A cardiac arrhythmia is a disturbance in the normal rhythmic and regular functioning of the heart. This loss of the normal “rhythmicity” can last for a few seconds or last for minutes, hours or days…. It can also be imperceptible to the patient or be very symptomatic, especially when the arrhythmia is very frequent or occurs with very fast heart rates.
Small irregularities in the cardiac rhythm related to extrasystoles are normal over the years. Extrasystoles are premature heartbeats that occur sporadically and affect virtually the entire population as we age, some people notice them and others do not. However, at other times they can be very frequent and symptomatic in relation to structural alterations of the heart and require treatment.
On other occasions, arrhythmias are due to the presence of circuits in the heart that allow them to manifest and be sustained. They generally generate rapid tachycardias that are symptomatic for patients and require specific treatment depending on the type of arrhythmia.
What are the causes of tachycardia?
As we have mentioned, the causes of the development of arrhythmias may be the normal aging of the heart itself and the presence of certain cardiovascular risk factors such as hypertension. On other occasions they may be related to hormonal imbalances, especially thyroid disorders, and to states of anxiety or stress.
There are also other cases, related to the development of structural problems of the heart: valvular problems, scarring of inflammatory or vascular processes, dilatation of cardiac cavities…. On other occasions, arrhythmias are the consequence of circuits present in the heart, which we are born with as a result of the embryonic development of the heart or which develop as a result of changes that the heart may develop over the years.
For these reasons, when a patient presents with clinical signs of sustained “tachycardias” or “arrhythmias”, he/she should be evaluated by a cardiologist who can diagnose the specific type of arrhythmia and identify potentially treatable causes.
What types of arrhythmias are there?
Arrhythmias can be classified according to their origin:
- Supraventricular: when they originate in the atria.
- Ventricular: when they originate in the ventricles.
The most frequent non-sustained arrhythmia (of short duration) are extrasystoles, which are classified as atrial or ventricular depending on whether they originate in the atria or ventricles. The most common sustained arrhythmias (of longer duration) are supraventricular tachyarrhythmias. The term “tachyarrhythmia” refers to the fact that, in addition to an abnormal heart rhythm, it occurs at a high rate (tachycardia). Supraventricular tachyarrhythmias encompass a broad spectrum of arrhythmias including atrial fibrillation, atrial flutter, intranodal reentrant tachycardias and accessory pathway-mediated tachycardias among others. Because of its clinical implications and prevalence, atrial fibrillation is the most relevant arrhythmia. Atrial fibrillation is associated with an increased risk of stroke and admission for heart failure, and for this reason these patients should be followed by a cardiologist.
However, the main problem and limiting factor in many cases is to diagnose patients with arrhythmias. In many cases the arrhythmias are brief, lasting minutes or a few hours, or produce ambiguous symptoms that the patient does not recognize, which prevents them from being documented on an electrocardiogram (ECG). Sometimes patients arrive at the Emergency Room or Health Center and the symptoms have already subsided and the ECG is normal. In many cases, the episodes are even classified as anxiety crises. Diagnosing arrhythmias is sometimes a real challenge due to their sporadic behavior and short duration. In the case of a patient with clinical symptoms of palpitation crises, it is advisable to be evaluated by a cardiologist specializing in arrhythmias who can propose different options, not only therapeutic but also diagnostic, which may even lead to electrophysiological studies.
What is the most effective treatment?
As we have seen, there are different types of arrhythmias and each arrhythmia has a specific treatment. As a general rule, when arrhythmias develop, we must initially treat the possible causes or factors identified as triggers. Once these factors have been corrected and the type of arrhythmia has been determined, there is a specific treatment for each one.
Some arrhythmias require medication to prevent crises or alleviate symptoms. On other occasions, specific treatment of arrhythmias involves electrophysiological studies and ablations.
An electrophysiological study is a minimally invasive procedure by which we can diagnose and treat arrhythmias definitively in many cases. It consists of placing venous introducers in the groin to access the femoral vein and through them, guided by X-rays, very fine wires that allow us to see the heart’s electrical signals and stimulate it. In this way we can induce the arrhythmias that the patient suffers and diagnose them, and in most cases treat them definitively in the same procedure by means of ablation. Ablation consists of destroying the fibers that generate the circuit in the heart and the arrhythmias by means of a burn which, depending on the technology used, can be performed with heat (radiofrequency) or cold (cryoablation). Ablation is generally the most effective treatment for most sustained arrhythmias, in many cases definitively curative.
For more information on cardiac arrhythmias and their treatment contact a Cardiology specialist.