Atrial flutter question

The typical treatment for atrial flutter is ablation of the CTI, and I understand that to be true because ablating the CTI should cut off the circular activation path in typical right atrial flutter.

But... is the initiation source with typical atrial flutter still the myocardial sleeve of the pulmonary veins, just as it often is with atrial fibrillation?

Always trying to understand better!

Karen

Typical flutter is in the right atrium. It is not directly triggered by activity from the PV, but it can be induced by AF generated in the LA. This often happens, the patient having afib with flutter intricated.
As you wrote, typical RA flutter is often treated ( with very good success rate) with a CTI ablation. Flutter is hard to stop with rhythm drugs.
It is said that RA flutter may trigger afib, but when you have both, it's likely the opposite. In this case, ablating flutter only is often useless ( it was useless for me, but the first EP I met thought it could work). But when afib is ablated, a CTI ablation is usually performed before removing the catheters.
There are atypical flutters too. They can appear after an AF ablation.
All this is among the reasons why it is repeatedly recommended to have the ablation procedure performed by a top grade EP. I've learnt (here and from my own experience) it's rarely the guy next door.

I agree with everything Pompon said. I had both afib and flutter, and I don't think the flutter ever triggered the afib, but the reverse sure happened. My episodes would often begin with a very irregular heartbeat that was undoubtedly afib, but then within seconds it would turn into flutter, which is very regular. I actually had multiple flutter circuits. An ablation in 2014 found and eliminated one of them, and then Natale zapped the other two in 2017. I had a left atypical flutter that originated from my left atrial appendage and produced a heart rate of 230-250, and also a right flutter that originated in my coronary sinus and produced a slower rate of about 120.

Another reason why flutter-only ablations often don't work, or don't work forever, is because there's good evidence that having flutter often means afib is in your future. The two are closely related.

Right. In this case, I am specifically asking about where the rogue electrical activity originates with typical (right) atrial flutter that appears subsequent to a confirmed afib diagnosis (in a 1yr paroxysmal AF patient) and before ANY cardiac ablation has been performed. I didn’t state my question clearly enough.

Is it safe to say that whatever the left atrial activation sites are in this case, without them, the flutter could not occur?

Ectopics in my RA came from superior vena cava. I don't know if those ectopics themselves triggered RA flutter, for my flutter was always intricated with afib.
I've had a more recent flutter episode, which happened in the beginning of the blanking period after my last touch up ablation. It was likely atypical flutter, triggered by 100mg of flecainide I took to stop an afib attack.
It did last a dozen hours, without any afib. The rhythm was regular, around 120bpm. Clearly, the flecainide had turned my afib to flutter.

@ Carey : I never experienced afib or flutter above 180bpm or so... How did you feel when having your very high rate flutter episodes ?

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kbog
Is it safe to say that whatever the left atrial activation sites are in this case, without them, the flutter could not occur?

That's an interesting question and I'm not sure anyone can answer with certainty. Afib definitely isn't a prerequisite. You can experience flutter entirely by itself without any afib activating it. Atrial flutter is a single signal going round and round in a circle propagating itself. It's usually caused by an electrical barrier of some sort with a gap in it. That barrier can be fibrosis, scar tissue, or an imperfect ablation line (my cause). So no matter what triggers it, once triggered it will sustain itself, potentially indefinitely. I think all it requires to be initiated is a single cell in the right location firing at the wrong moment in time. Without the flutter circuit, that single signal might not be noticeable even on ECG.

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Pompon
@ Carey : I never experienced afib or flutter above 180bpm or so... How did you feel when having your very high rate flutter episodes ?

I felt like crap, but I tolerated it remarkably well. The first time it occurred I just happened to be in my EP's office for a followup visit. It started when I was sitting in the waiting room. I knew I had a very fast pulse but I had no idea how fast until they got me into an exam room and hooked me up to the ECG. When the nurse saw the numbers her eyes got big and she went to get the EP. Even though it was varying between 240 and 250, I was sitting there talking to them, feeling like crap but in no apparent distress. That amazed them all. Every NP, PA, and RN in the building came in to marvel at the guy with a rate of 250 who was sitting up casually talking to them. They tried to slow it down with metoprolol, but even 200 mg didn't touch it. All that did was kick the chair out from under my BP, landing me in the EP lab with a BP of 50/nothing in need of an emergent cardioversion. In the ensuing months I became a regular at the local ER since cardioversion was the only thing that would stop it. Pretty soon they knew to get the propofol and defibrillator as soon as they saw me walk in without bothering with the usual attempts to slow it down with diltiazem, which I would refuse since I knew it wouldn't touch it.

OK, thanks. I had a PVAI + PW + SVC ablation 3 weeks ago with Dr. Natale. While off flecainide in the 5 days before the procedure, I kept going in and out of rhythm, and the ECGs they did both the day before and the day of the procedure showed typical atrial flutter. Since I'd had a CTI ablation in February of 2018, I was surprised that this was possible (however I now understand that, so that's not an issue here).

I asked Dr. Natale after the ablation whether he "went over" the CTI line (as he said during the consultation that he might), and he said he didn't end up doing so (all ablation was done on the left side). Now I'm just wondering whether the left atria were definitely the only source of arrhythmia for me. I guess I have to assume so at this point, since he could not initiate arrhythmia with isoprotenerol in either atrium after ablating(?).

I thought perhaps there was a known answer that meant any details of my individual case were immaterial, but it sounds like as with so many afib-related things, "maybe" or "it depends" is the answer.

The one thing I think you can be sure of is if Natale says he fixed it, it's fixed. :-)

Carey, it often amazed me how medical staff and even cardiologists or EP's couldn't imagine what WE afibbers are feeling when in afib or flutter..

Oh, I agree. I don't think anyone who's never had highly symptomatic afib or flutter really understands how miserable it can be. The "just live with it" mentality we see so often proves that.

Let’s stay on topic here, guys.

Actually, I realized after I wrote my last post that the SVC is located in the right atrium. So I guess there’s my answer!

Hi Karen,

Pompon and Carey both gave a good review of typical right atrial CTI Flutter. The SVC (Superior Vena Cava) is part of the CTI Flutter’s typical counterclockwise rotational circuit (that can also manifest as clockwise rotation as well as lower loop reentry) as it loops around from the IVC/TA junction at bottom of the right atria and following the Crista Terminalis to the SVC area at the top of right atria. And the fact that you had a prior CTI that ‘leaked’ causing some flutter episodes may well have been buttoned down from the SVC isolation in the right atria that Dr. Natale did during your ablation.

However, the actual ablation lines for acheiving a bi-directional block for a CTI flutter circuit happen at the far bottom of the right atria and runs only between the Tricuspid Valve annulus (TA) and the IVC (Inferior Vena Cava) via the Eustasion Ridge and across the ‘pouch’ including ablation across a number of small wave-like ridges between the TA and IVC.

Cheers!
Shannon



Edited 3 time(s). Last edit at 03/15/2019 10:36AM by Shannon.

Shannon, it's interesting precisions.
I'd like to see a drawing showing those ablation lines - other than typical PVI lines - on both atria, with their meanings. It's sometimes a bit difficult to imagine.