A conduction disorder is a problem with the electrical system that controls your heart's rhythm and rate. The electric signal that causes your heart to beat travels from the top of your heart to the bottom of your body. It causes your heart to contract and pump blood to your lungs and rest of your body. This electrical signal is either not produced properly or does not travel through the heart as it should.
Conduction disorders can occur anywhere along the cardiac conduction system: at the sinoatrial node (SA), the atrioventricular node (AV), or the bundle branches.
Known also as sinus node disease, sick sinus syndrome (SSS) can result in slow or fast heart rates, as well as difficulty increasing your heart rate when necessary, such as when exercising.
There are three degrees of atrioventricular block, depending on the severity of your condition. As a result of a complete heart block, no signals reach your lower chambers of the heart, causing serious symptoms such as a very slow heart rate, fainting, and chest pain.
The electrical signals in your heart travel more slowly on one side than on the other side, causing your ventricles to contract at different times. Depending on which side is delayed, you may have a left bundle branch block or a right bundle branch block.
Each heart muscle cell has tiny pores called ion channels, which produce your heart's electrical activity. Long QT syndrome is the most common form of ion channel disorder. Among the others are Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and short QT syndrome.
Conduction disorders can have various causes, such as:
Aging: As you get older, your heart’s electrical system may wear out or get damaged by diseases or injuries.
It is possible to have a gene mutation that affects the ion channels or the structure of your heart that leads to conduction disordersry disease, heart attack, cardiomyopathy, and rheumatic fever.
Medicines can slow or speed up your heart's electrical system. Examples include digitalis, beta blockers, calcium channel blockers, and antiarrhythmics.
Genetics: Some conduction disorders are inherited, meaning they run in families. You may have a gene mutation that affects the ion channels or the structure of your heart.
Other factors: Some factors that can trigger or worsen conduction disorders include electrolyte imbalances, thyroid disorders, infections, stress, alcohol, caffeine, and smoking.
Many people who have conduction disorders may not have any symptoms, especially if the condition is mild or intermittent. However, some possible symptoms include:
Palpitations: Feeling your heart skip a beat, flutter, or beat too fast or too slow.
Dizziness or lightheadedness: Feeling faint or unsteady, especially when you stand up or change positions.
Fainting or syncope: Losing consciousness or blacking out, usually for a few seconds or minutes.
Chest pain or discomfort: Feeling pressure, tightness, or squeezing in your chest, which may spread to your arms, neck, jaw, or back.
Shortness of breath: Having trouble breathing or feeling like you can’t catch your breath.
Fatigue or weakness: Feeling tired or having less energy than usual.
Confusion or memory problems: Having trouble thinking clearly or remembering things.
If you have symptoms of a conduction disorder, or if you have a family history of heart problems, you should see your doctor for a checkup. Your doctor will ask about your medical history, your symptoms, and your lifestyle. Your doctor also performs a physical exam and listens to your heart with a stethoscope. You may be ordered one or more of the following tests to diagnose a conduction disorder:
An electrocardiogram measures your heart's electrical activity using electrodes attached to your chest, arms, and legs. This test can determine whether your heart rate and rhythm are normal or abnormal, and if you have any conduction delays.
A Holter monitor records your heart's electrical activity continuously for 24 to 48 hours, which allows your doctor to see how your heart behaves over time and during different activities.
An event monitor records your heart's electrical activity when you feel symptoms, such as palpitations or dizziness. It is similar to a Holter monitor, but you only wear it when you feel symptoms.
Using sound waves, an echocardiogram can show the size, shape, and function of your heart chambers and valves, and detect structural problems that may affect your heart's electrical system.
This test measures how your heart responds to physical exertion, such as walking or running on a treadmill or a bike. It can show if your heart rate or rhythm changes during exercise, as well as if there are any signs of reduced blood flow.
Electrocardiology study (EPS): An invasive test involving inserting thin wires, called catheters, into your heart through a vein in your neck or groin. By stimulating your heart with electrical impulses, the catheters can help your doctor pinpoint the location and cause of your conduction disorder, and test the effectiveness of various treatments.
The treatment of conduction disorders depends on the type, cause, and severity of your condition, as well as your symptoms and overall health. Some possible treatments include:
Beta blockers, calcium channel blockers, antiarrhythmics, anticoagulants, and aspirin are some examples of drugs that can control your heart rate and rhythm, prevent or treat complications, and reduce your risk of future problems.
A pacemaker is an implantable device that allows your heart to beat at a normal rate and rhythm. It can help treat slow heart rates, complete heart blocks, and certain types of sick sinus syndrome.
A pacemaker-like implantable cardioverter defibrillator (ICD) can detect and correct fast or irregular heart rhythms that can be life-threatening, such as ventricular tachycardia or ventricular fibrillation. A shock can be delivered to your heart to restore a normal rhythm. Some types of ion channel disorders can be treated and sudden cardiac death prevented with it.
In cardiac ablation, the abnormal tissue or cells that cause your conduction disorder are destroyed or isolated with heat, cold, or radiofrequency energy.
Cardio resynchronization therapy (CRT) is a type of pacemaker that can improve the efficiency and function of your heart. It can be used to treat bundle branch block and heart failure.
You may need surgery to repair or replace damaged or diseased parts of your heart, such as a valve or chamber. This can improve the electrical system and blood flow of your heart.
It is not possible to prevent some conduction disorders, especially those caused by genetics or aging. However, you can take some steps to reduce your risk, including:
Follow your doctor’s advice and take your medications as prescribed.
Monitor your heart rate and rhythm regularly and report any changes or symptoms to your doctor.
Avoid or limit alcohol, caffeine, nicotine, and other substances that can affect your heart’s electrical system.
Manage your stress and practice relaxation techniques, such as deep breathing, meditation, or yoga.
Eat a healthy diet that is low in salt, fat, cholesterol, and sugar, and high in fruits, vegetables, whole grains, and lean proteins.
Maintain a healthy weight and lose weight if you are overweight or obese.
Exercise regularly and stay physically active, but avoid overexertion or activities that can trigger or worsen your symptoms.
Control your blood pressure, cholesterol, blood sugar, and other conditions that can affect your heart health.
See your doctor for regular checkups and screenings, and follow up on any tests or treatments that you may need.
If you have conduction disorder, or think you may have one, talk to your doctor about your options and how to manage your condition. They can cause a variety of symptoms and complications, and may require different treatments depending on the type and cause. Despite having a conduction disorder, you can live a long and healthy life with proper care and lifestyle changes.
