What is sinus bradycardia?
Sinus bradycardia is a condition where the heart rate is slower than normal, typically less than 60 beats per minute. It occurs when the sinus node (the heart's natural pacemaker) and generates electrical signals at a slower rate than usual. While it can be normal for athletes or during sleep, it may also be a sign of an underlying heart condition if symptoms like dizziness or fainting occur.Common related conditions
Causes of sinus bradycardia
Sinus bradycardia can be caused by:
- Heart conditions, like coronary artery disease, heart attack, or heart failure.
- An overactive vagus nerve, which slows down the heart rate.
- Hypothyroidism (an underactive thyroid)
- Electrolyte imbalances, like higher than average potassium levels.
- Certain medications, particularly beta-blockers or calcium channel blockers, that slow the heart rate.
Risk factors for sinus bradycardia
The following factors increase the risk of developing sinus bradycardia:
- Older age, as the heart’s electrical system can naturally slow with age.
- A family history of heart disease or heart attacks.
- Use of medications that affect the heart's conduction, like beta-blockers or digitalis.
- Hypothyroidism or other hormonal imbalances.
- High physical fitness levels, particularly in athletes, which can naturally lower the heart rate.
Symptoms of sinus bradycardia
Symptoms of sinus bradycardia may include:
- Fatigue or a general feeling of weakness.
- Dizziness or lightheadedness, especially upon standing up.
- Shortness of breath or difficulty exercising.
- Fainting or near-fainting episodes (syncope).
- Chest discomfort in some cases.
Diagnosing sinus bradycardia
To diagnose sinus bradycardia, doctors will typically use:
- Electrocardiograms (ECG or EKG) to observe the heart's rhythm and determine the rate.
- Blood tests or blood panels to check for electrolyte imbalances or thyroid issues.
- A Holter monitor to record the heart’s activity over 24-48 hours to capture episodes of bradycardia.
- Stress testing to assess heart function and determine if exercise induces symptoms.
Treatment of Sinus Bradycardia
Treatment depends on the severity of the symptoms and underlying causes:
- If bradycardia is not showing symptoms or is due to high physical fitness, no treatment may be necessary.
- You may be prescribed medications to treat underlying conditions, like thyroid hormones for hypothyroidism.
- If symptoms are severe or linked to heart disease, a pacemaker may be implanted to help regulate the heart rate.
- Adjusting medications that may be contributing to the slow heart rate.