Dear Leah,
I hope your atraial remains "controlled" or, better still that you revert to sinus rhythm, but can I take this opportunity to briefly explain a few things about atrial fibrillation that might help folk understand some of the issues with atrial fibrillation, and please excuse me if you understand all this quite... and I'm sorry as its always challenging to explain this in a few paragraphs ...but anyway, here goes. Please feel free to NOT read this if you get a headache.
Normal electrical conduction in the heart is initiated at the Sino Atrial node (you can liken this to the "spark plug" of the heart). The SA node "depolarises" or rapidly alters polarity as ions (mainly sodium and potassium) move through little "gates" in the cell membrane. This causes a wave of electricity to move across the atria (which is visible on your ECG in lead II, as a small, upright wave called the "P" wave). If the atria are healthy and have a good supply of blood and oxygen, this electical stimulation is rapidly followed by a well coordinated effective contraction of the atria and blood is pushed into the ventricles, giving them a "stretch" called the "atrial kick". This atrial kick is important, as it has an influence on the subsequet force of contraction of the ventricles....a bit like a rubber band...the more you stretch it (to a point) the better the subsequent force of ventricular contaction. Now, after the atria contact (and while the ventricles are filling and stretching) the electical impulse across the atria then pauses momentarily (about 0.2 of second +/1 a little bit) to allow the ventricles to stretch aand fill properly. This pause happens at the Atrio ventricular node (AV node). Its amazing...and quite a few things can cause all this to go wrong, and differnt drugs act on the SA node and the AV node and so on and so on...
NOW for the crunch....if our atria get stretched (after a faulty valve or whatever) or as it gets older over many years, of if AV node or the conduction pathways in the atria getphysically damaged during surgery, then the atria can get very "irritable" and instead of the SA node (or the spark plug) controlling the electrical stimulation of the atira, the atria themselves just go beserk, and start to "depolarise" or "fire off" all by themselves..l..and the catch is this..atria basically go beserk at a rate of about 300 times per minute, and this is seen on the ECG as small fiblatory waves...little squiggly lines between the big complexes on the ECG like...but if the AV node does its job properly, the ventricles will only get an electical impusle at reasonably normal intervals...this is called "atrial fibrillation with a normal (or controlled) ventricular response"...whilst the ventricular reponse will indeed be irregular (because the atria are going beserk at an irregular rate), and you can feel that as a randomly irregular pulse sometimes, BUT the pulse overall is at a fairly normal rate..ie below 100 Beats per minute or slower. Some people can live all their lives quite normally with this...although most people will require some sort of "anticoagulation " medication because the blood goes around and around in the atria ( with are fibrillating) and small clots can be formed in the atria (which is not good as this can cause a pulmonary embolus or a stroke). However, the atrial "kick" is lost, and the ventricles don't fill as good as when the atria are contacting normally, so some people may need some drugs to help their ventricle contract more strongly, but don't need their ventricle rate slowed, because the ventricle (albiet not filling completely) just don't contract rapidly for them. So dugs that make then ventricles contact forcefully (perhaps digoxin) might be needed, but not drugs that slow the heart rate itself.
BUT...some people, when their atria fibrillate, and their AV node does not "control" the ventricles properly, (or if there is a little "short circuit" into the ventricles), can have their ventricles contact rapidly when their atria fubrillate...and this is what Leigh is talking about. Palpiations, a fast heart rate (which really means that the ventricles are caontacting very fast) this condition is called..."atrial fibrillation with a fast ventricular response"...and kids and young children can tolerate this for quite a while (although quite rare in kids), but as for us, our ventricles get tired if they go too fast for too long, and eventually after minutes or hours we can develop chest pain...just as if our heart has run a marathon...and in this instance, the solution is a few methods...either stop the atria from fibrillating (ie going beserk) or slow the electical conduction through the AV node (the gatekeeper to the ventricles), or just slow the ventricles themselves... and thus the atria keep going beserk with afib, but the ventricles are "controlled" and the pulse slows to a normal rate......and the choice of what to do is sometimes a little tricky, and it needs expert medical care to determine what is the safest and most effective thing to do in your particualr situation.
So what does all that mean....
There are some medical choices, and it all depends on our age, the cause of the afib, the length of time we have been in afib (ie Hours vs days), what sort of drugs you can or can't tolerate, and the risk vs benefit etc etc..its not easy sometimes, and some very experienced medical care is the order of the day thats for sure.
1. Electical cardioversion, or a low energy shock across the chest can sometimes "revert" atrial fibrillation and get us back into a sinus rhythm. I needed this when I was in surgery and the cardiac bypass machine was taken off me. As my heart was rewarmed...it started up in "atrial fibrillation with a rapid ventricular
response"... my heart was immediately "cardioverted" with a very small electical shock and my heart went back into a "sinus" (normal) rhythm, and I was later placed on B Blocker in the hope that it would stay in a sinus rhythm, which it did...and the B blockers were stoped after a couple of months. Some people have automatic implanted cardioverting defibrillating pacemeakers, and they can do this cardioversion automatically sometimes.
2. Pharmacological "cardioversion" is another option. Where medicinces are used to stabilise the atrial cells to stop them going beserk.
3. Or ventricular rate control...ie let the atria keep going beserk, but control the electrical impulses (which are occurring randomly at over 300 per minutes in the atria) that get into the ventricles...so the ventricles themselves slow down, your pulse slows down ..some beta blockers can do this, digoxin (lanoxin) and some other drugs can do this, some can be used long term, some should only be used briefly. Amiodarone acts in a number of ways, and can have some effects on both the atria and the ventricles, so it can slow or stop the atria from fibrillating AND also slow ventricular rate...but there are risks and benefits and side effects with all these treatment options, and the right choice "just depends"...it depends on a whole range of thise, not the least of which isthe urgency of the need to do something.
Some people can collapse unconscious with atrial fibrillation with a rapid ventricular response, and they need urgent electrical cardioversion (with a defibrillator)
Some people live a normnal life with atrial fibrillation, and it is indeed THE single most common heart dysrhythmia...millions and millions and millions of people have atrial fibrillation...and most have a "controlled" ventricualr response (else they would get pain, light headed or collapse)...and digoxin was the most common medication used over many many years to treat or control atrial fibrillation and also make the heart contact more forcefully. There are now more options but once again ...it all depends.
So...what does all this mean...be guided by the experts as to how your afib is treated and managed, (if at all) as it depends on how long your afib has been going for, how old we are, what may have caused the afib, what drugs we can tolerate in the short erm, what drugs we can tollerate in the long term.
My hope would be that my atria actually stop fibrillating altogether..ie, then I have a sinus rhythm, my ventricles get the "atria kick" and I can avoid lifelong anticoagulation. So either an electrical cardioverting shock, or a short acting drug or as perhaps a lifelong drug..whatever is needed to stop the atria from fibrillating in my particualr situation...
If my atrial fibrillation could not be stopped, then the next thing I want is for my ventricles to be slowed so they at least contract at a normal rate, but I would then need to have aspirin and likely also warfarin to stop little clots forming in my "beserk" atria, and I might alos need something if
So if the doctor says I am going to give you amiodarone, it may not be for life, it MIGHT just revert the atrial fibrillation and slow the ventricles, and then you might be taken off the amiodarone....so ...after all that blurb...be careful what you ask for when they treat your atrial fibrillation ....sometimes you might get what you ask for, but that might come at another significant unwated cost. If I could get a bolus dose of amiodarone and then an infusion of IV amiodarone over 12 to 24 hours, and my atrial fibrillation stopped, and I didn't need any more treatment, I would be happy with that. I was on beta blcoers fo three months, my atrial fibrillation didn't return, and now, hopefully, it stays at bay for many many more years.
I am so sorry if I have confused folk, and I hate describing this all so briefly in writing when really it can be explained and demonstarted beautifully in a couple of hours face to face.....
PS
I had a very senior professor once say to me, if anyone ever says the words "rapid Atrai fibrillation" they are showing their misundertsanding of the condition. When atrial fibrillation occurs, the atria ALWAYS fibrillate very rapidly (aproximately 300 times a minute), but its the subsequent ventricular rate that usually dictates the urgency of any treatment...so medical staff should say "atrial fibrillation with a normal (or controlled) ventricular rate" or atrial fibrillation with a rapid ventricualr resposne"...because these are two different situations...does that make sense folks?
Cardiology 101 (on the back of a postage stamp) ...sorry!
