Correlación de sincronía de la contracción del ventrículo izquierdo con función sisto-diastólica, masa y excentricidad en diversas afecciones cardíacas mediante un software comercial dedicado de SPECT gatillado / Gated Spect evaluation of ventricular systolic synchrony: correlation with ventricular mass and excentricity in different forms of cardiac disease

INTRODUCCIÓN: Actualmente, hay nuevas herramientas de software disponibles para medir la sincronía de la contracción intraventricular izquierda mediante SPECT de perfusión miocárdica. Esta técnica permite identificar anomalías de la conducción, apoyar la terapia de resincronización en insuficiencia cardíaca refractaria e incluso la detección precoz de isquemia. OBJETIVO: Conocer la correlación de la sincronía de contracción con otros parámetros de disfunción sisto-diastólica ventricular izquierda. MÉTODO: Estudiamos 135 pacientes remitidos para pesquisa o evaluación de enfermedad coronaria conocida mediante SPECT gatillado. La evaluación de la interpretación inicial con programas QPS/QGS® visual y cuantitativo se efectuó a 50 casos con defectos de perfusión transitoria de diversos tamaños (isquemia), 25 de tipo fijo o mixto (infarto) y 60 sin ellos (normal). Los volúmenes telesistólicos oscilaron entre 26 y 458 mL. Se excluyeron casos con arritmias, anomalías de conducción y artefactos (actividad o movimiento extracardiaco). Los SPECT se procesaron retrospectivamente utilizando el programa Emory Synctool®. Del histograma de sincronía de la contracción, el ancho de banda (BW) y la desviación estándar (SD) se correlacionaron con la fracción de eyección (FEVI), volúmenes y excentricidades sistólico / diastólico, masa ventricular izquierda, tasa máxima de llenado (PFR) y tiempo al máximo de llenado (TPFR). RESULTADOS: Los BW y SD del histograma de fase de contracción fueron mayores en el grupo con defectos fijos y mixtos en comparación con los con perfusión normal. Las correlaciones en reposo y post estrés (Spearman) entre SD y BW con FEVI, volúmenes, excentricidad y masa fueron significativas (p <0,0002) salvo TPFR que no fue significativa. CONCLUSIÓN: La sincronía de contracción intraventricular sistólica izquierda medida con SPECT se correlaciona excelentemente con los parámetros funcionales sistólicos y diastólicos, así como con masa y excentricidad en diversas condiciones y tamaños cardíacos.

INTRODUCTION: New software tools are available to measure left intraventricular contraction synchrony by myocardial perfusion SPECT. This technique allows identification of conduction abnormalities, support resynchronization therapy in refractory heart failure and even allows early detection of myocardial ischemia. OBJECTIVE: To determine the correlation of systolic synchrony with other parameters of left ventricular systolic-diastolic dysfunction. METHODS: We studied 135 patients referred for screening or known coronary artery disease evaluation by triggered SPECT. Evaluation of the initial interpretation with visual and quantitative QPS/QGS® programs was performed in 50 patients with transient perfusion defects of various sizes (ischemia), 25 of fixed or mixed type (infarction) and 60 without abnormalities. Telesystolic volumes ranged from 26 to 458 mL. Cases with arrhythmias, conduction abnormalities and artifacts (extracardiac activity or motion) were excluded. SPECT scans were retrospectively processed using the Emory Synctool® software. Histograms of systolic contraction synchrony bandwidth (BW) and standard deviation (SD) were correlated with ejection fraction (LVEF), systolic/diastolic volumes and eccentricities, left ventricular mass, peak filling rate (PFR) and time to maximum filling (TPFR). RESULTS: BW and SD of the contraction pase histogram were higher in the fixed and mixed defect group compared to studies showing normal perfusion. Spearman correlations at rest and poststress between SD and BW with LVEF, volumes, eccentricity and mass were all significant (p<0.0002) except for TPFR. CONCLUSION: Left systolic intraventricular contraction synchrony measured with SPECT presents an excellent correlation with systolic and diastolic functional parameters, as well as with mass and eccentricity in various cardiac conditions and ventricular dimensions.

Cardiomiopatía amiloídea por transtiretina: diagnóstico y manejo en la actualidad / Transthyretin amyloid cardiomyopathy: a review

RESUMEN: La cardiomiopatía amiloide por transtiretina (CATTR) es una enfermedad caracterizada por depósito extracelular de fibrillas amiloides en el miocardio, a partir de transtiretina mal plegada, generando una miocardiopatía restrictiva. Esta proteína mal plegada puede tener origen hereditario o adquirido, siendo más frecuente en adultos mayores. La CA-TTR ha surgido como una causa subdiagnosticada de insuficiencia cardíaca con fracción de eyección preservada (IC FEp). El pilar fundamental para su diagnóstico es la alta sospecha clínica, basada en diversas banderas de alerta ya que la sintomatología que provoca suele ser inespecífica. Como veremos en esta revisión, el diagnóstico puede sustentarse con la cintigrafía ósea, reservando para situaciones particulares la toma de biopsia. Con el advenimiento de nuevas terapias que impactan en la sobrevida de esta enfermedad, el tiempo para realizar el diagnóstico certero y la diferenciación de otras causas de amiloidosis cardíaca como la de cadenas livianas, se ha tornado crucial.

ABSTRACT: Transthyretin amyloid cardiomyopathy (AT-TR-CM) is a disease characterized by extracellular deposition of amyloid fibrils in the myocardium, from misfolded transthyretin, generating a restrictive cardiomyopathy. This misfolded protein may be inherited or acquired, and is more prevalent in elderly patients. ATTR-CM has emerged as an underdiagnosed cause of heart failure with preserved ejection fraction (HF-PEF). The fundamental pillarfor its diagnosis is high clinical suspicion since the symptoms are usually nonspecific. The diagnosis can be made from bone scintigraphy, reserving myocardial biopsy for particular situations. With the advent of new therapies that affect the survival of these patients, a timely diagnosis has become crucial.

Efecto de la terapia de resincronización ventricular en los parámetros de disfunción endotelial y función sistólica izquierda en pacientes con insuficiencia cardíaca crónica y bloqueo completo de rama izquierda / Endothelial dysfunction, left ventricular function, and chronic heart failure with complete left bundle branch block: effect of resynchronization therapy

Resumen: Introducción: La insuficiencia cardíaca crónica (ICC) es una condición compleja asociada a inflamación sistémica y a disfunción endotelial (DE) cuya patogénesis no es bien comprendida. Objetivo: Evaluar una posible relación entre marcadores de DE periférica con la respuesta a terapia de resincronización ventricular (TRV). Método: 20 pacientes con ICC, QRS ≥120ms y fracción de eyección ventricular izquierda (FEVI) ≤35% se estudiaron pre y 6 meses post-TRV con: Minnesota Living with Heart Failure Questionnaire (MLHFQ); test de marcha (TM-6min); Ecocardiografía-2D y SPECT de perfusión gatillado en reposo; proteína C-reactiva ultra sensible (us-PCR); péptido natriurético cerebral (pro-BNP); células endoteliales circulantes (CEC); moléculas de adhesión soluble vascular (sVCAM) e intercelular (sICAM); interleukina-6 (IL-6) y Factor von Willebrand (FvW). Se clasificaron como respondedores o no a TRV según criterios preestablecidos. Resultados: Promedios basales: pro-BNP 5.290pg/ml; us-PCR 1,7ug/mL; MLHFQ 72; TM-6min 391 metros. Las CEC y sICAM estaban sobre límites normales. Post-TRV, el 50% fue respondedor: 11/20 mejoraron ≥1 clase NYHA y ≥10% del TM-6min; ML-HFQ disminuyó (p<0.0001); FEVI mejoró (p=0.003); volumen final sistólico disminuyó (p=0.008) y también pro-BNP (p=0.03). En los respondedores, las CEC disminuyeron, persistiendo elevadas, sobre lo normal. Existieron correlaciones entre cambios de pro-BNP con TM-6min y entre us-PCR con MLHFQ y FvW (p≤0.004 en todas). Conclusiones: En ICC existe evidencia de significativa DE, expresada por sICAM y CEC, biomarcador periférico sensible. Estas disminuyeron 6 meses post-TRV, persistiendo sobre el límite normal. Otros parámetros funcionales e inflamatorios se correlacionaron en el grupo total, sin diferencias entre grupos respondedores y no respondedores.

Abstract: Introduction: Chronic heart failure (CHF) is a complex condition associated with systemic inflammation and endothelial dysfunction (ED) whose pathogenesis is not well understood. Objective: to evaluate a possible relationship between peripheral ED markers and response to cardiac resynchronization therapy (CRT). Method: 20 patients with CHF, QRS ≥120ms and left ventricular ejection fraction (LVEF) ≤35% were studied before and 6 months post-CRT. Minnesota Living with Heart Failure Questionnaire (MLHFQ); walking test (6min-WT); 2D-echocardiography and gated perfusion SPECT at rest; ultra-sensitive C-reactive protein (us-CRP); brain natriuretic peptide (pro-BNP); circulating endothelial cells (CEC); vascular soluble adhesion (sVCAM) and intercellular adhesion molecules (sICAM); interleukin-6 (IL-6) and von Willebrand Factor (vWF) were measured in all subjects. They were classified as responders or not to CRT, according to pre-established criteria. Results: Basal means: pro-BNP 5,290 pg / ml; us-CRP 1.7 ug/mL; MLHFQ 72; 6min-WT 391 meters. The CEC and IL-6 were above normal limits. Post-CRT, 50% were responders: 11/20 improved ≥1 NYHA class and ≥10% increase in 6min-WT; MLHFQ decreased (p <0.0001); LVEF improved (p = 0.003); final systolic volume decreased (p = 0.008) and also pro-BNP (p= 0.03). In responders CEC decreased, persisting over normal limits. There were correlations between changes of pro-BNP with TM-6min and between us-PCR with MLHFQ and vWF (p≤0.004 in all). Conclusions: In CHF there is evidence of significant ED, expressed by sICAM and CEC, a sensitive peripheral biomarker that decreased 6 months post-CRT although persisting above normal limits. Other functional and inflammatory parameters were correlated in the total group, without differences between responders and non-responders.

Estratificación de riesgo de muerte a mediano plazo de pacientes evaluados por enfermedad coronaria con SPECT de perfusión miocárdica bajo efecto de dipiridamol / Predictive value of dipyridamole myocardial perfusion tomography on survival

Background: Dipyridamole (DIP) is the most commonly employed pharmacological stressor for myocardial perfusion tomography (SPECT) in patients unable to reach an adequate work load. Aim: To assess the predictive capacity of DIP SPECT on survival. Material and Methods: We included 985 adults aged 66 ±11 years (45% women) with rest and DIP-SPECT. The main indications for the procedure were coronary artery disease (CAD) screening in 66% and known CAD in 33%. Participants were followed up for a median of 65 months (interquartile range 54 to 86 months). During the follow up, 261 deaths were recorded and 98% had a specified cause in their death certificate. Results: Myocardial SPECT was abnormal in 44% of participants. Transient ischemic defects were observed in 34%, fixed defects concordant with infarction in 27% and post-stress systolic dysfunction in 23%. Twenty five percent of deaths were attributable to cardiac or ischemic cause and 22% to cancer. In a bivariate analysis, the hazard ratio (HR) of death of any cause was lower in females and higher in the presence of CAD. The multivariate analysis showed that being older than 46 years increased the HR of death of any cause. In a bivariate analysis, the HR for cardiac death was higher when the myocardial SPECT showed ischemia, necrosis or left ventricular dilation. In the multivariate analysis, post-stress left ventricular systolic function was associated with a lower risk of cardiac death. Conclusions: An abnormal myocardial SPECT, perfusion abnormalities, left ventricular systolic function or dilation are independent predictors of cardiac death in these participants.

Análisis de falsos negativos en la cintigrafía SPECT de paratiroides con sestamibi en pacientes con hiperparatiroidismo primario sometidos a cirugía entre 2008-2015 en hospital universitario / False negative spect parathyroid scintigraphy with sestamibi in patients with primary hyperparathyroidism

Background: 99mTc-sestamibi parathyroid SPECT scintigraphy is a useful tool in the pre-operative study of hyperparathyroidism. False negatives (FN) have been reported in 5.7-14% of the examinations. Aim: To characterize 99mTc-sestamibi FN in cases referred for primary hyperparathyroidism (PHP) to a university hospital. Material and Methods: Descriptive retrospective analysis. We included patients with PHP, studied with SPECT scintigraphy, operated at our center between 2008 and 2015. Clinical and surgical data were recorded; biopsies of the FN were blindly reviewed by one pathologist. Results: One hundred twenty one scintigraphies fulfilled the inclusion criteria. Seven (5.8%) were negative and 114 positive. There was no difference in age, sex and PTH levels between FN and true positive scintigraphies. At surgery, one FN case had two hyperplasic glands and two cases had ectopic glands. Pathology reported adenoma in three cases, hyperplasia in three and carcinoma in one. The largest diameter of the lesion was lower in FN (1.3 and 2.1 cm respectively, p = 0.02) and the proportion of adenomas was higher in true positive cases (29% and 75% respectively; p < 0.01). The interval between scintigraphy and parathyroidectomy was greater in FN with a median of 92 days (range 20 days-3.2 years, p < 0.01). The percentage of oxyphilic cells observed was similar in both groups. Conclusions: FN parathyroid SPECT scintigraphies in PHP are uncommon. They corresponded to lesions under the equipment's resolution limit and resulted in longer time lags between scintigraphy and surgery.

Seguimiento clínico en pacientes con buena capacidad metabólica en la prueba de esfuerzo con SPECT miocárdico / Follow-up of patients with good exercise capacity in stress test with myocardial single-photon emission computed tomography (SPECT)

Background: The evaluation of coronary artery disease (CAD) can be performed with stress test and myocardial SPECT tomography. Aim: To assess the predictive value of myocardial SPECT using stress test for cardiovascular events in patients with good exercise capacity. Material and Methods: We included 102 males aged 56 ± 10 years and 19 females aged 52 ± 10 years, all able to achieve 10 METs and ≥ 85% of the theoretical maximum heart rate and at least 8 min in their stress test with gated 99mTc-sestamibi SPECT. Eighty two percent of patients were followed clinically for 33 ± 17 months. Results: Sixty seven percent of patients were studied for CAD screening and the rest for known disease assessment. Treadmill stress test was negative in 75.4%; 37% of patients with moderate to severe Duke Score presented ischemia. Normal myocardial perfusion SPECT was observed in 70.2%. Reversible defects appeared in 24.8% of cases, which were of moderate or severe degree (> 10% left ventricular extension) in 56.6%. Only seven cases had coronary events after the SPECT. Two major (myocardial infarction and emergency coronary revascularization) and 5 minor events (elective revascularization) ere observed in the follow-up. In a multivariate analysis, SPECT ischemia was the only statistically significant parameter that increased the probability of having a major or minor event. Conclusions: Nearly a quarter of our patients with good exercise capacity demonstrated reversible defects in their myocardial perfusion SPECT. In the intermediate-term follow-up, a low rate of cardiac events was observed, being the isotopic ischemia the only significant predictive parameter.

Descripción de los hallazgos en el perfil lipídico y proteico de pacientes dependientes a cocaína, en abstinencia reciente / Serum lipid levels in a group of cocaine dependent subjects in recent abstinence

Background: Chronic cocaine users develop multiple potentially lethal ischemic vascular complications associated with accelerated atherosclerosis. Aim: To assess biochemical and lipid profiles among cocaine dependent subjects in recent abstinence. Material and Methods: A blood sample to measure blood count, biochemical and lipid profiles was obtained from 78 patients aged 19 to 53 years (78% males) who complied with DSM-IV criteria for cocaine dependency. Laboratory results were compared with a group of normal subjects. Results: All cases had positive urinary cocaine, with a mean consumption lapse of 7.6 years. The frequency of smoking was higher in cases. Dependent males had higher body mass index than controls. Compared to controls, dependent females had significantly higher triglyceride (TG) levels and lower HDL cholesterol. Therefore the relation total/HDL cholesterol was higher (p = 0.0365). Dependent males had higher TG levels than their normal counterparts. Dependent subjects consuming cocaine base-paste had higher TG levels. Total proteins, albumin, urea and blood urea nitrogen were lower in dependent subjects. Among males, serum creatinine was lower and blood urea was positively correlated with the daily amount of cocaine use (p = 0.03). After a month of strict abstinence, lipid profile was repeated in 27 patients and remained unchanged. Conclusions: Chronic cocaine use was associated with higher TG in both genders and lower HDL cholesterol in women when compared with a group of healthy counterparts.

Seguimiento a cinco años en pacientes diabéticos sin síntomas cardíacos estudiados con perfusión miocárdica / Myocardial perfusion studies in asymptomatic patients with diabetes mellitus are controversial

Antecedentes: El rendimiento del estudio de perfusión miocárdica en pacientes con Diabetes Mellitus (DM) y sin síntomas coronarios es controvertido. Objetivo: Efectuar un seguimiento a 5 años para eventos cardíacos mayores en DM asintomáticos estudiados con SPECT miocárdico en esfuerzo. Método: Se estudiaron 40 pacientes asintomáticos coronarios, con DM conocida por >5 años, >45 años de edad, con >2 factores de riesgo cardiovascular (FRCV) y electrocardiograma basal normal o con alteraciones inespecíficas. Todos efectuaron una prueba de esfuerzo (PE) adecuada y se estudiaron con Sestamibi-Tc99m repetido en 32 casos al 3° año. Además, se evaluó a 36 controles no diabéticos con >2 FRCV. El seguimiento fue de 64+/-11 meses. Resultados: En el grupo DM, 48 por ciento tenía Hba1c>7.5 por ciento; en ellos el SPECT mostró isquemia silente (IS) en 30 por ciento y la PE en 18 por ciento del total. No hubo variaciones significativas en SPECT al 3° año. Hubo una muerte no cardíaca en el 2° año; en el 4° año, se produjo una muerte por infarto agudo de miocardio, con mínima isquemia septal y otra asociada a miocardiopatía e insuficiencia cardíaca, con defecto de predominio fijo, ambos con PE negativa. En el grupo control, el 11 por ciento tuvo SPECT anormal y 8 por ciento PE positiva; hubo una muerte no cardíaca. El Odds Ratio para isquemia fue 3.42 [IC=0.99-11.85] entre DM vs controles y el Hazard Ratio para eventos cardíacos 6.75 [IC=0.40-108.2]. Conclusiones: En DM asintomáticos coronarios el riesgo de IS en SPECT fue mayor que en controles sin DM y con FRCV. Los eventos cardiacos mayores fueron más frecuentes, aunque no significativamente, en DM que en controles. Ello deberá reevaluarse conocidos los resultados del estudio multicéntrico.

The clinical value of myocardial perfusion studies in cardiac asymptomatic patients with Diabetes Mellitus (DM) is controversial. Aim: To conduct a 5 year follow-up study to detect major adverse cardiac events in asymptomatic DM patients using exercise stress and SPECT myocardial perfusion imaging. Methods: 40 patients with known DM for at least 5 years and without evidence of coronary artery disease, older than 45 years of age with >2 cardiovascular risk factors (CVRF) and either normal or minimally altered ECG underwent adequate exercise testing (ET) and 99mTc Sestamibi, repeated 3 years later in 32 cases. We also assessed 36 non-diabetic control patients, with >2 CVRF. Mean follow up was 64+/-11 months. Results: 48 percent of DM patients had HbA1c >7.5 percent; in them, the SPECT showed silent ischemia (SI) in 30 percent and positive ET in 18 percent. There were no significant variations in SPECT at 3 years. There was 1 non-cardiac death in the 2nd year and 2 deaths, one from acute myocardial infarction associated to minimal septal ischemia and another associated with cardiomyopathy and heart failure, with a fixed perfusion defect. Both patients had a negative ET. In the control group, 11 percent had abnormal SPECT and 8 percent positive ET and no cardiac deaths were observed. The Odds ratio for ischemia between DM and controls was 3.42 [CI=0.99-11.85 ] and the Hazard Ratio for cardiac events was 6.746 [CI=0.4205-108.2]. Conclusions: In asymptomatic coronary DM patients, the presence of SPECT ischemia detect was higher than in non-DM controls with CVRF. The incidence of major cardiac events was higher, although not significantly, in DM than control patients. This finding should be re-evaluated in the multicenter study.

Utilidad del estudio PET con FDG en la evaluación de sarcomas de diverso origen y de tumores no sarcoma-no epiteliales / Positron emission tomography with fluorine-deoxyglucose in sarcomas and non-sarcoma non-epithelial tumors

Background: The usefulness of positron emission tomography (PET) with fluorine-deoxyglucose (FDG) in sarcomas and non-sarcoma non-epithelial (NSNE) tumors is not clearly defined. Aim: To report a Chilean experience with NSNE tumors evaluated using PET with FDG. Material and Methods: Retrospective review of the database of a PET laboratory. Demographic data, indications and metabolic findings were compared with conventional imaging in 88 adults and children with diverse bone and soft tissue sarcomas as well as 24 gastrointestinal stromal tumors (GIST), 6 pleural malignant mesotheliomas in adults, and 9 medulloblastomas in children. Results: FDG showed good concordance with conventional imaging in NSNE tumors. It was helpful for staging, restaging, follow-up after treatment and for the detection of new not previously suspected lesions. Conclusions: PET with FDG could have a prognostic role and help in patient management, mainly in musculos-keletal and high grade or less differentiated sarcomas. In GIST, it was a good tool for immunotherapy control.

Daño vascular asociado a uso de cocaína: Caso clínico / Cocaine-induced vascular damage: Report of one case

Background: Cocaine abuse is associated with an increased risk of cardiac and cerebrovascular events, such as myocardial infarction, sudden cardiac death, and ischemic stroke. The underlying mechanisms leading to these complications are not fully understood although intravascular thrombus formation and accelerated atherosclerosis are prominent findings. We report a 39-year-old male addicted to cocaine, who presented with three consecutive ischemic events characterized by an acute myocardial infarction and two ischemic strokes complicated by cardiac failure and severe neurological sequelae. The pathophysiology of cocaine-induce vascular damage and the management of the ischemic complications are discussed.

Cardiología nuclear: actualización en diagnóstico y evaluación de enfermedad coronaria / Nuclear cardiology: updates in diagnosis and evaluation of coronary disease

En esta revisión se entrega una visión general de la situación de la cardiología nuclear en diagnóstico y evaluación de la enfermedad coronaria de una manera global y relativamente simple. Se revisa el rendimiento, las indicaciones y la correlación con otras técnicas disponibles.

This review provides an overview of the status of nuclear cardiology regarding diagnosis and evaluation of coronary artery disease in a comprehensive and relatively simple way. Overall accuracy, indications and the correlation with other available techniques are presented.

Síndrome de Tako-Tsubo: caso clínico / Tako-Tsubo syndrome: Report of one case

Tako-Tsubo syndrome resembles an acute myocardial infarction in symptoms, laboratory parameters and electrocardiographic changes. However, angiography does not show evidence of coronary occlusion, and typically an apical ballooning ofthe ventricle in systole is observed. We report a 78-year-old woman with no coronary risks factors, admitted to the emergency room due to acute chestpain and an electrocardiogram compatible with an acute coronary syndrome with ST elevation. Serum troponin and creatin-kinase (MB fraction) were elevated. An emergency coronary angiography did not show a coronary occlusion. Due to the apical ballooning observed in the left ventriculography, aprobable diagnosis of Tako-Tsubo was proposed. The patient had a favorable evolution. A treadmill test, echocardiogram and myocardial perfusión SPECT, performed one month later, disclosed no abnormalities.

Diferencias en la estimación de isquemia en SPECT de perfusión miocárdica con 99mTc-sestamibi usando bases de datos cuantitativos de ejercicio y dipiridamol / Different ischemia size estimation on exercise and dipyridamole quantitative databases with 99mTc-sestamibi myocardial SPECT

Introducción. Frecuentemente los estudios de perfusión miocárdica con dipiridamol (DIP) son analizados cuantitativamente usando bases de datos de ejercicio (EXE). Objetivo. Comparar un grupo de pacientes con enfermedad coronaria conocida, procesados con bases de datos de DIP y EXE. Métodos. Se analizó los SPECT de perfusión miocárdica con Tc99m-Sestamibi y DIP de 20 hombres y 19 mujeres. Luego de su procesamiento, las imágenes de DIP SPECT fueron comparadas con bases de datos de mapas polares de EXE y DIP. Se analizó la extensión (en pixeles) y la severidad (DS) de los defectos y de las zonas reversibles. Resultados. Hubo concordancia de 92 por ciento en las interpretaciones de los estudios que tenían necrosis, isquemia o ambos (kappa: 0,859). El tamaño de los defectos de estrés fue el mismo con ambas bases de datos tanto en hombres como en mujeres. Sin embargo, en hombres la reversibilidad fue mayor (156,4 +/- 107,7 versus 128,6 +/-113,6 píxeles; p=0,0251) y más severa (699,6 +/- 665,8 versus 486,6 +/- 551,9 SD; p=0,0003) con EXE. En mujeres la reversibilidad fue menor (92,8 +/- 110,3 versus 113 +/- 121,9 pixeles; p=0,0024) y menos severa (278,5 +/- 356,7 versus 363,8 +/-432,7 SD; p=0,0009) con EXE. Conclusiones. Los pacientes que se sometieron a DIP fueron clasificados correctamente como isquemia, necrosis o ambos usando bases de datos de mapas polares de EXE. No obstante, la base de datos EXE subestimó la extensión de los defectos en mujeres y la sobreestimó en hombres.

Background. Frequently, dipyridamole (DIP) myocardial perfusion SPECT is analyzed quantitatively using an exercise (EXE) database. Objective. To compare a group of patients with known coronary artery disease, processed with DIP and EXE polar maps. Method. We studied 20 males and 19 females with DIP Tc99m-Sestamibi myocardial SPECT. After similar processing, the DIP SPECT images were read using both EXE and DIP polar map databases. We analyzed defect and reversibility extension (in pixels) and severity in standard deviations. Results. Agreement to classify patients as having necrosis, ischemia or both was 92 percent (kappa: 0.859). Stress defect size was similar with both databases in males and females. However, in males reversibility resulted larger (156.4 +/- 107.7 versus 128.6 +/- 113.6 pixels; p=0.0251) and more severe (699.6 +/- 665.8 versus 486.6 +/- 551.9 SD; p=0.0003) with EXE. In females, reversibility resulted smaller (92.8 +/- 110.3 versus 113.0 +/- 121.9 pixels; p=0.0024) and less severe (278.5 +/- 356.7 versus 363.8 +/- 432.7 SD; p=0,0009) with EXE. Conclusion. Patients undergoing DIP stress were correctly classified as presenting ischemia, necrosis or both by EXE polar map database. However, EXE database underestimated ischemia extension in females and overestimated it in males.

Valor del índice de excentricidad del ventrículo izquierdo con tomografía spect de perfusión miocárdica en diversas condiciones / Value of eccentricity index of left ventricle with miocardial SPECT perfusion tomography in several conditions

Introducción: El índice de excentricidad (IE) obtenido con SPECT miocárdico permite evaluación de esfericidad ventricular izquierda en remodelación patológica. Objetivo: conocer IE en adultos con diversas condiciones cardíacas. Método: Grupo I: Controles (n=44) con >2 factores de riesgo cardiovascular exceptuando Diabetes Mellitus (DM); Grupo II: DM 2 (n=41). Ambos grupos asintomáticos sin enfermedad coronaria conocida. Grupo III: Con alteración de motilidad segmentaria y/o infarto de miocardio (n=64). Grupo IV: Dilatados (n=21) con alteraciones de motilidad difusa o miocardiopatías. Se utilizó Sestamibi-Tc99m y procesamiento QGS. (IE esfera valor

Background: The Eccentricity Index (EI) obtained with myocardial SPECT allows adequate assessment of left ventricular shape in pathological myocardial remodeling. Aim: To compare EIs in adults with different cardiac conditions. Methods: 170 patients were studied. Group I (n=44) were control subjects with >2 cardiovascular risk factors not including Diabetes Mellitus (DM); Group II (n=41) had type II DM. Patients in both groups were asymptomatic without known coronary artery disease or wall motion abnormalities. Group III (n=64) had seg-mental wall motion abnormality and/or myocardial infarction; Group IV (n=21) included patients with dilated ventricles and diffuse abnormal wall motion. We used gated 99mTc Sestamibi SPECT and QGS processing (EI sphere

Cuantificación paramétrica de los cambios en la perfusión cerebral producidos por abstinencia y con activación neurocognitiva en dependientes de cocaína / Changes in cerebral perfusion caused by abstinence in cocaine-dependent patients

Introducción. Los sujetos dependientes de cocaína pueden presentar deterioro neurocognitivo y alteraciones conductuales con importantes implicancias sociales. En esos pacientes se han demostrado diversas anormalidades en la perfusión cerebral, especialmente en la corteza prefrontal. Esta región cortical está relacionada con funciones ejecutivas y con el control de impulsos. El Wisconsin Card Sorting Test (WCST) fue diseñado específicamente para activar la corteza prefrontal. Objetivo. En sujetos dependientes de cocaína, cuantificar cambios en la perfusion cerebral basal y post activación con WCST inducidos por la detoxificación. Método. Se estudió a 23 pacientes entre 24 y 49 años de edad (19 hombres) que cumplían criterios DSM-IV para dependencia de cocaína y con consumo reciente demostrado. En todos ellos se obtuvo SPECT de perfusión cerebral en condiciones de reposo al ingreso y tras 4 semanas de hospitalización con abstinencia controlada. En 19 sujetos se realizó además SPECT cerebral con activación usando WCST, al inicio y al final de la hospitalización. Para comparar estas cuatro condiciones se utilizó Statistical Parametric Mapping (SPM). Resultados. Al comparar la perfusión en condiciones de reposo inicial y al mes de abstinencia se observó mejoría significativa de múltiples áreas corticales especialmente en región parieto-occipital bilateral y corteza prefrontal izquierda.El análisis grupal no demostró activación de corteza prefrontal con WCST al ingreso a la terapia de detoxificación. Luego de 4 semanas de abstinencia estricta, se observó significativa activación post WCST de corteza prefrontal dorsolateral izquierda.Conclusiones. Un mes de abstinencia estricta de cocaína produce mejoría de la perfusión cerebral en pacientes dependientes. Post consumo reciente, no se demuestra activación a nivel prefrontal con el estímulo del WCST, la cual se observa luego de abstinencia, lo que indica mejoría neurocognitiva...

Introduction. Cocaine-dependent subjects might have socially disruptive behavior. Several regional cerebral blood flow (rCBF) abnormalities have been described in these patients, mainly in the prefrontal cortex, area related to executive functions and impulse control. Wisconsin Card Sorting Test (WCST) was specifically designed to activate this cortical area. Aim. To quantify rCBF and to assess prefrontal activation pre and post detoxification on cocaine-dependant subjects. Methods. We studied 23 patients who met DSM-IV criteria for cocaine dependency ranging from 24 - 49 years old (19 males), all with positive urine cocaine test. Baseline 99mTc-ECD brain perfusion SPECT was performed at admission and after 4 weeks of controlled in-hospital abstinence; in 19 patients SPECT was acquired also after WCST activation. Statistical Parametric Mapping (SPM) was used to compare SPECT studies on these 4 conditions. Results. rCBF of bilateral parieto-occipital area, left prefrontal cortex and multiple small cortical region improved after 4 weeks of cocaine detoxification. The group analysis did not show significant prefrontal cortex activation induced by WCST on admission. After 4 weeks of strict cocaine abstinence, WCST was able to induce left dorsolateral prefrontal cortex activation. Conclusions. A month of strict cocaine abstinence improved brain perfusion in dependant patients. After recent consumption, there was no prefrontal activation when using WCST, but this was observed after abstinence, supporting neurocognitive improvement. These findings may have clinical implications as potential predictors of therapy response.

Alta frecuencia de anticuerpos anti-tiroperoxidasa (ATPO) positivos en sujetos adultos, sin patología tiroidea conocida, de Santiago de Chile / Frequency of positive anti thyroid peroxidase antibody titers among normal individuals

Background: Anti-thyroid peroxidase antibodies have a pathogenic role in Hashimoto thyroiditis. Between 10 and 19 percent of individuals without thyroid disease, have positive titers of these antibodies. Aim: To study the frequency of positive titers of anti-thyroid peroxidase antibodies in healthy individuals. Material and Methods: A blood sample, to measure anti-thyroid peroxidase antibodies and thyroid stimulating hormone (TSH) by chemoluminiscense assay, was obtained from 67women and 62 men aged 45 ± 14years, without a personal or familiar history of thyroid diseases and normal thyroid palpation. The cutoff point of the manufacturer to consider positive a titer of anti-thyroid peroxidase antibodies was set at 35 IU/ml. Results: Twenty-eight women and 28 men had positive antibody titers (43 percent of the sample). Subjects in the upper tercile of anti-thyroid peroxidase antibody titers had a higher TSH than those in the second tercile, although within normal limits (1.73 ± 0.74 and 1.37 ± 0.59 mlU/L, respectively p = 0.02) Conclusions: Forty three percent of the studied subjects without personal or familial history of thyroid diseases had positive titers of anti-thyroid peroxidase antibodies. Further prospective studies should evaluate whether this observation discloses an increase in thyroid autoimmune disease in a population with increased iodine intake.

Daño endotelial y activación del sistema hemostático asociado al uso crónico de cocaína: estudios ex vivo e in vitro / Endothelial damage and activation of the haemostatic system associated to chronic use of cocaine: an ex vivo and in vitro study

Antecedentes: Usuarios crónicos de cocaína tienen riesgo aumentado de presentar infarto de miocardio, angina,muerte súbita y accidentes cerebrovasculares. Aunque la patogenia del daño vascular es mayormente desconocida, se ha encontrado arterioesclerosis prematura y formación de trombos intravasculares. Objetivo: Demostrar evidencia de daño endotelial y activación del sistema hemostático en usuarios crónicos de cocaína. Métodos: Un grupo de 23 pacientes con criterios de dependencia a cocaína DSM-IV; 19 hombres (edad promedio 32 a), con exposición a la droga dentro de 72 h del estudio. Disfunción endotelial se evaluó por enumeración de las células endoteliales circulantes (CEC) y nivel de sICAM . Para activación del sistema hemostático se incluyó: complejos trombina-antitrombina (TAT) y generación de trombina; NAP-2 y RANTES para activación plaquetaria. In vitro, CE en cultivo (HUVEC), se expusieron a plasma de consumidores o controles. Se midió factor von Willebrand (FVW) en el medio y expresión de FvW y factor tisular (FT) sobre las CE. Adhesión plaquetaria estática se evaluó por microscopía. Resultados: En usuarios de cocaína, con respecto a controles, las CEC estaban significativamente elevadas...

Background: chronic cocaine users have an increased risk of developing myocardial infarction, angina, suddendeath and stroke. Although the pathogenesis of this effect is not completely known, premature atheromatosis and intravascular thrombosis appear to be involved.Aim: to provide evidence for the presence of endothelial damage and activation of the haemostatic system in chronic cocaine users. Methods: 23 subjects (19males, overall mean age 32) with DSM-IV criteria for cocaine dependency and exposure to the drug within 72 hours were studied. Endothelial dysfunction was determined by circulating endothelial cell counts (CEC) and sICAM levels. Thrombin-antithrombin complexes (TAT) and thrombin generation were used to characterize haemostatic status. In vitro, platelet activation was studied by NAP-2 and RANTES. EC in culture (HUVEC) were exposed to plasma from cocaine users and controls. Von Willebrand factor was measured in the culture media as well as its expression along with that of tissue factor in EC. Platelet adhesion was evaluated by microscopy. Results: Compared to controls, EC were significantly increased in cocaine users...