Atrial Fibrillation
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and results from abnormal electrical activity in the atria, causing rapid, uncoordinated contractions known as fibrillation. The condition is classified as a tachyarrhythmia, in which the heart rhythm is often fast and irregular. This rhythm disturbance produces turbulent blood flow within the heart and substantially increases the risk of thrombus formation. Such clots can dislodge and embolize, including to the brain, which markedly increases the risk of stroke¹.
Etiology and risk factors
The prevalence of atrial fibrillation increases with age and is particularly high among older adults. Hypertension, coronary artery disease and valvular disease are among the most common causes². Other risk factors include obesity, thyroid disorders, diabetes, chronic kidney disease, obstructive sleep apnea, smoking and high alcohol intake. In some cases, no clear precipitating cause is identified.
Three main forms of atrial fibrillation are described:
Paroxysmal AF: Episodes terminate spontaneously within seven days.
Persistent AF: Episodes last longer than seven days and often require electrical cardioversion or pharmacological treatment.
Long-standing persistent AF: A persistent rhythm disturbance lasting more than 12 months, in which rhythm-control treatment has either not been attempted or previous attempts have failed¹.
Epidemiology
The prevalence of atrial fibrillation is increasing globally, particularly as populations age. Among people over 80 years of age, the lifetime risk of developing atrial fibrillation has been estimated at 22%³.
Pathophysiology
Atrial fibrillation often develops secondary to structural or functional changes in the heart. Hypertension, valvular disease and ischemic heart disease are important triggers. The pathophysiology is complex and not fully understood, but genetic predispositions have also been identified, including changes involving chromosome 10¹.
Clinical presentation
Symptoms vary considerably. Many patients are asymptomatic, while others may experience an irregular pulse, palpitations, fatigue, dizziness, dyspnea or weakness². In some cases, the condition is detected incidentally, for example during blood-pressure measurement or cardiac auscultation in primary care.
Comorbidities
Atrial fibrillation is commonly associated with:
Stroke
Heart failure
Obstructive sleep apnea
Obesity
Diabetes mellitus
Mitral valve disease
Coronary artery disease⁴,⁵,⁶,⁷,⁸
Stroke is a particularly serious complication because thrombi forming in the left atrium can embolize to cerebral arteries and cause ischemic infarction.
Diagnosis
The primary diagnostic method is an ECG, which typically shows irregular R-R intervals and an absence of distinct P waves. Additional investigations may include:
24-hour ECG monitoring (Holter monitoring)
Echocardiography to assess structural changes
Blood tests, including electrolytes and thyroid function
Exercise-capacity tests, such as the six-minute walk test
Clinical examination focusing on an irregular pulse, irregular jugular venous pulsation and a variable first heart sound⁴,⁵,⁹
Elevated CRP may indicate systemic inflammation, which is often present in AF⁴.
Psychosocial consequences
A newly diagnosed heart-rhythm disorder can trigger worry, anxiety or depression. Fear of complications and required lifestyle changes may increase psychological burden and should be addressed as part of holistic follow-up.
Treatment and management
In newly diagnosed AF, it is important to identify and treat reversible causes. Anticoagulant therapy is considered to reduce the risk of thromboembolic complications. Beta-blockers are a first-line option for rate control¹⁰.
Other treatment options include:
Electrical cardioversion: Restoration of sinus rhythm using an electrical shock
Pharmacological cardioversion: Medical rhythm control
Ablation: Catheter-based treatment aimed at eliminating foci of abnormal electrical activity
Pacemaker: May be appropriate in bradycardia or treatment-resistant AF with heart failure¹
After successful conversion, maintenance therapy with antiarrhythmic medication is often initiated to reduce the risk of recurrence².
Physiotherapy considerations
There is limited research specifically on traditional physiotherapy interventions for patients with AF. However, obesity is a well-established risk factor, making weight reduction through physical activity an important component of preventive management.
Although findings regarding the optimal exercise dose in AF are mixed, moderate physical activity is generally recommended. Exercise intensity and comorbidities should be considered individually.
Interventions may include:
Individual guidance on lifestyle modification and weight management
Graded exercise focusing on endurance and functional capacity
Use of the six-minute walk test as a basis for exercise prescription
Collaboration with the physician regarding medical management and follow-up
Physiotherapists can also play an important role in identifying uncertainty and fear related to physical activity and support safe progression within medically appropriate limits.
Sources:
Nesheiwat Z, Jagtap M. Rhythm, Atrial Fibrillation (A Fib). InStatPearls [Internet] 2018 Oct 27. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK526072/
AIHW Atrial fibrillation in Australia :https://www.aihw.gov.au/reports/heart-stroke-vascular-diseases/atrial-fibrillation-in-australia/contents/what-is-atrial-fibrillation
Atrial Fibrillation Fact Sheet [Internet]. Center for Disease Control and Prevention; 2013 [updated 2015 August 13; cited 2016 April 5] Available from: http://www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_atrial_fibrillation.htm
Fuster V, Rydén LE, Cannom DS, Crijns HJ, Curtis AB, Ellenbogen KA, et al. ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): Developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. J Am Coll Cardiol. 2006: 114(7): p. 257-354.
Goodman CC, Snyder TE. Differential Diagnosis for Physical Therapists, Screening for Referral. 5th ed. St. Louis Saunders; 2012. p. 264-266.
Wadke R. Atrial Fibrillation. Disease-a-Month. 2013 March: 59(3): 67-73.
Oishi ML, Xing S. Atrial fibrillation: Management strategies in the emergency department. Emerg Med Prac. 2013: 15(2): p. 1-26.
Gami AS, Hodge DO, Herges RM, Olson EJ, Nykodym J Kara T, Somers VK. Obstructive Sleep Apnea, Obesity, and the Risk of Incident Atrial Fibrillation. J Am Coll Cardiol [Internet]. 2007 Feb [cited 2016 April 9]; 49(5): 565-571. : http://content.onlinejacc.org/article.aspx?articleid=1188673&...#tab1
Amerena JV, Walters TE, Mirzaee S, Kalman JM. Update on the management of atrial fibrillation. Med J Aust. 2013: 199(9): p. 592-7.
Radiopaedia AF: https://radiopaedia.org/articles/atrial-fibrillation?lang=us
