What is Atrial Flutter and How is Atrial Flutter Diagnosed?
The normal beating of the heart is controlled by electrical impulses. Atrial flutter is an abnormal electrical short circuit that results in a rapid or irregular heartbeat. It can occur in either the left or right atriumOne of the two upper chambers of the heart. of the heart, which are the top 2 chambers in the heart. The atriaThe two upper chambers of the heart. pump bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. to the larger ventricles below - to use a motoring analogy, they are bit a like fuel injectors or carburetors.
Typical Atrial Flutter
The most common type of atrial flutterAn abnormally fast but regular heart rhythm due to disturbances in the biological electrical system of the atria of the heart. It is a type of supraventricular tachycardia occurs in the right atrium and is known as typical atrial flutter. It is common from age 40 onwards. This is the same heart rhythm disorder that Tony Blair suffered from in 2004, and he went on to have a curative procedure called ablation.
Clockwise Right Atrial Flutter
In atrial flutter electricity rotates rapidly and regularly around the tricuspid valveA structure that allows fluid to flow in one direction only, preventing backflow., the valve between the right atrium and right ventricle. It can rotate in an anti-clockwise direction (known as typical flutter), or a clockwise direction (known as clockwise right atrial flutter). The direction of electricity can be identified on a standard ECGThe abbreviation for electrocardiogram, a tracing of the electrical activity of the heart to help in the diagnosis of heart disease..
This means that the atria beat about 300 times per minute – about 4 to 5 times faster than normal. Fortunately, most of the time not all of these signals conduct to the ventricles below, but the heart rate still increases to 150 per minute in healthy hearts. This can cause palpitationsThe feeling when you become aware of your heartbeat - when frightened, for example., breathlessness, dizziness or even collapse.
Atrial flutter and the risk of strokeAny sudden neurological problem caused by a bleed or a clot in a blood vessel.
When the atria beat 300 times per minute, blood can stagnate within them and this can lead to clotBlood that has coagulated, that is, has moved from a liquid to a solid state. formation in the heart, particularly in an area called the left atrial appendage. This is a tube-like chamber (a bit like the appendix in the bowelA common name for the large and/or small intestines.) attached to the left atrium. When clots form here they can dislodge and travel through the heart and circulate to the brain, causing a stroke.
To identify patients who are at risk of stroke when they have atrial flutter, we use a scoring system called the CHA2DS2-VASc scoring system.
The CHA2DS2VAScscore is an acronym. It stands for:
C = Congestive cardiacRelating to the heart failure (or heart failureFailure of the heart to pump adequately. or impairedventricularRelating to a ventricle (either in the brain or the heart) function)
H = Hypertension (or high blood pressureThe pressure of blood within the arteries.)
A2 = Age over 75
D = Diabetes
S2 = Stroke or TIATransient ischaemic attack; a brief interruption of the blood supply to part of the brain, which causes temporary impairment of vision, speech, sensation or movement.. (transient ischaemic attackAny neurological problem caused by an interruption in the blood supply to the brain that resolves within 24 hours. Abbreviated to TIA., or ‘mini-stroke’)
V = Vascular disease (heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction. or other arterial disease)
A = Age below 65
Sc = Sex category (female = 1 point)
If you have or have ever had one of these conditions you score one point for each, except Age over75 or Stroke/TIA which count as 2 points, hence the CHA2DS2VASCscore.
If you have a CHA2DS2VASC score of 1 or more it is recommended that you take warfarinAn anti-coagulant drug used to treat and prevent abnormal blood clotting. (or one of the newer types of anticoagulantA medication that prevens blood from clotting, or which reduces the likelihood of the blood to clot. medications) for life to reduce your risk of stroke, unless the atrial flutter is cured with a procedure called ablation (see below). So, if you are 65 or older and have atrial flutter, it is recommended that you are treated with an anticoagulant and not aspirinOne of the most used medicines., which is now known not to be beneficial.
How can Atrial Flutter be Identified and Diagnosed?
If you develop any of the symptoms described above, a simple ECGThe abbreviation for electrocardiogram, a method of recording the electrical activity of the heart muscle. It is useful for diagnosing heart disorders. (or heart tracing) easily identifies atrial flutter when you are feeling the palpitations. If your symptoms are intermittentStopping or ceasing for a time., you may need to wear a heart monitor for a longer period of time to try and capture an episode.
Atrial flutter can also be identified in patients with pacemakers or defibrillatorsDevices used for defibrillation, which involves giving a controlled electric shock to restore normal heart rhythm in cases of cardiac arrest. when their device is checked.
Very occasionally it is necessary to implant a small heart monitor under the skin to diagnose a patient’s palpitations, if they are very infrequent.
Treatment for atrial flutter
The first line treatment for typical atrial flutter is a procedure called catheterA tube used either to drain fluid from the body or to introduce fluid into the body. ablation. Ablation is a ‘key-hole’ procedure performed by inserting fine wires through the veinA blood vessel that carries blood towards the heart. at top of the right leg. The wires record signals from inside the heart and one of them can cauterize heart tissueA group of cells with a similar structure and a specialised function. by heating up at the tip (using something called radiofrequency energy – a bit like microwave energy).
The way typical atrial flutter (or clockwise flutter) is treated is by creating an ‘electrical road-block’ across one part of the abnormal circuit to prevent it from going round and round. Once the line is complete, the flutter stops and a normal rhythm returns. The place where this roadblock is created is between the tricuspid valve and the main vein that connects to the heart from the lower part of the body, called the inferior vena cavaThe large vein that carries de-oxygenated blood from the lower half of the body to the heart.. Therefore the ablation is technically called cavo-tricuspid isthmus ablation.
Ablation compared with Medication and / or Elictrical Cardio-version (shock treatment)
Ablation is preferred to medications or electrical cardio-version (shock treatments) because the procedure is highly effective (90% cure with one attempt) and has a very low risk (principally that of injury to a blood vessel at the top of the leg and a 1 in 500 risk of damage to the AV node requiring pacemaker implantation, or making a tiny hole in the heart – requiring drain insertion).
It has been shown in a number of randomised clinical trials that ablation is significantly better than drugs or cardio-version as a first line treatment for typical flutter. It is well known that atrial flutter is very resistantA microbe, such as a type of bacteria, that is able to resist the effects of antibiotics or other drugs. to medications and almost always recurs after cardio-version. The ablation procedure is usually quick (30-60 minutes) and patients can return home the same day. Ablation in this part of the heart can be painful and for this reason it may be performed under general anaestheticAny agent that reduces or abolishes sensation, affecting the whole body..
There are several other types of ‘atypical’ flutter, which can occur in the left and right atria. These are commonly seen after ablation procedures in the left atrium for another heart rhythm abnormality called atrial fibrillationA common abnormal heart rhythm causing a rapid, irregular pulse and failure of the upper chambers of the heart (atria) to pump properly. Abbreviated to AF. (or AFAn abbreviation for atrial fibrillation for short). They can also occur in patients with congenitalAny condition present since birth. heart defects (therefore young patients) or those who have had surgery to the heart.
They too can be successfully treated with ablation, but the ablation procedure tends to be more complex and takes longer to perform. The risk of ablation in the left atrium is slightly higher than that described above.
Who can have Ablation for Atrial Flutter?
Almost anyone can undergo ablation for typical atrial flutter. Patients must be able to lie flat without discomfort. Some patients may need to be able to tolerate a general anaesthetic. Most patients will have the ablation performed whilst taking blood thinning medications such as warfarin, usually for at least a month beforehand and so a previous history of bleeding may preclude this.
What are the Pros and Cons of Atrial Flutter Fblation?
Atrial flutter ablation is helpful as it completely cures the abnormal heart rhythm, meaning that there are no further symptoms of palpitation, breathlessness or dizziness. Curing atrial flutter also reduces a patient’s risk of stroke to where it was before they had the heart rhythm problem.
The cons are the small risk of the procedure, which is much less than 1%. I quote a 1 in 500 risk of serious complicationA condition that is linked to, or is a consequence of, another disease or procedure., principally that of damage to the normal wiring of the heart requiring pacemaker insertion, or making a small hole in the heart requiring drain insertion.
Is Atrial Flutter Ablation New?
No, ablation for typical atrial flutter has been performed for over 20 years. Ablation for atypical flutters are newer, according to where they occur in the heart, but none are recent or experimental.
Is Pain Relief given if General Anaesthetic is not used?
Yes, intravenousWithin a vein. drugs are administered for pain relief and for sedation to make patients as relaxed and pain free as possible. Local anaesthetic is also used at the top of the leg before the wires are inserted.
Is Surgery Required?
No, the wires (catheters) are inserted through small holes at the top of the leg, but a general anaesthetic is sometimes necessary.
Can Ablation be Repeated if unsuccessful the First Time?
Yes, ablation can be performed as many times as necessary to cure the atrial flutter and does not cause significant damage to the heart. In fact, by maintaining normal heart rhythm, it significantly improves heart function and reduces the risk of stroke.
Will I need to take Blood Thinning medication after Ablation?
In most cases of ablation for typical atrial flutter, blood thinning medication can be stopped one month after a successful procedure. However, if there is another reason for taking blood thinning drugs, then they will continue. For instance, it is not uncommon for patients to have both atrial flutter and atrial fibrillationAbnormally fast and uneven contractions of the muscle of the atria in the heart, so that blood cannot be pumped efficiently. If ablation is only performed for the flutter, then blood thinning drugs will continue according to a patient’s CHADS-VASc score.
How soon can I do Physical Exercise after Ablation?
It usually takes a couple of days for the small holes at the top of the leg to heal. Light exercise can then be resumed. Strenuous exercise is best delayed until a week after the procedure.
How long am I unable to Drive after Ablation?
If you are a Class 1 license holder (not HGV/passenger vehicles), then you cannot drive for 48 hours after ablation
What Post Treatment follow-up is required after Ablation?
Patients are usually seen once more after typical flutter ablation and an ECG is performed to check that they remain in normal rhythm. Sometimes it is appropriate for patients to wear a heart rhythm monitor for a few days (or sometimes longer) after the ablation to check the flutter has been cured.