Doctor's Notes on Atrial Fibrillation (AFib)
Atrial fibrillation is an irregular heart rhythm (arrhythmia) that is irregular, often rapid heart rhythm that causes the atrial chambers of the heart to beat rapidly. Signs and symptoms of atrial fibrillation (also termed A fib, AFib, A-fib) may include palpitations (sensation of a rapid and/or irregular heartbeat), dizziness or lightheadedness, weakness, chest pain and/or angina, shortness of breath and/or nausea.
The cause of atrial fibrillation is due to multiple sources of impulses in the atria that travel through the atria at the same time and cause irregular usually rapid contractions of the atria that are not correlated with ventricular contractions although ventricular contractions are also frequently increased. Other cardiac conditions may eventually cause atrial fibrillation. For example, heart valve disease, ventricular hypertrophy, coronary heart disease, congestive heart failure, advancing age and others.
Atrial Fibrillation (AFib) Symptoms
Symptoms of atrial fibrillation vary from person to person.
- A number of people have no symptoms.
- The most common symptom in people with intermittent atrial fibrillation is palpitations, a sensation of rapid or irregular heartbeat. This may make some people very anxious. Many people also describe an irregular fluttering sensation in their chests. This irregular fluttering sensation is due to the irregular rapid ventricular response (rvr) of the ventricles to the rapid irregular atrial electrical activity.
- Some people become light-headed or faint.
- Other symptoms include weakness, lack of energy or shortness of breath with effort, and chest pain or angina.
There are a few patients that have potentially life-threatening AFib symptoms that need immediate attention and intervention with electric cardioversion. The symptoms and signs are as follows:
Atrial Fibrillation (AFib) Causes
Atrial fibrillation may occur without evidence of underlying heart disease. This is more common in younger people, about half of whom have no other heart problems. This is often called lone atrial fibrillation. Some of the causes that do not involve the heart include the following:
- thyroid (overactive thyroid)
- Alcohol use (holiday heart or Saturday night heart; a condition of AFib, ventricular tachycardia, or other cardiac arrhythmia usually triggered by some holiday-related event such as increased alcohol drinking or discontinuing medications; the condition often subsides once the triggering behavior is ceased)
- Pulmonary embolism (a blood clot in the lungs)
Most commonly, atrial fibrillation occurs as a result of some other cardiac condition (secondary atrial fibrillation).
- Heart valve disease: This condition results from developmental abnormalities people are born with or can be caused by infection or degeneration/calcification of valves with age.
- Enlargement of the left ventricle walls: This condition is called left ventricular hypertrophy.
- Coronary heart disease (or coronary artery disease): This results from atherosclerosis, deposits of fatty material inside the arteries that cause blockage or narrowing of the arteries, interrupting oxygen delivery to the heart muscle (ischemia).
- High blood pressure: This condition is known as hypertension.
- Cardiomyopathy: This disease of the heart muscle leads to congestive heart failure.
- Sick sinus syndrome: This refers to improper production of electrical impulses because of malfunction of the SA node in the atrium of the heart.
- Pericarditis: This condition refers to inflammation of the sac surrounding the heart.
- Myocarditis: This condition causes inflammation of the heart muscle.
- Advancing age: The older a person is above age 40, the higher the risk.
Atrial fibrillation frequently occurs after cardiothoracic surgery or procedures, but often resolves in a few days.
For many people with infrequent and brief episodes of atrial fibrillation, the episodes are brought on by a number of triggers. Because some of these involve excessive alcohol intake or skipping medications, this is sometimes called "holiday heart "or "Saturday night heart." Some of these people are able to avoid episodes or have fewer episodes by avoiding their triggers. Common triggers include alcohol and caffeine in susceptible individuals.
Atrial fibrillation (AFib) is a heart rhythm abnormality caused by a problem with the heart's electrical system. Normally, the heart's electricity flows from the top chambers (atria) to the bottom chambers (ventricles), causing the normal contraction. In atrial fibrillation the electrical flow is chaotic causing the heartbeat to become irregular.
Atrial Fibrillation (A-Fib) : Test Your Medical IQ QuizQuestion
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Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.