Atrial Fibrillation
Introduction of the Disease
Atrial fibrillation is a type of supraventricular arrhythmia that causes atrial dysfunction, making it to quiver rather than beat. It will result in an irregular and fast heartbeat rate. This malfunction in the atria due to electrical signal disharmony will hinder its contraction thus pumping of blood to the ventricles is altered (William and Wilkins, 2017). The CDC (2019) reports that atrial fibrillation poses a burden globally as it is the most diagnosed type of heart arrhythmia. In countries such as the United States, atrial fibrillation has a reported incidence of between 2.7 million and 6.1 million with its prevalence expected to rise not only in the country but globally. In Australia and Europe, the prevalence has been estimated to be between 1% and 4%.
Etiology and Risk Factors
According to Lilly (2016), the exact cause of atrial fibrillation is unknown but studies have shown that it can be related to injury of the heart or its muscles. It can also be as a result of congenital anomalies, cardiovascular drugs and diseases. There are factors which predispose one to have atrial fibrillation. These include; hypertension, diabetes mellitus, environment, sedentary lifestyle, age, gender and genes. People of ages above 65 years are at a greater risk of getting atrial fibrillation as an increase in age comes along with many other comorbidities especially heart diseases which cause it (William and Wilkins, 2017). There is an increased risk of developing the disease if first degree relatives were affected by atrial fibrillation due to shared genes. Heart rhythm society (2019) also indicate a higher prevalence of atrial fibrillation in men than women. Lifestyle and environment are also risk factors as the two may entail alcohol consumption and obesity which may cause atrial fibrillation.
Pathophysiological Processes
Atrial fibrillation results from interruption of electrical signals of the myocardial cell. This interruption may result in altered ionic and molecular mechanisms of the cell which contribute to travelling of the signals. This disharmony prevents the signals from being generated in the SA Node (Sinoatrial) which is the hearts pacemaker. (Lilly, 2016)
They instead begin in the atria which causes premature activation of the atria. This makes the atria to fibrillate. The abnormal signals may also be conducted to the ventricles which limits their ability to pump blood to the lungs and the rest of the body. This may cause heart failure which is a common complication of atrial fibrillation. The patient’s ECG readings will indicate irregular QRS wave and an undetectable P wave. The quivering may also cause a blood clot to be formed in the atria. The clot may travel to the brain which causes a stroke which is a common complication of atrial fibrillation. (William and Wilkins, 2017)
Clinical Manifestations and Complications
A patient with Atrial Fibrillation may specifically present with palpitations, dyspnoea, pulse rate of more than 500bpm and ECG confirming a rapid QRS wave with a discernible P wave. The patient may manifest with symptoms such as fatigue, hypotension and syncope. (Lilly, 2016) These results from poor blood supply to body parts thus poor oxygenation throughout the body. The signs include pulse rate between 500-600bpm as the heart isn’t beating rather fibrillating. Atrial fibrillation can complicate to cause a stroke. If untreated the disease can cause Congestive heart failure as there is a dysfunction in the hearts blood pumping (Lilly 2016).
Diagnostics
Diagnosis of atrial fibrillation is done by performing electrocardiography on the patient. Blood tests such as arterial blood gas analyses (ABGs). This will indicate low levels of oxygen in the blood due to poor blood supply. Echocardiography can be done to detect a disruption in the contraction of the heart muscles which occurs in atrial fibrillation. (Lilly, 2016)
References
Centres for Disease Control and Prevention, 2019 National Centre for Health Statistic Underlying causes of death.
Heart Rhythm Society. (2019) A complication of Atrial Fibrillation.
Lilly, L. S., & Harvard Medical School. (2016). Pathophysiology of heart disease: A Collaborative project of medical students and faculty.
Lippincott Williams & Wilkins. (2017). Pathophysiology. Philadelphia: Lippincott Williams &Wilkins.