BRADYCARDIA | SLOW HEARTBEAT

Bradycardia is a condition in which the heart beats more slowly than expected. A slow heart rate can be normal in some people, particularly during sleep or in well-trained athletes, but persistent or symptomatic bradycardia may be caused by a problem with the heart’s electrical system and may require medical evaluation.

Not every slow heartbeat indicates a medical problem. The significance of bradycardia depends on the heart rate, associated symptoms, the patient's age and the presence of underlying heart disease or other medical conditions.

SYMPTOMS OF BRADYCARDIA

Some patients may have no symptoms, while others may experience:

• Fatigue and reduced energy.
• Dizziness or lightheadedness.
• Shortness of breath.
• Reduced exercise tolerance.
• General weakness.
• Difficulty concentrating or confusion in some cases.
• Near-fainting or fainting.
• Chest pain or discomfort in some cases.

CAUSES OF BRADYCARDIA

Bradycardia may occur due to normal physiological conditions or medical problems, including:

• Sleep.
• Regular physical training, particularly in athletes.
• Increasing age.
• Sinus node dysfunction.
• Heart conduction disorders.
• Certain heart diseases.
• Reduced blood flow to the heart muscle or acute myocardial infarction.
• Underactive thyroid gland.
• Abnormal blood electrolyte levels.
• Certain medications that slow the heart rate.
• In some cases, no clear cause can be identified.

THE HEART'S ELECTRICAL SYSTEM

The heart is controlled by a specialized electrical system that normally begins in the sinus node and travels through the heart in an organized manner.

When the generation or transmission of electrical signals is impaired, the heart may beat too slowly or irregularly.

Conduction disorders that can cause bradycardia include:

• Sinus node dysfunction (Sick Sinus Syndrome).
• Heart block.
• Certain disorders of electrical conduction between the atria and ventricles.

HOW IS BRADYCARDIA DIAGNOSED?

Diagnosis is based on the patient's symptoms, medical history and clinical examination, together with assessment of the heart rhythm and cardiac function.

Investigations may include:

• Electrocardiogram (ECG).
• 24-hour or longer Holter monitoring.
• Extended cardiac rhythm monitoring when necessary.
• Echocardiography (Echo).
• Blood tests, including thyroid function and electrolyte levels when appropriate.
• Exercise stress testing in selected cases.
• Additional cardiac rhythm investigations when required.

THE ROLE OF HOLTER MONITORING

Bradycardia can be intermittent and may not be present during a standard ECG.

Holter monitoring records the heart's electrical activity during daily activities and sleep. It can help identify periods of slow heart rate or conduction abnormalities and determine whether they are associated with symptoms.

WHEN DOES BRADYCARDIA REQUIRE TREATMENT?

Not every patient with bradycardia requires treatment.

If the slow heart rate is a normal finding and does not cause symptoms or affect cardiac function, regular follow-up may be all that is required.

However, if bradycardia is associated with significant symptoms or an important electrical conduction disorder, treatment may be necessary depending on the underlying cause and the patient's clinical condition.

TREATMENT OF BRADYCARDIA

Treatment depends on the underlying cause, severity and symptoms.

Treatment may include:

• Treating the underlying medical condition.
• Reviewing medications that may cause bradycardia and adjusting them when appropriate under medical supervision.
• Treating thyroid disorders or electrolyte abnormalities when present.
• Regular follow-up in appropriate patients.
• Pacemaker implantation in selected patients with significant symptomatic bradycardia or important conduction disorders.

PACEMAKER

A pacemaker is a small device implanted under the skin that delivers electrical impulses when needed to help maintain an appropriate heart rate.

A pacemaker may be recommended for selected patients with symptomatic bradycardia or certain significant electrical conduction disorders.

The decision to implant a pacemaker is based on a detailed assessment of symptoms, ECG findings, Holter results, the type of conduction disorder and the patient's overall health.

BRADYCARDIA DURING SLEEP

Heart rate normally decreases during sleep and this does not necessarily indicate a heart problem.

However, marked or repeated bradycardia during sleep, particularly when associated with symptoms or sleep apnea, may require further medical evaluation.

WHEN IS BRADYCARDIA AN EMERGENCY?

Urgent medical evaluation is required when severe bradycardia is associated with:

• Fainting.
• Severe dizziness.
• Significant shortness of breath.
• Chest pain or pressure.
• Severe weakness or sudden deterioration.
• Reduced level of consciousness.

SPECIALIZED EVALUATION

Bradycardia is not a single diagnosis. It may be a normal finding in some individuals or may result from a significant disorder of the heart's electrical system in others.

Evaluation focuses on determining the heart rate, the type of rhythm or conduction disorder, the presence of symptoms and the effect of the condition on cardiac function.

ECG, Holter monitoring, echocardiography and appropriate additional investigations can help identify the cause and determine the most suitable treatment or follow-up plan for each patient.

If you experience a slow heartbeat associated with dizziness, fatigue, fainting or reduced exercise tolerance, a cardiac evaluation is important to determine the underlying cause and the appropriate treatment.