A survey of atrial fibrillation in general practice: the West Birmingham Atrial Fibrillation Project

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1 Originl ppers A survey of tril fibrilltion in generl prctice: the West Birminghm Atril Fibrilltion Project GREGORY Y H LIP DANIEL J GOLDING MASOOD NAZIR D GARETH BEEVERS DAVID L CHILD R IAN FLETCHER SUMMARY Bckground. The mngement of tril fibrilltion (AF) hs chnged substntilly in recent yers, especilly with greter pprecition of the prophylctic role of ntithrombotic therpy ginst stroke. There is therefore need for further informtion on the prevlence of AF in Britin, the prevlence of (nd contrindictions to) nticogulnt tretment, nd the fctors tht influence doctors decisions in treting AF, including the investigtion of ptients with this rrhythmi. Aim. To investigte the prevlence, clinicl fetures nd mngement of ptients with AF in generl prctice setting. Method. Cross-sectionl survey of ptients using tretment prescriptions nd clinicl records in two generl prctices from the west of Birminghm (serving ptient popultion of ) where 4522 subjects (27.4%) were ged x50 yers. Results. One hundred nd eleven (2.4%) ptients who were ged x50 yers were found to be in AF (42 mles; men ge 76.6, SD 9.1); 77.5% were Cucsin, 2.7% Afro-Cribben, 0.9% Asin, nd 0.9% mixed rce; in 20 cses there ws no informtion on ethnicity. Of the AF ptients, 5.4% were ged yers, 16.2% ged yers, 20.7% ged yers, 20.7% ged yers, 24.3% ged yers, nd 12.6% ged >85 yers old, with femle ptients being significntly older thn mles. Eighty-one ptients (73%) hd chronic AF, while 30 ptients (27%) hd proxysml AF. The most common ssocited fctors were hypertension (36.9%) nd ischemic hert disese (28.8%), with no obvious cuse for AF in six ptients. Crdic filure ws ssocited with AF in 34 ptients (30.6%), nd stroke hd occurred in 29 ptients (18%). Only 20 ptients (18%) hd hd n echocrdiogrm, 26 (23.4%) chest X-ry, nd 58 (52.3%) thyroid function test. Only 30.6% hd ever presented to hospitl prctice. Wrfrin ws prescribed to 40 ptients (36%), with nticogultion intensity monitoring by the generl prctitioner (GP) in three cses (7.5%), by hospitl clinic in 30 (75%), nd by both GP nd G Y H Lip, MD, MRCP, senior lecturer in medicine nd consultnt crdiologist; D J Golding, medicl student; M Nzir, medicl student; nd D G Beevers, MD, FRCP, professor of medicine, University Deprtment of Medicine, City Hospitl, Birminghm. D L Child, MB, FRCGP, generl prctitioner, Cpe Hill Medicl Centre, Birminghm. R I Fletcher, MB, FRCGP, generl prctitioner, Lee Bnk Medicl Centre, Birminghm. Submitted: 7 July 1996; ccepted: 1 November British Journl of Generl Prctice, 1997, 47, hospitl in seven cses (17.5%). Of those not nticogulted (n = 71), only 12 ptients (16.9%) hd contrindictions to wrfrin therpy. Ptients treted with wrfrin were younger thn those who were not prescribed wrfrin (71.3 versus 79.6 yers, P<0.001). Aspirin ws being prescribed for 21 ptients (18.9%), primrily for previous myocrdil infrction. Only five ptients (4.5%) hd ever hd ttempted crdioversion. Conclusion. Atril fibrilltion is common rrhythmi in generl prctice, nd is commonly ssocited with hypertension, ischemic hert disese nd hert filure. There is suboptiml ppliction of stndrd investigtions nd use of ntithrombotic therpy or ttempted crdioversion; nd few ptients hve presented to hospitl prctice. Guidelines on the mngement of this common rrhythmi in generl prctice re required. Introduction TRIAL fibrilltion (AF) is the most common sustined disor- of crdic rhythm. Estimtes of its prevlence in the Ader community vry widely round the world. 1-8 To dte, British studies of the prevlence of AF in the community hve involved smll numbers of elderly ptients from unrepresenttive popultions. 3-8 These British studies hve concentrted only on reporting the prevlence or incidence, nd hve provided only limited descriptions of the etiology, clinicl fetures, investigtion or tretment. There hve been recent ppels for further informtion on the prevlence of AF in Britin, the prevlence of (nd contrindictions to) nticogulnt tretment, nd the fctors tht influence doctors decisions in treting AF, including the investigtion of ptients with this rrhythmi. 9 An understnding of these fctors is required for helthcre provision, especilly with regrd to the optimum methods of investigtion nd greter pprecition of the role of ntithrombotic therpy. 9 Two other studies hve looked t the tretment of AF mongst cute medicl dmissions to hospitl. 10,11 Both these studies hve demonstrted tht the ppliction of stndrd investigtions for AF is suboptiml nd tht there ws generl reluctnce to strt orl nticogultion or to consider crdioversion. 10,11 In ddition, there is lso considerble vrition mong clinicins in the clinicl mngement of ptients with AF. 12 It is likely tht GPs tret more ptients with AF thn do hospitl generl physicins, so we decided to investigte ptients in two lrge generl prctices: first, to determine the prevlence of treted AF in generl prctice popultion; secondly, to scertin wht use ws mde of locl crdiovsculr services; nd finlly, to exmine whether ptients were receiving optiml investigtion or tretment. Ptients nd methods As mny ptients with known AF will be prescribed either digoxin, betblocker, clss 1 or clss 3 ntirrhythmic drug, verpmil or diltizem, nd spirin or wrfrin, ptients ged over 50 yers who re prescribed these drugs by their GP were British Journl of Generl Prctice, My

2 GYH Lip, DJ Golding, M Nzir, et l Originl ppers Prevlence (%) gen- Figure 1. Age distribution of ptients with tril fibrilltion in erl prctice Age (yers) >80 chosen s our study popultion. We selected two generl prctices in the west of Birminghm in which prctice computers were ble to generte list of ll ptients who were tking the drugs listed bove. The generl prctice records of ll ptients who filled these criteri were crefully exmined to find documenttion of chronic AF, s defined by electrocrdiogrphy on t lest two occsions, six months prt. Proxysml AF ws defined s the presence of proxysms of AF ( 10 bets) previously documented on 24-hour Holter monitoring, or lterntively by presenttion to GP or hospitl with AF on two or more occsions, with subsequent reversion to sinus rhythm. A stndrd proform ws completed, which contined informtion on etiology, investigtions nd mngement. We lso noted investigtions done by the GP or hospitl doctors (s documented in the hospitl outptient clinic or dischrge letters), including thyroid function tests, serum digoxin levels, the lst recorded blood pressure mesurement, chest X-ry nd echocrdiogrphy. The prevlence of hypertension ws ssessed by the previous dignosis of this condition; the number of ptients with recent blood pressure reding of 160/90 mmhg or more ws lso noted. The number of ptients with AF who hd been dmitted to hospitl ws recorded, s were the ntirrhythmic drugs the ptients were receiving nd whether they were treted with spirin or wrfrin. Contrindictions to nticogultion, if ny, were lso recorded; ccepted contrindictions to nticogultion included dementi or frilty, dyspepsi, recent stroke (within the pst three weeks), gstrointestinl bleeding, chronic renl filure, liver disese, recent surgery, nd other bleeding disorders. Results Ptient demogrphy Of the 111 ptients ged over 50 yers who were in AF (Tble 1), 33 ptients (1.9%) were found in one prctice (1756 ptients ged 50 yers) nd 78 ptients (2.8%) from the other (2786 ptients ged 50 yers). Their men ge ws 76.6 yers (SD 9.1, rnge yers), with femle ptients being significntly older thn mles (unpired t-test P<0.001). The incresing prevlence of AF with ge is shown in Figure 1, with 41 ptients (36.9%) who were older thn 80 yers. There ws higher proportion of femle ptients with AF thn of femles ged over 50 yers mong the totl generl prctice popultion (χ 2 = 5.17, P<0.05). Of the 111 ptients with AF, 86 (77.5%) were Cucsin, three (2.7%) were Afro-Cribben, one (0.9%) ws Asin, one (0.9%) ws of mixed rce, nd in 20 cses there ws no informtion of ethnicity in the records. Eleven ptients (10.1%) with AF were smokers, 48 were ex-smokers (43.2%) nd 28 were non-smokers (25.2%); there ws no informtion on smoking sttus in 24 ptients. As we did not interview individul ptients, we did not hve detils on ctul lcohol consumption. Type of tril fibrilltion Eighty-one ptients (73%) hd chronic AF while 30 (27%) hd proxysml AF. There ws no difference in the type of AF (chronic or proxysml) between mle nd femle ptients (χ 2 = 0.36, P = not significnt) (Tble 1). Associted conditions nd complictions Hypertension ws the most common ssocited fctor for AF, being found in 41 ptients (36.9%), bsed on dignoses recorded in cse records. However, 40 ptients (36.1%) in the whole cohort hd lst-recorded blood pressure mesurement of >160/90 mmhg, but only 20 of these were recorded s hving Tble 1. Atril fibrilltion in generl prctice. Totl generl prctice popultion studied Totl generl prctice popultion ged >50 yers (27.5%) Totl number of ptients ged >50 yers in tril fibrilltion 111 (2.4%) 42 mle 69 femle Men ge (SD) 72.7 (9.9) 79.0 (7.7) Chronic tril fibrilltion Proxysml tril fibrilltion Associted conditions with tril fibrilltion hypertension 41 (36.9%) ischemic hert disese 32* (28.8%) vlvulr hert disese 29 (26.1%) previous hyperthyroidism 17 (15.3%) lcohol excess 6 (5.4%) crdiomyopthy 6 (5.4%) sick sinus syndrome 3 (2.7%) tril septl defect 1 In 6 ptients (5.4%), the medicl records did not identify ny etiologicl cuse for tril fibrilltion. Some ptients hd one or more possible etiologicl fctors. *Including 20 ptients with previous myocrdil infrction. 286 British Journl of Generl Prctice, My 1997

3 GYH Lip, DJ Golding, M Nzir, et l Originl ppers hd hypertension or were being treted for hypertension. Other ssocited crdiovsculr conditions re summrized in Tble 1. Sixty-three ptients were known to hve clinicl feture or compliction commonly ssocited with AF: 34 ptients (30.9%) hd ssocited crdic filure, 20 ptients (18%) hd previous stroke, nd nine ptients (8.1%) hd been dignosed s hving trnsient cerebrl ischemic ttck. Investigtions nd mngement Only 26 ptients (23.4%) hd hd chest X-ry (performed by GP or hospitl) nd only 20 ptients (18%) hd hd n echocrdiogrm. Fifty-eight ptients (52.3%) hd hd their thyroid function mesured t some time. Only 34 of the 111 ptients with AF (30.6%) hd ever been dmitted to hospitl. Ptients with AF included 102 who were tking digoxin (91.9%), six who were tking betblocker (5.4%; four were lso tking digoxin), seven who were tking miodrone (6.3%; six were lso tking digoxin), eight who were tking verpmil (7.2%, including six on digoxin), nd one ptient (0.9%) who ws tking flecnide (nd digoxin s well). Out of 102 ptients who were prescribed digoxin, only 40 (39.2%) hd ever hd their serum digoxin levels mesured; however, 18.6% were tking 62.5 µg dily, 46% were tking 125 µg dily, nd 31% were tking 250 µg dily. Only 40 ptients with AF (36%) were being treted with wrfrin, lthough it ws stted in the cse notes tht the wrfrin ws primrily for AF in only 20 ptients (50%). By contrst, wrfrin ws prescribed in six ptients (15%) for previous deep venous thrombosis, nd in four ptients (10%) for prosthetic hert vlve. Ptients tking wrfrin were younger thn those who were not nticogulted (71.3 yers, SD 9.2 versus those not nticogulted: 79.6 yers, SD 7.5; unpired t-test P<0.001). Anticogultion intensity in the 40 ptients ws monitored by the GP lone in three cses (7.5%), by the hospitl in 30 cses (75%) nd by both GP nd hospitl in seven cses (17.5%). Of the 71 ptients who were not nticogulted with wrfrin (64%), only 12 ptients (16.9%) hd ny recorded contrindiction (Tble 2). Only 21 (18.9%) of the 111 ptients with AF were prescribed spirin, nd in seven (33.3%) this ws primrily for previous myocrdil infrction. Thus, out of the totl smple, there were 38 ptients (34%) in whom ntithrombotic tretment might hve been indicted who did not receive either nticogultion or spirin. Only five ptients (4.5%) in our study hd hd n ttempted crdioversion. None of the ptients in the survey hd hd pcemkers fitted or bltion procedures crried out. Discussion This study is limited by being retrospective cross-sectionl study of generl prctice cse records nd by its dependence upon cses of AF who were known to the generl prctices. A forml screening progrmme for AF mong the 4542 ptients ged >50 yers in the two generl prctices would be time-consuming nd limited by cost, mnpower nd non-ttendnce, s illustrted by one previous screening exercise in generl prctice. 3 In ddition, our dependence upon prctice computer ptient lists, bsed upon drug prescriptions, ssumes tht ll ptients with AF were tking some form of mediction. We would therefore hve missed smll number of ptients ged <50 yers nd lso those with AF who were not tking ny drugs, or those who hd not been dignosed. It is likely tht underdignosis would be prticulr problem with proxysml AF, especilly if ptients hd few symptoms nd did not present to their GP. Some of these limittions my explin the minor difference in prevlence between the two generl prctices studied (1.9% versus 2.8%). Although we hve lso chosen two typicl well-orgnized generl prctices in Birminghm tht hd prctice computer drug lists, our popultion my not be generlizble to the popultion s whole. Nevertheless, this survey hs identified the clinicl fetures nd complictions in generl prctice cohort of ptients with AF, nd the suboptiml ppliction of stndrd investigtions nd ntithrombotic therpy in such ptients. The present survey of 111 ptients with AF represents one of the lrgest reported cohorts in the British generl prctice setting. In ddition, the present study ws performed fter recent trils hve estblished the beneficil use of ntithrombotic therpy s prevention ginst stroke nd thromboembolism in ptients with AF. 13 The prevlence of AF in ptients ged >50 yers in generl prctice popultion of over people ws found to be 2.4%. This figure is consistent with the prevlence reported by Hill et l, 5 but is lower thn tht reported mong cute medicl dmissions to hospitl. 10,11 In the present survey, hypertension ws the most common ssocited crdiovsculr condition, followed by ischemic hert disese (IHD) nd vlvulr hert disese. This is therefore consistent with epidemiologicl dt from the Frminghm survey; 14 however, in the hospitl-bsed Glsgow survey of cute dmissions with AF, IHD ws the most common dmission. 10 These differences my be reflection of the fct tht less thn third of the ptients with AF hd ever presented to hospitl, suggesting tht hospitl-bsed surveys my grossly misrepresent the true prevlence nd clinicl fetures of AF in popultion. 10,11,15 In ddition, ptients with AF nd IHD might hve been likely to hve complictions necessitting hospitl dmission. This survey hs confirmed previous observtions of n increse in the prevlence of AF with ge, 1,2 but in British generl prctice popultion. We re only wre of three smll studies in British generl prctice setting. For exmple, Hill et l 5 screened totl of 819 ptients ged >65 yers in single generl prctice popultion in Tmworth, nd found 30 ptients (3.7%) who were in AF. In the study by Cmm et l, 4 only 106 ptients were studied from totl of 268 ptients ged ³75 yers from generl prctice in Sussex, with AF being documented in eight ptients. Finlly, short report by Brnby nd Howitt 16 found only 76 ptients with AF in prctice popultion of (0.57%). In recent udit of generl prctice list of bout ptients in Bollington, 67 ptients were found to be in AF; this prevlence incresed with ge, rising from 1.5% in the sixth decde to 8% in the ninth (J R Coope, personl communiction, 1995). 17 It ws surprising tht over third of ptients with AF hd lst-recorded blood pressure mesurement of >160/90 mmhg; only minority were recorded s hving hd hypertension. In ddition, 30.6% of ptients hd ssocited crdic filure. These observtions re prticulrly importnt, since history of hypertension or hert filure significntly dds to the risks of stroke nd thromboembolism in AF. 18,19 The close ssocition between AF nd cerebrovsculr disese is illustrted by the finding tht nerly fifth of ptients in this survey hd previous stroke or trnsient ischemic ttck. In the present survey, only 18% of ptients hd been investigted with n echocrdiogrm. Previous evidence from the SPAF study hs demonstrted the importnce of echocrdiogrphy in risk strtifiction for stroke; the presence of dilted left trium or crdic impirment on echocrdiogrphy were independent risk fctors for stroke nd were dditionl to clinicl risk fctors such s hypertension, hert filure or previous stroke. 20 Echocrdiogrphy is lso essentil for defining ptients with lone AF. The low proportion of echocrdiogrphy per- British Journl of Generl Prctice, My

4 GYH Lip, DJ Golding, M Nzir, et l Originl ppers Tble 2. Contrindictions to nticogultion mong ptients with tril fibrilltion. Number of ptients with tril fibrilltion 111 Number who were not nticogulted 71 No contrindiction to wrfrin stted in clinicl notes 54 Number with contrindictions 12 Age 4 Dementi or frilty 3 Recent gstrointestinl bleeding 2 Dyspepsi 5 Chronic renl filure 1 Recent (<3 weeks) cerebrovsculr ccident or surgicl procedures 0 Some ptients hd more thn one contrindiction. formed on ptients with AF reflects limited ccess by GPs to hospitl echocrdiogrphy services. Open ccess echocrdiogrphy hs been incresingly recommended by GPs for the investigtion of hert filure, nd there my be strong cse for extending this service to ptients with AF. However, echocrdiogrphy is lso n under-used investigtion mong hospitl ptients with AF, suggesting widespred suboptiml ppliction of this importnt investigtion. 10,11 Furthermore, only hlf of ptients hd thyroid function test t ny time. Thyroid disese is often underrecognized s n etiologicl fctor in AF, especilly in the elderly where the clinicl mnifesttions my be less obvious. 21 Digoxin remins the most common drug prescribed for AF in generl prctice. This my prtly be reflection of prescribing hbits in Britin. It is well-recognized tht digoxin is useful in controlling the resting ventriculr response in AF, but ineffective in rte control during exercise or in conditions of high sympthetic drive nd in proxysml AF. 22,23 By contrst, digoxin is less populr in North Americ, where betblockers or clcium ntgonists (verpmil or diltizem) re used for rte control. Even in Britin, we hve recently demonstrted considerble physicin vrition in the mngement of AF, with more consultnt crdiologists thn non-crdiologists undertking investigtions for AF nd considering ntirrhythmic nd nticogulnt therpy or crdioversion to restore sinus rhythm. 12 Suitble ptients with AF should be considered for crdioversion to sinus rhythm in view of the demonstrble hemodynmic benefits nd possible reduction in thromboembolic risk. 24 In the present survey, we found tht only 36% of ptients with AF were being treted with wrfrin, nd of those not nticogulted only minority hd ny contrindictions. This is despite recent clinicl trils estblishing the benefits of wrfrin in preventing strokes in AF ptients, with risk reduction of pproximtely two-thirds. 13,19 However, nticogultion usge ppers to be better thn in hospitl-bsed reports 10,25 tht were published before the recent rndomized trils on nticogultion in AF. 19 The suboptiml use of wrfrin my reflect doubts whether evidence from the prevention trils pplies to clinicl prctice becuse of the highly selected nture of the ptient popultion in these rndomized trils. 9,26 Ptients tking wrfrin in the present survey were younger thn those who were not nticogulted, lthough ge lone should not be contrindiction to the use of wrfrin in AF. 19 However, in the SPAF-II study, wrfrin use ws ssocited with n excess of intrcrnil hemorrhge in ptients ged >75 yers, thus reducing the benefits of thrombotic stroke reduction by wrfrin. 27 Thus, decision bsed upon risks nd benefits is necessry, lthough, in study using decision nlysis techniques, the benefit for ll ptients with AF ws substntil within wide rnge of stroke risk rtes pplicble to ordinry clinicl prctice. 28 Incresing ge mens tht the risks nd benefits of tretment re more finely blnced, but recommending ginst the use of nticogultion on the bsis of ge lone is inpproprite. 26,29 Anticogultion intensity ws monitored by the GP in the minority of cses nd by the hospitl in the mjority. The min concerns bout wrfrin use re the inconvenience of regulr ttendnces t hospitl nticogulnt clinics, nd sfety (owing to the smll risk of bleeding ssocited with tking the drug). The sfety problem hs been shown to be relted to high INR vlues nd the stbility of nticogulnt intensity. 13 It hs previously been shown tht nticogulnt monitoring by GPs is much better thn tht in hospitl clinics, 30 nd mny ptients prefer to visit their locl GP rther thn busy hospitl clinics tht my be fr wy. However, GPs do vry in their willingness to undertke nticogultion monitoring; some prctices do not even offer this service. 31 If more, better, nd sfer use of nticogultion in ptients with AF is intended, incresing provision of GP-bsed nticogultion monitoring my become necessry step. In conclusion, AF is common rrhythmi in generl prctice, nd is commonly present in ptients with hypertension, IHD nd hert filure. There is suboptiml ppliction of stndrd investigtions nd use of nticogulnt therpy; nd few hve presented to hospitl prctice. Guidelines on the mngement of this common rrhythmi in generl prctice re required. References 1. Lke FR, Cullen KJ, de Klerk NH, et l. Atril fibrilltion nd mortlity in n elderly popultion. Aust N Z J Med 1989; 19: Furberg CD, Psty BM, Mnolio TA, et l. Prevlence of tril fibrilltion in elderly subjects. Am J Crdiol 1994; 74: Rose G, Bxter PJ, Reid DD, McCrtney P. Prevlence nd prognosis of electrocrdiogrphic findings in middle-ged men. Br Hert J 1978; 40: Cmm JC, Evns KE, Wrd DE, Mrtin A. The rhythm of the hert in ctive elderly subjects. Am Hert J 1980; 99: Hill JD, Mottrm EM, Killeen PD. Study of the prevlence of tril fibrilltion in generl prctice ptients over 65 yers of ge. J R Coll Gen Prct 1987; 37: Kennedy RD, Cird FI. The ppliction of the Minnesot code to popultion studies of the electrocrdiogrm in the elderly. Gerontology Clinics 1972; 14: Cmpbell A, Cird FI, Jckson TFM. Prevlence of bnormlities of electrocrdiogrm in old people. Br Hert J 1974; 36: Kitchin AH, Milne JS. Longitudinl survey of ischemic hert disese in rndomly selected smple of older popultion. Br Hert J 1977; 39: Sudlow CM, Rodgers H, Kenny RA, Thomson RG. Service provision nd use of nticogulnts in tril fibrilltion. BMJ 1995; 311: Lip GYH, Ten KN, Dunn FG. Tretment of tril fibrilltion in district generl hospitl. Br Hert J 1994; 71: Zrifis J, Beevers G, Lip GYH. Acute dmissions with tril fibrilltion in British multircil hospitl popultion. Br J Clin Prct 1997 (in press). 12. Lip GYH, Zrifis J, Wtson RDS, Beevers DG. Physicin vrition in the mngement of tril fibrilltion. Hert 1996; 75: Lip GYH, Lowe GDO. Antithrombotic tretment for tril fibrilltion. BMJ 1996; 312: Knnell WB, Abbott RD, Svge DD, McNmr PM. Epidemiologicl fetures of chronic tril fibrilltion. The Frminghm Study. N Engl J Med 1982; 306: Lok NS, Lu CP. Presenttion nd mngement of ptients dmitted with tril fibrilltion: review of 291 cses in regionl hospitl. Int J Crdiol 1995; 48: Brnby J, Howitt A. Antithrombotic tretment nd tril fibrilltion. [Letter.] BMJ 1993; 306: Lip GYH, Beevers DG, Coope JR. Atril fibrilltion in hospitl nd generl prctice. BMJ 1996; 312: Stroke Prevention in Atril Fibrilltion Investigtors. Predictors of thromboembolism in tril fibrilltion: I. Clinicl fetures of ptients t risk. Ann Intern Med 1992; 116: Atril Fibrilltion Investigtors. Risk fctors for stroke nd efficcy of ntithrombotic therpy in tril fibrilltion. Arch Intern Med 1994; 154: British Journl of Generl Prctice, My 1997

5 GYH Lip, DJ Golding, M Nzir, et l Originl ppers 20. Stroke Prevention in Atril Fibrilltion Investigtors. Predictors of thromboembolism in tril fibrilltion: II. Echocrdiogrphic fetures of ptients t risk. Ann Intern Med 1992; 116: Forfr JC, Toft AD. Thyrotoxic tril fibrilltion: n underdignosed condition? BMJ 1982: 285: Flk RH, Levitt JI. Digoxin for tril fibrilltion: drug whose time hs gone? Ann Intern Med 1991; 114: Lip GYH, Metclfe MJ, Re AP. Mngement of proxysml tril fibrilltion. Q J Med 1993; 86: Lip GYH. Crdioversion of tril fibrilltion. Postgrd Med J 1995; 71: Bth P, Prsd A, Brown M, McGregor G. Survey of use of nticogultion in ptients with tril fibrilltion. BMJ 1993; 307: Sweeney K, Gry DP, Steele R, Evns P. Use of wrfrin in nonrheumtic tril fibrilltion: commentry from generl prctice. Br J Gen Prct 1995; 45: Stroke Prevention in Atril Fibrilltion Investigtors. Wrfrin versus spirin for prevention of thromboembolism in tril fibrilltion: Stroke Prevention in Atril Fibrilltion II study. Lncet 1994; 343: Cro JJ, Groome PA, Flegel KM. Atril fibrilltion nd nticogultion: from rndomized trils to prctice. Lncet 1993; 341: Lncster T. Atril fibrilltion ssocited with ging. [Letter.] BMJ 1993; 307: Pell JP, McIver B, Sturt P, et l. Comprison of nticogulnt control mong ptients ttending generl prctice nd hospitl nticogulnt clinic. Br J Gen Prct 1993; 43: Tylor F, Rmsy M, Voke J, Cohen H. Anticogultion in ptients with tril fibrilltion: GPs not prepred for monitoring nticogultion. BMJ 1993; 307: Acknowledgements We thnk the generl prctice stff who ssisted in this survey. GL is recipient of the 1994 Edith Wlsh nd Ivy Powell Reserch Awrds for crdiovsculr disese reserch, nd the 1995 Nthniel Bishop Hrmn Reserch Awrd from the British Medicl Assocition. Address for correspondence Dr G Y H Lip, University Deprtment of Medicine, City Hospitl, Birminghm B18 7QH. British Journl of Generl Prctice, My