Arrhythmia
What is cardiac arrhythmia?
In healthy adults the resting heart rate typically falls within the range of 60 to 100 beats per minute. Arrhythmia refers to irregularities in the heartbeat which can display as being too fast, too slow or irregular in timing
In rare cases arrhythmia can cause blood clots to form leading to a possible stroke or pulmonary embolism. When a person has an arrhythmia for a prolonged period of time heart failure can occur due to the heart losing its ability to effectively pump blood.
There are four categories that arrythmia may fall under:
Characterised by a slow resting heart rate typically less than 60 beats per minute.
Marked by a fast heart rate exceeding 100 beats per minute.
Presenting as a rapid and disorganised heart rate.
Occurring as isolated extra heartbeats.
Causes and risk factors
Several factors can contribute to the development of arrhythmias, including:
- Heart disease: Conditions such as coronary artery disease, heart failure, heart valve disease or a previous heart attack can increase the risk of arrythmias.
- Electrolyte imbalance: Abnormal levels of potassium, magnesium or calcium in the blood can disrupt the heart’s electrical activity.
- High blood pressure (hypertension): Prolonged high blood pressure can strain the heart and increase the risk of arrhythmias.
- Thyroid disorders: Overactive or underactive thyroid glands can affect heart function and increase the risk of arrythmias.
- Smoking: Tobacco smoke contains chemicals that can damage the heart and increase the risk of arrhythmias.
- Alcohol or drug abuse: Excessive alcohol consumption or illicit drug use can disrupt normal heart rhythm.
- Family history: Genetics may play a role in predisposing individuals to certain types of arrhythmias.
- Age: Older adults are at higher risk of developing arrhythmias due to age-related changes in the heart’s electrical system.
Symptoms of arrhythmia
Keep in mind that some arrhythmias may not display symptoms. Heart arrhythmias may only appear during regular check-ups with your GP. Symptoms of arrhythmia include:
- A fluttering sensation in the chest
- Heart palpitations (being uncomfortably aware that your heart is beating)
- Dizziness and/or fainting
- Light-headedness
- Weakness
- Breathlessness
Diagnosis
The choice of diagnostic tests depends on various factors including your clinical presentation, symptoms and the suspected type of arrhythmia. A comprehensive evaluation (often involving multiple tests and assessments) is necessary to accurately diagnose and manage heart arrhythmias effectively.
An ECG is a standard diagnostic test used to detect and diagnose heart arrhythmias. It records the electrical activity of the heart and can identify abnormalities in the heart's rhythm such as irregularities in the timing or pattern of the heartbeat.
During an exercise ECG (also known as a stress test) your heart rhythm and function are monitored while you exercise on a treadmill or stationary bike. This test helps evaluate how the heart responds to physical exertion and can detect arrhythmias that may only occur during exercise.
A Holter monitor is a portable device that continuously records the heart's electrical activity over a 24- to 48-hour period while you go about you daily activities. This test is useful for capturing intermittent or sporadic arrhythmias that may not be detected during a standard ECG.
Similar to a Holter monitor a cardiac event recorder is a portable device that records the heart's electrical activity. However, it is typically worn for longer periods (up to 30 days) and is activated by you when you experience symptoms of an arrhythmia. This allows for the recording of arrhythmias that coincide with symptoms.
An echocardiogram uses sound waves to create detailed images of the heart's structure and function. It can help identify underlying structural heart abnormalities that may predispose to arrhythmias such as valve disorders or heart muscle abnormalities.
An EP study is an invasive procedure performed in a specialised cardiac electrophysiology lab. During the EP study catheters are inserted into the heart to map its electrical signals and provoke arrhythmias. This test is particularly useful for diagnosing and characterising complex or difficult-to-detect arrhythmias and guiding treatment decisions.
Treatments
Arrhythmias may not always pose life-threatening risk and might not necessitate immediate treatment. However, if treatment is deemed necessary the specialists at Cardiology Specialists Melbourne ensure a thorough assessment of your condition and comprehensive information before initiating any intervention. Treatment options include:
Antiarrhythmic medications work to suppress or control abnormal heart rhythms by regulating the heart's electrical activity. These may include beta-blockers, calcium channel blockers, sodium channel blockers and potassium channel blockers. Blood-thinning medications (anticoagulants) may also be prescribed to reduce the risk of blood clots and stroke particularly in patients with atrial fibrillation.
Maintaining a balanced diet low in sodium and saturated fats, engaging in regular exercise, managing stress, limiting alcohol and caffeine intake and quitting smoking can help manage arrhythmias and reduce their recurrence.
Cardioversion is a procedure used to restore normal heart rhythm in patients with certain types of arrhythmias such as atrial fibrillation or atrial flutter. It can be performed using electrical cardioversion where a controlled electric shock is delivered to the heart, or chemical cardioversion using medications to convert the abnormal rhythm to normal sinus rhythm.
A pacemaker is a small electronic device implanted under the skin near the collarbone that helps regulate the heart's rhythm. It consists of a pulse generator and leads (wires) that deliver electrical impulses to the heart to maintain a normal heart rate. Pacemakers are commonly used to treat bradycardia (slow heart rate) and certain types of heart block.
An ICD is a device similar to a pacemaker but is capable of delivering electrical shocks to the heart to terminate life-threatening arrhythmias such as ventricular tachycardia or ventricular fibrillation. It continuously monitors the heart's rhythm and delivers therapy as needed to restore normal rhythm and prevent sudden cardiac arrest.
In some cases, particularly when medications and other interventions are either ineffective or suggested to not be used, catheter ablation may be considered. This procedure involves using radiofrequency energy or cryotherapy to destroy abnormal heart tissue that is causing the arrhythmia thereby restoring normal heart rhythm.
More information
Learn more about arrythmia and access more patient resources:
Arrythmia – Heart Foundation
Download a checklist for identifying and monitoring possible arrythmia at home:
Consult a cardiologist
Are you experiencing an irregular heart beat? Contact Cardiology Specialists Melbourne. Our expert doctors are dedicated to caring for your heart health.