Atrial Flutter

Atrial Flutter is a common abnormal heart rhythm that is similar to atrial fibrillation arising from the upper chambers of the heart. It is a form of supraventricular tachycardia (SVT).  AFib causes the heart to beat too fast and in no regular pattern or rhythm. With Atrial Flutter, the heart beats abnormally fast, but often in a regular pattern. The fast, but regular pattern is what makes it unique.  Atrial Flutter causes the upper chambers (atria) of the heart to beat too fast, which causes atrial muscle contractions that are faster than and out of sync with the lower chambers (ventricles).  The atria can contract anywhere from 250-400 beats per minute. Typically on exam, the heartbeat is fast, but with medications, it can be slowed with either a regular or irregular pulse.

Atrial Flutter can appear in patients with no structural heart disease but is seen more frequently in patients with a history of prior cardiac surgery, congenital heart disease, or congestive heart failure. Conditions that can cause right-sided heart dilation and increased pressure can increase the incidence of this rhythm disturbance including; right-sided heart failure, hypertension, COPD, pulmonary hypertension, obesity, tricuspid or pulmonary stenosis.

Symptoms

Episodes of Atrial Flutter can produce rapid heartbeats with symptoms of palpitations, chest fluttering or tremoring. Patients may feel short of breath, dizziness, fatigue, or rarely, even fainting. Some people with Atrial Flutter may not experience any symptoms at all. Episodes of Atrial Flutter can last anywhere from minutes to days or even months. Patients with constant rapid heartbeats should seek medical attention.

Diagnosis

Atrial Flutter can be diagnosed by a cardiologist by using an electrocardiogram or an Ambulatory monitoring device, such as a Holter or Event monitor, especially during an arrhythmia event. Some events of Atrial Flutter are random (also referred to as paroxysmal) and not consistently present on a daily basis. In these situations, your cardiologist may recommend an Event monitor. This is a special ambulatory monitoring device that is patient-triggered when an Atrial Flutter event is happening.

Prognosis

Atrial Flutter, with proper treatment, is rarely life-threatening. However, similar to atrial fibrillation, Atrial Flutter increases your risk of stroke. The risk of stroke is not identical for everyone diagnosed with Atrial Flutter. Consequently, consultation with your cardiologist is crucial in establishing the presence of additional risk factors for stroke that might necessitate treatment with blood thinners. Risk factors include:

• Age,
• Presence of structural heart disease,
• Hypertension,
• Diabetes,
• History of stroke,
• Valvular heart disease,
• Heart failure,
• Coronary artery disease.

The decision to start long-term anticoagulation (blood thinners) must be individualized after a discussion between you and your Cardiologist.

Atrial Flutter causes rapid atrial contractions, and this leads to a pooling of blood in the atria; especially in the left atrium. The pooled blood is more apt to form clots that can move to the systemic circulation and the brain, leading to a stroke.

Besides the increased risk of stroke, prolonged episodes of Atrial Flutter can produce irreversible changes to the atria, including atrial enlargement and weakness (myopathy). Furthermore, continued episodes can make reversion and maintenance of normal sinus rhythm more difficult to maintain. Atrial Flutter with constant rapid ventricular rates (heart rates greater than 100 beats per minute) may cause a tachycardia-induced cardiomyopathy (weakening of ventricular muscle and heart function) along with symptoms of congestive heart failure. Atrial fibrillation and Atrial Flutter often co-exist. It is not unusual to have patients who have frequent episodes of atrial fibrillation after having radiofrequency catheter ablation to treat the Atrial Flutter.

Stopping the cause of the Atrial Flutter may or may not improve the issue of Atrial Fibrillation in some patients. Also, patients with atrial fibrillation who are treated with antiarrhythmic medications or post catheter ablation with pulmonary vein isolation are observed to revert to Atrial Flutter. In these circumstances, Atrial Flutter can be approached with a catheter ablation procedure with the eradication of the patient’s atrial arrhythmia.

Therapy for patients with Atrial Flutter include:

• Control of the heart rate.
• Conversion and maintenance of the normal sinus rhythm.
• Decrease possible stroke risk.

Medications used to restrict the ventricular rate during Atrial Flutter include:

• Beta-blockers,
• Calcium channel blockers, and
• Digoxin in some cases.

The medications can be dispensed orally or via intravenous route if necessary in the ER. Some patients may need a combination of medications from different classes.

Efforts to convert and maintain sinus rhythm can be attempted in one of three ways:

• In-hospital electrical or chemical cardioversion,
• Outpatient antiarrhythmic medication therapy, or
• Catheter ablation

Electrical cardioversion is a procedure usually performed in the hospital, where the patient is brought to an EP Lab room and briefly sedated to sleep. External defibrillation pads are positioned on specific locations on the patient’s chest. A quick electric shock (less than a second) is produced. The rate of success for converting Atrial Flutter to normal sinus rhythm is quite good with this procedure. Nevertheless, it does not guarantee that Atrial Flutter does not return since it is merely a reset.

Chemical cardioversion can also be implemented with the infusion of intravenous antiarrhythmic medications. The success rate of this technique, in contrast to external electrical cardioversion, can be lower particularly in patients with extended episodes of Atrial Flutter. Moreover, some intravenous antiarrhythmics can be contraindicated in certain groups of patients – especially patients with structural heart disease or kidney dysfunction.

Electrical or chemical cardioversion in a patient with an extended episode of Atrial Flutter (more than 48 hours) can only be performed after four weeks of documented therapeutic levels (INRs) on warfarin therapy or continuous novel anticoagulant therapy (Eliquis, Pradaxa, Xarelto, Savaysa).  Treatment with anticoagulation for this four week period has been shown to reduce, but not remove, the possibility of stroke with the cardioversion procedure.  The anticoagulation medications prevent the formation of additional clots in the left atrium and allow for resolution of any potential clot present before initiating anticoagulation. If the physician feels that cardioversion is needed more urgently, a transesophageal echocardiogram (TEE) can be performed to look for the presence of clots in the left atrial appendage the day of the procedure.

Outpatient oral antiarrhythmic therapy can be started in those patients who are normally on oral anticoagulation therapy. These medications can be helpful in maintaining normal sinus rhythm and preventing recurrences of Atrial Flutter after electrical cardioversion. The physician may choose to start antiarrhythmic medications in the weeks before your cardioversion procedure. There are several antiarrhythmic medications, with only a few necessitating a brief hospital stay for commencement. These pharmacologic therapies work by slowing the electrical conduction in the heart and increasing the time required for electrical recovery of the heart tissue. Drug therapy for Atrial Flutter is a “trial and error” plan of action.  It is impossible to know beforehand which medication will work the best in a specific patient. Maintenance of sinus rhythm with absolute suppression of Atrial Flutter may not always be achievable with medications. Improvements in the patient’s quality of life must continuously be reevaluated concerning the discomfort, small risks, and potential side effects associated with the prescribed treatment regimen. Antiarrhythmic medications are not without risk, as they can increase the incidence of other cardiac arrhythmias.

For patients that find that:

• Side effects from their medication are intolerable.
• They have recurring symptoms and episodes in spite of medical therapy.
• They have do not wish to take daily medications for a lengthy period of time.

Your physician may advise you to undergo an electrophysiology study (EPS) and catheter ablation.  Catheter ablation may offer a > 95% cure rate with a < 1% risk of major complication.  These procedures are performed in a dedicated operating room called the electrophysiology (EP) laboratory.  The EP Cardiologist utilizes specialized electronic and computer equipment, along with the intracardiac electrode catheters placed into the heart via the femoral (groin) veins. The physician then electrically maps the Atrial Flutter circuit and delivers radiofrequency energy to the site of abnormal conduction; thereby interrupting the short-circuit and ending the arrhythmia. Radiofrequency energy used during the catheter ablation procedure heats the tissue enough to destroy the local heart cell function. The long-term success rate is excellent for Atrial Flutter, but relapses can rarely occur as the heart tries to heal itself. If necessary, these relapses can be treated with a second catheter ablation procedure. Some patients may not be a candidate for an Atrial Flutter catheter ablation, and a conversation with your EP Cardiologist is essential to review the treatment options available to you.