A review of factors associated with maintenance of sinus rhythm after elective electrical cardioversion for atrial fibrillation

Abstract

Atrial fibrillation is the most common heart-rhythm disorder, affecting about 1.5% to 2% of the population with an increased risk of mortality and morbidity due to stroke, thromboembolism, and heart failure. If the conversion back to sinus rhythm does not happen spontaneously, pharmacological or electrical cardioversion (ECV) is the next available treatment options for some patients. However, the long-term success following ECV is variable. This review describes the factors that are associated with maintenance of sinus rhythm following ECV and proposes a clinical strategy based on the available evidence.Atrial fibrillation (AF) is a supraventricular arrhythmia characterized by extremely rapid and uncoordinated electrical activity in the atria with variable conduction through the atrioventricular node, resulting in irregular, and often rapid, ventricular contraction. AF is the most common sustained heart-rhythm disorder in the developed world, found in 1% to 2% of the general population, with a higher prevalence in females and older patients.1 Because of an aging population, it is likely that AF patient numbers will continue to rise, along with associated increases in healthcare costs. 2 Palpitations, breathlessness, fatigue, and reduced exercise tolerance are AF-associated symptoms, and there is an increased risk of stroke with AF, with the need for anticoagulation. 2In some patients, AF will be permanent and therapy is aimed at controlling the ventricular rate (rate-control strategy). In other patients, normal rhythm initially can be restored with pharmacological or electrical cardioversion (ECV) but often requires additional strategies to maintain sinus rhythm (SR; rhythm-control strategy).There is no convincing mortality benefit to achieving rhythm control over rate control; therefore, treatment decisions are usually based on the presence of symptoms and the perceived likelihood of successful cardioversion. Cardioversion can be achieved by pharmacological methods or ECV; however, maintenance of SR may only be temporary. [3][4][5][6][7] The use of ECV may be indicated where pharmacological rhythm-control strategies have failed and the patient remains symptomatic. Patient selection is important, as the maintenance of longterm SR can be difficult. The advantages of ECV are that it is associated with a high initial success rate (68%-98%) 8 ; however, it requires sedation or general anesthesia, and although initially successful, longterm maintenance of SR is not reliably achieved. 9 AF relapse following ECV is also associated with increased mortality, 10 thus highlighting the importance of identifying the correct patient group for cardioversion and, where possible, addressing reversible factors associated with poorer outcomes. Furthermore, it is crucial at the time of ECV that patients are appropriately prepared with adequate hydration and correction of any electrolyte abnormalities. ECV should also be avoided in stable patients with concurrent infection or significant inflammation.Many factors have been reported ...

Clinical factors related to successful or unsuccessful cardioversion in the EdoxabaN versus warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation (ENSURE‐AF) randomized trial

“…Possibly men could be affected by additional factors associated with unsuccessful cardioversion, like older age, comorbidities and weight. There is evidence 6 that women are less likely to be treated with cardioversion despite that they tend to be more symptomatic with AF. One of the reasons may be their higher risk of recurrence of AF after successful cardioversion when compared to men 7,8 …”

“…In addition, epicardial fat might also be a factor, which might interfere with the success of ECV 9‐11 . Moreover, patients with a higher body weight may have higher energy requirements for successful ECV 6 …”

Role for machine learning in sex-specific prediction of successful electrical cardioversion in atrial fibrillation?

“…We used existing literature to select candidate predictors of successful cardioversion (table 1). [2][3][4] We assessed all information on potential predictors before the cardioversion procedure. Heart rate was measured on the date of cardioversion.…”

“…Several characteristics have been identified as predictors of AF recurrence, such as high age, female sex, long duration of AF, heart failure, large left atrial size, hypertension, elevated body mass index, ischaemic heart disease, and chronic kidney disease. [2][3][4] However, the evidence of identification of patients who will benefit from cardioversion is weak and prediction of success is difficult in clinical practice.…”

The efficacy and safety of amiodarone combined with beta-blockers in the maintenance of sinus rhythm for atrial fibrillation

“…The risk of recurrence depends on age, AF duration, and the existence and severity of underlying heart disease. [ 8 , 9 ] The overall rate of AF recurrence without treatment is high. In the patients who have converted to sinus rhythm, only 20% to 30% could remain in sinus rhythm 1 year later.…”