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EDITORIALS: Christopher J Boos, Ranjit S More, and Jörg Carlsson Persistent atrial fibrillation: rate control or rhythm control BMJ 2003; 326: 1411-1412 [Full text]

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Rate and rhythm are both important in critically ill patients

Egbert Pravinkumar   (27 June 2003)

Puzzled

Rainer H Burchett   (1 July 2003)

Re: Puzzled

Andy Evans   (2 July 2003)

Rate control of atrial fibrillation

Elliot F Epstein   (2 July 2003)

Rate and rhythm are both important in critically ill patients 27 June 2003
Egbert Pravinkumar, Lecturer Institute of Medical Sciences, University of Aberdeen Send response to journal: Re: Rate and rhythm are both important in critically ill patients	Dear Editor The editorial by Boos et al [1], reaffirms that rate control is not inferior to rhythm control for the prevention of death and morbidity due to cardiovascular causes in atrial fibrillation (AF). However this information should not be extrapolated to critically ill medical and surgical patients. Atrial arrythmias are common in critically ill patients and are often associated with cardio-respiratory instability and increased mortality [2]. Both rate and rhythm control, in the acute and short term is vital in the management of these patients. Atrial arrythmia in critically ill is usually multifactorial there is often no need to continue the anti-arrythmic drugs beyond the critical care unit unless otherwise there is a strong case to do so. Amiodarone, diltiazem and magnesium infusions, beta-blockers, procianamide have all been shown to be safe and efficacious in achieving this goal [3-6]. Unfortunately direct current cardioversion has not shown to be useful in achieving sustained rate or rhythm control in critically ill [7]. Amiodarone, magnesium still remains the preferred drug for management of new onset AF in critical care patients and the awareness of amiodarone induced pulmonary toxicity remains high. Egbert Pravinkumar Academic Department of Intensive Care, University of Aberdeen, Scotland UK References: 1. Boos CJ. More RS, Carlsson J. Persistent atrial fibrillation: rate control or rhythm control: Rate control is not inferior to rhythm control. BMJ 2003;326:1411-1412 2. Edwards JD, Kishen R Significance and management of intractable supraventricular arrhythmias in critically ill patients. Crit Care Med 1986;14:280-282 3. Delle Karth G, Geppert A, Neunteufl T, et al. Amiodarone versus diltiazem for rate control in critically ill patients with atrial tachyarrhythmias. Crit Care Med. 2001;29:1149-53 4. Kumar A. Intravenous amiodarone for therapy of atrial fibrillation and flutter in critically ill patients with severely depressed left ventricular function. South Med J. 1996;89:779-85 5. Moran JL, Gallagher J, Peake SL et al. Parenteral magnesium sulfate versus amiodarone in the therapy of atrial tachyarrhythmias: a prospective, randomized study. Crit Care Med. 1995;23:1816-24 6. Chapman MJ, Moran JL, O'Fathartaigh MS, et al. Management of atrial tachyarrhythmias in the critically ill: a comparison of intravenous procainamide and amiodarone. Intensive Care Med. 1993;19:48-52 7. Mayr A, Ritsch N, Knotzer H, et al. Effectiveness of direct-current cardioversion for treatment of supraventricular tachyarrhythmias, in particular atrial fibrillation, in surgical intensive care patients.Critical Care Medicine 2003; 31:401-405 Competing interests:   None declared
Puzzled 1 July 2003
Rainer H Burchett, none retired Send response to journal: Re: Puzzled	I am a 64 year old lay reader who has suffered from AF for 4.5 years. Mostly it is controlled with 100 or 200 mg of flecainide daily, also 75 mg aspirin daily. Some of the time I manage without flecainide, I can usually trip back from AF to sinus by going for a gentle run. Under either regime I spend no more than 5% of my time in AF in a typical week, the rest in sinus rhythm. I have seen no great difference from when the problem was first diagnosed in late 1998. This is clearly rhythm control and my experience seems at variance with the conclusions of the studies. However the article does not mention exactly what rate control consists of. While the target readership will undoubtedly already know, people like me don't. Can the authors tell us? My cardiologist believes I will benefit from ablation when techniques have improved a bit further. Is there any further advice you can give? Yours faithfully Rainer Burchett Competing interests:   None declared
Re: Puzzled 2 July 2003
Andy Evans, SpR in Geriatric Medicine King's College Hospital, London SE5 Send response to journal: Re: Re: Puzzled	Dear Puzzled Rate control is based on the acceptance that someone who is in atrial fibrillation (AF) will remain in AF or if a treatment is performed (electrical or drug treatment) to get back into sinus rhythm that they will likely go back into AF in the near future. Typical drugs used for rate control are beta-blockers, digoxin and amiodarone (alone or in combination). The heart beats inefficiently when in AF which is now the major reason to try to restore sinus rhythm. However, the greatest worry for doctors and patients is the increased risk of developing a stroke. The risk of developing a stroke when in AF is affected by age, the presence of coronary artery disease, high blood pressure, diabetes, heart failure and structural abnormalities of the heart. When stroke risk is high, doctors usually recommend thinning the blood with warfarin (the most effective way of stopping blood clots forming). However, warfarin increases the risk of bleeding. There is a balance between the risk of stroke and the risk of bleeding, so that medium risk patients are recommended to have aspirin. It was hoped that by rhythm control, otherwise high-risk patients could avoid warfarin. Since so many go back into AF this does not seem to be a safe strategy for high-risk patients. It is important to realise that trials only look at the "average" patient and not individuals. Although I do not know your entire medical history, I suspect you are at low or low-medium stroke risk and your current treatment seems quite right. When you are in sinus rhythm your heart contracts more efficiently. In the future ablation may offer the chance to abolish the AF entirely, which should pose a minimal risk of going back into AF, so reducing stroke risk Hope this helps Andy Evans SpR in Geriatric Medicine King's College Hospital London Competing interests:   None declared
Rate control of atrial fibrillation 2 July 2003
Elliot F Epstein, Specialist Registrar, General and Geriatric Medicine City General Hospital, Stoke-on Trent, ST4 6QG Send response to journal: Re: Rate control of atrial fibrillation	A recent editorial in the BMJ (1) summarises the results of randomised controlled trials that demonstrate control of ventricular rate in patients with AF (atrial fibrillation) is comparable in efficacy to rhythm control. One of the unresolved issues in clinical practice is to determine the optimal ventricular rate that should be achieved in our patients. Analysis of the degree of rate control in these studies may be helpful. The AFFIRM investigators (2,3) aimed for a target heart rate of <80 beats per minute and <110 beats per minute during a six minute walk test or an average of <100 beats per minute on 24 hour Holter monitoring. The RACE (4) study aimed for a less aggressive target of a resting heart rate of <100 beats per minute. The PIAF (5) study used no target heart rate but used other indicators of efficacy such as improvement in symptoms of dyspnoea, palpitations, fatigue and dizziness. There are several unresolved issues concerning the correct manner to achieve rate control in patientsd with AF. We do not know the optimal resting heart rate that is to be achieved (6). To reach a target heart rate of, for example, <80 beats per minute may be technically difficult and may predispose the patient to adverse effects of rate lowering medication such as digoxin toxicity. Control of heart rate during exercise is thought to be important yet the desirable target is also not known (6) and may be difficult to measure in many of our physically dependant patients. Optimal rate control for an individual patient is usually decided by the treating physician and may depend on factors such as symptom control and quality of life without the benefit of adequate guidelines concerning control of ventricular rate. (1) Boos CJ, More RS, Carlson J. Persistent atrial fibrillation: rate control or rhythm control. BMJ 2003;326:1411-1412 (2) The Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) Investigators. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Eng J Med 2002;347:1825- 1833. (3) The Planning and Steering Committee of the AFFIRM Study for the NHLBI AFFIRM Investigators. Atrial fibrillation follow-up investigation of rhythm management-the AFFIRM study design. Am J Cardiol 1997;79:1198-1202. (4) Van Gelder IC, Hagens VE, Bosker HA, Kingma JH, Kamp O, Kingma T. A comparison of rate control and rhythm control in patients with recurrent atrial fibrillation. N Eng J Med 2003;347:1834-1840. (5) Hohnloser SH, Kuck KH, Lilienthal J. Rhythm or rate control in atrial fibrillation-pharmacological intervention in atrial fibrillation (PIAF): A randomised trial. Lancet 200;356:1789-1794. (6) Campbell RWF. How do we achieve optimal cardiovascular function in atrial fibrillation? Proceedings of the Royal College of Physicians of Edinburgh 1999;29 Suppl 6:16-19. Competing interests:   None declared