What is a cardiac arrhythmia?

The heart is one of the most important organs of the body. Of course, things can go wrong with that. Sometimes the heart beats too fast (tachycardia), sometimes too slowly (bradycardia) or there is an irregular heartbeat. It is not always something serious, but how can you have this checked?

Cardiac arrhythmia

A cardiac arrhythmia can be distinguished into three different types.

  1. Increased heart rate (tachycardia). The heart beats faster than 100 beats per minute.
  2. Slowed heart rate (bradycardia). The heart beats less than 60 beats per minute.
  3. Irregular heartbeat. The number of beats per minute is normal. An example is extrasystole, where the heart skips a beat.

A heart rhythm disorder does not necessarily have to be something serious. Heart failure can happen to anyone from time to time and is therefore harmless. Just like an increased heart rate during stress or exercise. On the other hand, a heart rhythm disorder can also be fatal.

A heart rhythm disorder can be diagnosed by making an ECG (more about this later). The difficult thing is to measure it when the disorder occurs. The complaints are not always present. If this is the case, or at least occurs with some regularity, a longer ECG (Holter ECG) can be made using a box that makes measurements.

What is normal?

The heart normally beats about once per second. A heart rate between 60 and 100 minutes is therefore normal (although it naturally becomes increasingly abnormal as it approaches 100).

Bradycardia is also common in endurance athletes. Their hearts need to beat less often to pump enough blood. This is also called athlete bradycardia. Tachycardia with anxiety and stress is also quite normal. The adrenaline and noradrenaline that are produced during these feelings influence the heart rate and therefore make it beat faster.


The symptoms of tachycardia and bradycardia are largely similar. Both suffer from shortness of breath and dizziness. Both may experience fainting and a feeling of weakness. Bradycardia is characterized by extreme fatigue. With tachycardia there is also a fluttering sensation in the chest and light-headedness.

Causes of cardiac arrhythmia

There are various causes for cardiac arrhythmias. A number of causes will be mentioned below for each type.


Causes for an accelerated heart rate are:

  • Response to stress. This is a normal phenomenon and happens to most people. During stress, but also during physical exertion, such as during sports, the heart rate can increase.
  • Dehydration.
  • Anemia.
  • Use of stimulants (coffee, cocaine).
  • Deficiency of vitamin B1/thiamine or aneurine (involved in carbohydrate metabolism)
  • Alcohol consumption. About fifteen minutes after taking.


  • Hereditary heart disease.
  • Scar tissue after a heart attack.
  • Aging. This is natural.
  • Heart block or the heart’s natural pacemaker not functioning properly.
  • Certain diseases or heart medications
  • Sick sinus syndrome;
  • Blockage of electric current passing from the upper to the lower chamber.


To find out whether you have a heart rhythm disorder, it is best to see a doctor. This can confirm or rule out the diagnosis with a specific test. An electrocardiogram (ECG) is often sufficient and sometimes an exercise test (exercise ECG) is performed.

Another test is the tilt table test or the Holter monitor is used. The latter is an ECG that lasts 24-72 hours. Electrophysiological research can also be performed. The tilt table test tests the cooperation between the brain and the heart and requires a day’s recording. The test is about posture and what the blood pressure and pulse rate are.


Cardiac arrhythmias can be treated with medications as well as surgery. During surgery, an ICD (implantable defibrillator) is placed to regulate the fast or slow heart rate. An ICD is about the size of a pocket watch and is placed under the left or right collarbone.