Bradycardia

The Heart Institute at Virginia Mason in Seattle provides diagnosis and treatment for bradycardia.

Bradycardia is an unusually slow heart rate. This condition also can occur as tachycardia-bradycardia, in which the heart alternates between quick and slow beats and is often referred to as sick sinus syndrome. Bradycardia is a medical condition usually occurring in individuals over the age of 50.

Causes include degeneration in the electrical conduction system of the heart that regulates normal sinus rhythm, and certain medications which can further slow the heart such as beta blockers; calcium channel blockers; and digoxin.

Symptoms of bradycardia may include a feeling of the heart beating (palpitations), fatigue, shortness of breath, chest pain (angina), dizziness and fainting.

Diagnosing bradycardia

Your physician may hear an abnormally slow heart rate when listening to your heart with a stethoscope during a physical exam. He or she also may detect normal or low blood pressure. Tests used to help in the diagnosis include the following:

Electrocardiogram (ECG)

This test measures your heart's electrical activity. Electrodes attached to your skin record electrical impulses that appear as waves on a monitor. Slow heart beats appear further apart than do normal rhythms.

To determine the extent or frequency of the heart rhythm disturbance, your physician may recommend that you wear a patient symptom-triggered Event Monitor for a week or two, or a Holter monitor for 24 hours to record — similar to the ECG — your heart's electrical activity. This small recording device easily can be worn on a belt or tucked inside a pocket.

Electrophysiology Study

This procedure is undertaken to obtain further measurements of the electrical activity in your heart. During this study, a catheter containing electrodes is inserted into a blood vessel in your groin and carefully maneuvered toward your heart. Once inside your heart, the electrodes are positioned to measure activity in the heart's electrical conduction system that connects the atria (upper chambers) and the ventricles (lower chambers). This study will tell your physician where in the heart the abnormal electrical activity is taking place as well as how severe it is, along with other possible heart ailments. 

Treating bradycardia

Oftentimes bradycardia has no symptoms and thus no treatment is recommended. However, if symptoms persist or become worse, or if you have bradycardia and tachycardia, your physician may recommend that you have a pacemaker placed that stimulates the heart to beat as soon as a slow rhythm begins. A pacemaker is about the size of a stack of three silver dollars and is implanted under the skin just below the collarbone. Wires or "leads" connected to it are gently maneuvered through blood vessels and into the heart where they are positioned to detect when the heart is not beating normally.