Atrial fibrillation

Normally, the healthy heart moves rhythmically at a rate of between 60 and 80 beats per minute. The heartbeat is controlled by the impulse generator in the area of the right atrium (sinus node) and leads to a regular movement (contraction) of the cardiac atria and the main chambers of the heart. In atrial fibrillation, there is an uncoordinated, arrhythmic sequence of events in the heart’s ventricles – a so-called “fibrillation”. The ventricles typically twitch 150 to 600 times per minute and are functionally at a standstill. This leads to an impaired onward transport of the blood into the main chambers. This can result in the following problems:

1. Restriction of physical resilience with palpitationsUnpleasant heartbeat., malaise and shortness of breath
2. Decrease in the heart’s performance
3. 4 to 5-fold increased risk of developing a strokeOcclusion of a cerebral artery or rupture of a vessel with subsequent cerebral haemorrhage. The affected nerve cells die due to lack of oxygen, leading to permanent loss and paralysis. due to blood clots being washed out into the brain vessels.

However, atrial fibrillationHeart rhythm disorder in which both atria beat irregularly more at than 300 times per minute. However, the excitation is only partially transmitted to the ventricles. does not necessarily cause symptoms and can be asymptomatic (symptom-free) in a certain proportion of patients.

There are many causes for the development of atrialConcerning the atrium (= upper chamber of the heart). fibrillation. Known risk factorsCollective term for factors that can pose a health risk. These include alcohol and nicotine consumption, obesity, high blood pressure, sugar and fat metabolism disorders, high cholesterol levels, stress, lack of exercise, etc. for atrial fibrillation include older age, high blood pressureIncreased pressure within the arterial system. The limit value is 140/90 mmHg (see Hypertension)., thyroid disease and other heart conditions. In particular, patients with long-standing valvularConcerning the valves heart disease are often affected.

General therapy

Treatment focuses on relieving symptoms and minimising risks, such as the development of a stroke. This is done with medicationAdministration and dosage of a medicine. in the early phase of the disease. Anticoagulant drugs (blood thinners) are used to prevent strokes. These cause an improvement in the flow properties of the blood and thus prevent the formation of blood clots in the atria. To restore a regular heartbeat, heart rate-lowering and rhythm-stabilising drugs (anti-arrhythmicsMedicines for the treatment of heart rhythm disorders.) are used.

If the use of anti-arrhythmic drugs does not stabilise the heartbeat, surgical sclerotherapy of the heart muscle in the area of the atria may be necessary. Surgical treatment of atrial fibrillation is mainly carried out when other heart diseases requiring treatment are present at the same time.

Surgical therapy – MAZE operation

In the Department of Cardiovascular Surgery at the German Heart Centre Munich, the surgical treatment of atrial fibrillation is performed as an additional interventionA quick medical measure to slow down the progression of a disease, e.g. with the help of the cardiac catheter (interventional cardiac catheter technique) an acutely occluded coronary vessel is reopened and thus the spread of the heart attack area is stopped. within the framework of other cardiac surgery in the area of the heart valves (especially mitral valveHeart valve between the left atrium and left ventricle. It got its name because of its shape, which has a strong resemblance to a bishop’s mitre. diseases) or the coronary vesselsCoronary arteries. The left and right coronary arteries originate above the aortic valve from the aortic root and initially run along the outside of the heart muscle before branching out into many sub-branches and dipping into the heart muscle tissue as fine arterioles..

Surgical treatment of atrial fibrillation is based on the principle of local sclerotherapy of heart muscle tissue (ablationDestruction of congenital, additional conduction pathways that cause cardiac rhythm disturbances. This is performed with the help of heat generation through cardiac catheters.). Here, heat (radiofrequency ablation) or cold application (cryoablation) is used to draw scar lines in the area of both atrioventricular chambers, which interrupt the spread of atrial fibrillation. The labyrinthine arrangement of these ablation lines makes it possible only for the normal excitationThe heart muscle consists of two different types of muscle fibres. One type of fibre forms the stimulus-forming and stimulus-conducting system, the other the working muscles. The conduction system is responsible for the formation and conduction of excitation. In other words, it spontaneously and rhythmically forms tiny electrical currents that spread throughout the heart in a specific sequence. The working muscles absorb these currents and convert them into pumping movements. waves triggered by the sinus nodeThe sinus node is the natural pacemaker of the heart. It triggers the heartbeat via electrical impulses. to propagate. This restores a regular heartbeat. In addition to surgical ablation, the standard procedure is to remove the left atrial appendage (blind sac in the area of the left atriumTerm for the uppermost chambers of the heart. There is a left atrium and a right atrium. The right atrium collects the oxygen-poor blood that flows back from the body to the heart; the left atrium collects the oxygen-rich blood that comes from the lungs. From the atria, the blood continues to the respective ventricles.) as the main source of blood clots. This significantly reduces the occurrence of strokes.

The success of surgical therapy depends primarily on the size and thickness of the atrial chambers and the duration of the atrial fibrillation. The success rate for regaining a regular heartbeat is on average between 50 and 80 per cent.