Cardiac arrhythmia: When the heartbeat stumbles

1. What are cardiac arrhythmias?
2. What are the consequences of cardiac arrhythmia?
3. What increases the risk of cardiac arrhythmias?
4. How can cardiac arrhythmias be prevented?
5. How are cardiac arrhythmia, diabetes and obesity related?
6. What are the symptoms of cardiac arrhythmia?
7. How are cardiac arrhythmias diagnosed?
8. How are cardiac arrhythmias treated?

A complex system in the body ensures that the heart muscle pumps blood through the blood vessels at a regular rhythm. At rest, this occurs at 60 to 90 beats per minute. This rhythm is controlled by electrical impulses. But sometimes the heart gets out of sync: It beats too fast, too slowly or irregularly. Experts then speak of what are called cardiac arrhythmias.

As there are many different forms of cardiac arrhythmia, they are classified according to several characteristics:

• According to the place of their origin: In the atrium (supraventricular) or in one of the two ventricles (ventricular)
• According to the heart rate: Accelerated heartbeat (tachycardia) or slowed heartbeat (bradycardia)
• According to the mechanism of origin: Disturbed formation of electrical impulses or faulty transmission of the excitation (excitation disturbances)

Cardiac arrhythmias are widespread in Germany. The most common is the atrial fibrillation. Over-excitation of the atria results in the atria no longer being able to pump efficiently and thus fill the downstream ventricles with less blood. In addition, the overall heartbeat is often too fast. As a result, cardiac output decreases as the heart muscle pumps less blood.

Around 1.6 million people in Germany (around 2 percent of the population) are affected. Experts believe that twice as many people will suffer from atrial fibrillation in the next 50 years. There are several reasons. Among other things, the fact that more and more people are overweight and are getting older plays a role.

Certain forms of cardiac arrhythmia occur more frequently in men, while others occur predominantly in women. The widespread atrial fibrillation, for example, is more common in men. However, women feel more affected by the symptoms of atrial fibrillation in everyday life.

Cardiac arrhythmias are generally harmless, especially in young people and people without pre-existing conditions. This can be caused, for example, by stress, caffeine or alcohol consumption. However, some forms of cardiac arrhythmia may also be dangerous. Then the cause is usually another heart disease. In general, symptoms such as heart stumbling should be clarified by a cardiologist – especially if there is already a family history of heart problems.

Many forms of cardiac arrhythmia are harmless – especially if there is no heart disease. However, if left untreated, certain forms of cardiac arrhythmia increase the risk of serious complications.

Atrial fibrillation is one of the most important risk factors for a stroke. Around 25 in 100 strokes caused by a blocked blood vessel are due to atrial fibrillation. The reason: The heart pumps less blood through the atria, so the blood coagulates more quickly and is more likely to form blood clots. These can enter the brain via the bloodstream, clog vessels there and lead to a stroke.

Much rarer, but highly dangerous, are malignant cardiac arrhythmias, which always represent an emergency and are typically accompanied by severe symptoms or even unconsciousness. This can be accompanied by the heart first beating over 300 times a minute (ventricular fibrillation) and then stopping beating (sudden cardiac death). This can occur, for example, in the event of a heart attack.

The following risk factors can promote cardiac arrhythmias:

• Heart diseases such as heart failure, coronary heart disease (CHD) and heart attack
• Congenital heart defects such as malformations of the conduction system
• Stimulants and drugs such as alcohol, caffeine, nicotine, cocaine or amphetamines
• Electrolyte deficiency (especially potassium and magnesium)
• Lifestyle factors such as obesity, elevated blood lipid levels or lack of exercise
• Age: Older people are more frequently affected by diseases that promote cardiac arrhythmias
• Drugs such as certain heart medications or antidepressants
• Mental illnesses such as depression
• Other diseases such as diabetes, sleep apnea (breathing disorders during sleep), chronic kidney disease, vascular disease, high blood pressure, hyperthyroidism or chronic obstructive pulmonary disease (COPD)
• High emotional stress such as stress, anxiety, anger and the like

You can prevent cardiac arrhythmias by trying to reduce or avoid possible risk factors. If you are sensitive to stimulants with caffeine such as coffee or energy drinks, it is best to avoid them. A balanced electrolyte balance is also important for normal heart function. An electrolyte deficiency can occur due to heavy sweating, diarrhea or the intake of dehydrating medication. In these cases, make sure you drink enough, for example mineral water or unsweetened tea, and eat plenty of fruit and vegetables.

You should also reduce the risk of cardiovascular diseases. To achieve this:

• Eat a varied diet
• Get enough exercise
• Avoid chronic stress
• Ensure healthy sleep
• Give up cigarettes and other stimulants containing nicotine
• Do not drink alcohol or reduce consumption as much as possible
• Reduce existing excess weight in the long term

If you already have cardiovascular diseases such as high blood pressure, you should get medical treatment, particularly in order to prevent atrial fibrillation.

The risk of atrial fibrillation is particularly high when elevated blood sugar levels are accompanied by high blood pressure, obesity and a disturbed fat metabolism. This combination of risk factors is also known as metabolic syndrome. Severely overweight (obese) people in particular are at risk of developing metabolic syndrome.

In addition, people with diabetes are more likely not to notice heart problems, as elevated blood sugar levels may also damage the nervous system and thus reduce sensitivity. However, unknown and untreated heart diseases may lead to life-threatening cardiac arrhythmias such as ventricular fibrillation. It is therefore important for people with diabetes to have regular check-ups for cardiovascular diseases. A healthy lifestyle can further reduce the risk of complications.

Some people with cardiac arrhythmia have few or no symptoms. Atrial fibrillation, for example, often causes no symptoms and therefore usually remains undetected for a long time. Long undetected or untreated atrial fibrillation can cause heart failure, which can lead to reduced performance, shortness of breath or death in affected persons. This tends to occur slightly more frequently in men than in women. On average, affected women experience certain symptoms – especially palpitations and feelings of anxiety – more intensely than men.

To diagnose cardiac arrhythmia, doctors first ask about the symptoms and the situations in which they occur, as well as any previous illnesses and heart diseases in the family. This is followed by further examinations.

Electrocardiogram

An electrocardiogram (ECG) shows whether the heart is beating normally or whether there are any irregularities. Since cardiac arrhythmias often only occur intermittently or under certain conditions, special ECG examinations are often necessary:

• Long-term ECG: A small recording device measures the heart activity over 24 hours.
• Event recorder: Records the heart currents over a longer period of time (several months). They can be worn as a bracelet, finger clip or plaster.
• Exercise ECG: Shows how the heart reacts to physical exertion.
• Smartwatches: Can support the diagnosis of cardiac arrhythmias. However, they are not yet a medical standard.

Ultrasound examination (echocardiography)

With the help of an ultrasound examination, the size, structure and movement of the heart muscle can be visualized and possible changes or diseases be detected. Sometimes doctors insert the transducer via the esophagus, which lies behind the heart. The images from a transthoracic echocardiogram (TTE or colloquially “swallowing echo”) provide particularly detailed images.

Further examinations

Further examinations may be necessary for a more precise diagnosis:

• Cardiac catheterizations reveal circulatory disorders in the vessels. Electrophysiological cardiac catheterization (EPC), on the other hand, can show exactly where cardiac arrhythmias occur in the heart.
• Blood tests, for example to clarify a thyroid disease.
• Further imaging examinations such as magnetic resonance imaging (MRI) or computer tomography (CT) to obtain detailed images of the heart.

For successful treatment, it is important to follow the treatment recommendations consistently. The earlier cardiac arrhythmias are recognized and treated, the better the prognosis. Targeted treatment can alleviate the symptoms and prevent undesirable consequences.