QTc

[Barb1]

My EP's report after my recent Ecg mentions QTc which I have never seen before. Mine is 467. Dr. Google says 451-470 is at risk of sudden cardiac death. Not something I wanted to read at almost 5pm on Friday the 13th. Can someone enlighten/reassure me? I have enough worries with a spine procedure whilst in AF on Sunday.

[etheral]

The QTC interval is a representation on your EKG of your systolic heartbeat. If this is longer then average you have a greater chance of a ventricular arrhythmia which can include ventricular tachycardia or fibrillation which can theoretically result in sudden death. Certain anti-arrhythmic medications prolong this interval this includes the fdoferilide

e which I am taking and does control my atrial fibrillation. I had to be hospitalized for 3 days while the first doses of the doferilide so that the interval could be measured and made sure that it was safe to give. Certainly other factors come into play and you should not assume that there is a one to one correlation between a long QTC interval and southern death. Please discuss this problem with your e p and feel free to ask me any further questions or discuss this matter further. Best of luck ethereal

[Barb1 in reply to etheral]

Thank you. If it wasn't the weekend I would contact him. I am to have a stress echo in early December before starting flecainide before my next ablation, so I guess things are in hand.

[dleppard60 in reply to etheral]

I have recently started taking Tikosyn which increases QTC. Mine was actually over 500 on my last ECG and my doctor said not to worry. He also said that the reading isn't accurate. He said he measured it by hand and it was much less than that.

[Buffafly]

Best wishes for the spine procedure 🦋

[Barb1 in reply to Buffafly]

Thank you. That's so kind.

[doodle68]

Hi Barb 😊 I would be reassured by the fact that your QTC interval has been measured and noted.

Wishing you well for Sunday.

[Barb1 in reply to doodle68]

Thank you. Think it would measure very different when in SR. Maybe that's why my EP wants to do the ablation as soon as, rather than the spring, as he said before....after COVID..Haha!

[Finvola]

Barb - your EP would have been in contact with you, had there been a problem. My QTc reading was 460 seven years ago and has remained stable at around that reading since then. My cardiologist is very content with my ECG's and, honestly, ignore Google which by its nature has to be non-specific.

By all means contact your EP for clarification but try not to worry. If your procedure was last Sunday, rest up and relax. If it is this weekend, very best wishes and relax. xx

[Finvola in reply to Finvola]

Forgot to say that my QT interval is lengthened slightly by my dose of Flecainide and the 'c' means that the reading is corrected for heart rate at the time of reading.

[Barb1]

Yes, you are right of course, he would have been in touch. Procedure is this Sunday in central London, so poor OH has to figure out what to do all day!

[Barb1]

I must say that I am a bit concerned about starting Flecainide. But the other alternative is Amiodarone!

[Ducky2003 in reply to Barb1]

I felt awful with flecainide and had to come off it after 3 days. I have taken Amiodarone on and off over the past 3 years and it's the only thing that keeps me in NSR awaiting an ablation.

[Barb1 in reply to Ducky2003]

That's a shame

[Ducky2003 in reply to Barb1]

To be fair, the only side effect I've had, that I'm aware of so far with the Amiodarone is the corneal deposits so fingers crossed, it stays that way. 😊

[daysyday1 in reply to Barb1]

I've been on flecanide 100 twice a day for a few years and it has really helped control my AF. I've never had any problems with it. Just have a blood test every year.

[Barb1 in reply to daysyday1]

That's good.

[Palpman]

QTc is unreliable if out of the 60 to 100 HB range. A HB of 140 would give you a QTcB of around 560ms if QT is normal.

Normal is no higher than 460ms but depending on which formula of the 4 are used by the machine.

Flecainide would increase this somewhat but you should not worry until it gets over 550ms as that is when VT can occur.

Mine with Flecainide and HB of 60 is 480ms.

[Barb1 in reply to Palpman]

At time of reading my hb was 89.

[Palpman]

I would not worry if it is lower than 490ms as this duration is very controversial.

This repolarization period should not include the depolarisation period as it does with QT. Nor should it be used if QRS is wide ( due to Flecainide).

It has been recommended to use the JTc period as it only incorporates the repolarization of the ventricles.

As a rule of thumb check if the the QT is less than half of RR. If it is then you good.

[Barb1 in reply to Palpman]

Thank you for this. I wish I understood it!