Questions on prolonged qtc

[spade22]

Hi,

I have very recently been  diagnosed with a Morbitz type I heart block and was informed a week ago that I also have prolonged qtc (460, and 470 ms on 2 EKGs, 2 months apart). I have a repeat EKG in a month to follow up on this and have been told, in the interim, to avoid medications that prolong the qt interval.  I have 3 questions:

1) What is the difference (symptoms, treatment options, medications to avoid) between someone with a prolonged qtc interval and someone who has qtc syndrome?

2) Are there any "safe" asthma or antidepressant medications that can be taken when someone has a prolonged qtc?

3) Is a prolonged qtc more concerning in someone with Morbitz I heart block than someone without?

thanks for your input!

[CCFHeartMD 12]

1) What is the difference (symptoms, treatment options, medications to avoid) between someone with a prolonged qtc interval and someone who has qtc syndrome?  -- Long QT syndrome is a genetic mutation in one of several ion channels in the heart muscle, which leads to prolonged QT and an increased risk of sudden cardiac death (ventricular tachycardia or ventricular fibrillation).  This is a rare inherited disorder which most likely had affected other family members.  Most of the time a person who is diagnosed with prolonged QT interval (often expressed as corrected QT or QTc) have a reversible cause, such as taking medications which could lengthen the QT interval, or having nutritional/electrolyte abnormalities (low potassium, magnesium or calcium).  You should check your medication list for agents that could prolong QT (go to http://www.qtdrugs.org/ for a comprehensive list).    Beware that the arrhythmia caused by long QT interval is often called Torsade de pointe (TdP or polymorphic ventricular tachycardia) You should seek medical care if you experience frequent palpitations, lightheadedness or passing out.

2) Are there any "safe" asthma or antidepressant medications that can be taken when someone has a prolonged qtc?  -- Most asthma and antidepressant agents are NOT known to prolong QT.  I would avoid citalopram (celexa).  Most importantly check with your doctors and inform them of your EKG finding. Make them aware of your ENTIRE medication list since oftentimes it is the drug-drug interactions that trigger QT prolongation and arrhythmia.

3) Is a prolonged qtc more concerning in someone with Morbitz I heart block than someone without? --  There should NOT be a elevated risk in patients with pre-existing Mobitz Type I heart block as far as prolonged QTc is concerned, since they affect separate tissues in the heart (conduction vs. contraction).  I would also check your EKG to see what the QRS duration is -- often when people have mobitz type I, the QRS is also widened, which would “stretch out” the QT interval -- a prolonged QT in this setting would not be considered a true QT prolongation.

[swoopy]

A related discussion, long qts was started.

[spade22]

Thank you so much for your input!

I have a follow-up appointment with my cardiologist in a month and the next steps (if any) will be determined (so far no blood work analysis to determine my electrolyte levels, and when I had a qtc of 470 ms I was not on any medication at all).  Albuterol and a number of antidepressatns such as Zoloft/Paxil/Prozac etc are on the list of medications that should not be taken in someone with qt syndrome (which I assume also applies to someone with prolonged qtc...).