Arrhythmia 

Statistics

• 1 in 10 Australians die suddenly due to an abnormal heart rhythm, this occurs most commonly just after a heart attack.
  
• 40 Australians die of a heart rhythm problem every day
  
• Atrial fibrillation is the most common heart rhythm disorder - 1 in 4 Australians will have an episode of atrial fibrillation in their life time.  
  
• About 200 young Australians under 18 die each year as a result of cardiac arrhythmia, 100 of these kids won’t even know they have a heart issue.
  

Definition

A heart arrhythmia is an abnormal heart beat or problem with your heart’s natural rhythm. Arrhythmias occur when the electrical signals, which control your heartbeats, do not work properly and cause your heart to beat too fast, too slow or irregularly.

A person with a healthy heart will have a heart rate of between 60 and 100 beats per minute when resting.

Different types of arrhythmias include:

Atrial fibrillation is an irregular and often rapid heart rate. The heart’s top chambers or atria quiver in a rapid and chaotic pattern, which can slow blood flow. The heart’s main pumping chambers, the ventricles, also beat unevenly which affects how well they push blood around the body. The heartbeat of a patient with atrial fibrillation is typically about 150 beats per minute but can reach 350 beats per minute in extreme cases.

Atrial flutter (AFL) is an abnormal rhythm that occurs in the top chambers or atria of the heart. In AFL, the atria beat regularly but too fast, which results in atrial muscle contractions that are faster and out of sync with the lower chambers or ventricles, of the heart. Patients with AFL typically experience heart rates of 150-180 beats per minute at rest, but rarely can reach 300-350 beats per minute.

Supraventricular tachycardia (SVT) is a rapid heartbeat caused by faulty electrical signals in the upper parts of your heart. Patients usually experience a burst of accelerated heartbeats. SVT usually affects young, healthy people, who will experience a heart rate between 160 and 200 beats per minute.

Ventricular tachycardia is an abnormal electrical impulse that begins in the ventricles and causes an irregular fast heartbeat. The ventricle will often contract more than 200 times a minute.

Ventricular fibrillation occurs when rapid and erratic electrical impulses cause the ventricles to quiver instead of pump blood properly. It is life-threatening and is often triggered by a heart attack.

Long QT syndrome (LQT) causes uncoordinated heartbeats which can lead to sudden, uncontrollable and dangerous arrhythmias. LQT syndrome can result in fainting, which typically occurs after increased stress or exercise. Patients with LQT syndrome have an underlying genetic problem.

Bradycardia occurs when your heart beats too slow – under 60 beats per minute. It is a normal phenomenon in people who are very fit (e.g. professional athletes). Bradycardia is however a problem if as a result there is not enough blood reaching your brain, which can cause you to pass out.  

Symptoms

Some patients have no associated symptoms with arrhythmia, while others may notice symptoms but not have a life-threatening arrhythmia.  It is important to have regular check-ups with your GP, especially if you are concerned.

Common symptoms of a heart arrhythmia include: 

•  Fluttering feeling in the chest
• Racing heartbeat
• Slow heartbeat
• Palpitations
• Dizziness
• Fainting
• Light-headedness
• Chest pain
• Breathlessness
• Shortness of breath
• Sudden or abnormal weakness
• Sweating  
• Confusion
• Trouble concentrating

Causes

There are a number of factors that can cause a heart arrhythmia, including:

• Heart attack or scarring of the heart tissue from a heart attack
• Coronary heart disease
• High blood pressure
• Smoking
• Genetics
• Changes to the heart’s structure e.g. from cardiomyopathy
• Diabetes
• Sleep apnea
• Some medication
• Alcohol abuse
• Excessive caffeine consumption
• Overactive thyroid gland (hyperthyroidism)
• Underactive thyroid gland (hypothyroidism)
• Drug abuse
• Stress

Diagnosis 

To detect an arrhythmia, your doctor will review your symptoms, medical and family history and conduct a physical examination. The following heart-monitoring tests may also be required:

• Electrocardiogram (ECG)
• Blood and urine tests 
• Echocardiogram 
• Holter monitor 
• Chest X-ray 
• Tilt-table test 
• Electrophysiologic testing (or EP studies)
• Heart catheterization

Treatment

Treatment is only necessary if symptoms are severe, or if you are at risk of a more serious arrhythmia or complication. Some treatments your doctor may advise include:

• Pacemaker
• Medications
• Cardioversion
• Catheter ablation
• Implantable cardioverter-defibrillator (ICD)
• Surgical procedure to disrupt abnormal electrical circuits (Maze procedure)
• Coronary bypass surgery
• Alternative medicine including yoga, meditation or relaxation techniques 

Prevention

If you have an existing heart problem, it is important to do the following:

• Know the symptoms of arrhythmia and report them to your doctor if they appear
• Have regular check-ups
• Maintain your treatment program
• Take your medication

If you have a normal, healthy heart do the following to keep it in check:

• Have regular check-ups
• Know the risk factors of heart disease and arrhythmia
• Exercise regularly
• Don’t smoke
• Eat a healthy diet
• Maintain a healthy weight
• Limit caffeine and alcohol consumption
• Limit or reduce stress

Research into Arrhythmia