Signo de Brockembrough-Braunwald-Morrow / Brockembrough-Braunwald-Morrow sign

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Valor pronóstico del SPECT de perfusión miocárdica en pacientes coronarios con enfermedad multivaso y disfunción ventricular izquierda, comparando revascularizados y no revascularizados* / Prognostic value of myocardial perfusion spect in multivessel coronary disease patients with left ventricular dysfunction, comparing revascularized and non-revascularized patients

Objetivo: Investigamos el valor pronóstico del SPECT miocárdico con 99mTc-Tetrofosmin (99mTc-TF) en pacientes disfuncionales con coronariopatía multivaso, que sufrieron revascularización (RV) o fueron sometidos sólo a tratamiento médico (TM).Métodos: En 78 pacientes coronarios con 2-3 vasos afectos y fracción de eyección del ventrículo izquierdo (FE) 40 por ciento (24 ñ 10 por ciento) hemos valorado la extensión del defecto de perfusión de esfuerzo (E), el porcentaje de reversibilidad (R), mediante cuantificación del diagrama polar a partir del SPECT miocárdico de esfuerzo-reposo (protocolo 2 días), el índice pulmón/miocardio (P/M), calculado en las imágenes originales del SPECT de esfuerzo, y la FE, mediante ventriculografía isotópica de equilibrio, obtenida a las 24 h del SPECT. Se utilizó un valor de R 8 por ciento para identificar a los pacientes viables (V). Un total de 28 pacientes sufrieron RV (by-pass) y 50 recibieron sólo TM. Tras un seguimiento medio de 22,9 ñ 20 meses (3-60) se consideraron como accidentes cardíacos (AC): muerte cardíaca, trasplante cardíaco e IAM, que aparecieron en 16/78 (20,5 por ciento). Resultados: No se encontraron diferencias significativas en las características del estudio pre-revascularización, salvo una R media mayor en los RV (10,6 ñ 9,5 por ciento) que en los de TM (6,4 ñ 7,8 por ciento) p: 0,03, siendo lo principal la menor incidencia de AC en los RV, 2/28 (7,1 por ciento) que en los de TM, 14/50 (28 por ciento) p: 0,02. Hubo menor incidencia de AC en los pacientes V que fueron RV (6 por ciento) que en los pacientes V con TM (45 por ciento), p: 0,03, no siendo significativa la diferencia en los pacientes no V entre los RV (7 por ciento) y los de TM (16 por ciento). Se obtuvieron las correspondientes curvas de supervivencia (Kaplan-Meier), que mostraron, en los pacientes V, una probabilidad de supervivencia libre de AC a los 5 años del 79 por ciento en pacientes RV y del 42 por ciento en pacientes con TM, p: 0,03, sin ser significativas las diferencias en los pacientes no V. Conclusiones: Los pacientes con miocardio viable en el SPECT miocárdico, presentaron buen pronóstico tras revascularización y mostraron mayor riesgo de AC cuando recibieron sólo tratamiento médico. La detección de viabilidad miocárdica es una valoración indispensable en la evaluación pronóstica, y sobre todo en la toma de decisiones terapéuticas en los pacientes disfuncionales con coronariopatía multivaso (AU)

[The prognostic factors after an acute myocardial infarct treated with fibrinolytics]. / Factores pronósticos tras el infarto agudo de miocardio tratado con fibrinolíticos.

BACKGROUND: The usefulness of the exercise test in evaluating patients with an acute myocardial infarction treated with fibrinolytics is controversial. On the other hand, the prognostic value of a patent infarct-related artery has not been clearly established. The objectives of this study were to assess the validity of the exercise test and to study the prognostic value of the artery patency after a myocardial infarction. MATERIAL AND METHODS: We studied 99 patients with a myocardial infarction treated with fibrinolytics, non-complicated. An exercise test and a cardiac catheterization were performed in the first month. The patients were followed-up for 2 years, recording the major cardiac events (death and reinfarction) and the minor events (angina class (II, left cardiac failure class (II or maintained ventricular tachycardia). RESULTS: On multivariate analysis with Cox regression, a workload < 4 METS at the exercise test was the only independent prognostic factor of major events (RR 5.6; CI 95% 1.68-19). The independent prognostic factors of minor events were: multivessel disease (RR 3.36; CI 95% 1.56-7.24), anterior infarction (RR 3.15; CI 95% 1.3-7.6), abnormal exercise test (RR 2.98; CI 95% 1.46-6.09) and ejection fraction < or = 40% (RR 2.48; CI 95% 1.07-5.74). The patency of the infarct-related artery was not a predictor of events. CONCLUSIONS: The exercise test is useful in predicting the prognosis in patients treated with fibrinolytics. An occluded infarct-related artery was not an independent predictor of cardiac events in 2 years of follow-up.

[Evolution of the filling pattern of the left ventricle during the first year after an acute myocardial infarct. The influence of the infarct size]. / Evolución del patrón de llenado del ventrículo izquierdo durante el primer año tras un infarto agudo de miocardio. Influencia del tamaño del infarto.

OBJECTIVES: Acute myocardial infarction induces diastolic dysfunction as a result of the alteration of left ventricular relaxation and stiffness caused by ischemia and fibrosis. This study analyzes the association of infarct size with the diastolic filling pattern and the evolution of the latter during the first postinfarction year. PATIENTS AND METHODS: The study group consisted of 68 patients with a first acute myocardial infarction treated with thrombolytic agents. A Doppler echocardiography was performed at 8 +/- 2, 32 +/- 7 and 370 +/- 23 days after infarction. Five measurements of the ratio between E and A waves peak velocities (E/A ratio) and of the E deceleration time (EDT, ms) were averaged in each echocardiographic study. The patients were divided according to infarct size into a large infarct group (creatine kinase > 1,000 U/ml; 1,913 +/- 883; n = 26) and a small infarct group (creatine kinase < 1,000 U/ml; 556 +/- 227; n = 42). RESULTS: The large infarct group exhibited a greater E/A ratio and shorter EDT than the small infarct group in the first week (E/A ratio: 1.4 +/- 0.7 vs 0.8 +/- 0.3; p = 0.0001; EDT: 159 +/- 49 vs 192 +/- 56; p = 0.02) and at one month (E/A ratio: 1.2 +/- 0.7 vs 0.9 +/- 0.3; p = 0.01; EDT: 170 +/- 55 vs 207 +/- 40; p = 0.004); however no differences were observed between either group at one year in either E/A ratio (0.8 +/- 0.2 vs 0.9 +/- 0.4; NS) or EDT (207 +/- 44 vs 219 +/- 54; NS). In the large infarct group, E/A ratio decreased and EDT increased at one year compared to the first week (E/A ratio: p = 0.0004; EDT: p = 0.0001) and the first month (E/A: p = 0.02; EDT: p = 0.003); in contrast, in the small infarct group there were no significant differences in E/A ratio nor EDT during the first year postinfarction. CONCLUSIONS: In the first month postinfarction, large infarcts exhibit a greater E/A ratio and shorter EDT than small infarcts. The evolution of large infarcts is characterized by an attenuation of this pattern, with a progressive reduction of E/A ratio and prolongation of EDT during the first year post-infarction.

[The significance of the elevation of basal and exercise segments on Q-leads after acute myocardial infarct]. / Significado de la elevación basal y al esfuerzo del segmento ST en derivaciones con onda Q tras un infarto agudo de miocardio.

INTRODUCTION: ST segment elevation on Q-leads has been related to a greater infarct size and to the existence of ventricular aneurysm. On the other hand, ST elevation during exercise testing has been related to the presence of myocardial viability. OBJECTIVES: In the present study we investigated the relation between ST segment elevation on infarct-related electrocardiographic leads at rest and during exercise with: a) the extension and severity of the regional dysfunction; b) the presence of myocardial viability (response to dobutamine), and c) the residual stenosis in the culprit artery. MATERIAL AND METHODS: The study group was composed of 51 patients; cardiac cathetherism (8 +/- 3 days) and exercise testing (8 +/- 2 days) were performed during the pre-discharge period. In contrast ventriculography (centerline method) we determined the circumferential extension (rads) and the severity (SD/rad) of the regional dysfunction at rest and after dobutamine (10 micrograms/kg/min). The minimal luminal diameter (MLD) in the culprit artery was also measured. Results are expressed as median [Q1-Q3] and the differences among the groups were assessed by Mann-Whitney U. RESULTS: Patients with ST segment elevation in two or more leads at rest (n = 36) showed a greater (41 [30-51] rads vs 20 [14-41] rads; p = 0.007) and more severe regional dysfunction (1.9 [1.5-2.5] SD/rad vs 0.6 [0.5-2.4] SD/rad; p = 0.01), less response to dobutamine (% of reduction of the dysfunction extension after dobutamine) (17 [0-42]% vs 50 [24-100]%; p = 0.004) and smaller MLD (0.5 [0-0.9] mm vs 0.8 [0.6-1.1] mm; p = 0.03). Likewise, patients with exercise-induced ST segment elevation (n = 28) showed less response to dobutamine (15 [0-45]% vs 40 [21-57]%; p = 0.03) and smaller MLD (0.5 [0-0.7] mm vs 0.9 [0.5-1] mm; p = 0.02). There were non significant differences between patients with and without ST elevation during exercise in the extension or severity of the regional dysfunction. ST segment elevation both at rest (RR 0.2; CI 95% 0.04-0.85) and during exercise (RR 0.19; CI 95%: 0.05-0.69) decreased the probability of improvement with dobutamine. CONCLUSIONS: We conclude that ST segment elevation on Q-leads at rest is related to a more extended and severe dysfunction. Patients with ST segment elevation (at rest or during exercise) show less response to dobutamine (myocardial viability less likely) and a more severe residual coronary stenosis.

[E wave deceleration time predicts left ventricular telediastolic pressure in acute myocardial infarction in patients with systolic dysfunction]. / El tiempo de deceleración de la onda E predice la presión telediastólica del ventrículo izquierdo tras un infarto agudo de miocardio en pacientes con disfunción sistólica.

OBJECTIVES: Left ventricular end-diastolic pressure (LVEDP) is a useful parameter for the management of postinfarction patients. As the current methods of estimating LVEDP are invasive, the existence of non-invasive methods would be of great practical value. This study investigates the relation between LVEDP and Doppler parameters such as E wave deceleration time (EDT) and E/A ratio, at one month following an acute myocardial infarction. METHODS: Eighty-nine patients with a first acute myocardial infarction treated with thrombolytic agents were studied. Doppler-echocardiography at 29 +/- 3 days and cardiac catheterization at 30 +/- 4 days postinfarction were performed. According to the ejection fraction (EF), the patients were divided into group 1 (n = 17) with EF < 45%, and group 2 (n = 72) with EF > 45%. RESULTS: Overall, the E/A ratio showed a weak correlation with LVEDP (r = 0.32; p = 0.007), and EDT did not correlate with LVEDP. When patients from group 2 were analyzed, no correlation was found between LVEDP and either E/A or EDT. However, in patients from group 1, LVEDP strongly correlated with both EDT (r = -0.83; p = 0.00001) and E/A (r = 0.70; p = 0.003). Moreover, the sensitivity and specificity of an EDT of less than 150 ms in predicting a LVEDP > 20 mmHg was 100%. CONCLUSIONS: We conclude that at the first month after a myocardial infarction EDT provides a non-invasive and useful parameter for estimating LVEDP in patients with systolic dysfunction.

[Methodology problems in the study of arterial hypertension]. / Problemas metodológicos en el estudio de la tensión arterial.

This text deals with the methodological problems researchers have to face when trying to determine and study blood pressure (BP). It describes the measuring methods, the apparatus and the equipment used as well as the recording procedures and their technical shortcomings, together with their most common errors. It also deals with the various special problems involved. Ambulatory BP recording has greatly contributed to the significantly increased knowledge gained about the changeability of BP and the physiological, pathological and therapeutical factors which induce it. Even though, this technique may also have its limitations and may be subject to errors, its application is becoming more widespread, and its future enhancement will no doubt change the light under which we see BP today. I high BP recording is not only a sign on which the common AHT syndrome is normally diagnosed, but its prognosis value has also been known for years. Finally, because of the frequent epidemiological studies on BP, the prevalence of AHT in the various populations, likely therapeutical influences (therapeutical trials), etc., a close look at the methodological aspects of BP recording should be worth while considering.