Some types of bradycardia produce no symptoms. Others may cause noticeable symptoms, such as:
- Fainting or loss of consciousness (“syncope”)
- Dizziness, sensation of light-headedness
- Mild fatigue
- Sensation of your heart fluttering (palpitations)
- Shortness of breath
- Chest pain
- Low blood pressure (hypotension)
Serious forms of bradycardia, such as complete heart block, are medical emergencies. They can lead to loss of consciousness or sudden cardiac arrest .
The doctor will ask about your symptoms and medical history, and perform a physical exam. In particular, the doctor will listen to your heart with a stethoscope.
Tests may include:
- Blood tests—to look for certain abnormalities that may explain the bradycardia (eg, electrolytes, glucose, thyroid function, and drug levels)
- Electrocardiogram (ECG, EKG)—a test that records the heart’s activity by measuring electrical currents through the heart muscle.
- Echocardiogram —a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart.
- Holter monitor or event monitor—a portable, continuous heart rhythm monitor that you wear as you perform normal daily activities.
- Exercise stress test —a test that records the heart’s electrical activity during increased physical activity.
- Nuclear scanning—radioactive material is injected into a vein and observed as it is distributed through the heart muscle to look for coronary artery disease.
- Coronary angiography —x-rays taken after a dye is injected into the arteries; this allows the doctor to look for abnormalities in the coronary arteries of the heart.