Therapy of atrial fibrillation
Before starting therapy, any possible remedial causes of atrial fibrillation should be clarified. Potassium deficiency or hyperthyroidism, for example, can be treated relatively easily with medication. In addition, concomitant diseases such as high blood pressure or cardiac insufficiency must also be treated!
Basically, the treatment of atrial fibrillation consists of heart rhythm and frequency control. In addition, the necessity of a blood-thinning therapy (anticoagulation) must be considered in each case. Various drugs are suitable for controlling the heart rate and rhythm.
The state of health, type of atrial fibrillation, as well as previous illnesses, determine the individual therapy concept. Particularly if atrial fibrillation has only been present for a short time, intravenous administration of so-called “antiarrhythmics” can often restore a healthy heart rhythm. Beta-blockers or cardiac glycosides, for example, are suitable for reducing the often too fast heart rate.
Fortunately, there have been some new developments on the pharmaceutical market in recent years, so that numerous innovations are now available, especially in the field of antiarrhythmics. More detailed information on this topic is available at Therapy of atrial fibrillationAnticoagulation means as much as blood thinning. However, this does not mean that the blood is otherwise too thick, but that the risk of blood clots forming is increased.
Due to the uncoordinated twitching of the atria, the blood flow gets “confused”, especially in the left atrial ear. The resulting turbulence and turbulence activates our blood platelets (thrombocytes) and thus leads to the formation of a blood clot (thrombus). In the worst case, the thrombus is transported further, blocking important blood vessels in the brain and thus causing a stroke.
Anticoagulation prevents the blood platelets from forming such dangerous blood clots. Nevertheless, not all patients need blood-thinning therapy (anticoagulation). This is particularly the case with atrial fibrillation.
Therefore, most people with atrial fibrillation should receive blood thinning therapy. Young patients, without any other diseases, can usually do without it. However, the older patients become and the more pronounced their atrial fibrillation and possible accompanying diseases are, the more likely anticoagulation is required.
Blood thinners are available in the form of syringes and tablets. The “thrombosis syringes” are often used in hospitals. However, they are given in higher doses for anticoagulation in atrial fibrillation than the syringes for thrombosis prevention.
However, since anticoagulation usually has to be administered for life, injections are not useful in the long term. Therefore, there are alternative tablets. For many years, tablets were the standard medication from the group of vitamin K antagonists.
These include Falithrom®Marcumar® (active ingredient: phenprocoumon).These tablets have the disadvantage that they are metabolized very differently from person to person, so there is no standard dose. Rather, a blood test must be checked regularly to avoid over- or underdosing the medication. When taking Phenprocoumon it is very important to keep an eye on the INR value.
A newer group of anticoagulants no longer have this problem. We are talking about the new oral anticoagulants, NOAKs for short. These include Xarelto® (active ingredient: rivaroxaban) and Eliquis® (active ingredient: apixaban).
They are taken in fixed doses once or twice a day unless kidney function is impaired. All of these drugs thin the blood and are thus intended to prevent strokes. There are few patients with atrial fibrillation who should not receive oral anticoagulation.
These include people who are in perfect health apart from atrial fibrillation (see the section on Score), people who have already suffered severe bleeding or very old people who are at risk of falling. Beta-blockers are drugs that affect heart function. They are very often used to treat high blood pressure.
But they also lower the heart rate and are therefore drugs that are very often prescribed for atrial fibrillation with a heart rate that is too fast. Some beta-blockers are also said to have a rhythm-stabilizing effect, i.e. they are said to help atrial fibrillation to change to a normal rhythm or to maintain the normal rhythm after changing. Examples of beta blockers are bisoprolol and metoprolol.
Catheter ablation is a treatment option for recurrent atrial fibrillation or for patients who suffer greatly from the symptoms of atrial fibrillation. The aim of ablation is to permanently restore normal sinus rhythm. Under local anesthesia, a catheter is first inserted through a small incision, usually in the groin, via the groin vein and advanced to the heart.
With the help of this catheter, scars are then made in certain areas of the heart wall and/or pulmonary veins. These scars are intended to eliminate those areas of the heart where unwanted spontaneous electrical excitation repeatedly leads to atrial fibrillation. The scars are placed by heat, cold or a laser.
For this purpose, diseased heart tissue, which transmits false excitation and thus triggers atrial fibrillation, is selectively sclerosed with heat and switched off. Using high-frequency current, part of the tissue is scarred or sclerosed so that it can no longer transmit electrical signals. The ablation treatment does not always succeed the first time, so it sometimes has to be performed several times.
However, even then there is no guarantee that atrial fibrillation will be safely eliminated. Up to now, ablation therapy has mainly been used for patients who do not have permanent atrial fibrillation, but in whom atrial fibrillation occurs in attacks. In technical jargon, this is referred to as paroxysmal atrial fibrillation.
In the case of catheter ablation, the patient usually does not require anesthesia; he or she is awake or lightly sedated during the examination. Only the insertion of the catheter via the groin is somewhat painful, the intervention on the heart itself causes no pain. After ablation, patients must remain in bed for 12 hours and are usually allowed to leave the hospital the next day.
At present, ablation is not a first-choice therapy (“second-line-therapy”). Therefore, it is usually only used if a drug therapy has been unsuccessful or if there are intolerances. Ablation is therefore effective, but rarely appropriate.
For this reason, only specialized and experienced centers should perform the procedure. Nevertheless, the method can represent a real chance, especially for young patients. In addition to the catheter ablation described above, surgical ablation can also be performed in very special cases.
During the operation, the defective heart tissue is removed by a heart surgeon under general anesthesia. Due to the higher rate of complications, this procedure is only performed if, for example, a bypass operation is planned and thus a surgical intervention is necessary anyway. Pacemakers are used to treat certain cardiac arrhythmias.
However, they are rarely used for atrial fibrillation. The only indication for implantation of a pacemaker in atrial fibrillation is bradyarrhythmia absoluta, i.e. a heart rate that is clearly too slow in the context of atrial fibrillation. If the heart beats so slowly that the patient feels symptoms such as dizziness or even becomes unconscious, treatment must be given here.Usually a 2-chamber pacemaker is installed.
It then works in the right atrium as well as in the right ventricle and ensures that the heart beats fast enough again. In the case of atrial fibrillation with a normal or too fast heart rate, a pacemaker cannot be considered as a therapeutic measure. Cardioversion is a procedure that is used to end atrial fibrillation immediately.
This may be necessary at different moments. For example, in a patient who has an unstable circulation due to atrial fibrillation. In this case, quick action must be taken, the goal is to end the atrial fibrillation as soon as possible.
But even in younger patients with new atrial fibrillation, an attempt can be made to end the cardiac arrhythmia with an electric shock. Especially in patients who have been suffering from atrial fibrillation for years, the long-term chances of success of cardioversion are rather low. In electrical cardioversion, the goal is to reactivate the primary pacemaker of our heart, the sinus node, with a short electric shock.
This is intended to stop the chaotic circular excitation in the atrium and then return the heart to normal sinus rhythm. The procedure is performed under short anaesthesia and under careful ECG control. Since dangerous blood clots can easily form during this procedure, it is essential to start a blood-thinning therapy in preparation.
Before cardioversion, it must be ruled out that there is already a blood clot in the heart. Otherwise, the electric shock could catapult the blood clot from the heart into the vessels supplying the brain, where it could trigger a stroke. To rule out the presence of a clot, a cardiac ultrasound scan is performed from the inside, i.e. through the esophagus (transesophageal echocardiography, TEE).
If a clot is ruled out, the patient is given a short anaesthetic. If the patient is asleep, a defibrillator is used to deliver a shock that is transmitted to the patient’s heart via electrodes attached to the patient’s body. Such a shock is often sufficient to bring the heart back into the right rhythm. In order to maintain this rhythm, however, in most cases patients must also take regular medication. And even then, the recurrence rate, i.e. the rate of recurrence of atrial fibrillation, is relatively high.
