Suddenly it rumbles in the chest, then absolute radio silence. Such short-term attacks are usually harmless - but sometimes they are harbingers of a heart condition. About 60- to 80-times a minute, a healthy heart muscle contracts, and shortly afterwards relax again and pump the blood through the circulation. A mini-power plant, the sinus node in the right ventricle, ensures that this rhythm of life is maintained. Regularly, this little tendon mesh sends out electrical impulses that set the rhythm of the heart. So the human heart has specialized cells, which serve on the one hand the electrical impulse formation and on the other hand the propagation of these impulses over the entire heart musculature.
What happens when the heart beats?
If the sinus node fails, there is no radio silence. Another area of the power line called AV node jumps in. If this emergency supply also fails, the His-fiber bundle can play the part of the clock, but with a significantly reduced pulse train of only 40 beats per minute. That is too little in the long run. Doctors then speak of a dangerous bradycardia. The circulation falters and man can even lose consciousness. Even with persistent turbulence of the heartbeat sequence, in the technical language tachycardia, something is wrong with the "heart electrics".
Cardiac arrhythmias: causes
Cardiac arrhythmias may be an expression of organic myocardial disease or isolated damage to the cardiac stimulatory and conduction structures.
In some cases, the organic or functional basis for cardiac arrhythmias may be inherent in the birth of a human. Cardiac arrhythmias can occur either at the earliest infancy or later in life. However, the following causes are much more common, especially in western industrial nations:
- high blood pressure
- Circulatory disorders of the coronary arteries
- Heart attack
- Valvular heart disease
- Heart muscle inflammation or
- a morbidly weakened heart.
But also an over-function of the thyroid or potassium deficiency bring the motor of life sometimes out of rhythm. In part, electrolyte disturbances or side effects of medication may be considered as triggers of cardiac arrhythmias. Since cardiac function is also strongly influenced by the autonomic nervous system, mental factors can also play an important role in the development of cardiac arrhythmias.
But: not behind every stumbling and irregular heartbeat is a disease. Stress and physical exertion, caffeine and alcohol, even certain medications can disrupt the "power supply" in the heart. The consequences are hunts and extra bats, in technical language called extrasystoles.
Symptoms and characteristics
If the heart deviates permanently from the normal pumping rhythm, severe health problems and sometimes even complete heart failure are at risk. The problem: In cardiac arrhythmias there is often a clear difference between the doctor's assessment of the disorder and the impairment of the patient. It can happen that even minute-long, life-threatening cardiac arrhythmias are hardly noticed by patients.
Other patients, on the other hand, may feel severely impaired in their state of health as a result of occasionally recurring extra harms of the heart which are in themselves completely harmless. Depending on the type and duration of cardiac arrhythmia, the following symptoms may occur:
- Palpitations, tachycardia
- irregular heartbeat
- Dizziness, collapse
- Fainting spells.
In extreme cases, it can lead to a malignant arrhythmia or sudden cardiac death. Important distinguishing criteria in cardiac arrhythmias are, on the one hand, their place of origin (atrium or ventricle), and on the other their duration as well as the question of whether they occur in the context of an acute heart disease, for example in a heart attack, or in a chronically damaged heart.
Common: atrial flutter
Basically, cardiac arrhythmias that have their origin in the atrium are of a harmless nature, while cardiac arrhythmias that develop in the ventricle may sometimes be life-threatening, especially in advanced organic heart disease.
The uncoordinated, rapid twitching of the atria is the most common form of cardiac arrhythmia. Especially the elderly and people with heart failure are affected by such atrial fibrillation or flutter. Although always the underlying disease should be treated first, the atrial fibrillation must be turned off so that a heart failure does not worsen. This is done by a so-called cardioversion, in which the heart is brought back into its normal impact sequence with medication or with the help of an electric shock.
But there are also cases in which a treatment of atrial fibrillation is not necessary. This can be, for example, patients who despite normal heartbeat have a normal heart rate and are symptom-free. However, they always have to be bothered by the increased risk of blood clots, which can clog vessels and, in the worst case, trigger a stroke.
Life threatening: Ventricular fibrillation
Heartbeat heartbeat is always dangerous if it leads to a drastic decrease in pumping power. This happens when, with a racing heartbeat, there is no time for the heart muscle to contract completely and the heart chambers can no longer fill with blood. The extreme case is the dreaded ventricular fibrillation, in which the heart muscle only twitches uncoordinated.
The speed can increase up to 300 such irregular beats per minute. At this speed of hell, the heart is not nearly able to supply the circulation with blood. Without rapid intervention, the result is heart failure, which kills 350 people a day in Germany. Rescue brings an electrical shock that is delivered by a defibrillator. The small device can almost eliminate the danger of dying from a life-threatening arrhythmia.
Course of cardiac arrhythmias
As far as the course of arrhythmias is concerned, no precise predictions are possible in individual cases. Cardiac arrhythmias can either be life-long or occur only in a certain period of life or they become permanent, unpleasant companions with increasing progress of organic heart disease.
To be able to assess their character more accurately and set up a possible treatment plan, it is essential for the doctor to document the arrhythmia in the resting or long-term ECG. This means that an electrocardiogram must be written at the time of the ongoing arrhythmia.
If the arrhythmia is clearly diagnosed, the doctor can decide whether an immediate medical treatment is eligible and the patient can then go home symptom-free or whether a longer hospital stay is needed for further clarification.