Dias, J. C. Pinto

Kloetzel, Kurt

English

Cadernos Espinosanos (E-Journal)

Rev. lnst. Med. trop. Si"ío Pa1i/.o JO(S):158-162, rnaio-}11,11.ho, 1968 UDC 616.937.3-091 616.987.3-092.9 THE PROGNOSTIC V ALUE OF THE ELECTROCARDIOGRAPHIC FEATURES OF CHRONIC CHAGAS' DISEASE J. e. Pinto DIAS ( 1 ) and Kurt KLOETZEL SUMMARY The Authors appraise the prognostic value of some of the electrocardiographic signs in subjects with a positive complement fixation test for Chagas' infection. Data on a non-selected group of individuais followed for a period of 18 years is analysed. The fatal cases among this material died on average 6, 7 years after the ECG was recorded. ln addition the :Authors report findings on a group of 566 fatal cases of T. cruzi infection, submitted to an electrocardiographic examination at variable times before death. The paucity of findings in the non-fatal cases, which disagrees with some other repQrts, c;,an probably be explained by the pro-longued follow-up. Righ bundle branch block, primary S-T changes and multifocal ventricular premature beats were significantly more frequent in the fatal group, but these features are compatible with survival for long periods of time. The presence in Chagas' disease of complete A-V block, left bundle branch block and atrial fibrillation or flutter is suggestive of a reduced life-expectancy, 91%, 100%, and 80% of the subjects respectively presenting these abnormalities expiring within 10 years, and 51%, 76% and 50% within 5 years. INTRODUCTION MATERIAL AND METHODS As reported elsewhere by the present Au-thors 3, the prognosis of infection by Trypa-nosoma cruzi seems less dramatic than sugges-ted by the hospital records, when a non-selected population from within the endemic areas is investigated. Thus, in a group of 1,088 individuais presenting a positive com-plement fixation test for Chagas' disease registered during 1949, 87.7% of those under 30 at the heginning of the follow-up period, and 70.9% of those above that age remain alive in 1967. The Authors availed themselves of the cli-nica! and laboratorial data accumulated since 1943 by the late Dr. Emmanuel Dias at the "Centro de Estudos do Instituto Oswaldo Cruz", in Bambuí. ln order to meet the re-quirements of strict non-selection of the human material, only the individuais regis-tered during 1949 were chosen for this study, since during that year a far-reaching survey was carried out in the district. To date 176 deaths have been reported in the 1,088 sero-positive individuais. During the intervening 18 years, however, 299 subjects moved to other localities, and 152 cannot be located 3 • For ali practical purposes this group has to be considered similar to the entire material. Hence positive serology is definitely not an indication of reduced life expectancy. ln the present paper the Authors will endeavo-ur to appraise the prognostic implications of the electrocardiographic abnormalities found m Chagas' infection. The analysis of Table II is based upon 387 ECG'S made on admission, in 1949. The "non-fatal" group is made up of individuals Supported in part by a grant from the 'World Health Organization (Division of Parasitic Diseases) (1) Instituto Oswaldo Cruz, Bambui (Minas Gerais, Brasil) 158 () Cl DIAS, J. C. P. & KLOETZEL, K. - The prognostic value of the electrocardiographic features of chronic Chagas' disease. Rev. Inst. Med. trop. São Paulo 1-0:158-162, 1968. still alive and residing in the county. The subjects cornprising the "fatal" group died on average 6.7 years after the ECG was recorde d. ln addition the initial electrocardiographic findings for 566 seropositive indi.viduals dying in Barnbuí since 1943 have been analysed, death frorn acute Chagas' disease having been exclused frorn the series. The electrocardiographic features in chro-nic Chagas' disease having been cornpetently described in a series of papers 1 • 2 , 4 • 5 • 6 , 7 , the present Authors will lirnit thernselves to an appraisal of the evolution and prognostic significance of sorne of these signs, because of their frequency, or by virtue of their unquestionable irnportance in estirnating the risk run by the individual with Chagas' infection. Whereas Table II thus cornprises only sorne of the electrocardiographic find-ings, a "normal" ECG irnplied not only in the absence of these features, but of the following as well: P and Q RS changes ( other than of intraventricular block), cardiac hy-pertrophy or strain, axis deviation, low vol-tage of the QRS cornplex, atrial prernature beats, or electrically silent areas of the rnyocardiurn. A P-R interval up to 0.20 seconds, a shift ir. the S-T segrnent up to 1 rnillirneter, sinus arrhythrnia, and unifocal ventricular prerna-ture beats were considered normal. A QRS typical of bundle branch block was not included as such in the table when complete auriculo-ventricular block was also present. A configuration of bundle brnnch block with a QRS cornplex between 0.10 and 0.12 seconds was considered to represent "incornplete bundle branch blÓck". RESULTS Table I reveals a substantial difference in age distribution between the fatal and non-fatal cases of the 1949 group, with a pre-dorninance in the latter of the individuais helow 30. Table II lists sorne of the more pertinent electrocardiographic findings in the 3 hurnan groups analysed. While complete RBBB is listed according to whether this is an isolated finding or occurs associated with other electrocardio-graphic abnorrnalities, this subdivision is ornitted for the other signs. Briefly, in only 4.7% of the ECG'S presenting rnultifocal ventricular prerriature beats was this the sole· abnorrnality to be found, the rno_st cornrnon association being with complete RBBB, pre-sent in 52.7% of the cases. Prirnary S-T changes were isolated findings in · only 5,5% of the instances where they were foimd, and atrial fibrillation or flutter occurred alone in 9.8%, TABLE I Age distribution of the human material: individuals with a positive . CFT for Chagas' infection, and submitted to an electrocardiogram at start of . follow-up period 1949 group All fatal cases Age (years) Non-fatal Fatal Number / % Number 1· % Number % .. 0-29 140 55.0 39 29.3 202 35.8 30-49 83 32.9 55 41.4 265 46.7 Over 50 31 12.1 39 29.3 99 17.5 . ' 159· H O'l. o Findings Total ECG's Normal ECG's 1st. or 2nd. degree A-V block Complete A-V block Incomplete RBBB Complete RBBB-all cases Complete RBBB-isolated Complete RBBB-associated with other signs ! Incomplete LBBB Complete LBBB Primary S-T changes Mu!tifocal ventricular premature beats Atrial fibrillation or flutter No. of abnormalities per abnormal EKG o TABLE II Some of the electrocardiographic findings in the human material o 1949 group Non-fatal Fatal" 0-4 No. \ % No. 1 % No. 1 % 254 100.0 133 100.0 334 100.0 155 61.0 37 27.8 20 6.0 7 2.8 4 3.0 15 4.5 o o.o 10 7.5 54 16.2 9 3.5 3 2.3 6 1.8 39 15.4 57 42.8 156 46.9 26 10.2 18 13.6 27 8.2 13 5.2 39 29.2 129 38.7 o o.o 1 0.8 13 3.9 o o.o 2 1.5 21 6.3 4 1.6 15 11.3 79 23.7 13 5.1 53 40.0 196 59.0 o o.o 7 5.3 40 12.0 1.5 - 2.0 2.1 -* - Death on average 6.7 years after the recording ** - Average follow-up of 13'.2 years All fatal cases Years before death 1 5-9 1 No. 1 % 127 100.0 28 22.1 1 0.8 16 12.6 7 5.5 60 47.3 18 14.3 42 33.0 1 0.8 3 ·.· 2.4 16 12.6 54 42.5 9 7.1 1.6 ... -1 Over 1 No. l 105 33 4 3 1 51 26 25 -o i, -~;., o 17 .. : - 38 :·: 5 1.5 10 ** % 100.0 31.5 3.8 2.9 1.0 48.5 24.8 23.7 o.o o.o 16.2 36.2 4.8 -ti H > "[/) ~-,., o "-< ~. e, 0 ('l g- ;d ~ go "' ~ :is ~- t-< "'o "'t<J ~..., !ll N t<J ?J_t-< "' "r ~I ;~ "'"' ?-, 'O ,., ~o o l)Q "'~ . o"' tlJ tt .,, " o 1:1< Q lll ~2' o "' ... o o ... ... <+ '-" ~ '{' "' ... (D m-t,.; (D - ~ f-',., <O o a," ~~ o. õ' l)Q ,., lll 'O e: " ~ lll <+ ~ ,., (D "' o M DIAS, J. C. P. & KLOETZEL, K. - The prognostic value of the electrocardiographic features of chronic Chagas' disease. Rev. Inst. Med. trop. São Paulo l<l:158-162, 1968. DISCUSSION Table II indicates that the simultane.ous occurrence of two or more electrocardiogra-phic abnormalities in quite frequent in Chagas' disease, not only in the fatal cases but in the subjects who survived the 18 years since the first recording. A comparison between the first and the last column shows that as early as 13 years before death, on average, electrocardiographic changes are clearly much more frequent in the fatal than in the non-fatal group. The question might be raised whether this diffe-rence should not be attributed to the diffe-rence . in age distribution between the two groups, age rather than Chagas' disease being responsible both for a high death rate and for the increased likelyhood of finding abnormal ECG'S. The Authors believe that the in-fluence of age on these findings is minimal. Under no circumstance would one expect to find 70% of abnormal ECG'S in the absence of Chagas' infection, even in older age groups. Moreover, the frequency of RBBB likewise points to the sarne conclu-sion: it has been sai d 8 that a region endemic for Chagas' disease could be recognized by a prevalence of RBBB higher than 1.5-2.0%, indicating how specific a feature this is. ln addition, in T. cruzi infection RBBB is frequendy associated with other electrocar-diographic abnormalities 7, likewise a com-monplace finding in our material. Thirdly, a remarkable disproportion between the pre-valence of right and left bundle branch block in an exposed population is said to be characteristic of Chagas' myocarditis 8 , the ratio in our own material being dose to 28:1. The electrocardiographic findings in our 11011-fatal group are indeed unremarkable when compared to other data in literature4 • 5 ; for instance, LARANJA et al. 4 and PORTO 5 respectively reported RBBB in 27.3% and 46.8% of their non-fatal cases. ln our opinion this disagreement must probably be ascriped to the fact that we were privileged to work with non-selected human material. Mo-reovei:, our follow-up period of 18 years is substantially higher than in other reports, many of the patients with severe myocarditis having already dropped out of the non-fatal group in the intervening years. Omitting discussion of partial auriculo-ventricular block, as well as incomplete RBBB, both features apparently just as common in severe as in benign Chagas' disease, we will briefly analyse the prognostic significance of some of the findings listed in Table II. Complete auriculo-ventricular block: This complication has been taken as an indication of bad prognosis in Chagas' disease 1 • 5 • Table II illustrates an increasing incidence in the years preceding death: 91'% of the subjects in our material did not survive 10 years after complete A-V block was recorded, and 51'% died within 5 years. Left bundle branch · block: Our data demonstrate that no patient presenting · this electrocardiogra-phic feature survived more than 10 years, 76% expiring with in 5 years after the de-monstration of the lesion. Atrial fibrillation and flutter: This sign has likewise been considered of 0minous prognosis in Chagas' myocarditis 1 • 2 • 5 • 7 • Ten-year survival was 20%, and 5 year survival was 50% in our material. The above features, useful in predicting prognosis in T. cruzi infection when present in the ECG, are too infrequent a finding, and thus cannot be used as sole criteria. Most of the other common electrocardiogra-phic abnormalities are likewise more fre-quent in fatal cases, but develop too early to afford an insight into the chances for survival. ln our material of 1949 RBBB is almost 3 times as common in the fatal cases as in those who survived for 18 years; un-questionably its presence worsens prognosis. However, as Table II indicates, RBBB is compatible with rather long survival, in keeping with the statement 8 that this feature precedes the other electrocardiographic ab-normalities during the evolution of Chagas' myocarditis. Our data further demonstrate that the prognosis of RBBB is less severe when this is the sole abnormality to be found in the ECG. Similar conclusions can be drawn with respect to primary S-T changes and multifo-cal ventricular premature beats. ln addition, the data of Table II seem to disclaim the statement '5• 7 that the latter feature is to be taken as an ominous sign. While the analysis was handicapped by the difficulty in securing strictly comparable .161 DIAS, J. C. P. & I~LOETZEL, K. - The prognostic value of the electrocarâiographic features of chronic Chagas' disease. Rev. Inst. Med. trop. São Paulo l<l:158-162, 1968. ,. control groups, the Authors have confessed clsewhere 3 their failure in proving that the rnortality risk increases in the presence of a positive compleoent fixation test, whereas it is undeniable that life expectancy is redu-ced in Chagas' myocarditis. One approach for demonstrating this fact is to compare the age dependent mortality of the Bambuí dis-trict ( an estimated 24.5% overall prevalen-ce of positive CFT) with the data in Table I. Taking all deaths reported in the town during 1963-66, excluding those before the age of 10 (since the youngest subject in our fatal group was 11 years old), we find that 10% were in the 10-29 age group, 32% were 30-4,9 years old at time of death, and 58% were older than 50, a distribution quite clifferent from that in Table I. RESUMO l mplicações prognósticas do eletrocardi.ogra-ma na doew;a de Chagas crônica Os Autores examinam o valor prognóstico ele algumas elas anormalidades do eletrocar-diograma em indivíduos com reação de fi. xação do complemento positiva para infec-ção chagásica. São analisados os dados co-lhidos em um grupo humano não selecionado, c seguido durante um período de 18 anos. As mortes neste material ocorreram em mé-dia 6,7 anos após a realização do eletrocar-diograma. São ainda descritos os achados em um grupo de 566 casos fatais submetidos a êste exame em diferentes períodos antes do óbito. A pobreza dos ach2clos no grupo de sobreviventes, fato que discorda de outras publicações, deverá ser explicado pelo longo período de segmento. Bloqueio de ramo di-reito, alterações primárias de S-T e a extra-sistolia ventricular multifocal são achados mais freqüentes no grupo de fatais, entre-tanto, são compatíveis com a sobrevida clu-162 rante período de tempo prolongado. A pre-sença na doença de Chagas de bloqueio A-V completo, bloqueio de ramo esquerdo e da fibrilação auricular ou do flutter indica mau prognóstico, re~pectivamente 91 %, 100% e 80% dos indivíduos falecendo dentro de 10 anos, e 51 %, 76% e 50% dentro de 5 anos após êstes achados. REFERENCES 1. BRASIL, A. - Evolução e prognóstico da doença de Chagas. Arq. Bras-il. Cardiol. 18: 365-380, 1965. 2. DIAS, E.; LARANJA, F. S. & NOBREGA, G. - Doença de Chagas. Mem. Inst. Oswaldo Cri,z 43 : 495-580, 1945. 3. KLOETZEL, K. & DIAS, J. C. P. - Mortality in Chagas' disease: life-table for the period 1949-1967 in an unselected population. Rev. Inst. Med. trop. São Pai,lo 10:5-8, 1968. 4. LARANJA, F. S.; DIAS, E.; NOBREGA, G. & MIRANDA, A. - Chagas'disease. A clinicai, epidemiologic and pathologic study. Circula-tion 14:1035-1060, 1956. 5. PORTO, C. C. - Contribidção do eletrocar-diograma no prognóstico e evolução da doen-ça de Chagas. Tese. Belo Horizonte, 1963. 6. RODRIGUES, N.; FERREIRA, E. P. & DIAS, J. C. P. - O eletrocardiograma na doença de Chagas crônica. Estudo de 100 casos. A rq. Brasil. Cardiol. 19: 225-234, 1966. 7. ROSENBAUM, M. B. & ALVAREZ, A. J. -The electrocardiogram in chronic chagasic myocarditis. Amer. Heart J. 50:492-527, 1955. 8. ROSENBAUM, M. B. & CERISOLA, J. A. -Epidemiolo;:::i:J. de la enfermedad de Chagas en la RepúbUca Argentina. Hospital (Rio) 60:75-100, 1961. Recebido para publicação em 10/7/1967. 

The prognostic value of the electrocardiographic features of chronic CHAGAS’ disease

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The prognostic value of the electrocardiographic features of chronic CHAGAS’ disease

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