Treatment of atrial fibrillation
If you suspect a significant etiological cause of the patient with the first occurrence of atrial fibrillation, you need to be hospitalized, but patients with recurrent episodes do not need mandatory hospitalization (in the absence of severe symptoms). The treatment tactic consists of monitoring the frequency of ventricular contractions, controlling heart rhythm and preventing thromboembolic complications.
Control of the frequency of ventricular contractions
Patients with atrial fibrillation of any length need to control the frequency of contractions of the ventricles (usually less than 80 per minute at rest) to prevent the development of symptoms and tachycardia-induced cardiomyopathy.
In acute paroxysms with high frequency (for example, 140-160 per minute) intravenous blockers of the AV-node are used.
ATTENTION! Blockers conducting through the AV-node can not be used in the Wolff-Parkinson-White syndrome, when an additional beam participates in the conduct (manifested by the prolongation of the QRS complex); these drugs increase the frequency of conductions along the bypass, which can lead to ventricular fibrillation.
Beta-blockers (such as metoprolol, esmolol) are considered preferable if a high content of catecholamines in the blood is assumed (for example, in thyroid pathology, in cases caused by excessive physical exertion), non-hydroperidine calcium channel blockers (verapamil, diltiazem) are also effective. Digoxin is the least effective, but may be preferred in heart failure. These drugs can be taken for a long time inward to monitor heart rate. If Beta-adrenoblockers, non-hydroperidinic calcium channel blockers and digoxin (as monotherapy and in combination) are ineffective, amiodarone may be prescribed.
Patients who do not respond to such treatment or who can not take medications that monitor heart rate can be subjected to RF ablation of the AV node in order to cause a complete AV blockade. After this, implantation of a permanent pacemaker is necessary. Ablation of only one route for AB-connection (AV-modification) allows reducing the number of atrial pulses reaching the ventricles and avoiding the need for implantation of ECS, but this intervention is considered less effective than complete ablation.
Control of rhythm
Patients with heart failure or other hemodynamic disorders directly associated with atrial fibrillation, the restoration of a normal sinus rhythm is necessary to increase cardiac output. In some cases, conversion to normal sinus rhythm is optimal, but antiarrhythmic drugs that can provide such conversion (la, lc, III classes), have a risk of side effects and may increase mortality. Restoration of sinus rhythm does not exclude the need for permanent anticoagulant therapy.
For an emergency recovery of the rhythm, you can use synchronized cardioversion or drugs. Before the beginning of the restoration of the rhythm, it is necessary to achieve a heart rate of <120 per minute, and if atrial fibrillation is present for more than 48 hours, the patient should be prescribed anticoagulants (regardless of the conversion method, it increases the risk of thromboembolism). Anticoagulant therapy with warfarin is performed for at least 3 weeks (until the rhythm is restored), and if possible, continue for a long time, as atrial fibrillation may repeat. Alternatively, heparin sodium treatment is possible. Transesophageal echocardiography is also shown; if an atrial thrombus is not detected, cardioversion can be performed immediately.
Synchronized cardioversion (100 J, followed by 200 J and 360 J if necessary) converts ciliary arrhythmia to a normal sinus rhythm in 75-90% of patients, although the risk of repeated attacks is great. The effectiveness of retention of the sinus rhythm after the procedure increases with the appointment of drugs la, lc or III class for 24-48 h before cardioversion. This procedure is more effective in patients with a short duration of atrial fibrillation, isolated atrial fibrillation or atrial fibrillation due to reversible causes. Cardioversion is less effective with an increase in the left atrium (more than 5 cm), a decrease in flow in the ears of the atria, or the presence of pronounced structural changes in the heart.
Drugs used to restore the sinus rhythm include la (procainamide, quinidine, disopyramide), lc (flecainide, propafenone) and III classes (amiodarone, dofetilide, ibutilide, sotalol) antiarrhythmic drugs. All of them are effective in approximately 50-60% of patients, but they have different side effects. These drugs should not be used until heart rate can be controlled with b-blockers and non-hydroperidine calcium channel blockers. These drugs, restoring the rhythm, are also used to maintain a sinus rhythm (with or without previous cardioversion). The choice depends on the patient's tolerance. At the same time, with paroxysmal atrial fibrillation that occurs only or mostly during rest or in sleep, when there is a high tone of the vagus nerve, drugs with a vagolytic effect (for example, dizopyramide) may be particularly effective, and the induced atrial fibrillation may be more is sensitive to beta-blockers.
ACE inhibitors and angiotensin II receptor blockers can reduce myocardial fibrosis, which creates a substrate for atrial fibrillation in patients with heart failure, but the role of these drugs in the routine management of atrial fibrillation has not yet been established.