What is Atrial Fibrillation (Afib)?
Atrial fibrillation (AFib) is the most commonly diagnosed arrhythmia, which is characterized by fast and irregular heart rhythms. It commonly causes decreased blood flow to the body.
During atrial fibrillation, the heart’s two upper chambers (the atria) beat fast, chaotically and irregularly — there is no coordination with the two lower chambers (the ventricles) of the heart. Atrial fibrillation symptoms often include heart palpitations, shortness of breath and weakness.
Patients experience either episodes of atrial fibrillation that come and go(Paroxysmal AF), or patients may develop atrial fibrillation that doesn’t go away(Persistent AF). Although atrial fibrillation itself usually isn’t life-threatening, it is a serious medical condition that sometimes requires emergency treatment. It can lead to complications. Atrial fibrillation may lead to blood clots forming in the heart that may travel to other organs and lead to blocked blood flow.
What are the symptoms of Atrial Fibrillation?
Individuals experience the symptoms of atrial fibrillation differently. Some who have this condition may not feel any symptoms, and their condition will go unnoticed until it is detected by a physician during a routine examination.
Those who do have atrial fibrillation symptoms may experience signs and symptoms such as:
- Palpitations, which is sensation of a racing heart, irregular heartbeat or a flip-flopping in your chest
- Weakness or Fatigue
- Exercise intolerance
- Lightheadedness or dizziness
- Shortness of breath
- Chest discomfort
CAUSES OF ATRIAL FIBRILLATION
Abnormalities, wear and tear or damage to the heart’s musculature are the most common cause of atrial fibrillation. Possible causes of atrial fibrillation include:
- High blood pressure
- Sleep apnea
- Abnormal heart valves
- Heart defects you’re born with (congenital)
- Coronary artery disease
- Heart attacks
- An overactive thyroid gland
- Exposure to stimulants, such as medications, caffeine or tobacco, or to alcohol
- Lung diseases
- Recent heart surgery
- Stress due to pneumonia, surgery or other illnesses
However, some people with atrial fibrillation don’t have any obvious evidence of heart defects or damage, a condition called lone atrial fibrillation. In lone atrial fibrillation, the cause is often unclear, and serious complications are rare.
Certain factors may increase your risk of developing atrial fibrillation.
- Age. The odds of developing atrial fibrillation increases with age
- Heart disease. Patients with structural heart disease or disorder — such as congestive heart failure, heart valve disorders, congenital heart disease, or a history of heart attack or heart surgery — has an increased risk of developing atrial fibrillation.
- High blood pressure. Poorly controlled high blood pressure, increases risk of atrial fibrillation.
- Heavy Alcohol use. Drinking large amount of alcohol can trigger an episode of atrial fibrillation.
- Obesity. Obese people have higher risk of developing atrial fibrillation.
- Family history. An increased risk of atrial fibrillation is occasionally seen in some families.
Atrial fibrillation can lead to Stroke and heart failure:
- Stroke or other organ damage from blood clots.. In atrial fibrillation, quivering of the upper chambers may cause blood to pool in the heart’s upper chambers and form clots. If a blood clots forms,they can travel to artery of the brain to cause a stroke.The risk of stroke in atrial fibrillation depends on several factors. This risk is often determined by your doctor usinf a scoring system. Oral anticoagulants or blood thinners are commonly used to greatly lower your risk of stroke or thrombo-embolism.
- Heart failure. Atrial fibrillation if not controlled, may weaken the heart and lead to heart failure — a condition in which your heart can’tpump enough blood to meet your body’s needs.
PREPARING FOR YOUR DOCTOR VISIT
- Write down any symptoms you’re experiencing, including any that may seem unrelated to atrial fibrillation.
- Write down key personal information, including any family history of heart disease, stroke, high blood pressure or diabetes, and any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements that you’re taking.
- Take a family member or friend along, if possible. Sometimes it can be difficult to understand and remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important, in case time runs out. For atrial fibrillation, some basic questions to ask your doctor include:
- What is likely causing my symptoms or condition?
- What are other possible causes for my symptoms or condition?
- What kinds of tests will I need?
- What’s the most appropriate treatment?
- What foods should I eat or avoid?
- What’s an appropriate level of physical activity?
- How often should I be screened for heart disease or other complications of atrial fibrillation?
- What are the alternatives to the primary approach that you’re suggesting?
- I have other health conditions. How can I best manage them together?
- Are there any restrictions that I need to follow?
- Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist? (You may need to ask your insurance provider directly for information about coverage.)
- Is there a generic alternative to the medicine you’re prescribing?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
In addition to the questions that you’ve prepared to ask your doctor, don’t hesitate to ask questions during your appointment.
TESTS AND DIAGNOSIS
To diagnose atrial fibrillation, your doctor may review your signs and symptoms, review your medical history, and conduct a physical examination. Your doctor may order several tests to diagnose your condition, including:
- Electrocardiogram (ECG). An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG translates the heart’s electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves. This test is a primary tool for diagnosing atrial fibrillation.
- Holter monitor. The Holter Monitor is a device that measures and records heart rhythm over 1-3 days. This test may be done when an ECG does not show the arrhythmia and it still is suspected to be the cause of symptoms. Patches with wires are placed on the chest. The wires are connected to a portable monitor that can be attached to a purse or belt.
- Event recorder. A device that monitors heart rhythm and rate for few weeks – up to one month. During this test, the patient wears a device on the wrist or around the waist. When symptoms are experienced, the patient presses a button on the device to make a recording of the heart activity that just occurred. You activate it only when you experience symptoms of a fast heart rate.When you feel symptoms, you push a button, and an ECG strip of the preceding few minutes and following few minutes is recorded. This permits your doctor to determine your heart rhythm at the time of your symptoms.
- Echocardiogram. Standard echocardiogram is performed by application of an ultrasound probe to the chest wall over your heart (outside the body). By using ultrasound waves, which are not felt and are harmless, a motion picture is made of your heart as it beats in your chest. This motion picture is recorded on videotape and studied by a cardiologist who makes a report for your physician.
- Trans esophageal Echocardiogram. A TEE provides clearer and more detailed pictures than a standard echo because the ultrasound probe is moved inside your food pipe (esophagus). Since your esophagus (the passageway from your mouth to your stomach) passes very close to your heart, placing the ultrasound probe down the esophagus gives a much better and more detailed picture of your heart.
- Blood tests. These help your doctor rule out thyroid problems or other substances in your blood that may lead to atrial fibrillation.
The initial treatment for atrial rhythm disorders is antiarrhythmic drug therapy. These drugs can slow the conduction of rapid atrial fibrillation and/or convert atrial fibrillation to a normal sinus rhythm. Drugs, however, do not cure heart rhythm disorders, and they are not effective in all patients. They also require that a patient maintain a very strict schedule of follow-up care with his or her physician. Many patients with atrial fibrillation require a blood thinner, such as Warfarin, to prevent the formation of blood clots, to prevent stroke.
Atrial Fibrillation is triggered by a single (or multiple) focus of muscle firing in the heart. The fibrillation is also maintained by a few rotors located in the atria. In most patients, these sites have been mapped to and around the pulmonary veins (vessels which empty blood from the lungs to the left side of the heart). These venous structures have sleeves of atrial tissue extending from the heart (left atrium) for variable distances into the main branch or its tributaries. This musculature when diseased or damaged is capable of generating ectopic complexes, or repetitive activity at very rapid rates. In susceptible patients, this may lead to and maintains atrial fibrillation. Atrial musculature around the pulmonary veins has parallel fiber orientation and scarring of this tissue allows for rotor to form and maintain atrial fibrillation.
Elimination of the triggers and rotors can lead to reduction or elimination of Atrial Fibrillation. Catheter ablation techniques have been designed and successfully applied to a variety of patients with AF targeting the pulmonary vein musculature and tissue surrounding it. These muscle sleeves/tissue have discrete and limited connections to the atria, which are vulnerable to catheter ablation. A mapping catheter and an ablation catheter are passed into the left atrium using a trans-septal puncture. Wide area circumferential ablation around the pulmonary veins is performed using radiofrequency energy. The pulmonary veins are disconnected from the Atria which results in complete isolation of the pulmonary vein musculature and abnormal tissue around them from the left atrium. This can be achieved in about 99% of targeted veins. The pulmonary veins continue to serve as conduits of oxygenated blood to the left atrium.
This procedure is successful in approximately 85% of patients, who will then require no further medical therapy. An additional 10% of patients may respond to antiarrhythmic drugs that were previous ineffective, or have substantial reduction in AF events. About 5-10% of patients have no response, presumably due to alternate triggers in the heart. Most patients benefit from a second procedure if the first was unsuccessful. The procedure has a small risk of about 1%. Fortunately, serious complications are infrequent. The potential complications include pulmonary vein stenosis (narrowing of the opening of the pulmonary veins due to aggressive scar tissue formation), small risk of stroke and risk of cardiac perforation requiring catheter drainage or surgery. Risk of catastrophic complications (heart attack, esophageal perforation and death) is extremely small.
Ideal candidates include patients who have symptomatic atrial fibrillation without major structural heart disease. Most patients with persistent or chronic AF are also candidates for ablation. Catheter ablation is an effective tool offering a curative treatment of atrial fibrillation.
- Single electrode Radiofrequency Catheters for Ablation
- Multielectrode Radiofrequency Catheters for Ablation
- Contact Force Sensing RF Catheters for Ablation
- Mapping and Navigation Tools for Ablation
- Balloon Catheters for Ablation
- Robotic Catheter Navigation for Ablation
In a subset of patients with paroxysmal (intermittent) or persistent atrial fibrillation, devices can be used to either prevent atrial fibrillation or convert it to a normal sinus rhythm. These devices include pacemakers and implantable cardioverter defibrillators (ICD).
You should always consider lifestyle changes that improve the overall health of your heart and you should prevent or treat conditions such as high blood pressure and heart disease. Your doctor may suggest several lifestyle changes, including:
- Eat heart-healthy foods. Eat a healthy diet that’s low in salt and solid fats and rich in fruits, vegetables and whole grains.
- Exercise regularly. Exercise daily and increase your physical activity.
- Quit smoking. If you smoke and can’t quit on your own, talk to your doctor about strategies or programs to help you break a smoking habit.
- Maintain a healthy weight. Being overweight increases your risk of developing heart disease.
- Keep blood pressure and cholesterol levels under control. Make lifestyle changes and take medications as prescribed to correct high blood pressure (hypertension) or high cholesterol.
- Drink alcohol in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.
- Maintain follow-up care. Take your medications as prescribed and have regular follow-up appointments with your doctor. Tell your doctor if your symptoms worsen.