Utilidad de los bloqueadores de los receptores plaquetarios IIbIIIa en síndromes coronarios agudos / Usefulness of the IIb- IIIa platelet receptor blockers in the acute coronary syndromes

Las manifestaciones clínicas de los síndromes coronarios agudos son un continuo entre la angina de pecho inestable e infarto agudo al miocardio (AIM) sin supradesnivel del segmento ST hasta el IAM con supradesnivel de ST y la muerte súbita. La trombosis coronaria y el rol que juegan las plaquetas en el síndrome coronario agudo son factores etiopatogénicos determinantes. Los procedimientos intervencionales coronarios pueden despertar igual respuesta vascular y plaquetaria. Los bloqueadores de los receptores plaquetarios IIbIIIa se han incorporado a los últimos años como un grupo de drogas alternativas que se suman al tratamiento convencional de los síndromes coronarios agudos en un subgrupo de pacientes. En nuestro medio los bloqueadores IIbIIIa disponibles son abciximab, tirofiban y eptifibatide. Existe un volumen creciente de estudios clínicos que se han publicado y se revisan en esta presentación. En términos generales durante la realización de procedimientos intervencionales coronarios el agente más estudiado es abciximab, con efectos benéficos comparativos superiores a tirofiban y eptifibatide administrado en forma previa o inmediatamente antes de la angioplastia (asociado o no a stent coronario) en pacientes que tienen riesgo de oclusión aguda por cuadro clínico o anatomía desfavorable. Eptifibatide con dosis de carga mayores ha demostrado resultados favorables en estudios recientes. En el grupo de pacientes con angina de pecho inestable e IAM sin supradesnivel del segmento ST, en quienes no se ha considerado una intervención angioplástica inmediata, tirofiban y eptifibatide representan una buena alternativa, especilmente para aquellos pacientes que demuestran ser refractarios a las medidas antiisquémicas habituales o tienen marcadores séricos, como troponina T e I elevados. Abciximab no está indicado en este contexto clínico

El Comité Asesor Internacional / The International Advisory Committee

The Editors of Revista Médica de Chile are taking steps aimed to improve the "visibility" of this journal and to stimulate local and foreign authors to submit better original articles, appealing to a broader and international readership. Until now, the journal's editorial policy has been to stress its educational role, focused in Chilean readers and authors. In the recent years, an increasing number of research articles is being received, including manuscripts from North America, Europe and other Latinamerican countries. This is explainable, in part, by the fact that this journal is indexed in MEDLINE, ISI (Current Contents/Clinical Medicine) and several other major databases. The Revista is also one of the oldest medical journals in the world, published since 1872. In this issue of the Revista we welcome the new members of an "International Advisory Committee", with prominent physicians, scientists and teachers from the U.S.A. and Europe. They accepted to advise the Editors in their task, to submit review articles, state-of-the-art or position papers on topics of their own interest, and to help in the assessment of some manuscripts. We thank them warmly for their enthusiastic response to our invitation

La autoría en los manuscritos publicados en revistas biomédicas / Authorship in manuscripts published in biomedical journals

Multiauthorship shows an increasing trend in biomedical and other scientific journals. A main concern for editors, reviewers and readers is to find out whether all individuals enlisted as authors actually fulfill criteria for authorship as defined in the document "Uniform Requirements for Manuscripts Submitted to Biomedical Journals". Revista MÄdica de Chile is addressing this relevant topic with a combined strategy: (1) A retrospective analysis of the manuscripts published in the recent decades in the Revista will quantify and illustrate the local trend in multiauthorship; (2) A "Statement of accountability": signed by all authors in manuscripts submitted to the Revista, is in use since 1997; and (3) A new form of this "Statement of accountability" requests all authors to identify their personal involvement in the work represented by the manuscript. This information will be available to every person participating in the editorial assessment of the manuscript (editors and external reviewers) but during a trial period of six months authors will be allowed to object the publication of this data, stating the reasons for this objection. After six months the editors will evaluate the information collected and the self-declared role of every author enlisted. The terms "Authors" and "Main author" will continue being used to designate participants because "contributor" (replacement alternative proposed by Rennie et al., currently in use by several leading general medical journals) has a different main meaning in Spanish than in English and it might have a negative effect

Síndrome coronario agudo asociado a neumonía por chlamydia pneumoniae, en dos casos / Acute coronary events associated to chlamydia pneumoniae infection: report of 2 cases

Epidemiological and clinical studies attribute to Chlamidia pneumoniae infections a pathogenetic role in atherosclerotic vascular lesions. We report two patients in whom this infection was followed by acute coronary events. A 51 years old male presented with a right lower lobe pneumonia and a positive immunofluorescence serology for Chlamidia pneumoniae, with a IgM titer of 1/64. On the second day of evolution, he experienced an acute myocardial infarction. A coronary arteriography demonstrated a 80 percent obstruction of anterior coronary artery and an angioplasty was performed. A 84 years old male was admitted with a right lower lobe pneumonia and a positive serology for Chlamidia pneumoniae, with an IgM titer of 1/32. On the fourth day of evolution, he developed unstable angina with electrocardiographic changes. A coronary arteriography demonstrated a three vessel disease. In both cases, a tight chronological association was observed between Chlamidia pneumoniae infection and acute coronary events

Artículos de investigación / Research articles

Since 1973, Revista Médica de Chile has classified biomedical and clinical prospective research papers in a Section named Research Articles, while purely clinical and retrospective studies were classified into another Section, named Clinical Experiences. This distinction seems no longer necessary, because both types of manuscripts are subjected to a uniform external peer-review system and their intrinsic quality is not a distinctive feature. Furthermore, the name of Sections where similar papers are classified by the major general clinical medicine journals is clearly non-uniform. Therefore, Research Articles and Clinical Experiences will from now on be included into a single Section: Research Articles

Heparina subcutánea durante el primer trimestre del embarazo en mujeres con prótesis valvulares cardíacas / Subcutaneous heparin during the first trimester of pregnancy in women with prosthetic heart valves

Background: Oral anticoagulation therapy in pregnant women with prosthetic heart valves is associated with a greater risk of abortion, fetal malformations and thromboembolic complications. Aim: To assess the use of subcutaneous heparin in women with pregnancies of less than 12 weeks as an alternative to oral anticoagulation therapy. Material and methods: Pregnant women were admitted to the hospital and coumarinics were replaced with not fractionated subcutaneous heparin in a dose of 10,000 IU every 12 hours, aiming at prolonging partial thromboplastin time, 2 or 2 1/2 times. During the hospitalization period, women were taught about the heparin injection technique. Coumarinics were restarted after week 13 of pregnancy until 10 days prior to the delivery date in which women were again admitted to the hospital and intravenous heparin was used until the delivery. Results: Between 1991 and 1997, this protocol was used during ten pregnancies in seven women aged 19 to 36 years old. Five had a Starr-Edwards prosthesis, one had a mitral Bjsrk-Shilley prosthesis and one, a double prosthesis (mitral Starr-Machi and aortic St Jude). Subcutaneous heparin was started in the fifth week of pregnancy in 1 case, in the sixth week in seven and in the seventh week in two. There was no maternal mortality and one transient ischemic attack without sequelae. One non compliant patient had a Bjsrk Shilley prosthetic valve dysfunction that required a valve replacement at the twelfth week of pregnancy and she had a spontaneous abortion at week 15. Other patient had a pneumonia at week 37 and gave birth to a stillbirth. There were no fetal malformations. Conclusions: This therapeutic protocol can be used among Chilean patients, but must be restricted to compliant women and a strict surveillance must be maintained

Angioplastia coronaria e implante de stent a través de la arteria radial: caso clínico / Coronary angioplasty and stent placement through the radial artery: report of case

Coronary angiography and percutaneous treatment of stenotic lesions have expanded in the last few years, due to availability of better diagnostic equipment. The femoral technique applied to this aims has prevailed, considering its efficacy, safety and wide acceptance. Since the beginning of this decade, an alternative access has been developed, in relation to miniaturization of the required elements to perform coronary diagnostic and therapeutic procedures. This new radial artery access is supported by multiple reports from many centers around the world that are increasingly using the technique. With this access it is possible to perform all the regular procedures done regularly through the femoral route. This case report illustrates a coronary angiography study through the radial access, followed by a stent implantation, through the same route

Infarto agudo del miocardio: una enfermedad en plena evolución de conocimientos / Acute myocardial infarction: a disease in evolving knowledge

Important advances in the knowledge of pathophysiology and management of acute myocardial infarction have occurred lately. The results of large multicentric randomized trials allowed the introduction of new diagnostic techniques, patient stratification tools, drugs and treatment strategies to clinical practice. As a result, a significant reduction in mortality has been achieved. However there is a great variation in the adoption of the new diagnostic and therapeutic recommendations in different countries. In this issue of Revista MÄdica de Chile, a registry of patients with acute myocardial infarction treated in Chile between 1993 and 1995, is reported. The mean age of patients (62 ñ 12 years old), the proportion of males (74 percent) and the prevalence of risk factors is similar to that reported in series from developed countries. Similarly, 33 percent of patients received thrombolytic therapy, and the pattern of drug use was comparable. The 13.4 percent global mortality can be improved. An early consultation to health services when an acute myocardial infarction is suspected should be encouraged in the population. Likewise, treatment norms for health institutions should be devised

Niveles de homocisteína en adultos sanos chilenos / Serum homocysteine levels in healthy chilean adults

Background: Hyperhomocysteinemia is a newly recognized cardiovascular risk factor that is present in 10 to 20percent of European and North American individuals. Aim: To measure homocysteine levels in healthy adults in Chile. Subjects and methods: Serum homocysteine levels were measured in healthy adults using a fluorimetric HPLC method. Folic acid, vitamin B12, serum lipids, creatinine and glucose were also assessed. All subjects answered a dietary habits questionnaire. Results: One hundred twenty eight subjects (90 female) aged 22 to 78 years old were studied. Homocysteine levels were 9.7 ñ 6.0 and 7.0 ñ 3.1 µmol/l in men and women respectively (p< 0.001). Folic acid levels were 6.1 ñ 2.7 and 6.1 ñ 2.9 ng/ml in men and women, and 24percent of individuals had values below 4 ng/ml. Vitamin B12 levels were 393 ñ 147 and 393 ñ 163 pg/ml in the same groups. There was a negative correlation between homocysteine and folic acid levels and a positive correlation between homocysteine and creatinine levels. Conclusions: Homocysteine levels in healthy Chilean individuals are similar to those reported abroad. Low folic acid levels were found in 24percent of subjects

¿Es la metodología de nuestros trabajos de investigación esencialmente inferior a la de estudios similares en revistas que se publican en inglés? / Is methodology in our original articles essentially inferior to similar papers published in english-speaking journals?

Randomised controlled trials reported in languages other than English are generally excluded from systematic reviews. This exclusion is often based in the biased opinion that the strictness of methodology and the quality of assessment of the results are essentially inferior to similar articles reported in English. A study published in 1996 in The Lancet compared completeness of reporting, design characteristics, and analytical approaches of 229 randomised controlled trials published in English, French, German, Italian or Spanish, between 1989 and 1994. Eight of those trials had been published in Revista MÄdica de Chile. No significant differences were found in any single item analysed, between trials published in English and in other languages. The peer review system applied by a journal and the editorial selection of original articles to be published are crucial determinants of the overall quality of its publications. The role of local journals that publish in languages other than English is most important for the communities they are intended to serve and their contribution to disseminating scientific and other important aspects of medicine should be acknowledged and considered by readers, authors and editors in English-speaking countries, especially when these local journals belong to the mainstream literature included in the major international indexing services

Instrucciones a los autores de manuscritos que se someterán a publicación en la Revista Médica de Chile / Instructions to authors of manuscripts to be submitted to Revista Médica de Chile

Instructions to authors of manuscripts to be submitted to this journal are published in the Junuary and July issue. These instructions consider the scope of the journal, the experience acquired along two decades applying the peer review system, and the most recent edition (Junary 1997) of the "Uniform Requirements for Manuscripts Submitted to Biomedical Journal". All articles are published in Spanish but each one starts with an abstract in English. The most common errors detected in formal presentation or in contents are briefly reminded in these instructions. A free translation of paragraphs chosen from the "Uniform Requirements..." allows the editors to emphasize some statements added to (or expanded in) this document: "Redundant or duplicate publication" and "Protection of patients' rights". Authors are requested to study the "Uniform Requirements..." and the specific "Instructions to the Authors" when preparing their manuscripts for submission to this journal

Término de un aniversario especial / Closing an special anniversary

During 1997 Revista Medica de Chile commemorated its 125th anniversary. The first issue appeared in july, 1872, and the journal has been published continuously since then. In this celebration, selected articles, distributed into12 monthly issues, dealt with important topics in clinical and biomedical research, medical education, the ethics of clinical, biomedical and biological basic research. Controversial aspects of the birth of human individuality after conception, artificial fertilization, and the cloning of mammalian species, were addressed by experts. The July issue contained studies on the history of Chilean medicine reflected in this journal; the evolution of the journal itself along its 125 years of age; a tribute to its founders; an epistemometric study of its current state: and the reforms in undergraduate curricula to be applied in the next years by eight Chilean Medical Shools. In 1997, international connections were stimulated through the Editor's participation in the International Congress on Peer Review and Global Communications and the meeting of the World Association of Medical Editors (WAME). The Revista contributed in ist October issue to the "1997 Global Theme Issue on Aging". The role and Revista prestige of Revista Medica de Chile as a general medical juornal is well established in the national stage and in the Latinamerican region

El perfeccionamiento de la edición de revistas médicas y la asociación mundial de editores médicos WAME / Improving the editing of medical journals and the World Association of Medical Editors WAME

Medical journal editing is a task with many facets. The role of the editors includes organizing and evatuating a peer-review system as a main tool for their decission making in selecting manuscripts to be published. The International Congress on Biomedical Peer Review and Global Communications was held in September, 1997, in Prague, Czech Republic, organized by JAMA, the BMJ and Project HOPE, and sponsored by several other organizations. A meeting áof the World Association of Medical Editors took place during this Congress and its institutional objectives and membership were discussed and enlarged, based on the previous foundation Conference held in Bellagio, Italy, in march 1995. The main goals of this Association: "To facilitate worldwide cooperation and communication among editors of peer-reviewed medical journals; to improve editorial standards, to promote professionalism in medical editing through education, self-criticism and self-regulation; and to encourage research on the principles and practices of medical editing" were accomplished in a warm and friendly atmosphere, with over 300 participants from 46 countries and every continent. Revista Medica de Chile was represented in these meetings by its former and present Editors. An analysis of the meetings by the editorial team will lead to changes intended to improve the editorial process in our journal

Homenaje al doctor Germán Schneider, primer Editor de la Revista Médica de Chile / A tribute to Germán Schneider, MD, Founder anf First Editor of Revista Médica de Chile

Germán Schneider was born in 1820 in Magdeburg, Germany, and graduated as M.D. at the University of Bonn. In 1848, caught by the political and intellectual reformist movement in Europe, he was exiled in Paris. As part of a large group of German immigrants, he arrived in Valdivia, Chile, in 1851. Later on he moved to Santiago and in 1871 he was nominated Professor of Clinical Medicine at the University of Chile School of Medicine. An active participant in the academic activities organized by Sociedad Médica de Santiago (a scientific society that evolved into the Chilean Society of Internal Medicine) he was the leader of a six-men team who founded Revista Médica de Chile, in 1872. As first Editor of this medical journal, he established the basis for its continuous success and devotion to medical progress and education. Dr. Schneider died in 1884, leaving several distinguished pupils who followed his path, and a medical journal that now stands as one of the oldest in the world

Las Escuelas de Medicina chilenas, en los albores del siglo XXI / Medical Schools in Chile, at the dawn of the 21st century

Since it was founded, Revista Médica de Chile has given special relevance to medical education, as experienced in Chile and in leading countries in the world. The Editors selected as main subject of this issue (which commemorates the first issue of the journal, printed in July, 1872), the planning or application of renovated medical curricular programs in Chile. The Deans of 8 Chilean Medical Schools or their representatives prepared ad hoc documents defining the "profile" of future medical doctors that their Schools will prepare and the distinctive characteristics of their curricula. The following documents were then submitted, as a tribute to this commemorative issue of Revista Médica de Chile

Angioplastía coronaria primaria: factores pedictores de mortalidad, fracaso y de isquemia recurrente / Primary coronary angioplasty: predictors of mortality, procedure failure and recurrent ischemia

La angioplastía primaria (PTCAP) ha sido sugerida como el tratamiento de elección del infarto de miocardio (IAM). Para evaluar su uso en nuestro medio y los factores que predicen fracaso de la técnica,mortalidad o recurrencia de la isquemia se estudian 201 pacientes que cursan un IAM < 12 h: 43 mujeres (21 por ciento), 87 en pared anterior (43 por ciento), de 61 ñ 12 años y 138 en Killip I (69 por ciento). Responsable del IAM fue la descendente anterior en 83 p, la circunfleja en 33 p, la coronaria derecha en 81 p, puente safeno en 2 p y el tronco en 2 p. Presentaban enfermedad de un vaso: 83 p, de 2 v: 53 p, de 3 v: 56 p, de tronco; 7 p. Dos p carecían de lesión > 50 por ciento. En 5 p no se intentó la PTCAP: 2 p por lesión de tronco, 2 p por lesión < 50 por ciento y 1 p por arteria chica. En los otros 196 p se intentó la PTCA la que fue exitosa en 179 p (91 por ciento): lesión residual < 50 por ciento y flujo TIMI III en 174 p (89 por ciento) o TIMI II en 45 p con clínica y ECG de reperfusión. En horario hábil se abrió la arteria "culpable" a los 96 ñ 45 min del ingreso y en el inhábil a los 119 ñ 48 min (p < 0.01). Mueren 11 p (5.5 por ciento). La mortalidad se asoció a edad > 70 a, IAM anterior, Killip > II, y especialmente al fracaso de la PTCAP (p < 0,001). El fracaso se asoció sólo al Killip > I (p < 0.001). Presentan isquemia residual 19 p (9.5 por ciento). Se asocian a ella: lesión residual > 40 por ciento, flujo TIMI < III y enfermedad de 3 v (p < 0.01).Durante la hospitalización 15 p (8 por ciento) requirieron de otra PTCA y 33 p (16 por ciento) de una revascularización quirúrgica; 2 p de inmediato, 3 p de urgencia y 28 p electiva. En nuestro medio, la PTCAP puede ofrecerse como el tratamiento de elección del IAM al asegurar un alto éxito en reperfundir la arteria, sin demora y sin lesión residual. Si ella fracasa deben extremarse las otras medidas de reperfusión por predecir un alto riesgo de fallecimiento

Ciento veinticinco años de publicación continua / 125 years of continuous publication

Revista Médica de Chile was founded in July, 1872. Along 125 years it has published a monthly issue. In 1979 this journal ranked 29 among all medical journals founded in the 19th century that were still active. The Revista publishes clinical research articles, a good proportion of biomedical experimental research papers and novel topics pertaining to other medical specialties besides internal medicine, including medical education and public health. Fifty to sixty per cent of every issue contains original articles; the rest includes case reports, review articles and special articles with educational value and other sections common to general medical journals. Manuscripts should conform its style to the recomendations updated by an international Comittee of Medical Journal Editors. Since 1970, most manuscripts are peer-reviewed and over 150 specialists collaborate every year in this process. Allthough most manuscripts are generated in Chile an increasing number of papers is being received from other Latinamerican countries and Europe. The journal is included in several important bibliographic indexes. With the historical perspective given by 125 years of continuos publication, the Editors plan to keep expanding its educational and scientific role, as a journal belonging to the mainstream of periodical biomedical publications in the world

Factores de riesgo cardiovascular en hombres adultos sanos: innfluencia de la actividad física e ingesta dietaria / Cardiovascular risk factors in adult healthy men: influence of physical activity and dietary intake

To study the influence of physical activity and certain dietary habits on cardiovascular risk factors in middle age men, healthy male workers were subjected to a physical activity inquiry, dietary recall, inquiry about smoking habits and anthropometric assessment. Also, blood pressure was measured and a fasting blood sample was obtained to assess serum total and HDL cholesterol, triglycerides and blood glucose. Multiple stepwise and canonical regressions were used to analyze data. Four hundred eleven subjects aged 46.8ñ10 years were studied. Twenty four percent smoked, mean body mass index was 26.4ñ2.6, mean caloric intake was 11.7ñ3 MJ/day and mean caloric expenditure 10.6ñ1.1 MJ/day or 1.52ñ0.13 times the resting metabolic rate. Physical activity, body mass index and fiber intake appreared as independent but weak predictor of total and LDL cholesterol. Alcohol intake, age and body mass index were predictors of HDL cholesterol and blood pressure was predicted by age, fiber intake and body mass index. Canonical analysis showed that 54 percent of blood pressure variation is explained by age, body mass index and fiber intake and in 31 percent of HDL cholesterol variation is explained by alcohol intake. Physical activity has a weak influence on serum total and LDL cholesterol. Alcohol intake is the main predictor of HDL cholesterol in these workers