Heart Block: Symptoms, Causes, and Prevention Ideas

A healthy heart beats 60 to 100 times in a minute. A single heartbeat is a heart muscle contraction that pumps blood to the body’s other organs. A heart block causes the heart to beat slowly or irregularly, almost stopping for 20 seconds at a time.

Usually, every heartbeat is created by an electrical signal that starts with the heart’s upper-right chamber. However, in the case of a partial heart block, the electrical impulse that controls the heartbeat is either delayed or blocked.

A complete heart block occurs when the signals ultimately come to a standstill. At this point, the heartbeat can drop to as low as 40 beats per minute.

What are the Symptoms of Heart Block?

Heart block symptoms differ based on the severity of the condition and its impact on the heart’s ability to pump blood.

• Chest pain or Angina may arise as a sudden pressure or tightness in the chest, resembling the sensation of heavy weight pressing down. This discomfort typically occurs in the middle or left side of the chest and is often triggered by emotional or physical stress.
• Shortness of Breath occurs when the heart can’t pump adequate blood to meet the body’s requirements.
• A heart attack occurs when there is a complete blockage in the heart. Common symptoms include intense, crushing pain in the chest, shoulder, or arm. Women may experience fewer symptoms than men, such as discomfort in the neck or jaw.
• Tiredness occurs when the heart is not pumping perfectly, leading to decreased oxygen supply to the body, making a person feel constantly fatigued.
• Heart palpitations refer to an irregular, fast, or pounding heartbeat, often described as a fluttering sensation in the chest.
• Rapid breathing happens when the body tries to compensate for the reduced oxygen levels caused by an inefficient heartbeat.
• Nausea can occur due to reduced blood flow to the digestive system, often accompanied by sweating.
• Dizziness results from insufficient blood supply to the brain, making a person feel lightheaded or unsteady.
• Fainting (syncope) happens when the brain does not receive enough oxygen-rich blood, causing a temporary loss of consciousness.

Types of Heart Block

A heart block can be present from birth (congenital) or develop later in life, often worsening with age and the progression of heart disease. It is categorized into three types:

First-Degree Heart Block

• Involves minor disruptions in the heartbeat, such as delayed electrical impulses.
• The electrical signal will reach the ventricles but move more slowly than normal through the AV node.
• Typically, it does not cause noticeable symptoms and may not require treatment.
• Commonly found in athletes, teenagers, young adults, and individuals with a highly active vagus nerve.

Second-Degree (Incomplete) Heart Block

Occurs when some electrical impulses fail to reach the ventricles, leading to dropped or skipped beats. It is further divided into two types:

• Type I (Mobitz Type I or Wenckebach’s AV Block): The electrical signal progressively slows until a heartbeat is skipped. Often less serious and may not require treatment. Symptoms may include dizziness or lightheadedness.
• Type II (Mobitz Type II): Some electrical impulses can’t reach the ventricles, causing an irregular and slower-than-normal heartbeat. It is more severe than Type I and often requires a pacemaker.

Third-Degree (Complete) Heart Block

• A third-degree heart block occurs when electrical signals do not pass from the atria to the ventricles.
• The ventricles generate their own impulses but at a much slower rate.
• Common in people with heart disease and can be life-threatening.
• Requires a pacemaker to restore normal heart rhythm and avoid serious complications, such as heart failure or cardiac arrest.

What Causes Heart Block?

Heart block happens when the electrical signals controlling the heartbeat are delayed or disrupted. Several factors can cause this condition, including:

• Heart conditions: Heart attack, coronary artery disease (CAD), cardiomyopathy, and heart valve diseases.
• Structural issues: Heart defects present from birth or scarring in the heart’s conduction system.
• Medical procedures: Heart damage from open-heart surgery.
• Medications: Side effects of beta-blockers, digitalis, and calcium channel blockers.
• Health conditions: Obstructive sleep apnea, thyroid disorders, and autoimmune diseases.
• Infections: Lyme disease and other infections affecting the heart.
• Toxins and genetics: Exposure to harmful substances or inherited conditions.

Preventive Tips for Heart Block

• Stay Active: Do 150 minutes of moderate aerobic exercise and 75 minutes of vigorous activity weekly. Simple daily activities like gardening, using the stairs, or walking your dog also contribute to a healthy heart.
• Eat a Nutritious Diet: Maintain a balanced diet high in fiber and low in fat by having fruits, vegetables, whole grains, lean meats, and fish in your meals.
• Maintain a Healthy Weight: Consult a doctor or healthcare professional to determine and maintain your ideal weight.
• Quit Smoking: Avoid smoking, as it significantly increases the risk of heart disease.
• Limit Alcohol Consumption: Stick to the recommended alcohol intake to protect your heart health.
• Manage Stress Effectively: Incorporate stress-reducing techniques into your routine to promote overall well-being.
• Take Prescribed Medications: If you have a condition that raises the risk of heart block, follow your doctor’s suggestion and take medications as prescribed.

Diagnosis for Heart Block

To diagnose heart block, your healthcare provider will review your medical and family health history, ask about your overall health, diet, physical activity, and symptoms, and discuss any medications you take, including prescription and over-the-counter drugs. They will also inquire about smoking or recreational drug use, listen to your heart, check your heart rate, and look for signs of heart failure, such as fluid buildup in your feet, ankles, or legs. If necessary, your cardiologist may refer you to an electrophysiologist, a specialist in the heart’s electrical activity.

Tests Used to Diagnose Heart Block

• Blood tests – These check for underlying conditions.
• Genetic tests – Identify inherited risks.
• Electrocardiogram (ECG) – Measures electrical activity in your heart.
• Ambulatory monitor – Tracks heart rhythms over time.
• Loop recorder – Continuously records heart activity for long-term monitoring.
• Electrophysiology study – Assess electrical pathways in your heart.
• Exercise stress test – Evaluate how your heart responds to physical activity.

Treatment for Heart Block

Heart block treatment varies based on individual needs. Your healthcare provider may admit you to the hospital for heart monitoring. To determine the best approach, your cardiologist will assess:

• The type and severity of your heart block.
• Its impact on your heart’s function.
• The symptoms you experience.

In some cases, adjusting medications or treating underlying heart conditions can resolve heart block. However, some individuals may require a temporary or permanent pacemaker to regulate their heartbeat.

• First-degree heart block: Usually does not require treatment.
• Second-degree heart block: Type 1 may not need treatment, but if symptoms appear, a pacemaker might be necessary.
• Third-degree heart block: This nearly always requires a pacemaker.

If you need a pacemaker, your provider will explain the best type for you and guide you through the procedure, including what to expect before, during, and after implantation.

Frequently Asked Questions