On a good number of occasions, extrasystoles are a chance finding that appears in the electrocardiogram (ECG) performed routinely, either in a company check-up or preoperatively.
However, it is in those cases in which they are accompanied by symptoms that they cause greater distress.
Because the patients who feel them feel it as a void, a sudden change in the heart, which seems as if it is not going to beat again and instead does so with a new strong beat, sometimes described as violent, which shakes the heart. the chest and can even be felt in the throat. This sensation, so unpleasant when perceived, typically manifests itself in moments of greater tranquility and it is very typical that they are described as more frequent or intense when they occur at night, in bed, especially if one is lying on the left side. .
The first thing that needs to be clarified is what is an extrasystole? This is what we call a heartbeat that is ahead of the normal cardiac cycle. The sinus node, a structure found in the right atrium, is responsible for setting the heart rate by generating an electrical impulse that triggers the contraction of the heart. The speed at which it does so is determined by various factors and its objective is to adjust the heart rate to the demands of the body.
Thus, while we sleep, we require less blood supply, so to speak, and the frequency will decrease. On the other hand, when we are subjected to physical or mental stress, the rhythm will increase in frequency. However, although it is the sinus node that is generally in control, all the cells in the heart have the ability to generate an impulse on their own and trigger the heartbeat. When this occurs, an "out of rhythm" heartbeat is generated, which is ahead of the normal heartbeat and is followed by a short pause until the normal rhythm resumes again. This pause is what corresponds to the feeling of emptiness or that "the heart stops for a moment" that patients describe to us.
Secondly, it is important to make it clear that in most cases, extrasystoles, in themselves, are benign, although they can be annoying, and although it may seem that way for a fraction of a second, the heart does not stop. It's going to stop after one of them. It is true that when they appear in a high number during the day (practically we all have a few dozen throughout the day, which is completely normal) they can sometimes be related to other types of arrhythmias or, in a relatively low percentage, to the presence of heart disease. For all these reasons, if they are discovered in an ECG or through symptoms, it is necessary to do a complete cardiological study to rule out the presence of any anomaly. This study, in general, should consist of an echocardiogram that allows us to evaluate structural abnormalities of the heart, a stress test in which we can see the response of extrasystoles to exercise (if they increase or, on the contrary, disappear) and a Holter monitor. ECG, which consists of a device that is worn for 24 hours and that allows establishing whether there are actually extrasystoles or not and, if there are, whether their number falls within normal parameters or is greater and should be monitored or other tests complementary, among which is usually cardiac magnetic resonance.
Even in those cases in which thousands of extrasystoles a day can be observed on a Holter, its behavior is benign and its prognosis excellent. In fact, the treatment that can be applied and ranging from pharmacological to ablation (a procedure that allows, by accessing the femoral vein, to reach the focus where the extrasystole originates in the heart and eliminate it), are only considered in patients whose symptoms interfere with their usual life or in those in which other heart disorders or arrhythmias are associated.
For all these reasons, if we are diagnosed with extrasystoles on the ECG or if we have compatible symptoms, we must be calm, however it is necessary to consult with a cardiologist who can adequately evaluate their nature, number, and rule out cardiac pathologies and who, if necessary, propose a treatment and monitoring plan, which, ideally, should be established by a cardiologist specialized in arrhythmias, also called electrophysiologists.
By Dr. Álvaro Lozano – Cardiologist of the Arrhythmia Unit