Atrial Fibrillation (AFib) is the most common type of heart arrhythmia, characterized by an irregular and often rapid heart rhythm originating in the upper chambers of the heart. The chaotic electrical signals cause the atria to quiver rather than beat effectively. Fatigue and excessive sleepiness are common and frequently distressing symptoms for those with AFib, often severely impacting daily life.
Fatigue and Excessive Sleepiness as Symptoms of AFib
Feeling constantly worn out is a hallmark symptom of an irregular heart rhythm. Fatigue is chronic exhaustion or a profound lack of energy that does not improve with rest. Excessive daytime sleepiness, or hypersomnia, is a distinct symptom characterized by an overwhelming urge to sleep during the day. Both are reported by a significant number of AFib patients and can occur even when the heart rate is controlled by medication. This persistent exhaustion indicates that the heart’s function is compromised, suggesting an urgent need for medical evaluation.
How AFib Causes Physical Exhaustion
The primary reason AFib causes exhaustion is the mechanical inefficiency of the heart’s pumping action. In a healthy heart, the upper chambers (atria) contract just before the lower chambers (ventricles), providing the “atrial kick.” This coordinated action contributes up to 25% of the blood pumped with each beat. In AFib, the atria merely twitch, eliminating this crucial atrial kick and significantly reducing the total amount of blood pumped by the heart.
This reduction in cardiac output means that oxygen-rich blood is delivered less efficiently to the body’s tissues and organs, including the brain. When cells do not receive adequate oxygen and nutrients, the body functions in a state of systemic depletion. This inefficiency forces the body to work harder to maintain basic functions, translating directly into profound weakness and low energy.
The heart muscle itself also becomes overworked. In AFib, the atria can attempt to beat chaotically at rates up to 400 times per minute, which is like an exhausting workout. This relentless, inefficient effort drains the body’s overall energy reserves, contributing to the chronic, drained feeling.
AFib often occurs alongside systemic inflammation. The presence of elevated inflammatory markers may contribute to general malaise, although the exact cause-and-effect link is complex. Cardiac stress markers, which indicate the heart is under strain, are also associated with higher levels of self-reported fatigue in patients with AFib. This ongoing physiological stress, combined with poor circulation, creates an environment where physical exhaustion is the inevitable result.
The Connection to Other Sleep Conditions
The relationship between AFib and sleep is often bidirectional. A major factor that compounds AFib-related sleepiness is the co-occurrence of Obstructive Sleep Apnea (OSA). Up to 50% of individuals with AFib also have OSA, a disorder characterized by repeated breathing interruptions during sleep.
OSA severely fragments sleep, leading to excessive daytime sleepiness, and exacerbates AFib through physical stress on the heart. Each apneic event causes a drop in blood oxygen levels and creates negative pressure within the chest cavity. This pressure increases strain on the heart’s upper chambers, promoting changes that sustain AFib.
AFib symptoms themselves can also cause nighttime sleep disturbances. Palpitations, shortness of breath, and frequent urination (nocturia) can awaken a person multiple times. This fragmented sleep prevents the restorative deep sleep necessary for physical and mental recovery, contributing directly to chronic fatigue and daytime sleepiness.
Strategies for Improving Energy and Rest
The most effective way to alleviate AFib-related fatigue is to achieve and maintain a normal heart rhythm, often through medical treatments like cardioversion or catheter ablation. Managing the condition also involves careful attention to lifestyle factors and medication management. A common cause of persistent tiredness is the side effects of rate-controlling medications, such as beta-blockers, which can cause a general “rundown” feeling. If this occurs, a physician may need to adjust the dosage or explore alternative anti-arrhythmic drugs.
Lifestyle adjustments can greatly enhance energy levels. Engaging in moderate, consistent physical activity (150 to 300 minutes each week) is recommended to improve overall cardiovascular fitness and energy. Limiting or eliminating known AFib triggers, particularly excessive alcohol (often recommended to be three drinks or less per week) and high amounts of caffeine, can also reduce the frequency of episodes that cause fatigue.
Optimizing sleep hygiene is a practical step to combat excessive sleepiness. This involves maintaining a consistent sleep schedule and ensuring the bedroom environment is dark, cool, and quiet. For those diagnosed with Obstructive Sleep Apnea, utilizing a continuous positive airway pressure (CPAP) machine is often crucial. Treating OSA not only improves sleep quality but can also make AFib treatments more effective, leading to a significant boost in daily energy.