There are numerous conditions of the heart, but one that we see very often is atrial fibrillation (AF). Sometimes this condition is spotted coincidently, but at other times people feel a transient pounding sensation in their chest accompanied by dizziness or an irregular heart beat and constriction sensation. Almost 2.5 million North Americans are afflicted. The heart is made up of four chambers. The pre-chambers are called atria. Blood flows from the atria to the main chambers called ventricles. Atria help the ventricles to pump blood. In humans, the left ventricle is responsible for pumping blood to most of the body, while the smaller right ventricle pumps returning blood to the lungs to be oxygenated. The pumping rate and action are synchronized electronically. The atria can start to beat very rapidly and irregularly for many reasons. When this happens, we call this condition atrial fibrillation. It should be distinguished from a similar sounding term called atrial flutter in which the atria beat in a quick but synchronous manner. The typical result of AF is a decrease in the amount of blood pumped and an increase in the rate of ventricular pumping, because they are quivering due to erratic electrical stimulation. The wildly erratic action of the atria is particularly concerning since it does not allow complete emptying of the chamber. Stagnant blood tends to clot quickly. The quivering can shake little flecks of clot out of the atria and into the main pump chamber where it is ejected into general circulation. If one of these clots travels to the brain or heart muscle, it may clog the pathway and deprive tissue from much needed oxygen otherwise known as a stroke or heart attack. It is highly recommended that AF sufferers be considered for treatment with aspirin, warfarin or a related medication to help prevent such catastrophes.
There are many causes for atrial fibrillation. Conditions such as thyroid over-activity, alcoholism and damage to the heart by previous attacks are common. Other times, intense stress, inflammation or use of certain medications can be contributors. In some people, AF appears without any identifiable causes at all, but most people have other medical conditions in play. Yet others develop the condition only transiently.
The diagnosis begins with an examination of the patient. A quick heart test called an electrocardiogram can often reveal the condition. Other tests such as blood testing, chest x-rays and an echocardiogram are also useful. Sometimes more sophisticated testing is required. This can involve angiography or electrical mapping of the heart.
If atrial fibrillation is diagnosed, the best treatment is to search for, find and correct the cause. When that fails, we turn to several other approaches. The most common approach is to try medications which may slow the heart beat down and allow the patient to feel better. Traditionally, these have included digoxin, beta-blockers and calcium-channel agonists. More recently, there has been a shift towards amiodarone. No medication can prevent the onset of AF. Another method to treat this condition is to deliver an electrical shock to the heart in hopes of resetting the rhythm. This is termed cardioversion. A similar procedure involves infusing a drug through an intravenous needle. At other times, minor surgery or pacemaker implantation is required to disrupt the area producing abnormal electrical impulses. In almost all cases, medication to prevent blood clots from forming is begun. Warfarin is an ancient substance that was traditionally used to poison rats. It inhibits a step in the pathway that promotes blood solidifying to form a clot. Since some foods, herbals and disease states influence this ability, careful monitoring with serial blood tests is essential. Countries with advanced health care now have simple finger stab tests that can do this. The rest of us must visit a crowded out-patient blood collection station to accomplish this.
● Fiber photo-catheters for invasive and less invasive treatment of atrial fibrillation (Abstract) by Igor Peshko, Vladimir Rubtsov, Leonid Vesselov, Gennady Sigal, and Hillel Laks, from Institute for Optical Sciences/University of Toronto (Canada) and other institutions.
● Atrial Fibrillation from MedicineNet, by Dennis Lee, M.D. What is atrial fibrillation? What causes atrial fibrillation? What are the symptoms of atrial fibrillation? What are the complications of atrial fibrillation? What are the risk factors for developing atrial fibrillation? How is atrial fibrillation diagnosed? How is atrial fibrillation treated? What is new in atrial fibrillation? Atrial Fibrillation at a Glance.
● Atrial Fibrillation Related Medications.
● Atrial Fibrillation Related Diseases & Conditions.
● Atrial Fibrillation from MedlinePlus.
● Atrial Fibrillation Related Procedures & Tests.
● MedlinePlus Medical Encyclopedia: Atrial fibrillation/flutter. Contents include: Illustrations, Alternative names, Definition, Causes, incidence, and risk factors, Symptoms, Signs and tests, Treatment, Expectations (prognosis), Complications, Calling your health care provider, Prevention.
● Atrial Fibrillation from eMedicine by Alan D Clark, MD.
● Atrial Fibrillation from eMedicine by Lawrence Rosenthal, MD, PhD.