An overview of atrial fibrillation

An overview of atrial fibrillation slit1Atrial fibrillation (AF) is a condition when the lovingness does not beat to its normal speeds or beat, often it beats faster than it should. This stultification leads to an change magnitude risk of throw and death. The pump geezerhoodncy of the bosom deteriorates as a dissolving agent of the un-coordination (due to uncoordinated excitation of muscles). The net result of impaired pump action is the upper chambers of the heart contract e very which way and at clock too quick for the heart to relax forrader it bottom of the inning contract again effectively.At the junction of the pulmonary veins in the left atrial musculature, abnormal neural impulses fire which override the heart indispensable pace farmr.thither atomic number 18 3 major mannikinifications for AFParoxysmal AF- lasts from 30 seconds to 7daysPersistent AF- weeklong the 7daysPermanent AF- AF that fails to terminate using cardioversion, or is end but relapses with in 24hours.If at that place ar no obvious perplex and all investigations argon normal, this is cognise as lone AF. Lone AF tends to buy the farm in Paroxysmal cases. separatewise the to the highest degree commonplace ca charges atomic number 18ischaemic heart diseasehypertensionmitral stenosishyperthyroid glandismOther causes which bent as common ar can be classified into 3 sub catagoriesCardiac Rheumatic heart disease, Sick sinus syndrome, Pre-excitation syndromes (such as Wolff-Parkinson-White syndrome) and heart failure. Less commonly, congenital heart disease, atrial myxoma , atrial septal defect, pericardial disease, and cardiomyopathy.Non-cardiac Drugs (e.g. bronchodilators/thyroxine), Electrolyte depletion infection, Pulmonary embolism, Lung cancer Diabetes.Lifestyle Obesity, high caffeine or alcohol intake1.A fast pulse (often 140bpm) which whitethorn or may not be irregular is the most common symptom of AF just it is also accompanied by tiredness, breath lit tleness, dizziness, angina1, stupefaction, cut down exercise tolerance, or polyuria2. The change magnitude efficacy of the pumping of the heart may result in the reduction of caudex pressure.AF is diagnosed by the use of an ECG and is characterised by the absence of consistent P waves and presence of fibrillation.The method of management of suffers of AF has two main strategies, either by the lead the arrhythmia aspect of the condition or by the tachycardia situation of the condition. Rhythm biddingling drugs include flecainide (and other like drugs), beta- finishers ( pickyly sotalol), and amiodarone. point controlling drugs such as beta-blockers bisoprolol atenolol or the calcium bank line blockers verapamil ordiltiazem.Thrombolytic and antiplatelet drugs are also used to manage the thromboembolic risk. There are non pharmacological ways to manage AF, the most common creation cardioversion. acetylsalicylic acid inhibits cycloxygenase from producing thromboxane A2 which is responsible for platelet activation and thus aggregationdiltiazem of use in AF for its affects on calcium channels on the heart. The blockade of calcium channels reduces excitability of cardiac muscle and hence change magnitude fibrillations it also decreases the force of contractionAtenolol is a beta receptor blocker(a classII), it decreases the do of the sympathetic drive to the heart, such that the neurotransmitters adrenaline and noradrenaline are competitively blocked. Thus the levels of cAMP decrease. cAMP mediates m whatever events in the heartdecreases stability in resting emfs (phase 4) of nodal create from raw material(AVN conduction SAN firing). In nodal tissue(myocytes) a decrease in cAMP reduces Ca2+ en see thus action potentials take longer, it also causes repolarisation to longer i.e. increasing the refractory periodAmiodarone has all four classes of drill (of Vaughan Williams system MAKE APPENDIX) however its main method of action is its class III mechani sm. By the blocking potassium channels the potassium efflux in an action potential is blocked, thus action potentials duration is a prolonged refractory period ( create a region of uni directive block remain refractory for longer effectively having a bi directional block)3Verapamil a non selective calcium channel blocker (classIV), by reducing the Ca2+ into the cell through L-type channels in the nodal tissue (SAN AVN) depolarization takes longer as does the refractory period list slow AVN conduction. Reduces tachycardic impulse from AVN to the ventricles and also AVN re-entrant rhythms. form 2 is limited in nodal tissue (myocytes and purkinje fibres) reduces triggered automaticity4.Warfarin inhibits the effective synthesis of biologically active forms of the vitamin K-dependent clotting factors II, VII, IX and X, as well as some(prenominal) regulatory proteins.Flecainide a class1c sodium channel blocker.There is decreased diastolic excitability and Phase 0 (depolarization) tak es longer as does the refractory period together causing s refuse conductions4.Propafenone is a class1c sodium channel blocker.There is decreased diastolic excitability and Phase 0 (depolarization) takes longer as does the refractory period together causing slower conductions4.digoxin is a K+/Na+ ATPase inhibitor which leads to an increase in the intracellular concentration of sodium this stimulates of sodium-calcium exchange as a result there is an increase in the intracellular concentration of calcium causing stronger less frequent contractions.Cardioversion may be tried in some people with AF. The heart is given a controlled electric shock to try to restore a normal rhythm1.Catheter excision is a procedure that very wangle beaty destroysthe diseased area of your heart and interrupts abnormal electrical circuits. It is an pick outence if medication has not been effective or tolerated1.A pacemaker may be fitted alternatively to drug treatment when it is not seize of failing1. Section 2AF is the most common rhytm disorder of the heart with up to 500,000 sufferes in the UK1. In the UK over 46,000new cases of AF are diagnosed each year5. The incidences increase with age, with a higher(prenominal) incidence in men, when data is adjusted for age6. AF is uncommon in the unripened unless there is an existing heart disorder. At 50-59years of age, the prevalence is around 0.5%. At 80-89years of age, the prevalence is around 9%.Section 3AF is a substantially increases the chance of rap and emboli. The decision to use antithrombotic therapy involves a intricate rapprochement of risks, benefits, and costs. The probabilities of shot, die harding complications, and death the associated costs of all treatment options and outcomes and the quality of living associated with treatment and disability. These have shown that warfarin therapy is generally cost-effective and often cost-saving. However, the economic value of antithrombotic therapy in legal injury of cos t-effectiveness is most strongly influenced by 2 factors slice risk and perceived quality of life.The cost-effectiveness models indicate that warfarin can be cost-effective or, indeed, cost-saving for a wide variety of unhurrieds with AF, provided that it is prescribed fittingly base upon stroke risks7In patients at high risk of stroke, anticoagulation is most cost effective, but not for those at low risk of stroke8.Aspirin 75mgx28 1.66, Aspirin 300mgx28 0.55, Warfarin 1mgx28 1.10, Warfarin 3mgx28 1.15, Warfarin 5mgx28 1.21, Atenolol 25mgx28 0.82, Diltiazem MR 60 mgx84 3.52, Diltiazem MR 60 mgx56 (or over 70yrs), verapamil 40mgx80 1.55.Section 4Symptoms should be monitored often AF has no symptoms, however you should look for the common presenting symptoms (stated in instalment 1).TestsHeart Rate- Should be done when treating with rate lowering drugsElectrocardiography- each 12months breed electrolytes, urea and creatinine- 1-2 weeks after unveiling, and 1-2 weeks after reach ing the maintenance dose, then every 6 months. For Beta-blockers, digoxin, amiodaroneMonitor blood pressureLiver function tests- every 6months for amiodaroneThyroid function test- when using amiodarone shopping center examinations- annual eye examinations.Plasma levels- for digoxin, shortly after initiation or after a dose increaee. 0.7and 2.0nanograms per millilitreDrugs to reduce the risk of thromboembolism (warfarin, aspirin and clopidogrel)The target INR for oral anti coagulants is 2-3 usually 2.5. Patients should be considered for warfarin use if risk is perceived to be medium or high fit in to nice (see appendix)9. It is pregnant that INR be measured cursory or bound days at initiation of treatment. Then at longer intervals depending on dose response up to 12 weeks10. Note the importance of increased monitoring as drugs are added to the regimen, pre-adjustment to warfrin are sometimes necessary e.g. diminish dose by one or two thirds before initiation of amiodarone1.Secti on 5Although systematic reviews have shown that aspirin reduces the rate of stroke by 25%8 The Atrial Fibrillation, Aspirin Anticoagulation Study show a reduction of strokes by 64% per year with warfarin (INR 2.8-4.2), compared with placebo, a 3.5% per year reduction. A non-significant reduction in stroke was seen with aspirin 75mg8. Where warfarin is contraindicated or patient requests not to initiate therapy, it has been raise that a combination of antiplatelets (aspirin and clopidogrel) was associated with a significant reduction in major vascular events compared with aspirin alone. The number of people that would need to be treated with aspirin sum total clopidogrel for 3.6years to prevent one vascular event was 421.According to a meta-analysis the combination of both aspirin and warfrin yielded no significant reduction in stroke rates and had increased side effects8.No mortality contravention was engraft between rhythm control and rate control. Although for people older t han 65years of age or those with coronary artery disease, a significant difference was found in favour of rate control in terms of all-cause mortality. Studies showed significantly higher rates of hospitalisation and adverse events in the rhythm control group and no difference in quality of life between the two groupsa.Incidence of ischaemic stroke, discharge and systemic embolism was similar in the two groups, but certain malignant dysrhythmias were significantly much believably to occur in the rhythm control groupa. No cognitive free fall was seen with the use of rhythm controlling drugs. Quality of life scores were similar in both groups. Therefore it is recommended that rate control, is used as it is less costly11.IA, IC and III drugs are effective in maintaining sinus rhythm but increased adverse effects. Class IA drugs may increase mortality.calcium antagonists versus digoxinSeven studies found no difference in ordinary heart rate between calcium antagonists verapamil o r diltiazem and digoxin either at rest or during periods of normal daily activity. Studies have found calcium antagonists resulted in a lower heart rate during exercise, compared with digoxin2.Beta-blockers versus digoxinThree studies found no difference in average heart rate between digoxin and beta blockers maculation at rest or during periods of normal daily activity. However, the beta blockers atenolol and labetalol controlled heart rate during exercise more effectively than digoxin did2.Beta-blockers versus calcium antagonistsOne crossover study found no difference between the calcium antagonist diltiazem and the beta-blocker atenolol in terms of either the mean heart rate over 24 hours or during exercise2.Beta-blockers with digoxin versus beta-blockersOne crossover study found no statistically significant differences in heart rate during periods of exercise. Some studies found the beta-blocker atenolol used in combination with digoxin to be associated with a lower heart rate over 24 hours than atenolol alone2.Calcium antagonists with digoxin versus calcium antagonistsFour crossover studies found that calcium antagonists diltiazem or verapamil used in combination with Digoxin to be more effective in controlling heart rate over 24 hours, as well as during periods of exercise, than either diltiazem or verapamil alone2.Section 6M whatsoever people whom suffer from AF suffer no symptoms, some have been diagnosed incidentally1. It is in these patients that concordance is a particular issue. tuition as to the risks and complications of the condition are necessary to achieve optimum concordance. It is important that patients are alert the side effects (SE) as well as the dosage regimen. Many of the dugs used in the management of AF have common and serious side effects which patients should be trained to spot.Interactions and side effects of tuberosity. Further information can be derived from the British field of study formulary (BNF) and a comprehensive an alysis available in the most online Stockleys drug interaction. Classes of drugs have been mentioned although this does not mean that the complete class provide interactAmiodarone Interactions Anti-arrhythmic (rate and rhythm modulating), Antibiotics, Anti coagulants, Tricyclic antidepressants, mizolastine, thyroid hormones, diuretics and phenytoin10.it is of note that due to its long half life amiodarone may palliate interact several months after treatment is stopped particularly applicable in the switching over of treatments.Amiodarone reduces the clearance of warfarin, prolonging prothrombin times (PTs) and elevating international normalized ratios (INRs). To avoid bleeding complications, the patient being put on amiodarone must have their catamenia dosage of warfarin reduced by at least one-third and PT and INR closely monitored until they are stabilized15. Although routine eye examinations should occur to asses the ocular effects of amiodarone, if a patient experiences an y visual impairment the treatment should be stopped10. Patients should be aware for the signs of thyroid dysfunction (signs and symptoms of which included in appendix 1)Warfarin interactions Alcohol, amiodarone, propafenone, analgesics, antibiotics, antidepressants, antiepileptics, thyroid hormones, ulcer healing drugs, lipid regulating drugs, hormones, corticosteroidsWarfarin levels are slowly effected by changes in fast, major changes in diet should be done in consultation with healthcare professional, commonly eaten foods that are known to interact with warfarin are cranberry, grapefruit and vitamin K rich foods16. bleed or bruise easily. Also, if you bleed, the bleeding may not stop as quickly as normally. For modelling, you may have bleeding gums nosebleeds prolonged bleeding from cuts blood in the urine.Beta blocker interactions Antiarrhythmics (rhythm and rate modulating), antibiotics, antidepressants, mizolastine, antipsychotics and diuretics.Beta blockers should be avoid ed in people with asthma attack, or with chronic obstructive pulmonary disease13, Beta-blockers should not be stopped explosively unless absolutely necessary there is a risk of rebound in the condition13. Doses are titrated for patients and are gradually increased10.Digoxin interactions Antiarrhythmics (rate and rhythm modulating), diuretics, anti biotics and anti epileptics.Signs and symptoms of digoxin toxicity are important to report promptly. Digoxin toxicity may cause drowsy, dizzy, and affect your vision, disorientation, confusion, headach or disyurbed vision14.Flecainde interactions Antiarrhythmics (rate and rhythm modulating), antidepressants, antihistamines, antipsychotics, diuretics and tolterodineRoughly 1% of the general population and 10% of asthma suffers are allergic to aspirin12. Each drug has the potential for interaction with other medication and even food.Self help adviceIn order to denigrate the risk of stroke and heart attacks it is important for patient to catch possible advise on diet as this will impact on blood cholesterol levels, weight management and blood pressure it is of particular importance when the patient is diabetic.Important components in a healthy diet are low fat and salt intakes, with an emphasis on complex carbohydrates found in vegetables. Advice on the sources of esstential fatty acids should be given (for example nuts and oily fish). Smoking cessation counseling and Nicotine replacement therapy should be offered, discussing the statistical significance smoking alone contributes to the Cardio vascular events.Section 7Pharmacists have contact at various stages along a patients treatment. A specialist PCT pharmacist may manage patients, prescribe, review and monitior. A community pharmacist should attempt medicine use reviews and prepare to make interventions on prescriptions when appropriate. Clinical pharmacists are involved in monitoring and providing guidance on protocols and current evidence.In the future ther e will be an increased scope for pharmacists to play a larger role when full patient records become available, full clinical reviews may be conducted victorious into account the persons autobiography (familial, drug, treatment, condition) and make appropriate interventions and recommendations according to the most current evidence.Section 8In order for the condition and the services to legislate effectively is necessary to run audits regularly. This will ensure the national standards are met. Nice guideline audit criteria either people presenting to direct or secondary care with a hypertension, heart failure, diabetes made or stroke and noted to have an irregular pulse to be offered an ECG and any new diagnosis of AF recorded2.All AF patients in whom a rate-control or rhythm-control dodging is initiated to have their involvement in choosing a treatment strategy recorded2.All patients who are prescribed digoxin as initial monotherapy for rate control to have the reason for this prescription recorded where it is not obvious (e.g. inactive patient presence of contraindication to alternative agents)2.All patients should be assessed for risk of stroke/thromboembolism and given thromboprophylaxis according to the stroke risk and have this perspicacity and any antithrombotic therapy recorded2.It is important for pharmacists to keep uodate and maintaining a high levels of competenacy. Advice should be evidence based and current. There are regular updates produced by nice NICE and the Guidelines for atrial fibriliation are a good source of information.Section 9the National Service Framework for coronary heart disease has a chapter pertains to AF. Arrhythmias are of great importance Cardiac arrhythmia affects more than 700,000 people in England and is consistently in the top ten reasons for hospital admission, using up significant AE time and bed days. AFis the most common arrhythmia, affects up to 1% of the population (rising to 4% in the over 65s) and absorbs a lmost 1% of the entire budget of the NHS to the NHS16. Of the three quality requirements there are two germane(predicate) in AF.Quality requirement one patient support. bulk with arrhythmias receive timely and high-quality support and information, based on assessment of their call for16.Markers of good practicePeople with arrhythmias receive a formal assessment of their support needs and those at significantly increased risk of anxiety, depression or a poor quality of life receive appropriate care16.People with long conditions receive support in managing their illness from a named arrhythmia care co-ordinator16.Good quality, timely information about arrhythmic conditions is given by appropriately trained staff16.Quality requirement two diagnosis and treatment. People presenting with arrhythmias, in both emergency and elective settings, receive timely assessment by an appropriate clinician to ensure accurate diagnosis and effective treatment and rehabilitation16.Markers of Good P ractice Initial TreatmentAll patients receive a hard copy of the ECG documenting their arrhythmia and a copy is determined in their records.Patients who survive out-of-hospital cardiac arrest and patients presenting with pre-excited AF are assessed by a heart rhythm specialist prior to hospital discharge.The following patients are assessed urgently by a heart rhythm specialistPatients with asphyxia or any other symptom(s) suggestive of an arrhythmia and a private history of structural heart disease or a family history of premature sudden deathPatients with continual syncope associated with palpitationsPatients with syncope and pre-excitationPatients with enter 3rd degree AV block (not associated with acute MI)Patients with continual syncope in whom a life-threatening cause has not been excludedPatients with documented ventricular tachycardiaThe following patients are referred to a heart rhythm specialistPatients with a presumed diagnosis of ventricular tachycardiaPatients wit h Wolff-Parkinson-White (WPW) syndrome or asymptomatic pre-excitationPatients with symptomatic regular recurrent supraventricular tachycardia which is unsuccessfully treated with one type of medication or who would prefer not to take long-term medicationPatients with recurrent atrial rumpusPatients with symptomatic AF despite optimal medical therapyFirst degree relatives of victims of sudden cardiac death who died below the age of 40 yearsPatients with recurrent unexplained fallsMarkers of Good Practice Ongoing TreatmentMechanisms are in place for urgent referral of patients with sustained or compromising arrhythmias for prioritisation of appropriate treatment.Implantable cardioverter defibrillators (ICDs) are considered in patients presenting with life-threatening ventricular arrhythmias and in those without demonstrable arrhythmia but identified as being at high risk.Catheter ablation is considered as the treatment of choice in patients presenting with sustained supraventricular tachycardia (SVT) other than AF, and cardioversion of new-fangled onset AF is considered as early as is clinically safe.Where further hospital treatment is not recommended, a care plan is agreed between the patient, GP and the arrhythmia care team, including follow up and support as required.Management of long term conditions and elderly also have a priority in the governments plans and frameworks for the future.Section 10Emphasis should be on patient centered care, projects such as near patient test for warfarin have proved to be effective at managing patients and their potential complications.Primary care workers such as GPs PCT pharmacist should blanket at risk patients. They shall be involved in the management of there condition frequently monitor patients. If required a referral can be made on lifestyle issues to manage the risk of stroke, e.g. if lipids are rattling(a) may want to refer to a dietitian. Community pharmacists have a role in conduction medicines use reviews and be prepared to make inventions in prescribing, regimen concordance and side effect management/referral. It is of terminus importance that the specialist (cardiologist) makes clear recommendation and maintains communications with their counterparts in primary care.