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

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Beta-blockade and exercise capacity in patients with mitral stenosis in sinus rhythm.

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine whether beta-blocker treatment (atenolol) improves cardiopulmonary exercise performance and ventilatory response in patients with mitral stenosis in sinus rhythm. METHODS: A prospective study comparing the results of cardiopulmonary exercise tests (CPETs) was performed before and after atenolol therapy in 17 patients in NYHA classes I and II with mitral stenosis in sinus rhythm. Transthoracic echocardiography was performed pre-study, and left ventricular diameters, ejection fraction and mitral valve area monitored. CPETs (Naughton protocol) were performed by two different investigators before and after one-week atenolol therapy (50 mg/day). The second investigator was blinded to the result of the baseline test. O2 consumption, CO2 production, ventilatory parameters and respiratory exchange ratios were measured on line. RESULTS: Maximal O2 uptake (VO2max) did not differ significantly before and after beta-blockade (median 16.8 and 15.0 ml/kg/min, respectively. Median heart rate at rest (72 versus 55 beats/min; p = 0.0003) and during peak exercise (153 versus 105 beats/min; p = 0.0003), and anaerobic threshold (10 versus 8.9 ml/kg/min; p = 0.02) were lower with beta-blockade compared with the baseline state. Minute ventilation at maximum exercise (41 versus 40 l/min) and ventilatory equivalent for CO2 (34 versus 35) were unchanged with atenolol therapy, indicating no improvement in ventilatory performance. When patients were grouped into those in whom VO2max was improved with atenolol therapy (n = 7) and those in whom it was impaired (n = 10), there were no inter-group differences with respect to age, left ventricular function, severity of mitral stenosis, NYHA class and grade of beta-blockade reached. Four patients felt symptomatically worse during atenolol treatment (lower NYHA functional class). CONCLUSION: Beta-blockade does not improve exercise tolerance in patients with mitral stenosis in sinus rhythm. In addition, ventilatory performance does not change with treatment.

Dispersión del intervalo QT y variabilidad de la frecuencia cardíaca postinfarto. evolución temporal y relaciones con la función ventricular izquierda / QT interval dispersion and heart rate variability following myicardial infarction. Time course and relations with the left ventricular function

Introducción y objetivos. Se investigaron los cambios precoces en la dispersión del intervalo QT y variabilidad de la frecuencia cardíaca en un grupo de pacientes consecutivos hospitalizados por infarto de miocardio de cara anterior, así como el curso evolutivo de estos indicadores pronósticos durante un período de 6 meses y la relación entre estas variables y los parámetros de función ventricular izquierda. Métodos. Se estudiaron 42 pacientes consecutivos ingresados por infarto de miocardio de cara anterior con onda Q. Se llevaron a cabo en la primera semana y a los 6 meses postinfarto un análisis de la variabilidad de la frecuencia cardíaca (Holter de 24 horas) empleando el método de la demodulación compleja, una medida de la dispersión del intervalo QT en el electrocardiograma (ECG) estándar de 12 derivaciones (QT máximo - QT mínimo) y se obtuvieron los parámetros de función ventricular izquierda a partir de la ventriculografía de contraste y la extensión de la disfunción regional ventricular izquierda. Resultados. La dispersión del QT disminuyó significativamente entre la primera semana (0,07s [0,050,08]) y los 6 meses (0,06s [0,04-0,08], p =0,029); la extensión de la anormalidad de la motilidad parietal mostró una tendencia similar (desde 51 por ciento [27-56] hasta 33 por ciento [11-46], p<0,00001). En cambio, la desviación estándar de los ciclos RR aumenta entre la 1ª semana (31 ms [22-44]) y los 6 meses (43 ms [32-58], p< 0,00001). Sin embargo, la fracción de eyección ventricular izquierda, volumen telediastólico, y volumen telesistólico (46 ml/m2 [31-67] no mostraron cambios significativos en este período de tiempo. En la 1ª semana, la desviación estándar (r = 0,46, p< 0,01) y el ciclo RR medio (r = 0,59, p < 0,0001) se relacionaron con la fracción de eyección, Sin embargo, la dispersión de QT no se correlacionó con la variabilidad de la frecuencia cardíaca o los parámetros de función ventricular en la primera semana o a los 6 meses de evolución. No existieron diferencias en los parámetros autonómicos o hemodinámicos entre los pacientes que presentaron unos valores de dispersión del QT < 0,08 (n=15) o 0,08 ( n=16) segundos. Conclusiones. a) La dispersión del QT disminuye y la variabilidad de la frecuencia cardíaca aumenta en los primeros meses postinfarto; b) la disminución de la variabilidad de la frecuencia cardíaca tiende a ser mayor cuanto mayor es el deterioro de la función ventricular secundario al infarto; y c) no se han encontrado relaciones entre la dispersión del QT y las características clínicas, variabilidad de la frecuencia cardíaca o parámetros de función ventricular izquierda en la primera semana o a los 6 meses postinfarto (AU)

[QT interval dispersion in hospital patients admitted with cardiac insufficiency. Determinants and prognostic value]. / Dispersión del intervalo QT en pacientes ingresados por insuficiencia cardíaca. Determinantes y valor pronóstico.

INTRODUCTION AND OBJECTIVES: The determinants and the prognostic value of the QT interval dispersion are analysed in a group of consecutive patients admitted to hospital with heart failure. METHODS: One hundred twenty-two consecutive patients admitted because of heart failure in whom a reliable measurement of QT dispersion in the first electrocardiogram was obtained (maximum QT-minimum QT) were studied. The main clinical, analytic and echocardiographic data were recorded. A control group (n = 35) matched in age and sex with the study group was also analysed. RESULTS: The study group showed a greater QT dispersion than the control group (62 +/- 30 vs 40 +/- 21 ms; p = 0.01). Those cases with a QT dispersion > 80 ms (n = 50; 41%) exhibited a lower natremia (138 +/- 6 vs 141 +/- 4 mEq/l; p = 0.01), a higher probability of ischemic aetiology (52 vs 33%; RR = 2.2; IC95% 1.05-4.7; p = 0.04), an increased mortality during the first year (20 vs 6%; RR = 4.7; IC95% 1.3-16; p = 0.01) and during the whole follow-up (38 vs 19%; RR = 3.4; IC95% 1.3 a 8.6; p = 0.01) than those patients with a QT dispersion < 80 (n = 72; 59%). There were no significant differences between both groups with regard to the clinical, analytic or echocardiographic data. In the multivariate analysis only the ischemic etiology (p = 0.002) and the NYHA grade (p = 0.02) were related to a greater mortality. CONCLUSIONS: Patients with heart failure show an increased QT interval dispersion. This parameter is a simple tool that suggests an ischemic etiology and can help in prognosis stratification.

[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.

[Determination of ejection fraction and left ventricular fraction using isotopic ventriculography and bidimensional echocardiography. Comparison with contrast ventriculography]. / Determinación de la fracción de eyección y volúmenes del ventrículo izquierdo mediante ventriculografía isotópica y ecocardiografía bidimensional. Comparación con la ventriculografía de contraste.

OBJECTIVES: The aim of this study was to determine the correlation and agreement between the values of left ventricular ejection fraction and volumes assessed by echocardiography and radionuclide ventriculography with the results obtained by contrast angiography, as well as the variability of each method in these measurements. PATIENTS AND METHODS: In a group of 59 patients with a first acute myocardial infarction we have determined left ventricular ejection fraction and volumes by two-dimensional echocardiography, equilibrium radionuclide ventriculography and contrast angiography initially and six months after myocardial infarction. We also assess the variability in the determinations in these three methods. RESULTS: We found significant correlations in ejection fraction and volumes by radionuclide ventriculography and echocardiography with contrast angiography. The correlation was higher in ejection fraction and end-systolic volume by radionuclide ventriculography (r = 0.88 and r = 0.73) than by echocardiography (r = 0.55 and r = 0.63; p < 0.01), whereas the correlation of end-diastolic volume was moderate by both methods (r = 0.58 and r = 0.47), without significant differences. The agreement between contrast angiography and radionuclide ventriculography was higher, with narrower limits of agreement than between contrast angiography and echocardiography in ejection fraction as well as in ventricular volumes. We have found high and significant correlations between two determinations by each method in all parameters, although they were higher in ejection fraction by contrast angiography (r = 0.96) and radionuclide ventriculography (r = 0.98) than by echocardiography (r = 0.70; p < 0.01). The limits of agreement were always wider in echocardiography, narrower in contrast angiography and the narrowest in radionuclide ventriculography, showing its superior reproducibility. CONCLUSIONS: In this group of myocardial infarction patients, the variability in the measurements was lower by radionuclide ventriculography than by echocardiography, this could be the reason for overall better results found in correlation and agreement between radionuclide ventriculography and contrast angiography than between echocardiography and contrast angiography in the assessment of left ventricular ejection fraction and volumes.

[Inflammatory response in acute myocardial infarction. Predictive values]. / Respuesta inflamatoria en el infarto agudo de miocardio. Valores predictivos.

INTRODUCTION AND OBJECTIVES: Our purpose was to investigate the significance of inflammatory acute phase response early after myocardial infarction. We also observed how these indices were influenced by trombolytic therapy. METHOD: We examined the blood samples of 200 non consecutive patients at the first day of acute myocardial infarction (155 [77%] males; mean age 65 +/- 13 years) to characterize the proteins and proinflamatory reactants profile. Results were correlated with hospital mortality. Thrombolytic therapy was administrated to 117 patients on admission and in these patients the samples were taken after the procedure. RESULTS: Overall mortality was 8%. Serum C-reactive protein (69 vs 41 mg/l), haptoglobine (237 vs 190 mg/dl), gammaglobuline (0.93 vs 0.84 g/dl), alpha-1-globuline (0.28 vs 0.23 g/dl) and alpha-2-globuline (0.7 vs 0.6 g/dl) were significantly higher in patients without trombolytic therapy. Conversely, patients who had received lytic therapy, had higher plasma concentrations of interleukin-1 beta (104 vs 40 pg/dl). The only clinical variable which was associated with mortality was a Killip class > or = 2 on admission (mortality = 21%; odds ratio = 5.2; p = 0.02). Other biochemical variables associated with a higher mortality were a white blood cell count > 10/nl (mortality = 12%; odds ratio = 5.4; p = 0.01), increased activated neutrophils > 80% (mortality = 18%; odds ratio = 5.4; p = 0.004) and C-reactive protein > 20 mg/l (mortality = 11%; odds ratio = 6; p = 0.05). Only patients with activated neutrophils > 80% on admission had a higher probability of dying during hospital stay (Exp[B] = 3.6; B = 1.2; r = 0.29; p = 0.001). CONCLUSION: The acute phase reaction in early myocardial infarction is determined by thrombolytic treatment. A high increase of activated neutrophils on patient admission is the only biochemical predictive value for hospital mortality.

[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.

[Biatrial thrombosis]. / Trombosis biauricular.

A fifty-eight year old patient presented subacute right heart failure. Transthoracic and transesophageal echocardiography revealed thrombi in both atria, and initial anticoagulation and subsequent surgical treatment were successful. Echocardiography is defined as being decisive to diagnosis, and the role of surgery in the treatment of these patients is commented.