Atrial flutter
Atrial flutter | |
---|---|
Atrial flutter with varying A-V conduction (5:1 and 4:1) | |
Specialty | Cardiology |
Diagnostic method | Electrocardiography |
Atrial flutter (AFL) is a common
Although this abnormal heart rhythm typically occurs in individuals with cardiovascular disease (e.g.,
A supraventricular tachycardia with a ventricular heart rate of 150 beats per minute is suggestive (though not necessarily diagnostic) of atrial flutter. Administration of
Atrial flutter was first identified as an independent medical condition in 1920 by the British physician
Signs and symptoms
While atrial flutter can sometimes go unnoticed, its onset is often marked by characteristic sensations of the heart feeling like it is
Atrial flutter is usually well-tolerated initially (a high heart rate is for most people just a normal response to exercise); however, people with other underlying heart diseases (such as
Prolonged atrial flutter with fast heart rates may lead to decompensation with loss of normal heart function (heart failure). This may manifest as exercise intolerance (exertional breathlessness), difficulty breathing at night, or swelling of the legs and/or abdomen.[8][citation needed]
Complications
Although often regarded as a relatively benign heart rhythm problem, atrial flutter shares the same complications as the related condition atrial fibrillation. There is paucity of published data directly comparing the two, but overall mortality in these conditions appears to be very similar.[9]
Rapid heart rates may produce significant symptoms in patients with pre-existing heart disease and can lead to inadequate blood flow to the heart muscle and even a heart attack.[1]
In rare situations, atrial flutter associated with a fast heart rate persists for an extended period of time without being corrected to a normal heart rhythm and leads to a tachycardia-induced cardiomyopathy.[1] Even in individuals with a normal heart, if the heart beats too quickly for a prolonged period of time, this can lead to ventricular decompensation and heart failure.[citation needed]
Clot formation
Because there is little if any effective contraction of the
Sudden cardiac death
Sudden death is not directly associated with atrial flutter. However, in individuals with a pre-existing accessory conduction pathway, such as the
Pathophysiology
Atrial flutter is caused by a
The impact and symptoms of atrial flutter depend on the heart rate of the affected person. Heart rate is a measure of ventricular rather than atrial activity. Impulses from the atria are conducted to the ventricles through the
Diagnosis
Typical atrial flutter is recognized on an electrocardiogram by presence of characteristic "flutter waves" at a regular rate of 200 to 300 beats per minute. Flutter waves may not be evident on an ECG in atypical forms of atrial flutter. Individual flutter waves may be symmetrical, resembling p-waves, or maybe asymmetrical with a "sawtooth" shape, rising gradually and falling abruptly or vice versa. If atrial flutter is suspected clinically but is not clearly evident on ECG, acquiring a Lewis lead ECG may be helpful in revealing flutter waves.[citation needed]
Classification
There are two types of atrial flutter, the common type I and rarer type II.[13] Most individuals with atrial flutter will manifest only one of these. Rarely someone may manifest both types; however, they can manifest only one type at a time.[citation needed]
Type I
Type I atrial flutter, also known as common atrial flutter or typical atrial flutter, has an atrial rate of 240 to 340 beats/minute. However, this rate may be slowed by
The reentrant loop circles the right atrium, passing through the cavo-tricuspid isthmus – a body of fibrous tissue in the lower atrium between the inferior vena cava, and the tricuspid valve.[1] Type I flutter is further divided into two subtypes, known as counterclockwise atrial flutter and clockwise atrial flutter depending on the direction of current passing through the loop.[1]
- Counterclockwise atrial flutter (known as cephalad-directed atrial flutter) is more commonly seen. The flutter waves in this rhythm are inverted in ECG leads II, III, and aVF.[1]
- The re-entry loop cycles in the opposite direction in clockwise atrial flutter, thus the flutter waves are upright in II, III, and aVF.[1]
Type II
Type II (atypical) atrial flutter follows a significantly different re-entry pathway to type I flutter, and is typically faster, usually 340–350 beats/minute.[14] Atypical atrial flutter rarely occurs in people who have not undergone previous heart surgery or previous catheter ablation procedures. Left atrial flutter is considered atypical and is common after incomplete left atrial ablation procedures.[15] Atypical atrial flutter originating from the right atrium and heart's septum have also been described.[citation needed]
Management
In general, atrial flutter should be
Cardioversion
Atrial flutter is considerably more sensitive to electrical
Ablation
Due to the reentrant nature of atrial flutter, it is often possible to ablate the circuit that causes atrial flutter with
References
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- ^ PMID 23050527.
- ^ PMID 25838435.
- S2CID 26126493.
- ^ Lewis T, Feil HS, Stroud WD (1920). "Observations upon flutter, fibrillation, II: the nature of auricular flutter". Heart. 7: 191.
- ^ "Atrial Flutter". Johns Hopkins Medicine. 22 February 2021. Retrieved 3 July 2021.
- ^ "Atrial Flutter". Johns Hopkins Medicine. 22 February 2021. Retrieved 3 July 2021.
- ^ "Atrial Flutter". Johns Hopkins Medicine. 22 February 2021. Retrieved 3 July 2021.
- PMID 12401530.
- S2CID 20652213. Retrieved 3 July 2021.
- PMID 29939631. Retrieved 3 July 2021.
- ^ "Atrial Flutter". The Lecturio Medical Concept Library. Retrieved 3 July 2021.
- ISBN 978-0-7216-8697-4.[page needed]
- ^ "Atrial Flutter: Overview". eMedicine Cardiology. Archived from the original on 26 February 2009. Retrieved 2009-03-06.
- PMID 18325846.
- PMID 25117151.