Atrial flutter is a very rapid, regular heartbeat that starts in the atria, or upper chambers of the heart.
What is going on in the body?
In a person with atrial flutter, the regular beating of the atria is replaced by a more rapid beating. During these episodes, the atria can beat as fast as 250 to 350 beats per minute compared to the normal 60 to 100 beats. The condition is caused by a short circuit in the electrical system of one atrium. This short circuit starts the heart beating much more rapidly than normal.
Fortunately, only some of the beats get through to the ventricles (pumping chambers), so the entire heart usually does not beat as fast as the atria.
What are the causes and risks of the condition?
Atrial flutter is caused by a short circuit in one atrium. The electrical system starts running out of control, forcing the heart to beat rapidly. Factors linked to atrial flutter include:
- congestive heart failure, in which a weakened heart is unable to pump blood effectively throughout the body
- coronary heart disease and certain other forms of heart disease
- digoxin toxicity, a condition caused by too much of the heart medicine digoxin (i.e., Lanoxin, Lanoxicaps)
- heart attack
- heart valve disorders, such as those caused by rheumatic fever
- high blood pressure
- hyperthyroidism, a condition caused by too much thyroid hormone
- increased age
- pulmonary embolism, in which a blood clot blocks part of the circulation to the lung
- recent open heart surgery
What can be done to prevent the condition?
Atrial flutter cannot always be prevented. Effective treatment of underlying disorders, such as high blood pressure, can lower a person's risk for atrial flutter. Once atrial flutter has been diagnosed, there are medicines that can reduce the episodes of atrial flutter. Atrial flutter can also be prevented by a surgical procedure that gets rid of the short circuit.
How is the condition diagnosed?
Diagnosis of atrial flutter begins with a medical history and physical exam. The actual diagnosis is confirmed with an electrocardiogram, or ECG.
A more specialized test, known as an electrophysiology study, can also be performed to locate the short circuit in the heart's electrical system. This test involves placing a catheter, or thin tube, through the skin and into an artery in the groin. The catheter is then advanced into the heart to map its electrical activity.
Long Term Effects
What are the long-term effects of the condition?
Atrial flutter affects the way the heart pumps blood. It increases a person's risk for:
- blood clots in the arteries
- congestive heart failure
- heart attack
What are the risks to others?
Atrial flutter is not contagious and poses no risk to others.
What are the treatments for the condition?
Treatment depends on the cause of the atrial flutter. In some individuals, the main goal of treatment is to control the heart rate. This is especially true for those who have congestive heart failure, chest pain, or hyperthyroidism. Medicines used to treat atrial flutter include:
- antiarrhythmic medicines, such as dofetilide (i.e., Tikosyn), procainamide (i.e., Procanbid, Pronestyl), and amiodarone (i.e., Cordarone, Pacerone)
- beta-blockers, such as metoprolol (i.e., Lopressor, Tenormin), atenolol (i.e., Tenormin), or nadolol (i.e., Corgard)
- calcium channel blockers, such as verapamil (i.e., Calan, Covera, Isoptin, Verelan) or diltiazem (i.e., Cardiazem, Cartia, Dilacor, Diltia, Taztia, Tiazac)
- digoxin (i.e., Lanoxin, Lanoxicaps)
Episodes of atrial flutter can be stopped using a procedure called cardioversion. The healthcare provider uses a pacemaker or paddles to deliver an electrical shock to the person's chest. This shock, a much lower voltage than that used to resuscitate a person in cardiac arrest, is synchronized with the person's electrical heart activity, If successful, it restores the heart to a normal rhythm. This is typically a planned procedure during which the patient is awake but sedated with medication.
Future episodes of atrial flutter can be prevented by destroying the short circuit in the atrium. This can be done by surgery or with sound waves.
What are the side effects of the treatments?
Medicines used to treat atrial flutter can cause a slow heart rate or low blood pressure. Some of the medicines used to control atrial flutter can cause arrhythmias or allergic reactions. Surgery can be complicated by bleeding, infection, or allergic reaction to anesthesia.
How is the condition monitored?
Atrial flutter is monitored by regular visits to the healthcare provider. The provider may order regular ECGs and blood tests periodically. Any new or worsening symptoms should be reported to the healthcare provider.
Medical Knowledge Self-Assessment Program 11, Part C, Book 2, p. 954.