Question: What is (are) Heart Block ?
Answer: Heart block is a problem that occurs with the heart's electrical system. This system controls the rate and rhythm of heartbeats. ("Rate" refers to the number of times your heart beats per minute. "Rhythm" refers to the pattern of regular or irregular pulses produced as the heart beats.) With each heartbeat, an electrical signal spreads across the heart from the upper to the lower chambers. As it travels, the signal causes the heart to contract and pump blood. Heart block occurs if the electrical signal is slowed or disrupted as it moves through the heart. Overview Heart block is a type of arrhythmia (ah-RITH-me-ah). An arrhythmia is any problem with the rate or rhythm of the heartbeat. Some people are born with heart block, while others develop it during their lifetimes. If you're born with the condition, it's called congenital (kon-JEN-ih-tal) heart block. If the condition develops after birth, it's called acquired heart block. Doctors might detect congenital heart block before or after a baby is born. Certain diseases that may occur during pregnancy can cause heart block in a baby. Some congenital heart defects also can cause heart block. Congenital heart defects are problems with the heart's structure that are present at birth. Often, doctors don't know what causes these defects. Acquired heart block is more common than congenital heart block. Damage to the heart muscle or its electrical system causes acquired heart block. Diseases, surgery, or medicines can cause this damage. The three types of heart block are first degree, second degree, and third degree. First degree is the least severe, and third degree is the most severe. This is true for both congenital and acquired heart block. Doctors use a test called an EKG (electrocardiogram) to help diagnose heart block. This test detects and records the heart's electrical activity. It maps the data on a graph for the doctor to review. Outlook The symptoms and severity of heart block depend on which type you have. First-degree heart block may not cause any severe symptoms. Second-degree heart block may result in the heart skipping a beat or beats. This type of heart block also can make you feel dizzy or faint. Third-degree heart block limits the heart's ability to pump blood to the rest of the body. This type of heart block may cause fatigue (tiredness), dizziness, and fainting. Third-degree heart block requires prompt treatment because it can be fatal. A medical device called a pacemaker is used to treat third-degree heart block and some cases of second-degree heart block. This device uses electrical pulses to prompt the heart to beat at a normal rate. Pacemakers typically are not used to treat first-degree heart block. All types of heart block may increase your risk for other arrhythmias, such as atrial fibrillation (A-tre-al fih-brih-LA-shun). Talk with your doctor to learn more about the signs and symptoms of arrhythmias.
Source: NHLBI

Question: What causes Heart Block ?
Answer: Heart block has many causes. Some people are born with the disorder (congenital), while others develop it during their lifetimes (acquired). Congenital Heart Block One form of congenital heart block occurs in babies whose mothers have autoimmune diseases, such as lupus. People who have these diseases make proteins called antibodies that attack and damage the body's tissues or cells. In pregnant women, antibodies can cross the placenta. (The placenta is the organ that attaches the umbilical cord to the mother's womb.) These proteins can damage the baby's heart and lead to congenital heart block. Congenital heart defects also may cause congenital heart block. These defects are problems with the heart's structure that are present at birth. Often, doctors don't know what causes these defects. Acquired Heart Block Many factors can cause acquired heart block. Examples include: Damage to the heart from a heart attack. This is the most common cause of acquired heart block. Coronary heart disease, also called coronary artery disease. Myocarditis (MI-o-kar-DI-tis), or inflammation of the heart muscle. Heart failure. Rheumatic (roo-MAT-ik) fever. Cardiomyopathy (KAR-de-o-mi-OP-a-the), or heart muscle diseases. Other diseases may increase the risk of heart block. Examples include sarcoidosis (sar-koy-DOE-sis) and the degenerative muscle disorders Lev's disease and Lenegre's disease. Certain types of surgery also may damage the heart's electrical system and lead to heart block. Exposure to toxic substances and taking certain medicinesincluding digitalis, beta blockers, and calcium channel blockersalso may cause heart block. Doctors closely watch people who are taking these medicines for signs of problems. Some types of heart block have been linked to genetic mutations (changes in the genes). An overly active vagus nerve also can cause heart block. You have one vagus nerve on each side of your body. These nerves run from your brain stem all the way to your abdomen. Activity in the vagus nerve slows the heart rate. In some cases, acquired heart block may go away if the factor causing it is treated or resolved. For example, heart block that occurs after a heart attack or surgery may go away during recovery. Also, if a medicine is causing heart block, the disorder may go away if the medicine is stopped or the dosage is lowered. Always talk with your doctor before you change the way you take your medicines.
Source: NHLBI

Question: What are the symptoms of Heart Block ?
Answer: Signs and symptoms depend on the type of heart block you have. First-degree heart block may not cause any symptoms. Signs and symptoms of second- and third-degree heart block include: Fainting Dizziness or light-headedness Fatigue (tiredness) Shortness of breath Chest pain These symptoms may suggest other health problems as well. If these symptoms are new or severe, call 911 or have someone drive you to the hospital emergency room. If you have milder symptoms, talk with your doctor right away to find out whether you need prompt treatment.
Source: NHLBI

Question: How to diagnose Heart Block ?
Answer: Heart block might be diagnosed as part of a routine doctor's visit or during an emergency situation. (Third-degree heart block often is an emergency.) Your doctor will diagnose heart block based on your family and medical histories, a physical exam, and test results. Specialists Involved Your primary care doctor might be involved in diagnosing heart block. However, if you have the condition, you might need to see a heart specialist. Heart specialists include: Cardiologists (doctors who diagnose and treat adults who have heart problems) Pediatric cardiologists (doctors who diagnose and treat babies and children who have heart problems) Electrophysiologists (cardiologists or pediatric cardiologists who specialize in the heart's electrical system) Family and Medical Histories Your doctor may ask whether: You have any signs or symptoms of heart block You have any health problems, such as heart disease Any of your family members have been diagnosed with heart block or other health problems You're taking any medicines, including herbal products and prescription and over-the-counter medicines You smoke or use alcohol or drugs Your doctor also may ask about other health habits, such as how physically active you are. Physical Exam During the physical exam, your doctor will listen to your heart. He or she will listen carefully for abnormal rhythms or heart murmurs (extra or unusual sounds heard during heartbeats). Your doctor also may: Check your pulse to find out how fast your heart is beating Check for swelling in your legs or feet, which could be a sign of an enlarged heart or heart failure Look for signs of other diseases that could be causing heart rate or rhythm problems (such as coronary heart disease) Diagnostic Tests and Procedures EKG (Electrocardiogram) Doctors usually use an EKG (electrocardiogram) to help diagnose heart block. This simple test detects and records the heart's electrical activity. An EKG shows how fast the heart is beating and its rhythm (steady or irregular). The test also records the strength and timing of electrical signals as they pass through the heart. The data are recorded on a graph. Different types of heart block have different patterns on the graph. (For more information, go to "Types of Heart Block.") A standard EKG only records the heart's activity for a few seconds. To diagnose heart rhythm problems that come and go, your doctor may have you wear a portable EKG monitor. The most common types of portable EKGs are Holter and event monitors. Your doctor may have you use one of these monitors to diagnose first- or second-degree heart block. Holter and Event Monitors A Holter monitor records the heart's electrical signals for a full 24- or 48-hour period. You wear one while you do your normal daily activities. This allows the monitor to record your heart for a longer time than a standard EKG. An event monitor is similar to a Holter monitor. You wear an event monitor while doing your normal activities. However, an event monitor only records your heart's electrical activity at certain times while you're wearing it. You may wear an event monitor for 1 to 2 months, or as long as it takes to get a recording of your heart during symptoms. Electrophysiology Study For some cases of heart block, doctors may do electrophysiology studies (EPS). During this test, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records your heart's electrical signals. Other Tests To diagnose heart block, your doctor may recommend tests to rule out other types of arrhythmias (irregular heartbeats). For more information, go to "How Are Arrhythmias Diagnosed?"
Source: NHLBI

Question: What are the treatments for Heart Block ?
Answer: Treatment depends on the type of heart block you have. If you have first-degree heart block, you may not need treatment. If you have second-degree heart block, you may need a pacemaker. A pacemaker is a small device that's placed under the skin of your chest or abdomen. This device uses electrical pulses to prompt the heart to beat at a normal rate. If you have third-degree heart block, you will need a pacemaker. In an emergency, a temporary pacemaker might be used until you can get a long-term device. Most people who have third-degree heart block need pacemakers for the rest of their lives. Some people who have third-degree congenital heart block don't need pacemakers for many years. Others may need pacemakers at a young age or during infancy. If a pregnant woman has an autoimmune disease, such as lupus, her fetus is at risk for heart block. If heart block is detected in a fetus, the mother might be given medicine to reduce the fetus' risk of developing serious heart block. Sometimes acquired heart block goes away if the factor causing it is treated or resolved. For example, heart block that occurs after a heart attack or surgery may go away during recovery. Also, if a medicine is causing heart block, the condition may go away if the medicine is stopped or the dosage is lowered. (Always talk with your doctor before you change the way you take your medicines.)
Source: NHLBI