Introduction

For the purpose of this assignment I have chosen to review a client with atrial fibrillation in a primary care setting. I will discuss the patient’s original presentation, including analysis and interpretation of his 12 lead electrocardiogram (ECG), diagnosis and subsequent management. Throughout the assignment I will discuss local and national guidelines and the evidence behind the chosen management for this client. For the purpose of this assignment the client will be referred to as Mr. Jones.

Cardiac arrhythmias affect more than 700,000 people in England is one of the top ten reasons for hospital admission (Department of Health 2005). Atrial fibrillation (AF) is the most common and important cardiac arrhythmia, it the most common of all the arrhythmias seen in general practice. AF affects 5% of the UK population over the age of 65 years, rising to 10% in those over 75 years of age (Kirby 2005). The principal significance, both to the patient and the healthcare system is the increased risk of embolic stroke. Atrial fibrillation is associated with 15% of all strokes and with 36% of strokes in patients over the age of 60 (Hobbs 1999). Having a diagnosis of AF increases the risk of stroke five fold. It is an arrhythmia associated with serious morbidity, mortality and health service utilisation. AF and its complications now consume 1% of the United Kingdom National Health Service budget (Watson, Shanstila, and Lip 2007). Despite this it is an area that frequently remains unrecognised in general practices.

Within primary care AF is an area that has not been fully addressed. However the introduction of the National Service Frameworks and updated National Institute for Health and Clinical Excellence (NICE) guidelines has brought this condition to the forefront of primary care teams. Standard five of the National Service Framework (NSF)
Older People (DOH 2001) states that primary care teams should have had in place by April 2004 the following ‘ Every general practice, using protocols, agreed with local specialist services, can identify and treat patients identified at being at risk of stroke because of high blood pressure, AF or other risk factors. This statement is supported by a component of standard three of the NSF for Coronary Heart Disease (CHD) which states that ‘warfarin or aspirin for people over 60 years old who also have atrial fibrillation’ (DOH 2000). Despite the fact that these should have been in place by 2004 many general practices are still struggling to address the many issues surrounding correct diagnosis, identification and management of patients with AF.

Unfortunately, the condition is often unrecognised both by clinicians and patients; this could be partly due to the fact that AF can be symptom less in many people. In the Cardiovascular Health Study (1994) 12% of new AF cases were identified on the basis of a yearly ECG recording alone, presumably because these patients had no symptoms. Sudlow (1997) states that in a population based survey of patients over the age of 65 years in northern England, only 76% of patients with AF were known to their General Practitioner (GP), whilst another similar study involving ECG screening in central England found that only 31% of patients with AF were recognised (Hobbs 1998). All of these surveys are a few years old now and one would hope that as AF becomes a more highlighted area within primary care, and the benefits and importance of appropriate anti coagulation and early cardioversion become more apparent these figures will improve dramatically. Ceresne and Upshur (2002) state that as the vast majority of care is now delivered within a primary care setting it is important to determine the number of clients who have AF and to ensure whether or not they are receiving the optimum treatment for their condition.

One of the main areas of concern in relation to the recognisation and identification of cardiac arrhythmias (especially AF) in general practice is in ensuring that the most appropriate method is used to both highlight and treat these clients. Pulse palpation is currently the most commonly used assessment within primary care but this has implications around correct technique. This should be helped by the introduction of primary prevention clinics and more training and evidence based guidelines being made available both to GP’s and nurses in relation to AF. There were no studies as to what would be the most appropriate method of identification within a primary care setting

Case Study

Mr Jones, a 66 year old gentleman, was invited to his local GP’s practice to attend a primary prevention screening clinic. He had no relevant past medical history and was currently taking no prescribed medication. He had a premature family history of heart disease (father died of a Myocardial Infarction aged 50 years; mother suffered a stroke aged 67 years). He was a smoker, was employed part time as a gardener, and felt that he was fairly fit. He took no regular exercise and had a body mass index of 26. At the clinic Mr Jones blood pressure was recorded at 162/85 and his pulse taken. On pulse palpation it was noticed that Mr Jones rate appeared irregular. On discussion with the client he stated that over the last six to eight months he had been feeling “an odd sensation in his chest”, when questioned further he said these could be described as palpitations and were becoming more regular. He had occasional shortness of breath and was more lethargic than usual, but felt that these did not significantly affect his quality of life. After discussion with the GP an appointment for an Electrocardiogram (ECG) was arranged for the following week. Not all GP practices have the facility to record ECG’s on the premises, this in turn could lead to problems around correct diagnosis and treatment within primary care, if the government guidelines and targets issued around AF in primary care are to be met there need to be adequate provision both in means of equipment, appropriately trained staff and primary care’s capacity to be able to implement these. Blood tests were taken at the practice, these included full blood chemistry, haematology, coagulation profile, glucose, thyroid function tests and liver function tests. These would help to exclude any underlying causes (e.g. hyperthyroidism), assess suitability for anti-coagulation and check baseline values prior to any commencement of treatment which may involve potentially toxic drugs (e.g. amiadarone). It was felt at this time this client may have atrial fibrillation and it was necessary to confirm this diagnosis and initiate treatment if necessary.

Patients with AF will usually present with palpations and/or symptoms of an underlying cause. For patients with a persistent AF breathlessness and poor exercise tolerance are more common symptoms, these patients are also prone to suffering episodes of fatigue, sleep disturbances, poor concentration and irritability (Josephson & McMullen 2003). It is therefore essential that with all AF patients a full and thorough history is taken alongside a physical examination. It is vital that any underlying cause for the AF is identified at an early stage. Several conditions are known to increase the risk of patients developing AF; these can range from thyroid problems, hypertension, Ischemic Heart Disease and heart failure.

The following week Mr Jones attended for a 12 lead ECG recording (see appendix 1). This confirmed the suspected diagnosis of AF. The blood results had shown no evidence of an underlying cause. An appointment was arranged for the patient to be reviewed by the GP and nurse. A referral was also made to a cardiologist within secondary care to enable an echocardiograph to be recorded and to discuss cardioversion in the future if required.

The ECG

In AF electrical activity in the atria is disorganised, this causes the atria to fibrillate or quiver rather than contract as a unit. The basis of this rhythm is rapid, depolarisation occurring throughout the atria (Haughton & Gray 1997). Hundreds of random electrical impulses are sent to the atrioventricular (AV) node, this can be as many impulses as 400 – 600 per minute. The AV node then protects the ventricles by preventing most of these impulses from reaching them; only about 120 – 180 of these impulses will reach the ventricles to produce the QRS complexes. As a result the ventricular rhythm is irregularly irregular, meaning the rhythm has no pattern. Loss of the “atrial kick” in AF reduces ventricular filling and can lead to a fall of 10-15% in cardiac input. Curtis (1999) states that it is now widely accepted that AF is due to a re-entrant mechanism, generally thought to be of the re-entry type.

When looking at the ECG for a client in atrial fibrillation there are key factors which can be identified. There is an absence of P waves, which normally represent atrial electrical activity, and an irregularly irregular ventricular rhythm. The QRS complexes look normal, unless the patient has a pre existing condition that affects the appearance of the QRS e.g. bundle branch block, but appear at irregular intervals.

Treatment

Treatment of AF is dependant on the symptoms of the patient, when he seeks treatment, the duration of this episode of AF and his medical history, as well as whether the patient has had previous AF episodes, the pattern of the AF presentation, their response to previous treatments, if any. Treatment has three main goals; controlling ventricular rate, re-establishing sinus rhythm and preventing thromboembolism.

The result of Mr Jones ECG confirmed a diagnosis of AF and at this point it was important to ensure that the client was commenced on the appropriate treatment and a referral to a cardiologist in secondary care was undertaken. It was unsure as to whether the client was in persistent AF or paroxysmal AF at this point.

There are many new guidelines surrounding the treatment and management of a patient with AF, for this patient the local guidance was implemented using the algorithm which had been developed by the North of England evidence based guidelines group for use in primary care (appendix 2). These guidelines are currently under review due to the publication of the NICE guidelines in 2006. It was necessary to also risk stratify the client at this time using the risk stratification tables issued as part of the NICE guidelines (appendix 3).

The client had symptoms, although not problematic, for over a six month period and no evidence of any underlying cause. It was felt that under the stroke risk stratification he was a moderate risk client and that anticoagulation would be appropriate. Using the primary care guidelines the appropriate treatment would be a rate control strategy. This was discussed with the client by the GP and a patient information leaflet was issued (appendix 4). There was a lot of discussion at this point as to whether anticoagulation using wafarin was the most appropriate method of treatment or the use of aspirin was just as valid. This is an area that has been discussed in many studies, and within a primary care setting I often wonder if the decision comes down to cost alone and the implication for a more vigilant follow up system when clients are commenced on warfarin.

Most of the morbidity and mortality associated with AF is related to the significant associated risk of stroke and thromboembolism (Lip 2007). It is therefore essential that this risk is reduced in those clients who have significant risk and no contraindications to the appropriate therapy. Kirby (2005) states that despite overwhelming evidence supporting the use of anticoagulation in these patients clinical practice seems reluctant to change. In a recent meta analysis of 13 randomised trials of anti-thrombotic strategies it concluded that compared to a placebo, adjusted dose warfarin offers a reduction in risk of ischaemic stroke or systemic embolism by two thirds, this figure can be compared to a risk reduction of 22% using aspirin ( Mehta, Grcott-Mason & Dubrey 2004). The efficacy of warfarin is only conferred by adequate anticoagulation and a target INR of 2.0 – 2.5 should be maintained in most patients. There is only one study available that looks at the use of warfarin in patients with AF in a primary care setting, this shows that out of 261 patients with AF 204 (approximately 78.2%) were currently being treated with warfarin. Upshur (2002) states that these numbers appear very high and that this may be that this medical centre is a tertiary care centre with cardiology services on site. This is not the case within the local area and no local general practices have cardiology services on the premises, maybe this is an area than needs to addressed in future plans. No other studies were available as a means of comparison. In the case of Mr Jones the decision to commence warfarin as opposed to aspirin and the evidence behind it were explained fully. As with many clients the risk of suffering a stroke was perceived as worse than death and Mr Jones was happy to comply with the treatment.

Once anticoagulation therapy had been discussed and initiated it was important that the client be commenced on the appropriate rate reduction therapy. Why a rate reduction pathway? Although cardioversion would not be ruled out for this client a rate reduction strategy was deemed to be the most appropriate as per local and national guidelines. It is known that the longer the AF has been present the less successful cardioversion procedures are, irrespective of the techniques used and in addition recurrence of the arrhythmia becomes more likely (Kirby 2005). Lip (2007) also states that a rhythm control strategy was associated with a higher rate of hospital admission and more frequent adverse reactions to medication. Early restoration and maintenance of sinus rhythm is believed by many clinicians to be superior to rate control, there is however little data that compares both strategies. The Atrial Fibrillation Follow-up Investigation of Rhythm management (AFFIRM) study showed that anticoagulation and maintenance of sinus rhythm were potent predictors to survival, and adequate rate control was achieved in 80% of clients.

As stated in the NICE guidelines (2006) beta blockers or rate limiting calcium antagonists should be the first initial monotherapy in all patients. Beta blockers should be used as first line agents as these are particularly effective at controlling ventricular rate. Although calcium antagonists like diltiazem and verapamil can be used to optimise rate control, these are mostly used initially if the patient cannot tolerate a beta blocker. Mr Jones was not aware of any reasons why he should not be prescribed a beta blocker, he had no known contraindications. Mr Jones was commenced on an initial dose of atenolol 25mgs with the aim for up titration if tolerated. There seemed to be some controversy as to the most appropriate beta blocker to use, but it was felt that the prescribed drug would be appropriate until seen by a cardiologist.

After a period of time Mr Jones was reviewed by the GP and another follow up ECG recorded (appendix 5). His ECG showed sinus rhythm with a rate of approximately 76 beats per minute. At this time his symptoms had reduced and he was currently unaware of any palpations, his blood pressure had reduced to within locally guided limits and he generally felt well. However this does not mean that at some future point Mr Jones symptoms may not reappear, it is therefore essential that he is put onto a AF register within primary care and reviewed on a regular basis (appendix 6) by either his GP or practice nurse. Mr Jones medication was changed to initiate an increase in his beta blockers, his INR was stable and no other changes were made.

AF represents a significant growing health problem in an ever ageing population; there is growing emphasis on the appropriate management of this condition. In primary care there is a need and important role for both doctors and nurses in the early detection and treatment of AF patients. All these patients seen in primary care should undergo risk stratification, a 12 lead ECG and appropriate bloods. There is an urgent need both locally and nationally for quicker access to secondary care services and a need for primary care to review the need to have on site ECG recording with appropriately trained staff, both at recording and interpretation. I think most GP’s would accept that this is not an area that is addressed sufficiently at the present. Patients should also be provided with consistent information on the risks and benefits of anticoagulation to assist them to make informed choices. Primary Health Care trusts require formal management protocols and care pathways for patients with AF; I await the updated local guidance on this condition with great anticipation.

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