Dofetilide, the hospital, and me

What an experience

by Gemita - 2024-06-16 03:40:33

SGMFish, thank you so much for the update.  We know from your previous post that two members have had success with Dofetilide (Tikosyn), and I hope you will too, although I do appreciate Dofetilide is a powerful anti arrhythmic med and may need to be monitored closely to make sure that you remain safe.  Hope you are not getting any unusual symptoms/side effects so far?

I am sorry you had a miserable time in hospital while they were testing Dofetilide but if taking Dofetilide leads to firm control of your atrial tachy arrhythmias, then it will all have been worthwhile. 

Personally, I don’t think the results were bad at all, other than the fact that you needed a cardioversion to restore normal sinus rhythm (NSR) during your hospital stay.  I would have hoped Dofetilide could have magically restored NSR on its own but you had persistent Atrial Fibrillation (AF) at the time so a helping hand was required.  I would be happy that you appear sensitive to Dofetilide at the lower dose.  I hope that once your body gets used to this medication, there will still be room for up-titration of Dofetilide if it is ever required to control any break through AF episodes without causing QT abnormalities. 

I suppose the question I would like answered, is what your QT interval range was without Dofetilide or before Flecainide/other meds?  Actually, I wonder what mine were too, especially before AF.  I see the QT interval changes in response to heart rate where the interval is shorter with tachycardia and longer with bradycardia. Therefore, QT interval is always corrected (QTc) for the given heart rate using a variety of mathematical formulae, a process often performed automatically by modern ECG recorders.

I see that a normal QT range for men is between 350 to 450 ms and for women between 360 to 460 ms, although 10%-20% of otherwise healthy folks may have values outside these ranges.  An abnormally long or abnormally short QT interval is associated with an increased risk of developing some serious heart rhythms disturbances.   If anyone wants to learn about the QT interval, the following link might be helpful on long QT:

https://www.ncbi.nlm.nih.gov/books/NBK441860/

and if any member wants to read about Dofetilide to treat an arrhythmia, I attach a link on this too:

https://www.ncbi.nlm.nih.gov/books/NBK459154/

I hope Dofetilide works for you SGMFish because I know you have tried absolutely everything to control your AF from cardioversions to ablations.  The next step would possibly be resynchronization therapy but I hope it won’t be necessary.  Stay patient.  Perhaps Dofetilide will be the answer?

Same

by godrew - 2024-06-17 09:41:46

I had similar experience when I changed meds to tikosyn.  Hanging in the hospital isnt great but i figured it could be worse.  I also had to be cardioverted on day 3.  I did the same stay years ago when I switched to verapamil from atenenol.  They do the vitals basically every 3 hours and that is a bit of an inconvenience, but I wasnt starpped to the bed and was able to walk around the floor and stretch the legs a bit.  I figured it would be better to be watched while trading meds incase something wasnt right than at home.  I have had a few AF episodes recorded over the last year, but the dr claims looks good as of my in person EP visit last week.  Hopefully it works for you and you have no issues taking it.

good luck.

The advanture continues

by sgmfish - 2024-06-17 16:32:22

Gemita, while it is true I did not enjoy my hospital stay, I said that a bit tongue in cheek since, of course, the only real discomforts were boredom and restlessness (I wasn't in pain or anything). And surely it was well worth it to find out if dofetilide (Tikosyn) will work for me. I am not noticing any side effects so far except yesterday while doing light yard work I felt strangely light headed, but perhaps I was just tired. I'll wait and see if that, or any other future, side effect continues. You are likely correct that my results may well be positive in the final analysis. From what I think I know, dofetilide's benefit will be that my Afib does not comes back, or at least doesn't for many months (as opposed to days as it's been in the past). This I won't know until enough time has past. If dofetilide does the trick, then clearly it will be to my advantage that I got the benefit from only a 125 mcg dose; however, I presume the odds of success are higher at higher doses. To answer your question, my QTc was 377 back in 2020 before any intervention (including my PM). My QTc was 378 msec a few months before I started flecainide, and rose to 504 msec in late 2022 within weeks of staring flecainide. A month or so before this dofetilide process, my QTc was 540 msec with readings usually anywhere from 415 to 495 during the previous year (note that 50 msec "PM bump" may be in those numbers too in a way I don't really understand). So my surmise is that my potential benefit from dofetilide will be limited due to me having so little "headroom" in my QTc. You mention the future......I have an appointment on 6/27 with my EP to discuss just that. CRT is definitely one of the options we've already discussed (altho we haven't thoroughly discussed where the new lead would go.....there are some therapies in which the lead goes into the septum in the right artium "below" where my AV node blockage may be if such a point can be found).

godrew, thanks for the "been there, done that" support. I does me good to hear from others who have been down this same path. I was especially heartened to know that you too had to be cardioverted on day 3 (altho I presume this is not atypical). I too was able to walk a bit if I unplugged the monitor battery charging source, but since I had to hold the monitor in my hand (or in the awkward pocket of the hospital gown), I found it easier to mostly just stay in bed.

I hope you stay in blissful normal sinus rhythm

by Gemita - 2024-06-18 03:39:26

Thank you so much SGMFish for the additional information. 

I recall I had a few problems on Flecainide which stopped working effectively after a few years.  Partly my fault because I wasn’t taking a rate control med like a beta blocker at the time to slow conduction through the AV Node, to protect the ventricles from being pushed too fast. 

My AF intermittently develops into Flutter at very high heart rates.  A beta blocker might have prevented this.   I am now doing well with my pacemaker and a very low dose beta blocker.  I have stopped all anti arrhythmic meds because they became pro arrhythmic.  My atrial tachy arrhythmias while still occurring, are well controlled duration wise, lasting minutes, occasionally lasting several hours, but always converting to NSR without intervention.

Your statement:  “I presume the odds of success are higher at higher doses” doesn’t always hold true, especially if “more” comes at too high a  cost in terms of worsening side effects, QT prolongation and a dangerous ventricular arrhythmia.

I expect you will be getting regular checks of your electrolytes and kidney function.  I know doctors like to monitor potassium and magnesium levels periodically in patients who start anti arrhythmic QT-prolonging medications like Dofetilide.  They also like to monitor kidney function since Dofetilide is renally cleared.  Any overdose/toxicity from Dofetilide would clearly show up as increasing QT prolongation, complete heart block or a dangerous ventricular arrhythmia, so I am sure all of these will be taken care of through normal monitoring/pacing.

As to the future, who knows what the future holds for any of us.  All we can ever hope for is to live well for today.  I hope that Dofetilide will help to control your AF to allow this.  My EP even mentioned an AV Node ablation at one stage, but I felt this was too final and certainly wouldn't stop the AF or any other atrial tachy arrhythmia in the atria from occurring.  An AV Node may still be in my future but for the moment I am leaving well alone.