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Atrial flutter occurs when an abnormal conduction circuit develops inside the right atrium. It is a re-entrant rhythm (categorized as an SVT). Atrial flutter typically rotates counterclockwise inside the right atria. It causes the atria to contract very fast, about 240-340 bpm. The AV node's built in safety mechanism will only allow approximately 150 impulses per minute to pass through and contract the ventricles. This would result in having ratio of 2:1 flutter waves per beat with a heart rate of 150 bpm. This rhythm can be regular or irregular. Atrial flutter with an equal number of flutter waves per beat will be regular, or with variable rate flutter, meaning it has a different number of flutter waves between each heartbeat, will be irregular. Type I and type II atrial flutter: Type I atrial flutter, also known as typical atrial flutter, is located in the right atria. Type I flutter is further divided into two subtypes depending on the direction the current is passing through the loop, 1. counterclockwise (most common) and 2. clockwise atrial flutter. Both have an atrial rate of 240 to 340 bpm. Type II flutter (atypical a-flutter) originates from the left atrium which is far more rare. It follows a significantly different re-entry pathway than type I flutter, and is typically faster, usually 340-440 bpm. You might find Left atrial flutter after incomplete left atrial ablation procedures. The main danger of atrial flutter is that the heart does not pump blood very well when it is beating too fast. Vital organs such as the heart muscle and brain may not get enough blood. Because the lack of effective contractions from the atria, there may be stasis (pooling) of blood in the atria. This may lead to formation of thrombus (blood clots) within the heart. Thrombus is most likely to form in the atrial appendages. Thrombus in the left atrial appendage is particularly important since the left side of the heart supplies blood to the entire body. Thus, any thrombus material that dislodges from this side of the heart can embolize to the brain with the potentially devastating consequence of a stroke. Thrombus material can embolize to any other portion of the body, though usually with a less severe outcome. Risk Factors for developing atrial Flutter Heart failure Previous heart attack Valve abnormalities or congenital defects High Blood Pressure Recent surgery Thyroid dysfunction Alcoholism (especially binge drinking) Chronic lung disease Acute (serious) illness Diabetes Symptoms of Atrial Flutter It is possible that many people may feel no symptoms at all. Those who do experience symptoms, may include: Heart palpitations (feeling like your heart is racing, pounding, or fluttering) Fast, steady pulse Shortness of breath Trouble with everyday exercises or activities Pain, pressure, tightness, or discomfort in your chest Dizziness, lightheadedness, or fainting General treatment goals for symptomatic atrial flutter are similar to those for atrial Fib. Control of the ventricular rate Restoration of sinus rhythm Prevention of recurrent episodes or reduction of their frequency or duration Prevention of thromboembolic complications Minimization of adverse effects from therapy Complications of Atrial Flutter A-flutter itself is not life threatening. If left untreated, the side effects of a-flutter can be potentially life threatening. AFL makes it harder for the heart to pump blood effectively. With the blood moving more slowly, it is more likely to form clots. If the clot is pumped out of the heart, it could travel to the brain and lead to a stroke or heart attack. Without treatment, a-flutter can also cause a fast pulse rate for long periods of time. This means that the ventricles are beating too fast. This can lead to cardiomyopathy, which can lead to heart failure and long-term disability. A-flutter can also degrade into atrial fibrillation (AFib).

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