? I know that QT prolongation is usually diagnosed by an EKG, but I was curious if LQTS 3 is also picked up on an EKG since that is typically only a problem at night or rest. Please clarify.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and understand your concern.

Palpitations can be induced by various precipitating factors like anxiety, panic attacks, smoking, alcohol, caffeine, or underlying cardiac issues. So these factors need to be taken care of.

Secondly, did any of your reports say long QT interval? Mostly, it is a genetic problem that runs in families and may lead to cardiac arrhythmia. Do you have any family history of such events?

Most importantly, you are taking Prozac (Fluoxetine Hydrochloride), which is known to cause long QT interval. Long QT can be picked through 24-hour Holter monitoring.

I suggest you share your echo and stress test report with me.

I hope these recommendations help you.

Feel free to reach out if you have any further questions or doubts.

I hope this answer helps you.

Thank you.

Answer 2

Hello,

Welcome back to icliniq.com.

I have gone through your reports (attachments removed to protect the patient’s identity). Your stress test is inconclusive; it does not signify any ischemic heart disease. Your long-term cardiac monitoring shows non-sustained ventricular tachycardia, which explains your short period of palpitations and shortness of breath.

I would suggest you start taking beta blockers like Metoprolol or Bisoprolol after consultation with your specialist doctor, which would control the abnormal heart rate and palpitations. If it had been a long QT, then it would have already been picked up on the above tests. Further workups, such as genetic testing, may be required if you have a family history of long QT syndrome. I would suggest you follow a few instructions.

Avoid excess tea, coffee, or alcohol.
Eat more fruits and vegetables daily.
Do breathing exercises and yoga as it works very well on heart rate control and palpitations.

Hope this helps.

Thank you.