Definition
A heart stumble is a clearly perceptible heartbeat that is not in time with the normal pulse. This phenomenon is based on so-called extrasystoles, i.e. excitation of the ventricle, which are accompanied by additional contractions of the heart muscles. A heart stumble that occurs only occasionally and lasts only a few heartbeats is not pathological and does not require treatment.
Its occurrence increases with age. If a cardiac stutter occurs more often and for a longer period of time (minutes to hours), the patient’s heart must be examined thoroughly, as this can be a sign of heart disease that must be investigated. If a heart stumbling occurs with existing heart disease, caution is also advised and a doctor should be consulted.
The Extrasystole
The heart stumbling is an additional activity of the ventricle that does not take place in the normal beat rhythm, this is called extrasystole. To understand why some people experience extrasystole, we must first look at the function of the heart. The heart consists of two atria, the right and the left, which are located in front of their respective chambers.
Not only does blood flow from the atrium towards the ventricle, but the electrical impulse conduction that gives the heart its rhythm also makes its way in this direction in the sinus node. The sinus node is the heart’s clock generator and is located in the right atrium. From here, a current flows to the AV node, which is located between the atrium and the ventricle and carries the stimulus into the ventricle.
The AV node serves as a safety barrier, so it does not allow the excitation to pass if the frequency is too high. This ensures that the heart remains in a frequency range in which the blood can be adequately pumped. Finally, in the chamber, the excitation spreads through special nerve fibers, the His bundles and Tawara legs, to cause the heart muscle cells to contract.
Extrasystoles always occur when this stimulation conduction is disturbed. If the disturbance is located in the atrium, this is called supraventricular extrasystole; if it is located in the ventricle itself, this is called ventricular extrasystole.
- Supraventricular extrasystoleSupraventricular extrasystoles can be caused by excitation cells in the atria or in the AV node that have disconnected from the normal excitation conduction, they are called ectopic centers.
Many people have such extrasystoles, which often go unnoticed but sometimes cause symptoms of heart stuttering. They are usually harmless.
- Ventricular extrasystoleVentricular extrasystoles do not usually occur in healthy hearts, but are associated with heart diseases such as coronary artery disease (CHD). Mostly, they originate from damaged heart cells, which are more easily excitable due to the damage.
These cells can induce ventricular excitation outside the beating rhythm, which then manifests itself as ventricular extrasystole.
If a patient presents with a heart stumbling, the doctor first measures the pulse and performs an auscultation of the heart with the help of a stethoscope. The nature of the pulse can already provide an indication of possible diseases such as valve disease or cardiac arrhythmia. During auscultation, special attention is paid to heart murmurs.
If two short tones that can be clearly distinguished from each other are heard in a healthy heart, these can change into a pathological sound in the case of diseases. This sound is longer and can be characterized by attributes such as hissing or the louder and softer (crescendo, decrescendo). The place on the chest where the sound is perceived most loudly can indicate to the doctor which heart valve is diseased.
If a sound could be found during cardiac auscultation, it is recommended to make a more precise diagnosis by means of an ultrasound examination of the heart. In addition to imaging the heart, this examination also allows a statement to be made about the flow of blood. Another very important examination to get to the bottom of the heart stumble is the ECG.
Here the electrical stimulation conduction on the chest wall is measured. With this examination, statements can be made about the heart rhythm, the regular transmission of the electrical system of the heart and inadequate heart actions. Furthermore, it can be determined exactly how many extrasystoles occur in a certain time interval.
If the ECG on site is not meaningful because the heart stumbling did not occur at the time of measurement, it is recommended to record a 24-hour long-term ECG. The data provide a better indication of possible cardiac arrhythmia.The patient’s blood pressure is also measured. In addition, blood values have to be determined, since disturbances of the electrolyte balance in the case of a heart stumble have to be taken into account.
In the laboratory, the thyroid hormones can also be measured in order to rule out possible hyperthyroidism. The causes of a heart stumble are varied and do not necessarily have to come directly from the heart. Hormonal disorders or shifts in the electrolyte balance can also be the background to the condition.
In some patients, heart flutter occurs after drinking coffee, cigarettes or alcohol. High blood pressure is another factor that promotes heart flutter. Existing heart diseases such as valve disease, coronary heart disease or other damage to the heart can also cause a heart stumble.
Some causes are explained in more detail below.
- Atrial fibrillationWhen atrial fibrillation occurs, the heart muscle cells of the atria are no longer regularly excited and contracted. A so-called circular excitation occurs and as a result, electrical signals with frequencies of up to 600/min are sent in the direction of the heart chambers.
Due to the AV node, these signals did not reach the ventricles, since the AV node only transmits significantly slower frequencies to protect the heart function. As a result, only occasional atrial fibrillation is transmitted into the ventricles, which leads to an arrhythmia, i.e. an irregular pulse, which is also elevated. This can cause the patient symptoms of atrial fibrillation, especially if the atrial fibrillation is only intermittent and then suddenly leads to an increased and irregular pulse.
- HypokalemiaIf hypokalemia occurs, i.e. too low a concentration of potassium in the blood, this can lead to heart stumbling.
The reason for this is the higher tendency to cardiac arrhythmia due to the shifted ion concentrations, since the heart muscle depends on a certain concentration ratio, especially of potassium and sodium, to function properly. In addition, hypokalemia increases the risk that drugs that can potentially cause heart failure will have this side effect due to the already critical situation for the heart. Cardiac glycosides, i.e. digitalis, are an example of this.
Hypokalemia can occur in severe vomiting or diarrhea, as well as in some kidney diseases due to increased loss of potassium or when taking diuretics such as furosemide.
- HyperthyroidismA hyperthyroidism results in increased hormone production, which is why an elevated thyroid hormone level in the blood can be measured. These hormones have a stimulating effect on the body, so in addition to an increased basal metabolic rate, there is also an increased heart rate, as the heart becomes more sensitive to the pulse-increasing adrenaline and noradrenaline. In the course of this, a heart stumbling can also occur.
The most common cause of hyperthyroidism is Graves’ disease, an autoimmune disease, and thyroid autonomy should also be considered as a common cause.
- Chemotherapeutics/other drugsChemotherapeutics used to treat cancer can damage not only cancer cells but also the healthy cells of the body, including the cells of the heart. After treatment, this can result in cardiac arrhythmia in addition to cardiac insufficiency, which is perceived as a heart stumble. In addition, other drugs that are used far more frequently can also cause a heart stumble.
These can include antidepressants such as amitryptilin or beta-blockers. Paradoxically, drugs that are used to treat cardiac arrhythmia can also cause a heart stumble. Particularly in the case of an overdose, there is a high risk of cardiac arrhythmia with heart stumbling, even with digitalis.
- Psychological Causes/Panic AttacksIn case of severe anxiety or panic attacks, the pulse rate increases suddenly, this can also lead to extrasystoles that some patients may feel. Other psychological stress can also cause a heart stutter and should be considered if no organic cause can be found and patients suffer from the symptoms.
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