About Bradycardia (Slow Heartbeat)

Bradycardia means your heart rhythm is slower than the body requires at a given level of activity. It can cause dizziness or shortness of breath during normal activities or light exercise.

Definition

Bradycardia is defined as a slow heart rhythm, usually less than 60 beats per minute. At this rate, the heart is not able to pump enough oxygen-rich blood to your body during normal activity or exercise.

Causes

Common causes of bradycardia include:

• A hereditary heart defect
• Certain illnesses or heart medications
• The natural aging process
• Scar tissue from a heart attack
• The heart's natural pacemaker is not functioning correctly (Sick Sinus Syndrome)
• The electrical impulse that travels from the upper to the lower chamber of the heart is irregular or blocked (Heart Block)
• Atrial Fibrillation (acquired abnormal heart rhythm) with slow conduction.

Symptoms

Symptoms of bradycardia include dizziness, fainting, extreme tiredness, and shortness of breath.

Risk Factors

Your risk of developing an abnormally slow heart rate (bradycardia) is greater if you:

• Have certain types of heart disease
• Are taking certain medicines
• Are age 65 or older
• Have recently had heart surgery

Diagnosis

Only your doctor can tell if you have bradycardia and how far the condition has progressed. To rule out or confirm the diagnosis of bradycardia, one or several of these diagnostic tests may be ordered depending upon the suspected heart rhythm problem:

• Electrocardiogram (ECG)
• Exercise ECG or stress test
• Holter monitor (24 to 72 hour ECG)
• Tilt table test
• Electrophysiology (EP) study

Your doctor may also use a monitoring device to better understand the cause of unexplained fainting episodes. These monitoring devices include:

• External loop recorder
• Insertable loop recorder

Next: Treatment Options