P POSTGRAD. MED. J. (1964), 40, 381 o s tg ra d CARDIAC ARRHYTHMIAS M e d LEON RESNEKOV, M.B., M.R.C.P. J From the National Heart Hospital and Institute of Cardiology, London, W.J. : firs t p u THE term "cardiac arrhythmia" indicates that membrane, Ca++ and Mg+-t+ concentration blis an irregularity of heart-beat is present. Many are all of great importance. h e states of disordered heart-beat, however, are Of great interest and clinical significance is d associated with an entirely regular rhythm, for the fact that many arrhythmias occur in hearts as example paroxysmal atrial tachycardia. In the that are otherwise normal-sino-atrial block, 1 0 description that follows I propose to limit my- premature beats, atrial tachycardia (35 per .1 1 self to cardiac arrhythmias presenting as an cent of these last attacks occur in normal 3 6 emergency requiring prompt recognition and hearts). Similarly, both atrial fibrillation and /p immediate action. This will be preceded by a atrial flutter may occur in the absence of any g m short account of the normal conduction path- recognisable heart disease. j.4 way and the etiology of cardiac arrhythmias. Katz and Pick (1956) in a study based on 0 50,000 patients observed over 25 years, found .46 Normal Conduction Pathway that the most common arrhythmia was ectopic 5.3 The study of the conduction tissue of the beats (14.5 per cent), then atrial fibrillation 8 1 heart began when Purkinje (1845) demonstrated (11.7 per cent), heart block (4.1 per cent), o the terminal part of the system in the heart atrio-ventricular dissociation (1.4 per cent) and n 1 of a sheep. Paradoxically, the pacemaker was atrial flutter (0.5 per cent). J u the final structure to be identified (Keith and ly Flack, 1907). Lewis (1925) demonstrated that Paroxysmal Tachycardia 1 9 transmission between the sino-atrial and atrio- This term was introduced by Bouveretc6 o4 ventricular nodes occurred through the atrial (1889) and indicates rapid regular ectopic beatspy. D muscle and not through specialised tissue. The arising from one focus which may be atrial,rigow fsuynsctteimonwaosfestthaebliasthreido-vbeyntrHiecruilnarg (c1o9n0d4u)ctwihoon ncioadtaeldorwivtehntrtihceulaprr.e-eOxcnietastpieocnialoftytpheeisWoalsfsof-,ht.nloa damaged the bundle of His in dogs, and the Parkinson and White syndrome. de befufnedctlse owferinetedrreumpotnisotnraotfedthebybrEapnpchiensgerofatnhde heaWritthrataellstoyfpebsettwheeeonns1e1t0isanusdua2l5l0y apberrumpitnauntde d fro m Rothberger, (1910). are usually found. Symptoms vary from none, h The normal impulse spreads from the sino- to breathlessness, palpitations, dizziness, syn- ttp a1t,r0i0a0l mnmod.eptehrrsoeucgohndthaendatrpiraoldmuucsesclteheatPawbaovuet c(oWpoeo,d,pre1c9o6r1d)iails pfareiqnueanntdlyafnoxiuentdy.durPionlgyurtihae ://pm of the electrocardiogram. Most of the P-R attack. The effects of the attack depend on j.b interval is taken up by the impulse spreading the functional state of the myocardium and m through the atrio-ventricular node, a structure its ability to increase cardiac output with the j.c o with a long refractory period, incapable of increase in rate. Normal hearts usuallv stand m rapid conduction (22 mm. per second). Once the period of tachycardia with no untoward o/ in the branches of the bundle of His and Pur- effects but where the heart is abnormal cardiac n J kinje fibres the passage of the impulse is rapid failure may follow. a n (4,000 mm. per second). Contraction occurs Attacks usually last for only a few hours u a as the impulse enters the ventricular muscle and but vary from seconds to weeks. The end is ry is followed by the resting state. usually abrupt. Frequently the diagnosis is 4 retrospective and depends on an accurate his- , 2 0 Aetiology of Cardiac Arrhythmias tory. The exact nature of the arrhythmia can 23 Any abnormal state affecting the myo- usually only be determined by an electro- b y cardium and any process interfering with the cardiogram during an actual attack. g normal action of the valves of the heart may ue bmeanryespmoentsaibbolleicfordiasntuarrbrahnyctehsmima.ayInpraedsdeinttioni,n AtrTihailsFimbaryilloatciconur- st. P this way, and in this connection the Na+ and 1. As a paroxysmal rhythm, or ro K+ interchange across the myocardial cell 2. As an established rhythm. tec te d b y P 382 POSTGRADUATE MEDICAL JOURNAL July, 196o4 s tg ra d M e d J : firs t p u b FIG. 1.-Atrial Fibrillation. ECG Lead 2. lish e d a s It occurs most frequently in association with contraction the jugular venous puilse show 1s 0 rheumatic heart disease (35 per cent), coronary no "a," wave and as in any arrhythmia carefu.1l 1 artery disease (32 per cent) systemic hyper- inspection of the form of the venous wave3s 6 tension (17 per cent), thyrotoxicosis (8 per will be rewarding. Carotid sinus compressio/pn cent), cor pulmonale (5 per cent). Congenital may slow the ventricular rate but this is onlgmy heart disease is an unusual cause of atrial fibril- temporary and in any case the irregularity j.4is lation, of which atrial septal defect is the com- unaffected. 0 monest, but this rhythm may also be found The rhythm should be differentiated fro.46m in other forms of septal defect especially if multiple premature beats arising from differen5.3t pulmonary hypertension is associated. Peri- foci, atrial flutter with a varying degree o81f cardial disease is a numerically small but func- atrio-ventricular block and any form of atrio o- tionally important precipitating cause of atrial ventricular heart block with an irregulan 1r fibrillation. response. Any patient already receiving digi J- u Atrial fibrillation may occur in the absence talis in whom a rapid irregular rhythm lyis of any detectable organic heart disease and found should have the possibility of paroxysma 19l under these circumstances may precipitate atrial tachycardia with atrio-ventricular blcooc64k heart failure if the ventricular rate is very seriously considered and the differentiationpyo. Df rapid for a prolonged time. this from atrial fibrillation will be considerigreowd FliPerginaznmdetaKlr,ugeCror(d1a9y5,0)Bwrielrl,e aSbellleertso, sOhbolwatbhy, latTerh.e effect of exercise (where the clinht.icanloal hbmieigahfitslwpmoeeed.dbacsIiincnettmyhapeteosfgirrosaftphamtyirintauhltatecoinintrrtrhaeicgsutliaaorrnrhcmyotanhy-- fasitsbartietlhlaealtlioronawtset)hesihnrochruyelatdshemaslwbbaeuyctsombweeistthmrioemrd.aeniIyrnreoagtturhlieaaded fromrrl tractions at 10,000 to 40,000 per minute involve irregular rhythms this becomes less marked ah s a small area of the atrial wall. In addition, the rate increases. This is specialily useful fottpr altarrigaerawtav4e-0l0iketoco6n0t0racpteironsmisnwueteep. aTchroessttrhuee tdiefnfderetnotiadtiisngappmeulatripwlehepnremhaeatrutrerabteeastsewxhciece://pmdh mechanism underlying the arrhythmia is still 120 per minute. j.b As with any arrhythmia an electrocardiom- under dispute but the most widely accepted gram will establish the diagnosis (Fig. 1). j.c theory suggests that it is initiated by a unifocal o m fIsrtrrioemmguulluamsranwryhei-ecnphtorritiesisonrseopclcoaufcredtahrebisyiantgmruilaftlrioplmmeusacfnloyec-.i TreAa.tmeTnot control the ventricular rate: on J/ where within the atria. If this is so, a true Digitalis-This is the drug of choice anand mother circus movement does not exist. should alwavs be used where the ventriculauar rate is raised ry theCliinrirceaglullyaritthye ohfalvlemnatrrkicouflartherataer.rhyTthhimsiahaiss venItfrihceualratr fraaitleureanhdaswhreesrueltendofrdiogmitaalisrahpai 4, 20sd always been considered in the past as a chance formerly been given, digitalisation should b23e occurrence. Recent studies, however, by Soder- speedily performed. The approximate ora bl strom (1958) suggest that in any one patient digitalising dose for an adult is 2 to 5 mg. oy gf the nature of the ventricular response can be digoxin. 1.0 mg. may be given orally followedue preTdhicetedd.iagnosis depends on the recognition ebfyfec0t.5hamsg.beeenveraychiseivxedh.ours until a desirest. Pd of a completely irregular cardiac rhythm. For extreme urgency 1.0 mg. digoxin mayrote Because of the absence of organised atrial be given intravenously followed by a furtherc te d b y P July, 1964 RESNEKOV: Cardiac Arrhythmias 383 o s tg 1.0 mg. in 3 hours. Thereafter 0.5 mg. may be standstill, rapid ventricular rates, ventricular rad given in three or six hours depending on the ectopic beats or tachycardia may all occur and M clinical state. This dose can be repeated at patients receiving quinidine in high dosage are ed toisthnurattetrsasvtereidinmsoektuhsaitnatthneirednvrtaarlpaytvaheseanroenuesieundnsdetocadsonamcgbemeusotni.sidtenommtausnwtdiitnbhge- cbtsetaaattrnitdtoeinroogstsrrhcaeoimault.lleoddscFaiaolncpwiilahcioytssimpeoisbtneailft,aootrrpihrinaemgnfmdeer.oadfbilatytheewitreelhseuccstocrnio--- J: first pu b In patients with nausea or in whom oral A higher incidence of systemic embolisation lis therapy is not possible intramuscular digoxin may occur at the time of attempts at version he shoWuhledrebethuesreed.is no urgency 0.5 mg. digoxin cofoagaturliaanltftibhreirlialpatyiosnhotuoldsibneuscornhsyitdhermedanindeavnetriy- d as may be given orally and 0.25 mg. 8 hourly case. If used, a therapeutic level should have 10 thereafter until the ventricular rate is slowed. been present for at least 14 days before the .1 1 A maintenance dose will then be needed, attempt. Following successful mitral valvotomy 3 6 usually 0.25 mg. 12 hourly but varying from or closure of an atrial septal defect and in cases /p 0.25 mg. on alternate days to 0.25 mg. 8 hourly of treated thyrotoxicosis anticoagulant therapy gm in individual patients. is probably not needed. j.4 Occasionally digoxin, even in adequate dos- Attempts to restore sinus rhythm should 0.4 age, fails to control the ventricular rate. This always be made where there is no underlying 6 may occur in hypokaimmia or if thyrotoxicosis heart disease responsible for atrial fibrillation 5.3 is present and specific treatment for these must but results may be disappointing (McDonald 81 always be given when needed. One of the and Resnekov, 1964). Similarly, in successful o n presentinig signs of digitalis overdosage is an post-operative mitral valve disease and treated 1 uncontrolled ventricular rate and this should thyrotoxicosis sinus rhythm should be aimed at. Ju always be considered where the ventricular rate Likewise, atrial fibrililation precipitated by in- ly remains rapid or increases despite large doses fection should be brought into sinus rhythm 19 of digoxin. once the infection has responded to treatment.co64 Occasionally patients respond better to one Once atrial fibrillation develops in the natural py. D form of digitalis preparation than another. history of a disease process, especially mitral rigow dTohsiessiosfnostomaeuosfuatlheocccoumrmroenncleybauvtaielqaubilvealpernet- pvlaaltveeddiastetaesmep,tsantdowrheestroeresusrigneursyrihsyntohtmcbonytaenm-y ht.nloa parations are: means are frequently unsuccessful and are not de d DPiogwodxeirne,d0.d2i5gitmagli.s leaf, 60 mg. wit2h.outDirriesckt, acnurdresnhtouslhdocbke-atvhoiisdedwi.ll be dis- from Digitoxin, 0.075 m,g. cussed in detail later in the paper. h Lanatoside C, 0.25 mg. (excretion more ttp rapid than digoxin). Atrial Flutter ://p B. To restore sinus rhythm. m 1. Drug therapy. Quinidine is the drug of inLtiwkoe aftroiramls,fibprialrloatxiyonsmaatlrialorfluetsttearblmiasyhedo.ccuIrt j.bm choice. If quinidine is used alone it may allow is far less common than atrial fibrillation; for j.c a 1:1 ventricular response at a dangerously every 15 cases of atrial fibrillation one of atrial om high rate. This can be prevented by preliminary flutter will be encountered. Nevertheless, it is o/ digAitnaliasadteiqoun.ate blood level (4.0 to 10.0 mg. tnhoattarerqaurierecsauismemeodfiaatseudtdreeantmreanpti.d arrhythmia n Ja n quinidine per litre) is essential for successful Atrial flutter is usually found in association u a version. with rheumatic heart disease, coronary artery ry A satisfactory regime for oral quinidine is disease, thyrotoxicosis and systemic hyper- 4 0.3G two hourly for three doses on the first tension and is less frequently encountered than , 20 day, 0.6G two hourly for three doses on the atrial fibrillation in hearts that are otherwise 23 second and 0.9G similarly on the third. Great normal. Atrial septal defect, especially post- b individual response to quinidine is found and operative, is the commonest associated con- y g where facilities exist a blood examination to genital heart disease. u e cheHcypkertsheenslietvievlitoybttaoinequdinwiidllinbeeisusneofutl.uncom- onAsaniniartrriitaalblfiebrfiolclautsioninthtehaerrahtyrtihummiawdheipcehndisn st. P tmioonn,s tsoymfpetveorm,snavaursyeianganfdrocmolslkapisne.manCiafredsitaac- baenatastripuemr inminfluuttet.er bTeahtes arthyftrhomm 2i6s0 utsoua3l4l0y rotec te d b y 384 POSTGRADUATE MEDICAL JOURNAL July, 1964 P o s tg ra d M e d J : firs FIG. 2.-Atrial Flutter. ECG Lead 2. An irregular ventricular response is shown. t pu b lis h e d a s 1 0 .1 1 3 6 /p g m FIG. 3.-Paroxysmal Atrial Tachycardia. ECG Lead V, P and T waves are superimposed. j.4 0 .4 6 regular, the ventricles responding to every Treatment: 5.3 second or third atrial impulse. By increasing 1. Drug therapy. 81 vagal tone, as for example with carotid sinus (i) Digitalis-Adequate doses should b oe compression, a greater degree of physiological given. Oral digoxin is always to be preferren 1d block can be achieved. This is important diag- unless there is real clinical urgency. A satis Ju- nostically as carotid sinus compression causes factory oral dose is digoxin 0.5 mg. 8-hourllyy a sudden temporary slowing of the heart rate which should be given to the point of toxicit 19y which increases again as soon as the pressure or until atrial fibrillation, as shown oncoa64n is released. electrocardiogram, has occurred. Digoxinpy. Dis Clinically the arrhythmia presents with a then stopped and in at least one half ofrigthowe regular heart rate (but irregular ventricular cases sinus rhythm will follow. ht.nlo response may be found) of between 120 and (ii) Quinidine-this should never be usead d 220 per minute unaffected by exercise or respir- alone in cases of atrial flutter for it may alloew d satoiuonndansdhowuiltdh athveariveedntirnitceunlsairty rofesfpiornstseheabret tshoerveesnutlrticilnesatodaknegeepropuascetawcihtyhcartdhiea.atria an fromd irregular (Harvey and Levine, 1945). In atrial flutter, therefore, its use should bh e The clinical effects of the arrhythmia depend reserved for those cases who have had theittpr upon the ventricular rate. As long as this is atrial flutter converted to atrial fibritllation bu://pt less than 90/min. little fall-off in cardiac who have failed to come into sinus rhythm omn output occurs. withdrawing the digoxin. The dose to be usej.bmd carAdtiroigarlapfhluitcterahpapsearaanvceery d(iFisgt.inct2i)v.e elAetcrtiraol- ifasipbpralisyl.ladteisocnriabneddtuhendsearmethepretcraeuattimoennst aonfdartirsikaj.comsl oscililations are seen, especially in standard o/ leads 2 and 3 and in the precordial leads V1 2. Direct current shock-see later. n and V2. When atrial activity is in doubt, how- In the small number of patients with atria Jal ever, an aesophageal lead will show up the flutter who cannot be brought into atrial fibrilnu- activity. In the usual type of atrial flutter lation as a preliminary to sinus rhythm a suitary- inverted f (flutter) waves are present in stan- able maintenance dose of digoxin should b 4e dard leads 2, 3 and in aVF. The less common used to maintain a satisfactory ventricular rate, 2. form presents with upright waves in these Alternatively direct current shock should b02e leads. tried. 3 b y Usually there is a 2 :1 or 3 :1 ventricular Paroxysmal atrial tachycardia g response but occasionally atrial flutter occurs Here rapid regular beats occur from the samuee wstiatnhceas 1th:e1vceornydurcatpiiodn.venUtnridceurlarthersaetecciorncsutmi-- flaosctusf.orThaefoenwsesteicsonsdusd,dehnouarnsdotrhedaatytsacbkefmoaryst. Pe tutes a serious emergency. ending suddenly. rote c te d b y P July, 1964 RESNEKOV: Cardiac Arrhythmias 385 o s tg In a review of 350cases of paroxysmal supra- (b) Digitalis-This is the drug of choice in rad ventricular tachycardia, Kissane, Brooks and paroxysmal atrial tachycardia. Full oral dosage M e Clark (1950) found that underlying heart as previously described is usually adequate d d(i3s4eapseer wceanst),prresheenutmaatsicfo(l3l4owpse:r nceonnte),daertteecrtieod- asenrdvedintfroarventohues vdeirgiytalriasraetioncassehouolfd gbeenuirnee- J: firs sclerotic (14 per cent), systemic hypertensive urgency. t p (3 per cent) and thyrotoxic (5 per cent). In the (c) Prostigmine 0.5 to 1.0 mg. subcutaneously u b remaining 10 per cent, tachycardia was asso- and acetylbetamethylcholine 2.5 to 60 mg. lis ciated with a wide variety of other conditions. subcutaneously may terminate an attack. he The arrhythmia originates from a focus out- Untoward side effects include severe hypoten- d a side the sino-atrial node from which an impulse sion, urgent defaecation and micturition, and s travels simultaneously in all directions and abdominal colic. Except for hypotension, these 10 there is no evidence at present that it results can be speedily ended by atropine sulphate .1 1 from a circus movement. intravenous;ly which should be given onily if 36 In most cases the ventricular rate varies essential. Cholinergic drugs should not be used /p g between 120 and 240 per minute although in patients with a history of bronchial asthma. m much faster rates have been recorded. In the (d) Sedation-heavy sedation may succeed j.4 normal heart an increase in cardiac output where other measures fail. 0.4 occurs with rates up to 170 to 180 per (ii) Direct Current Shock see later. 6 5 minute. Thereafter the stroke volume is re- .3 duced and cardiac output falls. In previously 2. Prevention of Attacks 81 diseased hearts this fall-off occurs at slower (a) Digoxin-in maintenance dosage, pro- o n heart rates so that congestive failure may be bably the drug of choice. 1 produced in prolonged tachycardia whilst with (b) Quinidine-0.3 to 1.OG 8 hourly. J u rapid heart rates, even shortlived, breathless- (c) Procaine amide-0.25 to 0.5 G 8 hourly. ly ness, syncope and angina may all occur. (d) Sedation-regular mild sedation may 19 Polyuria during the attack (Wood 1961) is an help to prevent attacks. co64 interesting association. In every patient with paroxysmal tachycardia py. D Paroxysmal atrial tachycardia may be sus- particular attention must be paid to any un- rigow pected in the presence of a rapid regular heart derlying heart disease which is amenable to ht.nlo rate or retrospectively following a character- treatment and to the presence of heart failure a d istic history. The arrhythmia should be or thyrotoxicosis. Even when all these have e d dsimfaflereanttriiaatledtafcrhoymcarndoidaalwtiatchhyactarridoi-av,enptraircouxlya-r rbeemeaninesxclaudsemdalolr gderaolutpwiwtihthsatfirsefqaucetonrtilyatttahcekrse fro m block, atrial flutter, ventricular tachycardia (if which respond poorly to the measures outlined. h bundle branch block is present in addition) In these circumstances the outcome may be ttp and sinus tachycardia. Carotid sinus com- very serious unless the attack can be curtailed. ://p pression may have no effect or the heart rate Fortunately these instances are excessively rare. m may be temporarily halved or rarely, the j.b arrhythmia may be cured. Paroxysmal tachycardia with the Wolff- m The electrocardiogram (Fig. 3) shows P Parkinson-White Syndrome of pre-excitation. j.co waves similar to those in atrial premature Wolff, Parkinson and White (1930) described m beats but these may be frequently superimposed a condition which they called physiological o/ n on a preceding T wave. The rhythm is regular. heart block and which was characterised by J The QRS complexes are normal in shape a shortened P-R interval with widening of the an unless bundle branch block be present or a QRS, (Fig. 4). The condition is probably due ua widening shown due to aberration. to accelerated conduction at the atrio-ventricu- ry Treatment lcahrarancotdereis(tPicrindzemletatalwaavnedisothseeresn 1o9n50t)heanedleca- 4, 20 1. During the attack trocardiogram for it is the first part of the 23 (i) Cholinergic drugs and reflex vagal stimu- vector of the QRS that is affected. An other- b y lation. These act by prolonging the refractory wise normal heart is present in over 70%/. g period of the sino-atrial node and atrio- and the abnormality is often intermittent. ue ven(tar)icuClaarrotniodde.sinus compression (one side anPdatrhoexyastmtaaclkstaacrheyfcraerqduieantmlayyreloactceudrtoinef5fo0rt%. st. P aVtasaaltviame)m,anocceuulvarreprmeassyuraell(sbiemihlaerllpyf)ul.and the unaTsrseoactimaetendt iwsitahs ftohrepWaorlofxfy-sPmaarlkitnascohny-cWahridtiea rotec te d b y P 386 POSTGRADUATE MEDICAL JOURNAL July, 196o4 s tg ra d M e d J : firs t p u b lis h e d a s 1 0 .1 1 3 6 /p g m j.4 0 .4 6 5 .3 8 1 o n 1 J u ly 1 9 c6 o4 py. D rigow ht.nlo a d e d fro m h ttp ://p m j.b m j.c o m dFIeGl.ta-4w.a-vWeolafbfn-oPramrakliintsyon-ofWhitthee QSyRnSdrocmoem.pleTxhewePl-lRshinotwenr.valPoissisthiovretdaenfldectthioenschaarraectesrhisotwinc on/ over right ventricular praecordial leads (Type A). This tracing is from a patient following J ma-yocclairndiicaallly-ipnrfoavrecnt miynoctahrediaplresiennfcaerctoifonW.anPd.W.illuSsytnradtreosmet.heSd-iTfficsuelgtymenotf adnidagnTosinwgavea anu changes may be part of the conducmtyioocnardaibanlormdaisleiatsye.and by themselves do not indicate ary 4 , 2 0 syndrome but the tachycardia is often more tention until Lown and Levine (195238) resistant to therapy. emphasised again its relation to digital bis y overdosage. g Paroxysmal atrial tachycardia with atrio- Clinically the arrhythmia is characterisueed vAelntthroiucuglharfbirlsotckdescribed by Lewis (1909) bwiyththevendterviecluloaprmenecttoopficabceaartdsiaicniraregpualtaireist. Pntty tahnids aitmtproibruttaendttoardrighiyttalhimsiabyrMeaceciKveendzisecan(t191a1t)- hreeacretivirnatge,ditghietaldiesv.eloSpimmielnatrloyf aanraipnicdreraesgeulrotecainr te d b y P July, 1964 RESNEKOV: Cardiac Arrhythmias 387 o s tg ra d M e d J : firs t p u b FIG. 5.-Paroxysmal Atrial Tachycardia with atrio-ventricular block. ECG Lead V,. Atrial rate lis 215 per mintute. Irregular ventricular response. Note the iso-electric line separating the he P waves. Atrial fibrillation returned after discontinuing digoxin and diuretics and increasing d the potassium intake. a s 1 0 .1 1 3 6 /p g m j.4 0 .4 6 5 .3 8 1 o n 1 J u ly FIG. 6.-Ventricular Tachycardia. ECG Oesophageal Lead. Clear evidence of dissociated 1 atrial and ventricular activity is demonstrated. 9 c6 o4 py. D ranhytohtmherwwhiesne autrnieaxlplfiabirnielldatiionncrweaassepriensenhteaorrt dthoesageleecatrreocparredsieongtracmli:nicfalolry eaxnadmpcloen,fircmoeudploednright.ownlo a failure in patients receiving digitalis should all ventricular ectopic beats and typical ST d e lead the physician to suspect the development segment and T wave changes. Atrial flutter d of the arrhythmia. It is particuilarly liable to and atrial fibrillation may be recorded in a fro occur in patients who have potassium deple- long strip of the electrocardiogram varying with m pttiioootnnenitnmeptorhtceeunrmtiyiaoalctoarrasdniodafltcthehelilaazarinrddheytihndmiituharie.stiTccohsneneaacrr-e- Tthreeaatrmrehnytthmia (Oram and others, 1960). http://p m rhythmia may occur in an otherwise normal A. Of the acute attack. j.b heart in the presence of digitalis overdosage 1. Where digitalis is the cause stop the drug m and a lowered myocardial potassium as des- forthwith. j.c cribed by Oram, Resnekov and Davies (1960) 2. Discontinue diuretic therapy and give addi- om and these authors also stress that as long as tional potassium; IG potassium chloride is o/ the arrhythmia is recognised and appropriate n equivalent to 13 m Eq. potassium and 26 m Eq. J measures taken the prognosis is far better than a every four hours may be given. Where there n assumed previously. u is extreme urgency and assuming satisfactory a atrTiahleraetelevcatrryoicnagrdfirogormam150(Fitgo.2550) psehromwisnuatne renal function this amount may be given ry 4 with a varying degree of atrio-ventricular diluted intravenously. , 2 block (2 :1, 3 :1, 4 :1 with occasional 1 :1 3. Beta-adrenergic blockade. The efficiency of 02 response). Where digitalis is the cause, carotid this group ofdrugs in stopping digitalis induced 3 b soiuntusafcfoemctpirnegssitohen iantrciraelasersatet.hisTbhleockelewcittrho-- a(rStrohcykthamniadsDalheas196b3e)e.n described recently. y gu e cardiogram shows P waves which are small, B. Prevention. s upright and peculiarly pointed and are usually Re-adjustment of digitalis and diuretic t. P separated by a short length of iso-electric therapy with increased potassium supplements ro line. Frequently other signs of digitalis over- will usually prevent a recurrence. tec te d b y P 388 POSTGRADUATE MEDICAL JOURNAL July, 196o4 s tg ra d M e d J : firs t p u b lis h e d a s FIG. 7.-Ventricular fibrillation. ECG Lead 2. 1 0 .1 1 Ventricular Tachycardia Ventricular Fibrillation 3 6 This is uncommon but is certainly found No effective ventricular systole is possibl/pe g more frequently than previously thought. with this arrhythmia owing to the inco-ordinatme Although almost always associated with organic type of ventricular contraction. Arterial presj.4- 0 heart disease it infrequently does occur in the sure falls abruptly and death may occu.4r absence of any recognised disease. within a few minutes. In the transient form65, The arrhythmia is rapid and the heart beat however, spontaneous recovery may occur.3. 8 almost, but not quite reguilar. Cannon waves Frequently it is found as a terminal event i1n o may be seen in the neck. patients dying from heart disease. Irreversiblne The electrocardiogram is usually character- cerebral damage may occur if the attack las 1 Jts istic but difficulty may arise in differentiating longer than four minutes. u it from supraventricular tachycardia if the The electrocardiogram (Fig 7) is characterly 1- latter is associated with bundle branch block. ised by bizarre ventricular oscillations withou9t c6 A6)nfcoersocplheaagreaelvildeeandcemaoyfbae vdeirssyochiealtpefudl,at(rFiiagl any suggesting QRS complex or T wave. opy4. D and ventricular activity may be obtained in Treatment rigow this way. To be effective speed is essential. ht.nlo 1. Adequate oxygenation - mouth-to-moutadh Treatment breathing with an adequate airway or an endoe- d 1. AQ.uinDirduignse.-the drug of choice. Oral btraagchienafllatitounb.e with oxygen administered b fromy administration 0.3 to 0.6G every three hours 2. Closed chest massage-a firm supporh t is to be preferred but where there is genuine under the back of the patient is essential. Ittpn need 0.6G quinidine gluconate intramuscularly the accompanying record (Fig 8) a goo://pd may be given every four hours. brachial artery pressure pulse is maintained imn In the very rare instances that intravenous a patient with ventricular fibrillation treatej.bd m administration is indicated 0.5 to 1.0G of by external cardiac massage. A good pressurj.ce quinidine gluconate may be given diluted in pulse does not of itself necessarily meaon m 5m0inumtle.s 5%/uOndgelrucosdeireocvter ealecpterroicoadrdioofgr1a0p-hi2c0 a3.deCqoumabteatfilnogw, haocwiedvoesri.s-intravenous sodiu on/m control. bicarbonate (1 ml. of 8.4 per cen Jat 2. Procaine amide-0.5 to 1.0G every two NaHCO3 1 mEq. HCOC3). Where largnue to four hours may be given orally, intramus- amounts are administered and up to 200 mlary. cularly or intravenously. The intravenous may be needed to fully correct the acidosi 4s administration is frequently followed by severe the effects of a large infusion of Na+ mus, 2t hypotension requiring urgent supportive also be remembered as renal function is ofte02n measures. depressed at this stage. 3 b B. Direct Current Shock-see later. 4. Repeated doses of 1-5 ml. of 1/10,000 adrey g- Despite a popular belief to the contrary naline intravenously. ue cveonntgreisctuilvaer tcaacrhdyicaacrdfiaailsurheoulddevbeeloptirenagteddurwiitnhg i5.ntRreapveenaotuesdlyd.oses of 5 ml. 1%/, calcium chloridst. Pe digitalis unless there is good evidence that 6. Should normal sinus rhythm not develorotep digitalis is the cause of the arrhythmia. within a short space of time external electricacl te d b y P July, 1964 RESNEKOV: Cardiac Arrhythmias 389 os tg ra d M e d J : firs t p u b lis h e d a s 1 0 .1 1 3 6 /p g m j.4 0 .4 6 5 .3 8 1 o n 1 J u ly 1 FIG. 8.-Ventricular fibrillation treated by external cardiac massage. Upper tracing- 9 Brachial artery pressure pulse recorded with an indwelling cannula and pressure transducer. co64 Lower tracing-Simultaneously recorded ECG Lead 2. Time markings in seconds. py. D NOTE.-With the onset of ventricular fibrillation pressure in the brachial artery falls rigow to a mean level opfre3s0surmem.ofHg.aboEuxtter1n0a0l cmamrd.iacHgm.asswaigtehinis foonlelowseedconbdy. a brachial artery ht.nlo a d e d sdehfoiublrdillbaetioanttweimtphteddi.rect or alternating current fboyllaonwy uwnalrensisng.theTwvietncthriicnlgess abnedgicnonvtuolsiboenast from oa7.fmiIOdnGecdei0l.us2ti5en-du0s.i5nGr5h4y60thmhmlo.uhroalfsy5roperetrurscnleeondwt pdirenoxfctuarsioinsoene cquosunuiasclck.iloyusAannedsvsirviesdchoovfuellrudsyhtahaftececrovem1np0tarnisicelecesosndrbseetguiirsnnuntt-oo http://p may prevent further attacks. abtetaatc.k. TPhaeroaxtyrsimaaclonvteinntureicutloarbetaatchdyucraridnigatoher mj.b f8a.ilSuurpe.portive measures for treating any cardiac fibrillation may be associated and require mj.c urgent treatment. o It is doubtful whether there is still a place m for internal cardiac massage unless cardiac Treatment o/ tamponade is present or external electrical A. Adequate airway and oxygenation. n J defibrillation fails despite the measures out- B. Drugs: a n lined above. If attempted it should be done 1. Adrenaline 1-5 ml. 1 in 10,000 solu- ua only in an operating theatre or equivalent as a tion intravenously. ry sterile procedure. 2a.llyIsoe-vperreynal3ineto106toho2u0rsmgt.osuibnlcirnegaus-e 4, 20 Stokes-Adams Attacks ventricular rate. 23 In these attacks syncope results from ven- 3. Long acting preparations of iso- b y tricular standstill and constitutes a real prenaline, for example, "Saventrine" g emergency. Although they occur in about half may be taken orally to a total of ue tcihaeticoansesthoefy caormepleetsepecaitarliloy-vecntormicmuolanr dwihsseon- 4b.etEwpeheendr2i0n0ea3n0dt3o0060mgm.g.petrhrdeaey.times st. P poafrtcioanlscihoeuarstnesbsloicskabbreupctomaensd cisomnpoltetper.eceLdoesds maadnaaygehmaesnat toifme-thhoesneourceadsesplabcuetinitthies rotec te d b y P 390 POSTGRADUATE MEDICAL JOURNAL July, 196os4 tg ra d M e d J : firs t p u b lis h e d a s 1 0 .1 1 3 6 /p g m j.4 0 .4 FIG. 9.-The Lown Cardio6- vmeorntiert.orinAgntheoscEilCloGscoLpeeadfo5.382r, waanrdniangtascyhsotmeemtse,rawriethproavuiddiebdl1 on.e In addition, provision is mad 1e for external or internal pacin Jg should thfis be neededu. Approximate dimensions arly 1e 22 x 28 x 12 in. 9 c6 o4 py. D rigow ht.nlo a d e d fro m h ttp ://p m j.b m j.c o m o/ n J a doubtful whether it is more effective Direct Current Shock nu than iso-prenaline. Although apparatus for both alternatinaryg 5. Steroids-adrenal steroids accelerate and direct current shock was available at th 4e atrio-ventricular conduction (Prinzme- end of the last century it is largely due to th, 2e 0 tal and Kennamer 1954) and prednisone work of Lown and his colleagues (1962 a, b2) 3 up to 60 mg./day has been given, that this form of treatment is now accepte bd reducing slowly over one week. Results in the treatment of ventricular and supraventriy g- have been disappointing. cular arrhythmias. u e C. ATrhtiisfictieaclhpnaiqcueemaiksindge.scribed fully in capWaictihtorthoef L16owmnicrCoafradriaodvsertiserc*ha(rFgiegd. b9)y st. Paa other article in this issue-see R. aWn.- variable DC transformer. The capacitor dirotes- Portal: Cardiac Arrest (p. 370). c * American Optical Company Ltd. te d b y