What is Heart Block?
Heart block is a condition in which electrical signals traveling from the heart’s upper chambers (atria) to the lower chambers (ventricles) are delayed or completely blocked. This can result in a slow or irregular heartbeat.
Heart block can be classified into different degrees based on the severity of the conduction delay.
Types of Heart Block
Heart block is categorized into three main types:
- First-Degree Heart Block: Electrical signals are delayed but still reach the ventricles. Often asymptomatic and requires no treatment.
- Second-Degree Heart Block: Some electrical signals fail to reach the ventricles, causing skipped heartbeats and symptoms like dizziness or fatigue.
- Third-Degree (Complete) Heart Block: No electrical signals reach the ventricles, leading to a dangerously slow heart rate. This requires immediate medical intervention.
Causes and Risk Factors
Heart block can develop due to various underlying conditions, including:
- Congenital Heart Defects: Some people are born with heart block.
- Age-Related Degeneration: Natural wear and tear on the heart’s electrical system.
- Heart Attack: Damage to the heart muscle can disrupt electrical signals.
- Cardiomyopathy: Heart muscle disease affecting electrical conduction.
- Electrolyte Imbalances: Abnormal potassium or calcium levels may interfere with heart signaling.
- Medications: Certain drugs, such as beta-blockers or calcium channel blockers, can slow electrical conduction.
Symptoms of Heart Block
Symptoms vary depending on the degree of heart block. Common symptoms include:
- Slow Heart Rate (Bradycardia): A heart rate below normal.
- Dizziness or Lightheadedness: Caused by reduced blood flow.
- Fainting (Syncope): Loss of consciousness due to insufficient oxygen to the brain.
- Fatigue: Feeling tired due to a slow heart rate.
- Chest Pain or Discomfort: May occur in severe cases.
- Shortness of Breath: Difficulty breathing, especially during activity.
Diagnosis of Heart Block
Doctors use several tests to diagnose heart block and determine its severity:
- Electrocardiogram (ECG): Measures electrical activity in the heart.
- Holter Monitor: A portable ECG device worn for 24-48 hours to detect intermittent heart block.
- Event Monitor: Used for longer-term monitoring of irregular rhythms.
- Echocardiogram: Ultrasound imaging to check for structural abnormalities.
- Stress Test: Evaluates how the heart responds to exertion.
Treatment Options
Treatment depends on the severity of the heart block:
- First-Degree Heart Block: Usually requires no treatment but may be monitored over time.
- Second-Degree Heart Block: May require a pacemaker if symptoms are severe.
- Third-Degree Heart Block: Requires an implantable pacemaker to regulate the heartbeat.
- Medication Adjustment: Stopping or adjusting drugs that slow conduction.
- Electrolyte Correction: Treating potassium or calcium imbalances to restore normal conduction.
Prevention and Lifestyle Changes
Preventing heart block involves managing underlying conditions and maintaining heart health:
- Control High Blood Pressure: Keeping blood pressure in check reduces strain on the heart.
- Manage Heart Disease: Treating coronary artery disease and other cardiac conditions lowers risk.
- Avoid Excessive Medication Use: Consult a doctor before taking drugs that affect heart rhythm.
- Monitor Heart Health: Regular check-ups and ECGs can detect early changes.
- Exercise and Healthy Diet: Maintaining a heart-healthy lifestyle supports normal electrical function.