A closer look at A-fib
Editor’s Note: This is the second in a series of columns to be published in The Express during February — National Heart Month — and authored by Dr. Alfred Casale, a cardiothoracic surgeon at Geisinger Medical Center.
If you live in the United States and watch TV, listen to the radio or read magazines, you’ve certainly heard of A-fib. Commercials are EVERYWHERE, marketing drugs that treat the condition. And for good reason; A-fib is common, growing and an important public health issue in our aging population.
Atrial fibrillation, A-fib or AF for short, is an irregular heartbeat and the most common type of arrhythmia, affecting between 2.7 and 6.1 million Americans, according to the Centers for Disease Control and Prevention (CDC).
In 2009, a study titled “Out of Sync: The State of A-fib in America” suggested only 33 percent of people living with A-fib thought it was a serious condition and that less than half of those patients believed they were at higher risk of dangerous conditions or death as a result of their heart-rhythm disorder.
Hopefully the number of available therapies and their TV ads and news segments have, over the past decade, brought more awareness to the condition and the necessity to treat it.
Symptoms of A-fib vary widely, ranging from unnoticeable to severe, but regardless of how disturbing the symptoms, there are important consequences to the disorder if untreated. Understanding how A-fib can affect your health begins with understanding the condition itself.
When your heart beats normally, it contracts and relaxes in a regular pattern, moving blood from the upper chambers of the heart, the atria, to the lower chambers of the heart, the ventricles. During normal operation, the sinoatrial (SA) node, the heart’s “natural pacemaker,” sends electrical signals regularly to the atrioventricular (AV) node, the heart’s “gatekeeper,” and the heart muscle contracts and relaxes in an orderly fashion.
But when either the SA node fires erratically or when other areas in the atria “highjack” the pacemaker’s function, the heart’s atria begin to quiver (fibrillate); the resulting pattern is chaotic and inefficient; and the top and bottom chambers of the heart no longer beat in coordination. The most immediate effect of this uncoordinated beating is a marked reduction in the heart’s pumping efficiency of around 15 percent.
Some people with A-fib don’t have any symptoms, so without diagnostic tests like electrocardiogram (ECG), echocardiogram, and Holter monitoring, these folks might not know they’re living with A-fib. Among those with noticeable symptoms, heart palpitations, lightheadedness, extreme fatigue, shortness of breath and chest pains are common.
The risk of developing A-fib increases with age. Other factors that increase the chance of developing A-fib include high blood pressure, obesity, European ancestry, diabetes, heart failure, ischemic heart disease, hyperthyroidism, chronic kidney disease, heavy alcohol use and enlargement of the heart’s left side chambers.
Among worrisome conditions that can result from A-fib are chronic fatigue, additional heart-rhythm issues and decreased blood supply to the body’s other organs, but the two most concerning complications are stroke and heart failure.
The CDC reports that A-fib increases a person’s risk of stroke by four to five times. In addition, A-fib causes 15 to 20 percent of ischemic strokes, which means those strokes resulting from interruption of blood flow to the brain because a blood vessel is blocked by a clot (in A-fib) or fatty deposit (from atherosclerosis).
When A-fib causes inconsistent blood flow from the atria to the ventricles, blood pools in nooks and crannies within the atria like leaves and debris collect in the backwaters of streams. The blood that puddles in these areas of stagnation often clots. When clots break loose and travel throughout the circulatory system, they often wind up clogging brain arteries, causing a stroke. If not treated quickly, ischemic stroke will do lasting damage to the brain and can be deadly.
Another problem arises when A-fib causes the heart to beat so fast and erratically that it cannot fill with enough blood to pump adequately to meet the body’s needs. When the heart cannot provide the other parts of the body with a sufficient blood supply, heart failure develops. Heart failure leads to fluid buildup in the lungs and throughout the body and can make everyday physical activity difficult. The condition can be managed but is very serious.
The spectrum of treatments for A-fib begins with healthy lifestyle changes and medications that can regulate heart beat or prevent blood clotting. It includes heart-rate monitoring and may require invasive procedures that include the implantation of pacemakers, destruction (ablation) of abnormal heart tissue that is negatively influencing electrical pathways, and implantation of devices that ward off ischemic stroke.
Next week, we’ll take a closer look at these therapies and how the whole spectrum can improve quality of life for people with A-fib.
Dr. Alfred Casale, a cardiothoracic surgeon, is chief medical officer for surgical services for Geisinger and chair of the Geisinger Heart Institute. For information on alternative treatment for atrial fibrillation, visit https://geisinger.cc/2E2N8n8.