Arrhythmia, from Ancient Greek ἀρρυθμία (arrhuthmía), is a serious cardiac rhythm disturbance, characterized by either too fast, or too slow heart rate sometimes combined with premature contractions. It is manifested when there is organic damage to the heart such as valvular heart disease, myocardial infarction, or when there is disturbance of the vegetative nervous system, salt-water disbalance or intoxication. It is possible for arrhythmia to appear in healthy individuals as a result of fatigue, cold, extreme excitement, consumption of large quantities of alcohol. 65-100 heart beats per minute are considered normal. Arrhythmias can appear both with normal and decreased heart rate.
Bradycardia and Tachycardia
Bradycardia is a heart rate that slows down to under 60 beats per minute, while tachycardia is an increase to over 90-100. Cardiac rhythm disturbances decrease the amount of blood coming from the heart. When cardiac output drops to a critical value, blood flow to the brain is reduced which can lead to loss of consciousness. This happens both with increased and decreased heart rate. Heart rate lower than 30-35 beats and higher than 200 beats is considered life-threatening.
Types of arrhythmias
- Benign cardiac arrhythmias which are considered harmless;
- Malignant ventricular arrhythmias. These present an immediate life risk and are the most common cause of sudden death. There are 3 forms: out-of-hospital ventricular fibrillation (VF), recurrent sustained ventricular tachycardia and torsades de pointes ventricular tachycardia in the long QT syndrome. Each condition has a high 1-year mortality rate. Most of the malignant arrhythmias occur at the muscle chambers of the heart, disturbing its output function and blood flow. Chance of death is extremely high if heart function is not stabilized within minutes.
Causes of malignant arrhythmias vary depending on the individual’s age. In people under 30 years of age they are a result of inborn structural disorders in the heart – the so-called cardiomyopathies.
- Hypertrophic cardiomyopathy – when the heart muscle becomes abnormally thick. This is the most common cause of death in professional athletes;
- Heart enlargement and disturbance of its output capability;
- Coronary arteries anomalies;
- Electrical heart diseases caused by anomalies in heart’s electric system that regulates the steady heartbeat;
- In older people the most common cause is ischemic heart disease.
What to look for?
Malignant arrythmia’s onset is sudden causing the patient to lose consciousness. Immediate help can only be brought by a person nearby should they have enough first aid knowledge.
Performing CPR while waiting for an ambulance, equipped with defibrillator, has saved many lives. The patient should not be slapped, hit, or given any water because they can choke. Clearing their airways and CPR are the only necessary measures.
Quick and adequate reactions are critical in most cases, and witnesses of accidents trying to perform CPR are 10 times less likely to harm the patients rather than not doing anything:
If we just stay and wait for the ambulance chances of survival are 40-60%. CPR increases them to 90%.
In some people, heart function could return on its own – this is known as syncope.
Benign cardiac arrhythmias
Most arrhythmias are completely benign and inconsequential.
Outside heart’s electric system that regulates heart rhythm there are zones that can send impulses on their own disturbing the normal rhythm.
How to distinguish it?
Benign cardiac arrhythmias occur with skipped beats, palpitations and/or quick, uneven or sometimes even pulse.
There are several methods that can help taking control of the situation in most cases.
When someone feels that they are having an arrhythmia, causing them to be dizzy due to decreased blood pressure, it is recommended to lie down or sit down, and to start coughing strenuously and frequently. Coughing keeps arterial pressure by increasing pressure in the chest. That alone could interrupt some arrhythmias.
When arrhythmia is combined with quick heart rate, it can be interrupted by activating a nerve called vagus. This can be done in several ways:
- reaching with your fingers down the throat to induce vomiting;
- pressing with two fingers on both eyes (unless you have some eye condition);
- taking a deep breath, closing your mouth and nose and contracting your stomach.
These methods are effective in 50% of the cases.
Atrial flutter and atrial fibrillation
These are two important, usually benign arrhythmias, that can occur both in hearts with certain conditions and healthy hearts. They don’t present immediate risk but are a risk factor for developing clots in a small heart cavity. In most cases these clots are transported to the brain, causing a stroke. That is why, patients are given anticoagulants, should the arrhythmia cannot be treated. Atrial fibrillation manifests itself via palpitations, shortness of breath, fainting, and tiredness. It can be found mostly in older people or in those with genetic predisposition present. It is often combined with other conditions of the heart like ischemic heart disease, congenital and acquired valve defects, some problems of the endocrine system.
Genetic predisposition is the most important factor. Others include arterial hypertension, diabetes, obesity, metabolic syndrome. Lifestyle is also important – stress, depression, unhealthy eating, and alcohol abuse could cause disorders in the heart rhythm.
You should immediately seek help from doctor if you have the following complaints:
- Heart palpitations;
- Pain and pressure in the chest;
- Trouble breathing;
- Dizziness and nausea;
- Fainting feeling.
When a person feels there is a problem with their heart rate, they should visit a cardiologist who would first ask for a description of the system and then order the necessary tests to be made. The first one to be made is electrocardiogram (EKG), after that a 24-hour EKG Holter monitors. A report from these would support the diagnosis, because there are other rhythm disorders that could manifest similarly.
The approach in treatment depends on the cause. In all cases, the underlying condition is being treated and in patient with malign arrythmia, cardiac defibrillators are used in combination with medicines. These are small devices that are placed hypodermically like pacemakers. Special electrodes come out of them that go to the heart. They detect the arrhythmia and produce electric impulses to restart the heart. Arrythmias related to ischemic heart disease are usually treated by treating the disease itself.
In most cases this will deal with the arrhythmia. When not sufficient, additional medications are being given to the patients. There are also innovative invasive methods, the so-called electrophysiological procedures, that are used to find out the “hotspots” that send the bad impulses so that they can be removed. This method, called ablation, is the most effective one in treating some benign arrythmias appearing in structurally healthy heats. Through the method, hotspots are removed without the need of operation. Through veins in the legs (most common approach), electrodes go to the hotspots. Using high frequency radio waves, cold and other methods, they are removed. When using medications, the most common ones are antiarrhythmic agents – a group of drugs that aims at prevention of future onsets or make them slighter and more tolerable.
If heart rhythm problems are being overlooked or inadequately treated, this can lead to complications – thrombus. That is why the most common effect of these complications is brain embolism (known as stroke) as well as other embolisms in the body – legs, arms, internal organs.