Cardiac arrhythmia

The heartbeat is triggered by electrical impulses that begin in the right atrium of the heart. These impulses are usually sent out in a steady rhythm and spread quickly throughout the heart muscle. The heart then beats slower or faster depending on its load and in this way always pumps enough blood through the body. But even the heartbeats of healthy people are never completely free of defects. The rhythm can, for example, “trip” several times a day and there are what is known as extrasystoles. Doctors talk of cardiac arrhythmia when the heart rate is more disrupted than normal or does not match the respective load.

The heart can for example:

• beat too slowly – health professionals refer to this as bradycardia or bradyarrhythmia. A typical example is AV block where the impulses between the atria and ventricles are transmitted delayed or interrupted.
• beat too quickly – those affected have tachycardia or tachyarrhythmia. This form is also known as heart palpitations in everyday language and can be harmless. But tachycardia also often occurs with severe arrhythmia, for example with atrial fibrillation.
• beat irregularly – doctors call this arrhythmia, regardless of whether the heart is beating too quickly, too slowly or normally.

Sometimes several arrhythmias also occur at the same time. This means that the hearts of people with atrial fibrillation can beat too quickly and also irregularly.

If the heart “trips” for only a short time, some people do not notice the arrhythmia. Others experience an irregular heartbeat as a skipped heartbeat or palpitations. A high heart rate can become noticeable as heart palpitations when the heart is beating very quickly even though the person affected is not exerting themselves.

Most of the time, other complaints only arise when the heart rhythm is so out of step that the blood is not pumped through the body properly. If this doesn’t supply the brain with enough oxygen, it can result in dizziness or fainting.

The heart muscle itself also needs enough oxygen. If an arrhythmia causes it to be under-supplied, this can lead to chest pain, shortness of breath and weakness.

Cardiac arrhythmias are often caused by heart diseases. These include:

• coronary heart disease (CHD) and heart attack
• heart valve disease
• myocarditis
• cardiac insufficiency
• abnormalities of the conduction system

High blood pressure, smoking, drug consumption and also too much alcohol can also damage the heart and make cardiac arrhythmias more likely.

Other possible causes of cardiac arrhythmias are:

• an overactive thyroid
• chronic kidney disease
• diabetes mellitus
• accidents and injuries as a result of an electric current

But cardiac arrhythmias can also happen in people with healthy hearts and no pre-existing conditions – these are called idiopathic cardiac arrhythmias.

Some medication can also trigger cardiac arrhythmias as a side effect. These include some blood pressure-lowering medicines and cardiac agents, anti-depressants, antibiotics or cancer medication.

Cardiac arrhythmias are common, especially in older people and in people with other heart problems. People with these conditions usually also have to be treated. Younger and otherwise healthy people have cardiac arrhythmias that are less harmful.

Cardiac arrhythmias can start unexpectedly and can disappear again a few seconds or minutes later. Some people have these episodes repeatedly. Certain disorders can also persist.

Some people suddenly pass out as a result of a cardiac arrhythmia – they then run the risk of falling and injuring themselves. Cardiac arrhythmias can also cause heart failure or make existing heart failure worse.

With atrial fibrillation, blood clots in the heart may develop. If these clots dissolve, they can be washed into the brain with the blood and cause a stroke.

Life-threatening complications usually only arise when the heart is already damaged. Then cardiac arrhythmias can lead to circulatory failure, cardiac arrest or ventricular fibrillation. The heart rate is so fast that the individual heartbeats are too weak to pump enough blood through the body. If the person affected is not revived, they can die (sudden cardiac death).

Cardiac arrhythmias can also make themselves felt as rapid heartbeat or skipped heartbeat or palpitations. Sometimes when measuring your heart rate or listening to it with a stethoscope, the doctor discovers that your heartbeat is too slow, too quick or irregular.

Cardiac arrhythmias can be accurately determined and differentiated from one another through an electrocardiogram (ECG). If the ECG is normal when a cardiac arrhythmia is suspected, the problem may only occur occasionally or only during physical exertion. To be on the safe side, a 24-hour ECG or an exercise ECG is often performed.

Other tests can also be a good idea to clarify the causes or complications of cardiac arrhythmias. Heart failure can be determined by performing an ultrasound scan of the heart (echocardiogram or “echo test”), for example.

Whether and how cardiac arrhythmia is treated will depend on several factors:

• the type of the problem
• the causes and whether they can be fixed
• the severity of the problem
• whether the problem causes symptoms
• the risk of complications such as for example a stroke or ventricular fibrillation

The procedure for cardiac arrhythmias can be very different: some people who are affected cope without treatment. With others the cardiac arrhythmia can be stabilized with medication. Sometimes heart surgery can help – this involves, for example, tissue of the conduction system that triggers the cardiac arrhythmia being destroyed (ablated). If the heart rhythm has to be permanently assisted, electrical aids such as a pacemaker or a defibrillator are options to consider.

People with cardiac arrhythmias can have symptoms such as weakness and difficulty breathing. Those affected can then be less physically fit or need help in their daily routine. Sometimes the treatment can also be a burden – when for example the person has to regularly take blood-thinners due to atrial fibrillation. The everyday life of people who have been fitted with a pacemaker or defibrillator is also restricted.