Introduction
Atrial fibrillation is a rapid, irregular heart rhythm that leads to blood clots. It occurs when atrial beats are not in sync with the ventricular beats. It is the most typical sustained cardiac rhythm disorder. Initially, it was referred to as auricular fibrillation.
The late William Harvey might be the first scientist to have described the condition. Willem Einthoven published the first human electrocardiogram showing atrial fibrillation in 1906 (Rosenthal, 2021). For most patients, atrial fibrillation does not have any symptoms. However, when symptoms appear, they include difficulty in breathing, pain in the chest, palpitations, general body weakness, and dizziness.
Several empirical studies, which form part of the primary sources for this work, have been conducted on atrial fibrillation. According to empirical research by Wang et al. (2022), the prevalence of atrial fibrillation (AFib) is 37.574 billion cases, translating to 0.51% of the global population. Older adults between 60 and 70 comprise about 70% of the patients suffering from AFib (Wang et al., 2022).
In the United States, close to 6.1 million people have the disease. The prevalence of AFib in the country increases with age. Approximately 9% of adults above 80 years suffer from the disorder, the highest percentage in the country (Rosenthal, 2021). Alongside the aging population, the increasing levels of diabetes and obesity will contribute to a higher prevalence of the disease over the coming years.
Normal Anatomy and Physiology
To care for, treat, and prevent the disease, the requisite foundation of knowledge of anatomy, physiology, and pathophysiology of the organ system and its connection to other body parts, and the result of the disease, is critical. AFib primarily affects the upper part of the heart (atria) (Wijesurendra & Casadei, 2019). However, the condition can also have an impact on the ventricles.
Atria refers to the two upper chambers of the heart responsible for the blood’s reception and propelling it into the ventricles, the heart’s lower chambers. An appendage, a venomous component, and a vestibule constitute an atrium (Rosenthal, 2021). The septum separates the left and right sections of the atria. They are separated from the ventricles by atrioventricular valves that facilitate the diastolic process, filling the ventricles with blood and preventing the backflow of blood to the atria.
The primary function of the atria is to receive blood from the other parts of the body. When obtaining blood, the atria perform three functions: a reservoir during systole, a passive conduit during early diastole, and a booster during late diastole (Tan & Zimetbaum, 2020). On the other hand, ventricles are located below the atria and separated by a septum that prevents the mixing of oxygenated and deoxygenated blood. The septum comprises thick muscle tissues to perform its functions better. The primary role of the ventricles is to pump blood out of the heart into either the pulmonary or systemic circulation.
The atria are connected to other systems of the heart through the circulatory, nervous, and respiratory systems. They are essential to blood circulation as they receive blood from different body organs and transfer it to the ventricles, which then pump the blood back to the organs (Wijesurendra & Casadei, 2019). In the nervous system, they initiate electrical impulses through the sinoatrial node. The electrical impulses generated from the correct atrium control heart rate and facilitate contractions of the ventricles when pumping blood.
Lastly, the atria promote the oxygenation and deoxygenation of the blood through the left and right atriums, where the former intakes deoxygenated blood and the latter obtains the oxygenated one (Wang et al., 2022). The atria receive blood and transport it to the ventricles, which pump it to other body parts for oxygenation and deoxygenation.
Changes to Physiology and Anatomy
Anatomical Changes
During atrial fibrillation, the heart receives electrical signals outside the sinoatrial node. Electrical signals cause irregular contractions transmitted to the ventricles by the atria (Dobrev et al., 2019). Atrial fibrillation results when the beating of the atria and ventricles is not in sync. The condition leads to anatomical changes in the atria. As a result of irregular contractions, fibrosis, atrial enlargement, and thrombosis may arise.
Primarily, repeated episodes of atrial fibrosis may lead to fibrosis. Fibrosis refers to the formation of fibrous tissues in the atria (Qiu et al., 2021). Fibrosis in the heart affects the electrical activity in the heart. The presence of fibrotic myocardial tissue in the atria will likely lead to further arrhythmias.
Additionally, atrial fibrillation can cause atrial enlargement or result from an enlarged heart. Research has shown that patients suffering from AFib likely have left atrial enlargement (Dobrev et al., 2019). Irregular heartbeats in the atria slow blood flow in the heart. Atrial fibrillation increases pressure within the atria due to the heart trying to compensate for the decreased blood flow (Qiu et al., 2021). The increased pressure in the atria causes them to dilate or enlarge.
Further still, the long-term effect of AFib is linked to the formation of blood clots. A clot formed in either the veins or the arteries is called a thrombus (Quintanilla et al., 2021). The reduced blood flow in the atria due to irregular heartbeats causes thrombus formation. The clots from the stagnant blood flow travel to different body parts during blood circulation, posing severe complications.
Physiological Changes
Patients with AFib are likely to experience physiological atrial changes. Physiological changes in the atria due to Afib are electrical, structural, and contractile remodeling. Electrical remodeling in AFib patients refers to changes in the electrophysiological properties of the atria. It occurs due to altered electrical activation by the heart as a complementary mechanism to avoid changes in the ionic equilibrium of the atria; moreover, atrial muscles in patients with AFib contract irregularly.
Also referred to as contractile dysfunction, contractile remodeling refers to the ineffective functioning of muscles and tendons (Quintanilla et al., 2021). Continuously dysfunctional atrial muscles might lead to heart failure. There is also the case of prolonged AFib leading to morphological changes in the structures of the atria. Some of the changes likely to occur in the heart due to long periods of atrial fibrillation are thrombi formation, atrial enlargement, inflammation, aging, oxidative stress, and atrial tissue disorganization.
Prevention and Treatment Options
Although regarded as a trivial disorder, AFib reduces cardiac output, which is clinically significant. The consequences of a reduced cardiac output are decreased exercise capacity, low blood pressure, and pulmonary congestion, all expressions of heart failure (Tan & Zimetbaum, 2020). Therefore, understanding the prevention and treatment strategies of atrial fibrillation is essential.
Prevention is the first line of treatment. To prevent AFib disease, people are encouraged to maintain a healthy lifestyle and to monitor other risk factors such as underlying medical conditions and heart complications. Exercise and healthy diets are vital in reducing AFib-related symptoms and preventing heart complications (Dobrev et al., 2019). Exercise reduces stress levels and boosts blood circulation, ensuring normal heart functioning.
Additionally, reducing alcohol and caffeine intake is essential to preventing atrial fibrillation. Caffeine speeds up the heart rate, whereas alcohol raises blood pressure. Receptors in the heart cells are stimulated by caffeine to increase the heart rate. Increased heart rate and high blood pressure are likely causes of AFib (Dobrev et al., 2019). Therefore, to reduce the risk of atrial fibrillation, people are advised to quit smoking and alcohol.
Four treatment strategies exist for atrial fibrillation: medications, palliative care, surgery, and medical procedures. Medical procedures are conducted through catheter ablation or cardioversion. The types of medicinal drugs available for the treatment of AFib are Beta blockers, Calcium channel blockers, antiarrhythmics, and anticoagulants.
However, an empirical study by Quintanilla et al. (2021) has shown that these drugs have side effects, especially on the older generation. Palliative care for atrial fibrillation patients can be carried out through cardiac monitoring, using electronic devices to monitor heart rhythm. Lastly, surgery is offered in Cox-Maze and Minimaze procedures (Rosenthal, 2021). The difference between the two procedures is the use of tiny cameras to generate electrical signals in the Minimaze procedure.
Conclusion
This paper has discussed atrial fibrillation in detail, from its history to available treatment options. The epidemiology study of the disease in this work has shown that most people suffering from it are older than 60. As such, health practitioners and the general public should pay much attention to this group.
Also, as discussed in this paper, AFib is a common heart condition that can have significant health effects. Therefore, understanding the disease’s prevention and treatment mechanism is vital despite being labeled a “trivial” heart condition. Due to the side effects of the drugs and the negative health implications of the other treatment options, prevention is seen as the most effective mechanism to combat the prevalence of atrial fibrillation.
References
Dobrev, D., Aguilar, M., Heijman, J., Guichard, J.-B., & Nattel, S. (2019). Postoperative atrial fibrillation: Mechanisms, manifestations and management. Nature Reviews Cardiology, 16(7), 417–436. Web.
Qiu, D., Peng, L., Ghista, D. N., & Wong, K. K. (2021). Left atrial remodeling mechanisms associated with atrial fibrillation. Cardiovascular Engineering and Technology, 12(3), 361–372. Web.
Quintanilla, J. G., Shpun, S., Jalife, J., & Filgueiras-Rama, D. (2021). Novel approaches to mechanism-based atrial fibrillation ablation. Cardiovascular Research, 117(7), 1662–1681. Web.
Rosenthal, L. (2021). Atrial fibrillation. Medscape. Web.
Tan, A. Y., & Zimetbaum, P. (2020). Atrial fibrillation and atrial fibrosis. Journal of Cardiovascular Pharmacology. Web.
Wang, J., Liu, S., Bao, Z., Gao, M., Peng, Y., Huang, Y., Yu, T., Wang, L., & Sun, G. (2022). Patients’ experiences across the trajectory of atrial fibrillation: A qualitative systematic review. Health Expectations, 25(3), 869–884. Web.
Wijesurendra, R. S., & Casadei, B. (2019). Atrial fibrillation mechanisms. Understanding Atrial Fibrillation, 21–91. Web.