When the heart is completely out of rhythm, one often also speaks of atrial fibrillation in the context of cardiac arrhythmias. The human heart beats about 60 to 100 times a minute. In this way, it pumps the blood unceasingly through our body. It requires a perfectly coordinated action of the two larger heart chambers and two smaller atria.
Between the atria and the heart chambers are the so-called Atrioventrikularklappen (short AV valves), which prevent like a valve that the blood flows back into the atria. When the atria contract, the blood is transported into the chambers. Once these are completely filled, they also contract and pump the blood into the circulation. For this coordinated pumping process to take place, it is necessary that specialized cells of the so-called sinus node transmit electrical impulses to the atria and from there to the heart chambers (AV nodes).
Atrial fibrillation is the most common cardiac arrhythmia
Occasionally the heart gets a bit out of rhythm. That's not bad. But it can also be quite out of rhythm as is the case with rare, life-threatening ventricular fibrillation and frequent atrial fibrillation. Around 1 million - especially older - patients in Germany have atrial fibrillation. In her heart, the wave of excitation emanating from the sinus node loses its alignment. The atria then no longer contract, but only twitch irregularly up to 600 times per minute.
Atrial fibrillation means that the heart chambers are no longer filling properly and the pumping power of the heart is reduced. There are several types of atrial fibrillation: One speaks of paroxysmal atrial fibrillation, if it occurs as an attack and the disorders disappear after hours or days by itself. If it does not stop by itself and needs to be treated, it is called Persistent Atrial Fibrillation.
In extreme cases, there is a permanent atrial fibrillation, which can not be controlled by conventional measures, because electrical and mechanical remodeling processes have greatly changed the atria. The problem is that the atrial fibrillation itself amplifies, as the atrial cells change so that they are electrically activated faster and faster.
By contrast, atrial flutter, which is rarer than atrial fibrillation, occurs when the atria contract 250 to 300 times per minute. Atrial flutter often leads to palpitations without drug treatment.
Atrial fibrillation: symptoms and causes
If your heart beats for a short time, most patients will not notice it at all. If the flicker lasts longer, the following symptoms of atrial fibrillation occur:
- Completely irregular pulse
- difficulty in breathing
- difficulty in breathing
- fluid retention
Possible causes of atrial fibrillation include underlying heart diseases such as constriction of the coronary arteries and myocardial diseases. Furthermore, heart surgery, heart attack, pulmonary embolism, myocardial tissue inflammation, chronic lung disease, chronic sleep apnea syndrome and hyperthyroidism increase the risk of cardiac arrhythmias such as atrial fibrillation. Hypertension, pathologically altered heart valves (especially the mitral valves), congenital heart defects, strong nicotine consumption and increasing age are further risk factors.
Atrial fibrillation can also be triggered acutely by excessive alcohol consumption (holiday-heart-syndrome) and emotional stress. However, there are also cases where no cause of atrial fibrillation is detectable.
Diagnosis and treatment of atrial fibrillation
Early diagnosis and early treatment for the first signs of atrial fibrillation are important. For diagnosis, the doctor scans the pulse and listens to the patient with the stethoscope. An electrocardiogram (ECG) allows him to confirm the diagnosis. Appropriate drugs in the therapy include the slowing the heart rate beta-blockers and calcium channel blockers (eg verapamil) and the rarely used cardiac glycosides (eg Digitoxin). If atrial fibrillation persists, the cardiac rhythm can only be normalized by electric shock (electrical cardioversion).
If the mentioned therapy methods are not sufficient, a catheter ablation can take place. Cardiac ablation ablates the junctures of the pulmonary veins into the atria. In order to maintain the normal rhythm, so-called antiarrhythmics are used for the subsequent treatment. Atrial fibrillation can be life-threatening as the risk of embolism is increased due to altered blood flow conditions. In small extractions of the atria, called the ears of the heart, the blood then flows very slowly, so that clots form more frequently there. The risk of a stroke is increased by a factor of five.
Atrial fibrillation guidelines
The latest guidelines (2010) for atrial fibrillation call for a more consistent anticoagulant therapy than was previously the case. Evaluations of data collected by AFNET in recent years show that only about half of the patients with high or very high risk of stroke in general practice and less specialized regional hospitals were treated with anti-coagulant drugs. In university hospitals and in established cardiologists or in specialized centers, at least 70 percent of the patients with atrial fibrillation were adequately treated.
Conventional anticoagulants such as warfarin and phenprocoumon require constant dose adjustment and laboratory controls. New drugs, including dabigatran, which was approved in early 2011, improve stroke prevention and do not have the disadvantages mentioned for patients with atrial fibrillation.