Health Corner

Is arrhythmia dangerous?

Arrhythmia is one of the most common heart conditions in Hong Kong. It refers to any abnormality in the rhythm or rate of heartbeat. It is estimated that about 1% of Hong Kong’s population suffers from arrhythmia, most commonly atrial fibrillation and ventricular fibrillation.
The risk increases with age. Although arrhythmia is not immediately life-threatening, if not detected and treated in time, the risk of stroke and heart failure is approximately five times and three times higher, respectively, than in people without it. Mortality risk also doubles.

What is arrhythmia?

Arrhythmia refers to any abnormality in the heart’s rhythm or rate.

In a healthy person at rest, the heart beats steadily between 60 and 100 times per minute. A resting heart rate lower than 60 beats per minute (bradycardia) or higher than 100 (tachycardia) is considered abnormal.
Some people have a normal heart rate but irregular rhythm, which may suggest premature beats (extrasystoles) or atrial fibrillation.

What problems can arrhythmia cause?

1. Ventricular Fibrillation (VF)

VF is a type of sudden cardiac arrest that can be fatal. Multiple parts of the ventricles beat chaotically, preventing the heart from pumping blood and oxygen to the brain and body.
Without immediate cardiopulmonary resuscitation (CPR), the patient can die within minutes once the heart stops completely.

2. Atrial Fibrillation (AF)

AF occurs when the atria quiver rapidly and irregularly, causing the heartbeat to become erratic (up to 200 beats per minute). It can last from a few seconds to several days.
While not directly fatal, it can cause noticeable symptoms such as:

• Palpitations or irregular heartbeat

• Shortness of breath

• Dizziness or fainting

Because blood flow becomes turbulent, clots may form in the heart. If a clot travels to the brain, it can cause a stroke.

What are the symptoms of arrhythmia?

At rest, normal heart rates range from 60 to 100 beats per minute.
When the heartbeat becomes abnormal, you may experience:

• Fatigue

• Shortness of breath

• Dizziness

• Chest tightness

• Chest pain

• Tiredness

• Fainting or loss of consciousness

Why do I have arrhythmia?

Common risk factors include:

• Thyroid disorders

• Hypertension

• Ischemic heart disease

• Heart failure or valvular heart disease

• Side effects of medication

• Idiopathic causes (no identifiable reason)

How is arrhythmia diagnosed?

• Electrocardiogram (ECG): The primary diagnostic test. For long-term monitoring, a 24-hour ECG or event recorder may be used.

• Blood tests: To assess electrolyte balance and thyroid function.

• Further evaluations: Exercise ECG, CT coronary angiography, or electrophysiological catheter tests for detailed assessment.

How can arrhythmia be treated?

Effective treatment depends on the underlying cause.

• Medication: Antiarrhythmic drugs are used to manage various irregular heart rhythms.

• Catheter Ablation: A common and standard minimally invasive procedure performed under local anesthesia. A cardiologist guides a catheter into the heart, locates areas causing abnormal electrical activity, and ablates them. It offers high success rates for many arrhythmia types.

• Implantable Devices:

  • For slow heart rates with fainting episodes, a pacemaker may be needed.

  • For abnormally fast heart rhythms or risk of sudden cardiac death, an implantable cardioverter-defibrillator (ICD) may be recommended.