Tachycardias are cardiac arrhythmias with a strongly accelerated heartbeat (over 100 beats per minute).
Tachycardias are cardiac arrhythmias with a strongly accelerated heartbeat (over 100 beats per minute). A distinction is made between two main types:
- Supraventricular tachycardia: The impulse for the accelerated heartbeat originates in the area of the sinus node, the atria or the so-called AV node. The heart suddenly starts beating very fast, 150 to 220 times per minute. Such an attack of palpitations can last a few seconds, but also several hours, and then sometimes disappears abruptly. Paroxysmal, i.e. intermittent, tachycardia often occurs in young, healthy people, can recur throughout life, is rarely dangerous, but is unpleasant. In people who already have heart disease, supraventricular tachycardia can lead to angina pectoris, dizziness or loss of consciousness, for example - treatment is therefore necessary.
- Ventricular tachycardia: The impulse for the accelerated heartbeat originates in the area of the heart chambers. The most common cause is severe heart disease, e.g. a heart attack. Rapid, uncoordinated pumping movements of the ventricles and atria occur. The arterial blood pressure drops, sufficient blood flow to the body is no longer guaranteed. The situation can become life-threatening and requires immediate medical attention, preferably in hospital.
- Atrial fibrillation and atrial flutter: Tissue damage in the heart can disrupt the conduction of excitation. The excitation wave originating from the sinus node only affects part of the atrial muscles, while other areas are not yet excited. The excitation wave then runs not only via the AV node towards the ventricle, but also to the atrial muscle cells that are not yet excited. This can cause a circular excitation wave within the atrial muscles.
In atrial flutter, this circular excitation still leads to pumping actions of the atrial muscles. In atrial fibrillation, different excitation waves circulate chaotically within the atria, beating too fast, irregularly and uncoordinatedly. Not enough blood can be pumped into the circulation. This is often not completely ejected from the heart, so that blood clots (thrombosis) can form and subsequently embolisms or strokes. The ventricles can only compensate for this drop in performance in the short term. Over time, heart failure (cardiac insufficiency) can develop as a result of prolonged overload.
Atrial fibrillation is one of the most common persistent cardiac arrhythmias, especially in older people. About four percent of people over 60 and ten percent of people over 80 are affected. Although atrial fibrillation is usually not an acute danger, it is a progressive, i.e. worsening, and potentially dangerous condition that sometimes causes massive discomfort: those affected have an increased risk of death, as they are more likely to suffer a stroke, heart failure or cardiovascular arrest.
Pocket - Guideline: Supraventricular tachycardia (2019)
Pocket guideline: Diagnosis and treatment of atrial fibrillation (2020)
Source: GESUNDHEIT.GV.AT (Cardiac arrhythmias)