Atrial flutter is a supraventricular arrhythmia, originating in the right atrium (through a macro-reentrant circuit, most commonly at the level of anatomical structures called cavotricuspid isthmus). Depending on the method of production and appearance on the atrial flutter resting electrocardiogram may be typical or atypical, dependent on the cavotricuspid isthmus. Atrial flutter can be paroxysmal (sudden onset and ends, spontaneously, without any therapeutic intervention) or chronic. Paroxysmal flutter occurs in conditions without a cardiac pathology, but the chronic one usually occurs in pre-existing cardiac diseases, and most of the time they coexist with atrial fibrillation.
Atrial flutter is generally an unstable rhythm that converts (spontaneous) to atrial fibrillation or to sinus rhythm (spontaneously or by medical intervention). It is unusual for a patient to remain in a chronic atrial flutter.
Clinical signs and symptoms
Depend on the ventricular rate and on the nature of the underlying disease. Below 120 beats / minute symptoms are minimal, and the patient is less symptomatic. At higher frequencies the main symptoms are palpitations, dyspnea (shortness of breath), weakness, fatigue, or syncope (brief loss of consciousness), anxiety.
Clinical examination of the patient
May show signs of underlying disease (heart failure), or be without pathological changes. Auscultation of the heart may reveal tachycardia heart sounds, regular or irregular, heart murmurs (in the presence of other valvular heart disease).
The resting electrocardiogram (ECG) shows typical appearance where “F” (saw waves) in the inferior leads. The management of the electrical impulse from the atria to the ventricles is not done usually 1:1 (atrioventricular block appears and so from the atria to the ventricles leadership can be 2:1, 3:1). This explains the fact that the frequency of fibrillation is around 300 beats / min, while the ventricular rate may vary (usually 150 b / min).
Transthoracic echocardiography: may show atrial or ventricular dilatation, valvulopathy. There are specific elements of cardiac ultrasound to diagnose atrial flutter, but it can be useful in diagnosing other associated cardiac pathologies.
Transesophageal echocardiography: involves placing an ultrasound probe in the esophagus (through swallowing) to better visualize the heart chamber. May reveal the presence of thrombi in the atria.
Holter monitoring ECG: is useful for paroxysmal atrial flutter. It involves monitoring the heart rate by an electrocardiograph, small in size, portable, usually for a period of 24 hours. The information obtained can then be downloaded to the computer and interpreted by a cardiologist.
Test effort: requires exercise (cycling, treadmill walking) under ECG monitoring and tense. It can be performed to diagnose atrial flutter induced by exercise.
Laboratory investigations: There is no specific change to the laboratory to diagnose atrial flutter.
Diagnosis of the atrial flutter is done by electrocardiogram of rest. Carotid sinus massage can be useful to make differential diagnosis with other arrhythmias.
As with atrial fibrillation, flutter treatment must be focused on the control of ventricular rate, heart rate control, and prevention of thromboembolic events. The targets of the treatment vary from case to case, as well as methods of treatment chosen, but didactic treatment of atrial flutter can be presented as follows:
Control of the ventricular rate: it is harder to obtain than in the case of atrial fibrillation and is a priority when the patient is symptomatic or when it shows the deterioration of hemodynamic status. This can be achieved by blocking drugs such as beta-blockers or non-Dihydropyridine calcium channel.
Restoration of sinus rhythm: the treatment of choice for most patients in the first episode of atrial flutter is electric conversion. This attitude is mandatory when driving flutter with 1:1 or hemodynamic impairment. The success rate of electrical cardioversion is higher than 95%. Usually low energy external electric shocks (50 J) are effective. Pharmacological conversion to sinus rhythm can be an alternative to electrical cardioversion. You can use drugs such as dofetilide, ibutilide and class IC antiarrhythmic drugs (flecainide, propafenone). Studies have shown that the combination of prior antiarrhythmic drugs electric conversion improves the chances of maintaining sinus rhythm after cardioversion.
Prevention of thromboembolic events: it is necessary, as in the case of atrial fibrillation. If atrial flutter persists for more than 48 times in a patient without anticoagulation therapy before conversion to sinus rhythm tempt requires three weeks of effective anticoagulation or Transesophageal ultrasound to rule out the presence of thrombus in the cardiac chambers. If they choose anti-vitamins K treatment requires periodic evaluation of INR values getting 2-3. One can opt for the new generation of oral anticoagulants (dabigatran, apixaban) in patients without valvular and no other contraindications (for example mechanical prosthesis wearers or patients with renal dabigatran). These new-generation drugs have the advantage of not requiring regular monitoring of INR. Anticoagulation after conversion to sinus rhythm is needed for a minimum of 4 weeks because in this period there is the risk of thromboembolic events.
Radiofrequency ablation current: this procedure is performed electively after proper investigation of the patient. It is an interventional procedure that is performed in the electrophysiology laboratory, in order to restore sinus rhythm of the heart or to prevent recurrence of atrial flutter by removing macro-reentrant circuit in the right atrium. For patients with recurrent symptomatic atrial flutter, depending on the isthmus cavotricuspid existing electrophysiology laboratories experienced a success rate of radiofrequency ablation current greater than 95%.
Radiofrequency ablation involves placing through current venipuncture of catheters to the heart cavities through which it makes an electrical map of the heart and then is given by ablation shooting, aiming remove macro-reentrant circuits. The procedure is performed under local anesthesia at the site of venipuncture, and under X-ray exposure.
It has been shown that radiofrequency ablation improves quality of life for current patients; reduce the number of hospitalizations and the number of antiarrhythmic drugs required. But on long-term radiofrequency ablation current predispose to atrial fibrillation, but nevertheless this procedure is a safe option for the treatment of atrial flutter.
Prevention of atrial flutter recurrence. Is an important goal of therapy and is made with different antiarrhythmic drugs according to the associated pathologies of the patient, for example:
Patients without other structural heart disease: benefit of treatment with class IC antiarrhythmic agents (flecainide);
Patients with cardiac hypertrophy left without ischemia or impaired leading: it can be used Amiodarone;
Patients with ischemic heart disease: sotalol or Amiodarone;
Significant systolic dysfunction: Amiodarone.
Amiodarone is an antiarrhythmic drug with high efficacy, but with numerous adverse effects to the eyes, thyroid, skin, liver, lungs. Recommendation for this medication should be taken after evaluation of clinical and laboratory features of the patient, taking into account all associated pathologies.
It depends on associated comorbidities of the patient. Persistent atrial flutter in a long time can lead to cardiomyopathy tachyarrhythmia. Another risk not negligible is the one of thromboembolic events.
Patients with atrial flutter of isthmus dependent type, which is achieved by radiofrequency current ablation still, have an excellent prognosis. Patients in whom atrial flutter associated with atrial fibrillation represent cases more difficult to manage with a less good prognosis.
Patient education and lifestyle changes
As with any other conditions the patient should be educated regarding to the medication administered, in addition to patients with atrial flutter who are receiving anticoagulant therapy with Antivitamins K must be trained regarding the interaction of this drug with other drugs and with food. You must dissuasive eating green leafy vegetables (for example spinach, kale) rich in vitamin K, and grapefruit consumption (due to enzyme induction phenomenon). New generation anticoagulants do not require these restrictions in terms of nutrition.
Physical activity prohibition is not necessary but is recommended for patients with atrial flutter efforts to avoid excessive extended. Also should avoid emotional stress and other factors excitable (coffee, tea, tobacco).