Cardiac arrhythmias: a curable epidemic

The cardiovascular intervention unit at Hospital Helicópteros Sanitarios in Puerto Banús (Marbella), formed by Dr Luis Iñigo, Dr Eduardo Molina, Dr Pedro Brugada and Dr Juan Sieira, performs all types of interventions related to arrhythmias, ischaemic heart disease and congenital or structural heart disease.

We discuss cardiac arrhythmias with Professors Pedro Brugada and Juan Sieira. Professor Brugada is Head of the Arrhythmia Unit at the Hospital Helicopteros Sanitarios in Puerto Banús.

How important are heart conditions today?

Heart conditions remain the number one cause of death in the Western world. One in three people die from heart failure. Heart failure can occur in any of the three components of the heart: mechanical, circulatory or electrical.

What can alter the electrical function of the heart?

Heart failure, angina pectoris and myocardial infarction (heart attack) can all alter the electrical function of the heart. Changes in the supply of oxygen and other nutrients to the cardiac cells alter their electrical function, causing tachycardias or bradycardias. The consequences are highly variable, ranging from being unknown to the patient, to causing palpitations, loss of consciousness (syncope) and even sudden, unexpected death.

Is sudden death due to arrhythmias common?

Approximately 30,000 people die every year in Spain from sudden, unexpected deaths caused by cardiac arrhythmias. These sudden deaths, however, are not always unexpected and are not necessarily fatal. The key to their prevention and effective treatment is a high degree of suspicion on the part of the physician. These potentially fatal arrhythmias occur both in people with structural heart problems and in people with a completely normal heart structure who suffer from an isolated problem with heart electricity.

How can arrhythmias in people with structural heart disease be treated?

When arrhythmias are the consequence of structural heart disease, correction is the most important basis for preventing sudden death. To do this, we must identify those at risk. Starting with an interview with the patient where we obtain clinical information that we will complete with examinations such as heart imaging through ultrasound, radiology (CT) and magnetic resonance imaging (MRI) that have revolutionised cardiology. The genetic-familial factor must also be taken into account and all relatives of a patient with heart problems must be investigated. With early diagnosis, there are many possible treatments and they are very effective.

So, can a structurally normal heart suffer arrhythmias?

Yes, in these cases the problem lies in the formation and conduction of the heart's electrical impulse. There are potentially fatal arrhythmias that cause slow heart rates and even electrical cardiac arrest, bradycardias; and rapid arrhythmias, tachycardias. When they occur at the level of the ventricles, we speak of ventricular tachycardias, which can be fatal even in a normal heart.

What causes tachycardias that can be severe in a structurally normal heart?

These tachycardias are generally caused by hereditary conditions with very specific patterns. These include right ventricular dysplasia, which results in degeneration of the right heart muscle and causes rapid ventricular arrhythmias leading to sudden death, usually at a young age. Another purely electrical heart condition, also hereditary, is the well-known Brugada syndrome caused by alterations of the heart's sodium channel, which is of vital importance for the formation of the electrical impulse. Another condition, catecholaminergic tachycardia, affects the ventricles comprehensively and typically causes arrhythmias and sudden death during exercise, because the heart cells suffer from a genetic defect that makes them very sensitive to adrenaline.

And which arrhythmias are the most common?

The heart can suffer arrhythmias as a consequence of increased abnormal electrical activity in the atria, atrial tachycardia and atrial flutter; and by abnormal impulses in some areas such as the pulmonary veins, atrial fibrillation, a very frequent and important arrhythmia.

The classic treatment is by means of antiarrhythmic drugs, although these need to be taken daily and do not cure the arrhythmia, merely prevent it or improve the symptoms, apart from the side effects they have. That is why today ablation techniques are preferred, which cure flutter and atrial tachycardia in almost all cases and in a very high percentage of cases of atrial fibrillation. A catheter is used to record local activity within the heart, locate the site of origin of the tachycardia and destroy this area by means of heat or cold.

Other common arrhythmias in young people are Wolff-Parkinson-White syndrome or WPW and intranodal tachycardia, the latter very common in young women.

Without further ado, we bid farewell to Professors Pedro Brugada and Juan Sieira, in the knowledge that having them available to answer any queries you may have at Helicópteros Sanitarios is a great comfort. Thank you very much.