Atrial fibrillation (AFib) is a prevalent heart rhythm disorder, particularly among older individuals. It involves an irregular and often rapid heartbeat originating in the heart’s upper chambers, the atria. Instead of a coordinated electrical signal, the atria quiver chaotically, rather than contracting effectively. This leads to inefficient blood pumping and an increased risk of blood clots and stroke.
How the Aging Heart Changes
Aging naturally changes the heart, increasing susceptibility to AFib. Over time, heart tissues stiffen, affecting the atria and making them less flexible. This stiffening impairs the heart’s ability to fill and empty blood efficiently.
The heart’s electrical pathways also alter with age. Fibrosis, or scar tissue, can occur in the atria, disrupting electrical signals needed for a regular heartbeat. Changes in the sinoatrial node, the heart’s natural pacemaker, also contribute to electrical instability. Atria may also enlarge with age, further increasing AFib risk. These structural and electrical modifications make the heart more prone to irregular rhythms.
Heart Conditions That Lead to AFib
Several pre-existing cardiovascular conditions, common in older adults, significantly contribute to AFib. Hypertension, or high blood pressure, is a primary factor; chronic high blood pressure strains the heart, leading to structural changes in the atria, known as atrial remodeling. Coronary artery disease (CAD), characterized by narrowed or blocked arteries, affects heart function by reducing blood flow and oxygen to the heart muscle.
Heart failure, where the heart cannot pump enough blood, is strongly associated with AFib. The risk increases significantly as heart failure severity worsens, with up to 50% of advanced patients experiencing AFib. Valvular heart disease, such as issues with the mitral or aortic valves, can cause increased pressure and volume in the atria, leading to enlargement and strain. A history of heart attack or prior heart surgery can create scar tissue within the heart, interfering with normal electrical signals and triggering AFib.
Other Health Issues and Lifestyle Factors
Beyond direct cardiac conditions, other health issues and lifestyle choices contribute to AFib, especially in older adults. Thyroid disorders, particularly hyperthyroidism (an overactive thyroid), can lead to a rapid and irregular heartbeat. This condition is associated with a threefold increased risk of AFib.
Metabolic conditions like obesity and diabetes are significant contributors. Diabetes is an independent risk factor that can lead to structural and electrical changes in the atria. Sleep apnea, a disorder causing pauses in breathing during sleep, and chronic lung diseases like Chronic Obstructive Pulmonary Disease (COPD) can strain the heart and increase AFib risk. Excessive alcohol consumption is another factor; even moderate daily drinking can increase AFib episodes.
Specific Triggers and Medications
Certain acute events and medications can trigger or worsen AFib. Acute illnesses or infections, such as pneumonia or sepsis, can place significant stress on the body and heart, leading to an irregular rhythm. Imbalances in electrolytes, like low potassium or magnesium, can disrupt the heart’s electrical stability and precipitate AFib.
Some medications can induce or exacerbate AFib. Over-the-counter decongestants, found in many cold and flu remedies, can raise blood pressure and heart rate, potentially triggering AFib. Certain asthma medications, some antibiotics, and some cancer treatments have been linked to an increased risk of AFib. AFib is a common complication following cardiac or thoracic surgery, often attributed to inflammation and changes in the heart’s electrical system post-procedure.