EFFECT OF ATRIAL FIBRILLATION ON CARDIAC OUTPUT

Transcription

1 Brit. Hert J., 1965, 27, 719. EFFET OF TRIL FIBRILLTION ON RDI OUTPUT BY P. B. HLMOS* ND G.. PTTERSON From the Royl Victori Hospitl, Belfst Received Octoer 12, 1964 The introduction y Lown, mrsinghm, nd Neumn (1962) of sfe, simple, nd effective method of converting tril firilltion to sinus rhythm hs incresed the interest in the effects of this rrhythmi on the circultion. Previous reports indicte scnt greement regrding the effects of tril firilltion on the crdic output. Studies on groups of ptients with nd without tril firilltion hve een ssocited with the difficulty of otining strictly comprle groups. rdic output studied on the sme ptients efore nd fter drug conversions to sinus rhythm hve een complicted y the effect on output of the drugs employed. The present study ws undertken to determine the chnges, if ny, on crdic output when tril firilltion ws removed y direct current conversion. SUBJETS ND METHODS Studies were crried out on 3 ptients who hd hd tril firilltion for periods vrying from 3 weeks to 1 yers. Dt on these ptients re given in Tles I nd II. Of the 3, 23 hd rheumtic hert disese, 3 hd idiopthic tril firilltion, 2 ischmmic hert disese, one controlled thyrotoxicosis, nd in one tril firilltion persisted following pericrdectomy for constrictive pericrditis. Of the 23 ptients with rheumtic hert disese, 2 hd hd mitrl vlvotomy from 3 weeks to severl yers efore conversion. ll the ptients were on mintennce digitlis. None showed evidence of crdic filure. The ptients were in hospitl for t lest 24 hours efore output studies were mde. rdic output ws mesured in the erly morning y the dye dilution technique.(bruce nd Shillingford, 1962). The procedure ws explined to the ptient the previous evening. The hert rte ws recorded t the time of ech output estimtion. n ttempt ws mde to estlish sinus rhythm within few dys of the crdic output estimtion. Sinus rhythm ws chieved in 2 ptients. When sinus rhythm ws estlished digitlis therpy ws discontinued. fter conversion 8 ptients received quinidine sulphte 1 2 g. dily, nd 6 received potssium chloride 8 g. dily given in divided doses. The remining 6 received no drug therpy. Digitlis therpy ws continued in the group of 1 ptients in whom sinus rhythm ws not chieved. rdic output ws mesured gin pproximtely one week fter conversion or ttempted conversion. In 6 ptients in whom sinus rhythm hd een estlished third estimtion of crdic output ws mde 6-1 weeks fter conversion. t this time tril firilltion hd ppered in 3, while in the others sinus rhythm hd een mintined. RESULTS Figure I shows the results of output studies in 2 ptients efore nd fter conversion to sinus rhythm. In 18 ptients the output ws incresed nd in 2 it remined unchnged. The verge * In receipt of Royl Victori Hospitl Reserch Fellowship. 719

2 72 HLMOS ND PTTERSON TBLE I DETILS OF 2 PTIENTS IN WHOM ONVERSION TO SINUS RHYTHM WS SUESSFUL Ptient, Durtion Before conversion fter conversion ge (yr.), nd of sex.f..o. Stroke vol..o. Stroke vol. H.R. (1./minm) (ml.) H.R. (/min.) (ml.) M.T. R.S. 52 M 3 wk M.F. 49 F 6 mth Q R.T. 32 M 3 yr Q J.T. 31 F 3 yr H.T. 65 M 2 yr Q M.M. 43 F 3 yr Q S.R. 4 M 5 yr Q K.O. 66 F 2 mth K O.F. 5 M 1 mth Q.R. 41 M 18 mth Q J.S. 58 F 16 yr K M.G. 53 F 6yr Q W.G. 52 M I yr K S.L. 52 M l yr K.B. 37 M 3 mth K W.M. 42 M 2 mth S.P. 61 F 1 mth K J.. 56 M 3 yr M.K. 39 F 18 mth W.. 64 M 1 yr O., crdic output; H.R., hert rte;.f., tril firilltion; M.T., mintennce drug therpy; Q, quinidine 1 *2 g. dily; K, potssium chloride 8 g. dily. TBLE II DETILS OF 1 PTIENTS IN WHOM ONVERSION TO SINUS RHYTHM WS UNSUESSFUL Ptient, Durtion Before conversion fter ttempted conversion ge (yr.), nd of sex.f. (yr.) H.R..O. Stroke vol..o. Stroke vol. I._H.R. (1./min.) (ml.) H.R. (1./min.) (ml.) M.T. R.P. 5 F D M.H. 42 F D R.. 32 F * M.F. 47 F D N.D. 53 F D S.W. 4 M G.S. 56 M S.D. 43 F T.W. 66 M D S.O. 54 M *9 52 D.O., crdic output; H.R., hert rte; M.T., mintennce drug therpy; D, digoxin -25 mg. twice dily. increse in crdic output following conversion ws 53 per cent of the pre-conversion vlue. In one (No. 1) the output incresed from 3-6 to 11 5 l./min.: this ptient hd repet output mesurement 1 weeks lter nd vlue of ws otined. linicl investigtion reveled no cuse for the high crdic output. Thyroid hyperctivity ws excluded. Figure lb shows the chnge in stroke volume following the estlishment of sinus rhythm. In 19 of the 2 ptients there ws n increse in stroke volume. In one there ws little chnge from the

3 EFFET OF TRIL FIBRILLTION ON RDI OUTPUT 721. ' I- 4c U o s. I-- 1 so B /-z w U,o s,o, <5 ~~~ FIG. 1.-) The crdic output efore () nd fter () successful conversion from tril firilltion to sinus rhythm. (B) The stroke volume. () The chnge in stroke volume expressed s percentge of the resting vlue. l '.94 i 1 I I- u 4 o J 1- O 5 VI B FIG. 2.-() The crdic output efore () nd fter () filure to convert tril firilltion to sinus rhythm. (B) The stroke volume. () The chnge in stroke volume expressed s percentge of the resting vlue. z It ul. 4c I-- VI I pre-conversion figure. In Fig. I the increse in stroke volume hs een clculted s percentge of the resting stroke volume. Of the 3 ptients with tril firilltion who were given direct current shock in n ttempt to olish the rrhythmi, tril firilltion persisted in 1. Fig. 2 shows the crdic output mesurements in these ptients otined efore nd fter ttempted conversion. In ll of them there ws little chnge in crdic output. Fig. 2B shows the stroke volume nd Fig. 2 the chnge in stroke volume expressed s percentge of the resting stroke volume. There is little chnge in stroke volume in this group. Three ptients in whom sinus rhythm hd een estlished ut in whom tril firilltion hd reppered hd further mesurement of crdic output mde (Fig. 3). The reppernce of tril firilltion ws ccompnied y fll in crdic output nd stroke volume to ner the pre-conversion level. In 3 ptients in whom sinus rhythm hd een mintined the crdic output nd stroke volume remined ner the level otined one week fter conversion to sinus rhythm. The results re shown in Tle III. Of the 2 ptients in whom sinus rhythm ws chieved, 8 were given quinidine sulphte nd 6 potssium chloride s mintennce therpy. The remining 6 received no drug therpy. Fig. 4 shows the crdic output nd percentge increse in stroke volume occurring in these three groups. TBLE III DETILS OF 6 PTIENTS STUDIED TmIRD TmE, 6 TO 8 WEEKS FTER ONVERSION; 3 PTIENTS HD REVERTED TO TRIL FIBRILLTION Ptients Before conversion fter conversion 6-8 weeks lter.o. Stroke.O. Stroke.O. Stroke H.R. (./min.) vol. (ml.) H.R. (./min.) vol. (ml.) H.R. (1./min.) vol. (ml.) Rhythm M.G F. I.S F. H.T *9 74 S.R..R F. R.T. 75 4* S.R. J S.R..O., crdic output; H.R., hert rte;.f., tril firilltion; S.R., sinus rhythm.

4 722 i ạ 1* I- U u HLMOS ND PITERSON The crdic output nd stroke volume increse occurring fter conversion to sinus rhythm re unffected y the therpy employed. > '4. z o X FW s O //,\\\\% DISUSSION /Ss"; Ferrer et l. (1952) nd Wde et l (1952) mesured the crdic output in ptients with tril firilltion nd in ptients I 1. c c in sinus rhythm. They found the men FIG. 3.-() The crdic output efore (), fter (), nd crdic output to e higher in the ltter some time fter (c) conversion of tril firilltion group. ll suffered from rheumtic hert to sinus rhythm. The dotted line indictes rever- disese nd the two groups hd similr sion to tril firil[ltion in 3 ptients. (B) The stroke volume. ( ) The chnge in stroke volume degree of clinicl disility. They concluded expressed s peroentge of the resting vlue. tht the crdic output ws reduced in ptients with tril firilltion. However, similr clinicl disility does not necessrily men similr himod) ynmic disturnce. Ptients with tril firilltion my e more ffected y the disese process thn ptients in sinus rhythm nd thus the difference in crdic output in the two groups might not e due to the presence or sence of tril firilltion lone. Kory nd Meneely (1951) nd Hecht, Osher, nd Smuels (1951) studied 8 nd 15 ptients respectively, mesuring the crdic output efore nd fter conversion to sinus rhythm y quinidine sulphte. They demonstrted n increse in resting crdic output in the mjority fter conversion to sinus rhythm. This increse ws more mrked when the crdic output fter exercise ws studied. Hnsen, Mclendon, nd Kinsmn (1952) studied 14 ptients. No chnge ws found in 5 nd there ws n increse of less thn 1 per cent in the remining 9. QUINIDINE K..L. NIL Smll increses in crdic output fter conversion to ' lo.7/ sinus rhythm hve lso een noted y Storstein nd / / Tveten (1955), Broch nd Muller (1957), nd Gilert et!. (1963) > j ; These results indicte some increse in crdic output fter conversion from tril firilltion to sinus rhythm. Quinidine ws used for conversion nd for mintining u sinus rhythm. The prt plyed y quinidine in the,=; B incresed crdic output is uncertin. 1.z QUINIDINE K..L. NIL More recently, Grettinger, rleton, nd Muenster (1963) studied 21 ptients. With one exception no < 5 /Zg / increse in crdic output ws found though the stroke //s volume did increse. In recent pprisl of tril,1// trnsport function Burchell (1964) ws not impressed y o>o t theevidence.. for decrese in crdic output following. the. onset [ of tril firilltion. He quotes one cse of e tril firilltion developing during crdic ctheteriz- FIG. 4.-Theupperpnel shows thechngein tion where no chnge in oxygen sturtion of mixed crdic output efore () nd fter () con- venous lood occurred in spite of considerle increse version of tril firilltion to sinus in hert rte. rhythm. The lower pnel shows the chnge Our results demonstrte well-mrked rise in the in stroke volume expressed s percentge of the resting figure. () Ptients given resting crdic output of ptients with tril firilltion qtssiune suhlporhidte. (c) Ptients ngtivren following conversion to sinus rhythm. The verge inceiving ny drug therpy. crese in these 2 ptients ws 53 per cent. When tril

5 EFFET OF TRIL FIBRILLTION ON RDI OUTPUT firilltion reppered in 3 ptients the crdic output returned towrds pre-conversion levels. In 3 ptients studied in whom sinus rhythm persisted the crdic output remined rised. In the 1 ptients in whom the ttempted conversion filed the verge chnge in crdic output ws 2-7 per cent. The only difference etween the tretment of the ptients who converted to sinus rhythm nd those who did not ws tht the ltter received digitlis. Tle I indictes tht the hert rte in the ptients with tril firilltion who were receiving digitlis therpy ws similr to the hert rte fter conversion to sinus rhythm. The stroke volume shows considerle increse fter conversion. The increse in crdic output ws not relted to drug therpy given fter conversion. We hve found tht similr increses occur whether ptients receive quinidine sulphte, potssium chloride, or no therpy following conversion. SUMMRY The resting crdic output ws estimted in 3 ptients with tril firilltion efore nd fter ttempted direct current conversion. n increse in output nd stroke volume ws noted in the 2 ptients in whom sinus rhythm ws estlished. The men increse in output ws 53 per cent. This increse ppers to e independent of drugs. No significnt chnge in the crdic output ws noted in 1 ptients in whom direct conversion filed. When, fter successful conversion, tril firilltion recurred crdic output fell to pre-conversion levels. We wish to thnk Dr. J. F. Pntridge for helpful criticism nd for permission to study these ptients who were under his cre. REFERENES Broch,. J., nd Muller,. (1957). Hemodynmic studies during uriculr firilltion nd fter restortion of sinus rhythm. Brit. Hert J., 19, 222. Bruce, T.., nd Shillingford, J. P. (1962). The norml resting crdic output: seril determintions y dye dilution method. Brit. Hert J., 24, 69. Burchell, H. B. (1964). clinicl pprisl of tril trnsport function. Lncet, 1, 775. Ferrer, M. I., Hrvey, R. M., thcrt, R. T., oumnd,., nd Richrds, D. W., Jr. (1952). Hemodynmic studies in rheumtic hert disese. ircultion, 6, 688. Gilert, R., Eich, R. H., Smulyn, H., Keighley, J., nd uchincloss, J. H. (1963). Effect on circultion of conversion of tril firilltion to sinus rhythm. ircultion, 27, 179. Grettinger, J. S., rleton, R.., nd Muenster, J. J. (1963). ircultory consequences of chnges in crdic rhythm produced in ptients y trnsthorcic direct-current shock. (strct). J. clin. Invest., 42, 938. Hnsen, W. R., Mclendon, R. L., nd Kinsmn, J. M. (1952). uriculr firilltion: hemodynmic studies efore nd fter conversion with quinidine. mer. Hert J., 44, 499. Hecht, H. H., Osher, W. J., nd Smuels,. J. (1951). rdiovsculr djustments in sujects with orgnic hert disese efore nd fter conversion of tril firilltion to norml sinus rhythm. J. clin. Invest., 3, 647. Kory, R.., nd Meneely, G. R. (1951). rdic output in uriculr firilltion with oservtions on the effects of conversion to sinus rhythm. J. clin. Invest., 3, 653. Lown, B., mrsinghm, R., nd Neumn, J. (1962). New method for terminting crdic rrhythmis; use of synchronized cpcitor dischrge. J. mer. med. ss., 182, 548. Storstein, O., nd Tveten, H. (1955). The hemodynmic effect of restoring norml sinus rhythm in ptients with uriculr firilltion. Scnd. J. clin. L. Invest., 7, 167. Wde, G., Werko, L., Elisch, H., Gidlund,., nd Lgerlof, H. (1952). The htmodynmic sis of the symptoms nd signs in mitrl vlvulr disese. Qurt. J. Med., 21,