![]() Calcium channel blockers (CCB) and beta blockers are both effective agents to reduce the ventricular rate.Patients with duration of AF of over 48hrs and/or patients with chronic cardiac complaints as per CHADS 2 should have rate control and anticoagulation started. For this reason Amiodarone is the preferred ED option for chemical cardioversion. In the ED we will rarely know a patent has normal ventricular function and coronary arteries. the optimum initial energy for bi-phasic is 100 Joules.įor a patient with atrial fibrillation who has normal left ventricular function and no coronary disease, flecainide is preferred by cardiologists.bi-phasic waveform is better than mono-phasic.positioning of the pads matters: anterior and posterior is better than anterior and lateral.The most potent rhythm control agent is DC cardioversion, with success rates well above 90% in published trials. There is no clear evidence for this time, however it is widely accepted and stated in guidelines. In an otherwise healthy person (stable) with AF for less than 48hrs, chemical cardioversion is appropriate.Ĭardioversion (electrical or chemical) to achieve rhythm control is not recommended where onset of AF is thought to be more than 48 hours earlier (unless unstable). Most patients require control of heart rate for symptomatic relief and to prevent tachycardia-induced cardiomyopathy. While rate versus rhythm contol is a key issue in the management of AF, the AFFIRM study showed no statistically significant difference in mortality or in quality of life with either management. ![]() ![]() Source: Medi, C, Hankey, G, Freedman, S (2007) Atrial Fibrillation, Medical Journal of Australia, vol. Enhanced automaticity (focal atrial fibrillation)Ītrial fibrillation without associated heart diseaseĪtrial fibrillation associated with medical conditions.Primary or metastatic disease in or adjacent to the atrial wall.Myocardial disease leading to systolic or diastolic dysfunction (ischaemic cardiomyopathy, dilated cardiomyopathy, hypertrophic cardiomyopathy).Valvular heart disease (mitral or tricuspid valve disease).Hypertension (particularly when left ventricular hypertrophy is present).Cardiac, pulmonary, oesophageal, or general surgeryĪtrial fibrillation with associated heart disease.Prevent thromboembolism (balancing the risk of stroke against risk of bleeding from anticoagulation) - CHADS2, HASBLED.īack to the top Reversible causes of atrial fibrillation.Decide on rate control or rhythm control.electrolyte deficiencies, particulalry magnesium and potassium.temperature control and antibiotics where there is an infection.Identify and treat associated or causative factors which may abort the arrhythmia.Transthoracic echo is ideal, if available. Coagulation studies should be sent in patients where anticoagulation is likely to be commenced, or in patients already on warfarin. Hepatic and thyroid function should also be considered. Blood tests including renal function, full blood count and magnesium levels are routine. In stable patients, evaluation involves history, examination and ECG. For example a patient who appears well and has atypical chest pain and has no shortness of breath will not get cardioverted, whereas a patient who is diaphoretic, appears unwell and has a systolic of 80 should get cardioverted urgently. The need for urgent cardioversion should also be anticipated in patients where decompensation is thought likely. This is uncommon in the setting of uncomplicated AF. Patients assessed as unstable require immediate cardioversion to prevent further deterioration to cardiac arrest. Systolic of less than 90mmHg (or 30-40mm less than the patient’s usual SBP).Shortness of breath (due to heart failure).Parameters suggesting instability include: In patients with an unknown duration of AF, or significant cardiac or other illness disease, emphasis should be on rate control.Īn assessment of haemodynamic instability should be made first. In otherwise healthy patients with acute AF, a strategy to return them to sinus rhythm as soon as possible seems reasonable. ![]() This is partly because there is a reasonably high spontaneous reversion rate – around one third in the first 6 hours, and the adverse event rate is very low making it hard to differentiate any strategy on the basis of safety. There is no strong evidence to favour either a rate control or rhythm control strategy. With the increasing age of the population, AF is becoming more prevalent in the community. It is associated with increased cardiovascular morbidity and mortality and preventable stroke. AF is the most common sustained arrhythmia affecting approximately 1-2% of the population.
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