Relationship of Electromechanical Dyssynchrony in Patients Submitted to CRT With LV Lead Implantation Guided by Gated Myocardial Perfusion Spect / Relação entre Dissincronismo Elétrico e Mecânico em Pacientes Submetidos a TRC com Implante do Eletrodo de VE Orientado pela Cintilografia GATED SPECT

Abstract Background: Heart failure (HF) affects more than 5 million individuals in the United States, with more than 1 million hospital admissions per year. Cardiac resynchronization therapy (CRT) can benefit patients with advanced HF and prolonged QRS. A significant percentage of patients, however, does not respond to CRT. Electrical dyssynchrony isolated might not be a good predictor of response, and the last left ventricular (LV) segment to contract can influence the response. Objectives: To assess electromechanical dyssynchrony in CRT with LV lead implantation guided by GATED SPECT. Methods: This study included 15 patients with functional class II-IV HF and clinically optimized, ejection fraction of 35%, sinus rhythm, left bundle-branch block, and QRS ≥ 120 ms. The patients underwent electrocardiography, answered the Minnesota Living with Heart Failure Questionnaire (MLHFQ), and underwent gated myocardial perfusion SPECT up to 4 weeks before CRT, being reassessed 6 months later. The primary analysis aimed at determining the proportion of patients with a reduction in QRS duration and favorable response to CRT, depending on concordance of the LV lead position, using chi-square test. The pre- and post-CRT variables were analyzed by use of Student t test, adopting the significance level of 5%. Results: We implanted 15 CRT devices, and 2 patients died during follow-up. The durations of the QRS (212 ms vs 136 ms) and the PR interval (179 ms vs 126 ms) were significantly reduced (p < 0.001). In 54% of the patients, the lead position was concordant with the maximal delay site. In the responder group, the lateral position was prevalent. The MLHFQ showed a significant improvement in quality of life (p < 0.0002). Conclusion: CRT determines improvement in the quality of life and in electrical synchronism. Electromechanical synchronism relates to response to CRT. Positioning the LV lead in the maximal delay site has limitations.

Resumo Fundamento: A insuficiência cardíaca (IC) afeta mais de 5 milhões de pessoas nos Estados Unidos, com mais de 1 milhão de internações/ano. A terapia de ressincronização (TRC) pode beneficiar pacientes com IC avançada e QRS alargado; entretanto, percentual significativo de pacientes não respondem à TRC. O dissincronismo elétrico isolado pode não representar um bom preditor de resposta, e o local da última ativação do ventrículo esquerdo (VE) pode influenciar na resposta. Objetivos: Avaliar o dissincronismo eletromecânico na TRC com o implante do eletrodo do VE orientado por GATED SPECT. Métodos: Incluídos 15 pacientes com IC classe funcional II-IV, otimizados clinicamente, com fração de ejeção de 35%, ritmo sinusal, bloqueio de ramo esquerdo, QRS ≥ 120 ms. Realizaram eletrocardiograma, Questionário Minnesota Vivendo com Insuficiência Cardíaca (MLHFQ) e cintilografia GATED SPECT até 4 semanas antes do implante. Reavaliados 6 meses após. Análise primária visou determinar a proporção de pacientes com redução da duração do QRS e resposta favorável à TRC dependendo da concordância ou não na posição do eletrodo, utilizando teste Qui-Quadrado. Análise das variáveis pré e pós TRC foi feita através do teste t de Student, assumindo significância de 5%. Resultados: Realizamos 15 implantes com 2 óbitos no seguimento. As reduções das durações do QRS (212 ms vs 136 ms) e do IPR (179 ms vs 126 ms) foram significativas (p < 0,001). Em 54%, o eletrodo foi concordante com o local de maior atraso. No grupo respondedor, a posição lateral foi prevalente. O MLHFQ mostrou melhora significativa da qualidade de vida (p < 0,0002). Conclusão: A TRC determina melhora da qualidade de vida e do sincronismo elétrico. O sincronismo eletromecânico relaciona-se com a resposta à TRC. O posicionamento do eletrodo de VE no sítio de maior retardo tem limitações.

Análisis de fase en estudios Gated-SPECT como predictor de mortalidad en pacientes con enfermedad coronaria y función ventricular izquierda deprimida / Phase analysis in Gated-SPECT studies as a predictor of mortality in patients with coronary diseases and impaired left ventricular function

Resumen Antecedentes: La enfermedad coronaria es una de las principales causas de morbimortalidad en los países occidentales. En etapas avanzadas de la enfermedad, los procesos de remodelación miocárdica pueden conducir a insuficiencia cardíaca progresiva y disfunción ventricular izquierda. El análisis de fase de los estudios de perfusión miocárdica Gated-SPECT muestra parámetros que han sido caracterizados como marcadores válidos de asincronía ventricular. Objetivo: Evaluar los parámetros del análisis de fase en Gated-SPECT como predictores independientes de mortalidad en pacientes con enfermedad coronaria avanzada e insuficiencia ventricular izquierda. Materiales y método: Estudio retrospectivo de cohortes históricas de 185 pacientes consecutivos (140 hombres; edad media=67,6±12,7 años) a los que, entre enero de 2009 y marzo de 2011, se les hizo estudio isotópico de perfusión miocárdica con estimulación farmacológica con resultado positivo para isquemia/necrosis con FEVI ≤ 55%. Adicionalmente, se les realizó seguimiento medio de 32,4±10,5 meses registrándose la aparición de eventos cardíacos mayores (infarto agudo de miocardio no mortal, ingreso hospitalario y revascularización coronaria tardía) y mortalidad total. Resultados: Durante el seguimiento se registraron eventos mayores en 51 pacientes así como 28 fallecimientos, de los cuales, 82,1% mostró valores alterados de los parámetros de fase: media=141,1(±17,6(; desviación estándar=15,8(±10,1(; ancho de banda=59,1(±36( y FEVI=42,4%±10,8%. El análisis de Cox mostró al ancho de banda como un predictor independiente de muerte, disminuyendo significativamente la supervivencia y aumentando el riesgo de muerte (hazard ratio=2,68; p<0,05). Conclusiones: El ancho de banda en el análisis de fase se comporta como un predictor independiente de muerte en pacientes con miocardiopatía conocida y FEVI deprimida.

Abstract Background: Coronary disease is one of the main causes of morbidity and mortality in western countries. In the advanced stages of the disease the myocardial remodelling processes can lead to progressive heart failure and left ventricular impairment. The phase analysis of Gated-SPECT studies of myocardial perfusion show parameters that have been characterised as valid marker of ventricular asynchrony. Objective: To evaluate the phase analysis parameters in Gated SPECT as independent predictors of mortality in patients with advanced coronary disease and left ventricular failure. Materials and method: A retrospective historic cohort study was conducted on 185 consecutive patients (140 males; mean age = 67.6±12.7 years) on whom, between January 2009 and March 2011, an isotope myocardial perfusion study was carried out with pharmacologic stimulation and with a positive result for ischaemia / necrosis, and with a LVEF ≤ 55%. A mean follow-up of 32.4 ±10.5 months was also performed, recording the appearance of major cardiac events (non-fatal acute myocardial infarctions, hospital admission, delayed coronary revascularisation, and total mortality. Results: Major events were recorded in 51 patients during follow-up. There were also 28 deaths, of which 82.1% showed abnormal values of the phase parameters: media=141.1(±17.6(; standard deviation=15.8(±10.1(; bandwidth=59.1(±36(, and LVEF = 42.4%±10.8%. The Cox analysis showed the bandwidth as an independent predictor of death, significantly reducing the survival and increasing the risk of death (hazard ratio=2.68; P<.05). Conclusions: The bandwidth in the phase analysis behaves as an independent predictive factor in patients with known myocardial disease and an impaired LVEF.

Implicancia pronóstica de los estudios gated-SPECT normales en pacientes mayores de 70 años / Pronostic implication of normal gated SPECT studies in patients over 70 years old

Introducción: un resultado normal en la centellografía de perfusión miocárdica gatillada (gated-SPECT) tiene un alto valor predictivo negativo para enfermedad coronaria grave; existe un período de tiempo variable en que los pacientes permanecen con una tasa de eventos baja (menor a 1%). Sin embargo, algunas evidencias sugieren que este período de garantía (PG) no es el mismo en todos los grupos etarios. Objetivo: establecer el período de tiempo en el cual los pacientes ancianos (mayores de 70 años) mantienen una tasa de eventos cardíacos por debajo de 1%. Material y método: se estudiaron 554 pacientes mediante gated-SPECT, divididos en dos grupos: Grupo 1: (n=354) con gated-SPECT normal, y Grupo 2: (n=200) con gated-SPECT anormal. Definimos un gated-SPECT normal como aquel con score de suma en estrés (SSS) < 4 y parámetros funcionales normales. El seguimiento medio fue de 30,6 meses (rango: 12-62 meses) para la pesquisa de los eventos cardiovasculares (EC): muerte cardíaca (MC) e infarto agudo de miocardio no fatal (IAMNF), y eventos combinados (ECB): EC+ angioplastia coronaria, cirugía de revascularización miocárdica e implante de cardiodesfibrilador. Se utilizó prueba no paramétrica de Pearson y se calculó el estadístico x2, con un valor de p ?0,05 para el rechazo de la hipótesis nula (IC: 95%). Resultados: la comparación entre ambos grupos muestra diferencias en los tres primeros años para la aparición de EC (p <0,0001), MC (p <0,0001) y ECB (p <0,0001). La tasa de EC en el Grupo 1 para cada año fue de 0,56%, 0,59% y 0,50%, respectivamente, con una tasa acumulada a tres años de 1,65%. La tasa en el Grupo 2 fue de 2,50%, 1,58% y 3,84%, respectivamente (tasa acumulada: 7,92%). El período de tiempo en el cual los pacientes del Grupo 1 mantuvieron un riesgo de EC por debajo de 1% fue de 18 meses. Conclusión: el pronóstico de los pacientes ancianos que presentan un resultado normal en el gated-SPECT es muy bueno, con una tasa de EC menor a 1% por un lapso de 18 meses.

Introduction: a normal result in myocardial perfusion scintigraphy (gated-SPECT) has a high negative predictive value for severe coronary artery disease; there is a period of time in which patients remain with a low event rate (less than 1%). However, some evidence suggests that this guarantee period (PG) is not the same in all age groups. Objectives: to establish the period of time in which elderly patients (older than 70 years) maintain a rate of cardiac events below 1%. Material and methods: 554 patients were studied through gated-SPECT, divided into two groups: Group 1: (n = 354) with normal gated-SPECT, and Group 2: (n = 200) with abnormal gated-SPECT. We define a normal gated-SPECT as that with a stress sum score (SSS) <4 and normal functional parameters. The mean follow-up was 30.6 months (range: 12-62 months), for the investigation of cardiovascular events (CE): cardiac death (CD) and nonfatal infarction (NFAMI), and combined events (CBE): CE + coronary angioplasty, myocardial revascularization surgery and implanted cardiodefibrillator (ICD). Pearson's nonparametric test was used and the Χ2 statistic was calculated, with a value of p <0.05 for the rejection of the null hypothesis (CI: 95%). Results: the comparison between both groups shows differences for the appearance of CE: (p <0.0001), CD: (p <0.0001) and CBE: (p <0.0001). The CE rate in Group 1 for each year was 0.56, 0.59 and 0.50%, respectively, with a cumulative 3-year rate of 1.65%. The rate in Group 2 was 2.5, 1.58 and 3.84%, respectively (cumulative rate: 7.92%). The period in which Group 1 patients maintained a risk of CD below 1% was 18 months. Conclusion: the prognosis of elderly patients presenting a normal gated-SPECT result is very good, with a cardiac event rate of less than 1% for a period of 18 months.

Influencia de la experiencia profesional del cardiólogo clínico sobre la adecuación de las indicaciones clínicas de la gated-SPECT de perfusión miocárdica / Influence of the professional experience of the clinical cardiologist on the adequacy of the clinical indications of myocardial perfusion gated-SPECT

Resumen Objetivo: Durante el período de formación, el residente de cardiología ha de entrenarse en todo lo relacionado con la indicación, la interpretación y realización de imágenes en cardiología nuclear que usan la tomografía computarizada por emisión de fotón simple (SPECT). El objetivo del presente estudio fue analizar la relación existente entre la adecuación de las indicaciones del gated-SPECT de perfusión miocárdica y los años de experiencia desde la finalización de la residencia de cardiología. Método: Registro descriptivo, retrospectivo y unicéntrico, en el que se analizaron las indicaciones (uso adecuado e inadecuado), según las guías de la gated-SPECT de perfusión miocárdica, prescritas por cardiólogos de un hospital universitario. Resultados: Se analizaron un total de 950 pruebas de gated-SPECT de acuerdo a la indicación adecuada e inadecuada y se distribuyeron por cuartiles los años de finalización de la residencia del cardiólogo prescriptor. Los cardiólogos de menos de 10 años de experiencia clínica indican de forma inadecuada una mayor proporción de pruebas de gated-SPECT que los cardiólogos de mayor experiencia (87,6 vs. 9,3%: p < 0,001). Tras ajustar por edad, sexo y factores de riesgo cardiovascular, el análisis multivariante mostró que por cada año de experiencia tras finalizar la residencia de cardiología aumenta un 33% la probabilidad de indicar de forma adecuada la prueba (OR: 1,33; IC 95%: 1,29-1,38; p < 0,001). Conclusiones: La experiencia profesional del cardiólogo clínico es el factor más importante para realizar una indicación adecuada de la gated-SPECT de perfusión miocárdica.

Abstract Objective: During cardiology training, the cardiology fellow has to be trained in all things related to the indication, interpretation, and performing of nuclear cardiology studies using single photon emission computed tomography (SPECT). The aim of the present study was to analyse the relationship between the adequacy of indications of myocardial perfusion gated-SPECT and the years of experience since the completion of cardiology training. Method: A descriptive, retrospective analysis was performed on a single-centre register, in which the indications (adequate or inadequate use) were recorded according to myocardial perfusion gated-SPECT guidelines, prescribed by cardiologists of a university hospital. Results: A total of 950 gated-SPECT tests were analysed according to the appropriate or inade- quate indication. The sample of study was distributed in quartiles (years) since the cardiologist finished the residency. Cardiologists with less than 10 years of clinical experience reported a higher proportion of gated-SPECT tests compared to the more experienced cardiologists (87.6 vs. 9.3%, P < .001). After adjusting for age, gender, and cardiovascular risk factors, the multiva- riate analysis showed that, for each year of experience after completion of cardiology training, the probability of adequately indicating the test (OR: 1.33, 95% CI: 1.29-1.38, P < .001) was statistically significant. Conclusions: The professional experience of the clinical cardiologist is the most important factor to perform an appropriate indication of gated-SPECT myocardial perfusion.

Efectos de la estimulación endocárdica prolongada sobre la sincronía mecánica ventricular izquierda. Ensayo piloto aplicando análisis de fase por tomografía computada por emisión de fotón único gatillada. Estimulación prolongada y disincronía mecánica / Effects of prolonged endocardial stimulation on left ventricular mechanical synchrony. A pilot study applying gated-SPECT phase analysis. Endocardial stimulation and dyssynchrony

Resumen: Objetivo: Evaluar la disincronía mecánica ventricular izquierda (DMVI) asociada a la estimulación endocárdica prolongada del ventrículo derecho mediante el ensayo piloto de una nueva técnica de imagen en Uruguay. Métodos: Se estudiaron 12 pacientes con marcapasos implantados al menos hace un año utilizando SPECT gatillada con 99mTc-MIBI y análisis de fase en reposo. Se registraron variables clínicas, duración del QRS, tasa, modo y sitio de estimulación ventricular, presencia y extensión de infarto e isquemia, volúmenes cavitarios y FEVI en reposo. Utilizando V-Sync de Emory Cardiac Toolbox se obtuvieron desviación estándar y ancho de banda de fase en reposo (grados), comparando los individuos con FEVI ≥ y < 50% con una población control. Resultados: Los pacientes de la serie con estimulación endocárdica prolongada en el ventrículo derecho exhibieron marcada DMVI. Los pacientes con FEVI moderada/severamente disminuida (con diámetros cavitarios mayores, estimulación septal, infarto extenso o isquemia significativa) exhibieron mayor disincronía que aquellos con FEVI conservada/levemente disminuida (ancho de banda = 144.33o vs. 77.41o, p < 0.05; desviación estándar = 46.67o vs. 26.81o, p < 0.05). Conclusiones: En la cardiopatía isquémica la elevada tasa de estimulación endocárdica crónica se asocia con marcada DMVI, aun cuando la función sistólica esté conservada. El análisis de fase podría ser una herramienta válida para evaluar la disincronía asociada al infarto en pacientes con marcapasos, y aportar a la indicación oportuna del pasaje (upgrading) al modo de estimulación biventricular.

Abstract: Objetive: To evaluate left ventricular mechanical dyssynchrony (LVMD) associated with prolonged right ventricular pacing through an innovative imaging technique as a pilot study in Uruguay. Methods: A 99mTc-MIBI gated-SPECT and phase analysis was performed in 12 patients with pace-makers implanted at least one year before scintigraphy, due to advanced atrioventricular block. Clinical data, QRS duration, rate, mode and site of pacing in right ventricle, chamber diameters, presence and extension of myocardial scar and ischaemia, as well as LVEF at rest, were recorded. Using V-Sync of Emory Cardiac Toolbox, a standard deviation (PSD) and band-width (PBW) from rest phase histogram was obtained and these indexes were compared with controls in the subgroups of patients with LVEF ≥ 50% and < 50%. Results: Patients with prolonged RV endocardial pacing exhibited marked LVMD. More severe dyssynchrony was found in patients with impaired LVEF than in patients with preserved LVEF (PSD: 46.67o vs. 26.81o, P < .05; PBW: 144.33o vs. 77.41o, P < .05). Higher left ventricle diameters, extensive infarct, or significant ischaemia were found in patients with impaired LVEF. Conclusions: Chronic right ventricular pacing was invariably associated with LVMD, even when systolic function was preserved. Phase analysis could be a potentially useful technique to evaluate LMVD associated with myocardial scar in patients with pacemakers, and to decide promptly the upgrading to biventricular pacing.

Disincronía ventricular izquierda en la estimulación septal prolongada / Left ventricular dyssynchrony in prolonged septal stimulation

La estimulación por marcapasos se asocia con eventos adversos graves. En la siguiente serie de casos se evaluó la disincronía mecánica intraventricular izquierda (DMVI) en la estimulación endocárdica prolongada del ventrículo derecho a nivel septal. Se estudiaron 6 personas con marcapasos implantados no antes de un año utilizando SPECT gatillado con 99mTc-MIBI y análisis de fase en reposo. Se registraron variables clínicas, duración del QRS, tasa y modo de estimulación ventricular, presencia y extensión de isquemia y/o infarto, volúmenes cavitarios y FEVI en reposo. Utilizando V-Sync de Emory Cardiac Toolbox se obtuvieron el ancho de banda (AB) y el desvío estándar de fase (DEF) en reposo (grados), comparándolos con una población control. La estimulación endocárdica prolongada en el septum ventricular derecho se asoció con marcada DMVI, aun cuando la función sistólica estaba conservada. Aquellos con FEVI moderada/gravemente disminuida (caracterizados por diámetros cavitarios mayores, infarto o isquemia grave) exhibieron mayor disincronía que aquellos con FEVI conservada/levemente disminuida (AB: 177.3o vs. 88.3o; DEF: 53.1o vs. 33.8o). En los casos con cardiopatía isquémica portadores de marcapasos, el AF es una herramienta válida de potencial utilidad para evaluar la disincronía asociada al infarto y, eventualmente, aportar a la decisión oportuna del pasaje al modo de estimulación biventricular.

Pacemaker stimulation is associated with unpredictable severe cardiac events. We evaluated left ventricular mechanical dyssynchrony (LVMD) during prolonged septal right ventricular pacing. We performed 99mTc-MIBI gated-SPECT and phase analysis in 6 patients with pacemakers implanted at least one year before scintigraphy due to advanced atrioventricular block. Using V-Sync of Emory Cardiac Toolbox we obtained phase bandwidth (PBW) and standard deviation (PSD) from rest phase histogram. Clinical variables, QRS duration, rate and mode of pacing in septal right ventricle wall, chamber diameters, presence and extension of myocardial scar and ischemia and rest LVEF were recorded. Prolonged septal endocardial pacing is associated with marked LVMD, even when systolic function was preserved. More severe dyssynchrony was found in patients with impaired LVEF, higher left ventricle diameters, extensive infarct or severe ischemia than in patients with preserved LVEF (PBW: 177.3o vs. 88.3o; PSD: 53.1o vs. 33.8o). In the patients with ischemic heart disease and pacemaker, gated-SPECT phase analysis is a valid and potentially useful technique to evaluate LMVD associated with myocardial scar and to decide the upgrading to biventricular pacing mode.

Evaluation of ventricular-vascular coupling in patients with type 2 diabetes mellitus using 2-dimensional speckle tracking imaging / 华中科技大学学报（医学）（英德文版）

The elastic and functional coupling of heart and vessels makes the stroke work (SW) of the heart optimal. Speckle tracking imaging (STI) can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction (EF): the diabetes mellitus with normal EF (DMN) group and the diabetes mellitus with abnormal EF (DMA) group. Forty-two volunteers served as control group. The relative wall thickness (RWT), left ventricular mass index (LVMI), stroke volume (SV), SW, rate-pressure product (RPP), systemic vascular resistance index (SVRI), left ventricular end-systolic elastance (Ees), effective arterial elasticity (Ea) and ventricular-vascular coupling index (VVI) were measured and calculated by conventional echocardiography. The longitudinal strain (LS) at basement (LSBA), papillary muscle (LSPM) and cardiac apex (LSAP) was assessed with STI. It was found: (A) compared with control group, in DMN and DMA groups, LSBA, LSPM and LSAP decreased, and they were lower in DMA group. (B) VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. (C) LSBA, LSPM, and LSAP had negative correlation with VVI. LSAP, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic (ROC) curves was used for identification of DMA and DMN with LSBA, LSPM, and LSAP, and the area under the ROC of LSAP was the largest. This study supports that myocardial LS could reflect the ventricular-vascular coupling. Different segments had an order to "respond to" the state of the coupling, and the cardiac apex might be the earliest.

Impaired Coronary Flow Reserve Is the Most Important Marker of Viable Myocardium in the Myocardial Segment-Based Analysis of Dual-Isotope Gated Myocardial Perfusion Single-Photon Emission Computed Tomography

OBJECTIVE: The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), 201Tl perfusion status at rest, 201Tl 24 hours redistribution and systolic wall thickening of 99mTc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. MATERIALS AND METHODS: A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 +/- 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. RESULTS: The left ventricular ejection fraction (LVEF) significantly increased from 37.8 +/- 9.0% to 45.5 +/- 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and 201Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). CONCLUSION: Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

Cintilografia de perfusão miocárdica e comprometimento cardíaco na fase indeterminada da doença de chagas / Myocardial perfusion imaging and cardiac involvement in the indeterminate phase of chagas disease

FUNDAMENTO: A cintilografia de perfusão miocárdica (CPM) tem sido utilizada na avaliação da cardiopatia chagásica. OBJETIVO: Investigar o valor da CPM com tomografia computadorizada por emissão de fóton único (gated-SPECT) para detectar comprometimento cardíaco precoce em pacientes chagásicos na fase indeterminada, que apresentam anomalias de movimento segmentar detectadas por exame de imagem por Doppler tecidual (IDT) strain derivada. MÉTODOS: Foram incluídos 40 indivíduos (idade média: 25 ± 2 anos, 50% homens) de uma área endêmica da doença de Chagas e com diagnóstico sorológico positivo. Todos foram submetidos à CPM com gated-SPECT de 2 dias (repouso e estresse) e ecocardiografia. RESULTADOS: Trinta indivíduos (75%) apresentaram resultados normais. Em três casos (8%), a CPM apresentou resultado ligeiramente anormal e em sete foi ambígua. Em todos os casos com defeitos reversíveis, os segmentos afetados foram coincidentes com aqueles com anomalias de movimento. Foi encontrada redução na fração de ejeção ventricular esquerda (FEVE) > 5% (ΔLVEF% < -5) pós-estresse em 11 dos 40 indivíduos (28%). Tanto o desvio padrão fasederivado como a largura da banda do histograma mostraram diferença significativa entre o pós-estresse e a fase de repouso. Em ambos os casos, houve ligeira dessincronia em repouso normalizado no pós-estresse. CONCLUSÃO: Uma abordagem estresse-repouso com gated-SPECT é válida para detectar alterações miocárdicas precoces, bem como dessincronia intraventricular na fase indeterminada da doença de Chagas em pacientes com anomalias no movimento segmentar previamente detectadas pela IDT strain derivada.

BACKGROUND: Myocardial perfusion imaging (MPI) has been used in the assessment of chagasic heart disease. OBJECTIVE: To investigate the value of gated-single photon emission computed tomography (gated-SPECT) MPI to detect early cardiac involvement in chagasic patients in the indeterminate phase, who present segmental motion abnormalities detected by tissue Doppler imaging (TDI)-derived strain. METHODS: Forty individuals (mean age: 25±2 years, 50% males) from an endemic area of Chagas disease and with positive serologic diagnosis, were included. All underwent gated-SPECT two-day (stress-rest) MPI and echocardiography. RESULTS: Thirty individuals (75%) showed a normal scan. In three cases (8%) the MPI was slightly abnormal, and in seven it was equivocal. In all cases with reversible defects, the affected segments were coincident with those with motion abnormalities. A post-stress left ventricular ejection fraction (LVEF) reduction > 5% (ΔLVEF < -5%) was found in 11 out of 40 individuals (28%). Both the phase-derived standard deviation and the histogram bandwidth showed a significant difference between post-stress and rest. In both cases there was a slight dyssynchrony at rest which normalized at post-stress. CONCLUSIONS: A stress-rest gated-SPECT is a valid approach to detect early myocardial alterations, as well as intraventricular dyssynchrony in the indeterminate phase of Chagas disease in patients with segmental motion abnormalities previously detected by TDI-derived strain.

Gated [99m]Tc-MIBI myocardial perfusion SPECT in patients with right bundle branch block but without evidence of coronary artery disease

We aimed to investigate the effect of right bundle branch block [RBBB] on perfusion and functional parameters in dipyridamole stress/rest Tc99m-MIBI gated myocardial perfusion SPECT [GSPECT] which may be helpful in interpretation of myocardial perfusion imaging. We studied 73 patients with low pre-test likelihood of coronary artery disease in two groups: 38 patients with RBBB and 35 subjects with normal ECG. Both groups underwent two-day dipyridamole stress-rest Tc99m-MIBI GSPECT. Two groups were matched. There was no significant difference in sex and age variable between two groups. Visual calculated SSS and SRS in all patients were between 0 and 3. Regarding the prone images, diaphragmatic attenuation and breast attenuation, all patients GSPECT findings were within normal limits. There was no significant difference in TID ratio between two groups: RBBB group: TID ratio= 1.02 +/- 0.16 and control group: TID ratio= 0.96 +/- 0.14 [P=0.09]. There was no significant difference in left ventricular end-systolic volume, end-diastolic volume, ejection fraction, summed stress and rest motion and thickening scores between RBB patients group and control group. No regional LV wall motion abnormality was noticed in any patient in either group. High normality rate of the LV myocardial perfusion and functional indices in the presence of RBBB was noticed in gated Dipyridamole stress/rest Tc-99m sestamibi myocardial perfusion SPECT. No remarkable false positive perfusion findings or abnormal LV functional indices acquired by GSPECT in this group of patients

Assessment of the integrated role of myocardium perfusion gated SPECT study in patient with parathyroid adenoma by [99m]Tc-sestamibi

The purpose of this study is to assess the integrated role of scintigraphy by Tc99m MIBI in diagnosis of parathyroid adenoma and its impacts on the myocardium, and to evaluate whether myocardium perfusion gated SPECT study could be a complementary routine workup for patient with positive parathyroid adenoma on Tc99m MIBI parathyroid scan. Rest myocardium perfusion gated SPECT study was performed on the same day of parathyroid scintigraphy, the stress study were completed on the next day for complete assessment of the myocardium perfusion and LV functions. Population included 30 patients; 56% were positive for parathyroid adenoma and compared to 44% negative for parathyroid adenoma, the latter was considered as control group, the gated SPECT EF was normal in 62.5% and abnormal 37.5%. Myocardial perfusion was abnormal in 43.75%, the overall hemodynamic disorder including EF abnormalities as well as the perfusion defects in the study group were 62.5% compared to 27.5% in the controlled group with statically significant relationship [P value=0.03]. The risk of premature cardiovascular death in p HPT is a serious problem and the present study indicates that scintigraphically detected parathyroid adenoma has an impact on the overall hemodynamic of the myocardium and the complementary role of rest/ stress two days protocol Tc99m MIBI myocardium perfusion gated SPECT study may be promising, but its usage as routine workup specially in patient with positive parathyroid adenoma and have high risk warranted further evaluation and reassessment

Gated myocardial perfusion SPECT in patients with left bundle block but having low probability of coronary artery disease; as compared to the patients with normal electrocardiogram

We aimed to investigate of effect of left bundle branch block [LBBB] on perfusion and functional parameters in dipyridamole Tc99m-MIBI gated myocardial perfusion SPECT which may be helpful in interpretation of myocardial perfusion imaging. We studied 70 patients with low pre-test probability of coronary artery disease in two groups: 35 patients with LBBB and 35 subjects with normal ECG. Both groups underwent two-day dipyridamole stress-rest Tc99m-MIBI GSPECT. From 35 patients with LBBB, 6, 12, and 3 patients had reversible, fixed and partially reversible defects respectively. In 35 patients with LBBB, 8 [22.9%], 6[17.1%] 15[42.9%] and 10 [28.6%] patients had perfusion defects in the apicoseptal, mid-anterior segments, mid-anteroseptal and mid-inferoseptal segments respectively. There was significant difference in TID ratio between two groups: LBBB group: 1.07 +/- 0.21 and control group: 0.96 +/- 0.14 [P=0.01]. There was a significant difference in end systolic volume and ejection fraction between LBBB patients group and control group, while no significant difference was noticed in end-diastolic volume. Nineteen, 14 and 2 from 35 patients with LBBB had normal LV wall motion, paradoxical septal wall motion, and septal hypokinesia, respectively. False positive septal, anterior and apicoseptal perfusion abnormalities are frequently seen on Tc99m-MIBI GSPECT, in patients with LBBB without CAD. Moreover reversible defects are frequently seen with Tc99m-MIBI. Even Tc99-MIBI and vasodilator stress do not increase diagnostic accuracy to clinically useful levels. Lower systolic performance and higher TID ratio could be seen in these patients

Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

Although coronary artery disease [CAD] is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging [MPI] is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography [ECG], routine laboratory tests and exercise treadmill test [ETT] were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months [mean 21.7 months] and any cardiac event was recorded. We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively.75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3 +/- 1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up [17-26 months]. Mean stress end diastolic volume [EDV] was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings [62.0 +/- 31.6 Vs 48.5 +/- 18.4 ml, P=0.04]. Blood glucose and HA1c were significantly higher in patients with ischemia compared to patients without ischemia [P<0.05]. Meanwhile the ratio of TG to HDL was 6.06 +/- 3.2 in ischemic patients compared to 4.8 +/- 2.3 in normal subjects [P=0.03]. Reversible defects are commonly seen in myocardial perfusion SPECT in asymptomatic diabetic patients and are mild in severity and not associated with adverse cardiac events. Routine approach for detection of CAD beginning with ETT seems to be appropriate in these patients

Estudio preliminar de índices ecocardiográficos que permitanoptimizar la indicación de resonancia cardíaca en pacientes conTetralogía de Fallot reparada / Echocardiographic indexes help predict the need for nuclear magnetic resonance evaluation of patients with repaired tetralogy of fallot

Introducción: La Tetralogía de Fallot reparada (TOFr) a largo plazo evoluciona frecuentemente con insuficiencia pulmonar (IP). La resonancia magnética cardíaca (RMC) juega un rol fundamental en la indicación de recambio valvular pulmonar destinada a evitar las complicaciones de la IP. Objetivo: El objetivo de este trabajo es buscar qué índice(s) ecocardiográfico(s) permite(n) identificar a los pacientes con TOFr que tienen VD dilatado y fracción de eyección (FE) disminuida en la RMC. Método: En 20 pacientes (9 mujeres, 8-25 años, promedio 15,8 años) con TOFr se realizó ecocardiograma (ECO) y RMC en el Hospital Sótero del Río. Por ECO se obtuvieron mediciones de excursión sistólica máxima anular tricuspídea (TAPSE), onda s tisular, aceleración miocárdica isovolumétrica (IVA), y grado de IP (leve, moderado o severo). Por RMC se midieron la FE, volumen fin de diástole (VFD) del VD y fracción de regurgitación de la arteria pulmonar (FR). Se realizó un análisis estadístico multivariado. Resultados: No se obtuvo ninguna correlación entre algún parámetro de ECO versus VFD o FE del VD. Sin embargo, se encontró un modelo basado en el TAP-SE e IP que en nuestros pacientes pudo predecir el VDF del VD con un r2 = 0.6. (VDF-VD = 8.60*TAPSE + 36.19*IP - 77.213). Al comparar la IP con la FR se encontró que la ecografía puede distinguir correctamente aquellos casos que tienen IP leve de severa (p<0.001), o moderada de severa (p=0.004), pero no puede diferenciar con significancia estadística aquellos casos de IP leve de moderada (p=0.272). Conclusión: En este estudio preliminar se encontró un modelo estadístico basado en el TAPSE e IP que podría ser útil en la selección de pacientes que son derivados para estudio con RMC. La estimación del grado de IP medida por ECO es un parámetro fácil de obtener, sin embargo no siempre es informado en forma categórica (leve, moderado o severo). Si bien este estudio se debe validar en un mayor número de pacientes, éste nos indica la...

Background: Pulmonary insufficiency (PI) frequently appears long-term after repair of Tetralogy of Fallot (TOFr). Cardiac magnetic resonance (CMR) plays a fundamental role in the indication of pulmonary valve replacement, in order to avoid complications of PI. However, CMR is a scarce and expensive resource in our reality, which is why its indication must be optimized. Aim: The objective of this work is to find echocar-diographic indices to identify patients with TOFr with dilated RV and reduced ejection fraction (EF). Method: Images from echocardiograms (ECHO) and CMR in 20 patients (9 women, 8-25 years of age, average 15,8 years old) with TOFr were retrospectively reviewed. From ECHO images we obtained measurements for tricuspid annular plane systolic excursion (TAPSE), tissular s wave, isovolumetric acceleration (IVA), and severity of PI (mild, moderate, or severe). From CMR images, we measured EF, end diastolic volume (EDV) of the RV, and regurgitant fraction (RF) of the pulmonary artery. We performed a multivariate statistical analysis to explore the relation between ECHO parameters and CMR findings. Results: No correlation was found between individual ECHO parameters and EDV or RV EF. However, we did find a model based on the TAPSE and PI that was able to predict the EDV of the RV with an r2 = 0.6. (FDV-RV = 8.60*TAPSE + 36.19*PI - 77.213). After comparing the PI with RF, we found that that echocar-diography could correctly distinguish cases with mild PI from those with severe PI (p<0.001), or moderate from severe (p=0.004), but not mild from moderate PI. Conclusion: In this preliminary study, we found a statistical model based on the TAPSE and PI which could be useful in the selection of patients with TOFr that are referred to CMR. While this study needs to be validated on a greater number of patients, it indicates the relevance of some echocardiographic parameters, which should always be included in the evaluation of patients with TOFr.

Diagnostic value of left ventricular function after adenosine loading detected by gated myocardial perfusion imaging for prediction of major adverse cardiac events / 生物医学工程学杂志

This study was aimed to analyze the value of the SPECT MPI to myocardial ischemia and cardiac function parameters in the CAD prognosis assessment. A total of 890 patients with suspected CAD underwent adenosine loading stress gated SPECT. At a mean follow-up of (2.3 +/- 0. 4) year, a total of 37 adverse events occurred, including 12 cardiac deaths and 25 nonfatal myocardial infarctions. Univariate Cox analysis showed that diabetes (wald 6.95, P < 0.01), SSS (wald 24.31, P < 0.001), EF (wald 17.14, P < 0.001), ESV (wald 8.58, P < 0.01) and EDV (wald 7.95, P < 0.01) were significant predictors of MACEs. Multivariate Cox analysis showed that SSS (wald 6.69, P < 0.05) and EF (wald 4.70, P < 0.05) were independent predictors. According to the results, SSS and EF are both independent predictors of MACEs.

Valor diagnóstico da cintilografia miocárdica em pacientes com doença coronariana multiarterial / Diagnostic value of myocardial radionuclide imaging in patients with multivessel coronary disease

FUNDAMENTO: A cintilografia de perfusão miocárdica (CPM) é um método não invasivo extremamente útil na avaliação de isquemia em portadores de doença coronária. Entretanto, persiste o conceito de que não seria um bom método para os portadores de doença coronária multiarterial. OBJETIVO: Avaliar o valor da CPM com gated-SPECT na identificação de isquemia induzida por estresse farmacológico em pacientes com diagnóstico de doença coronária obstrutiva multiarterial. MÉTODOS: Foram incluídos 68 pacientes com diagnóstico de doença coronária obstrutiva multiarterial pela cineangiocoronariografia (cine) para realização de CPM sob estímulo farmacológico com dipiridamol. Os exames foram analisados por dois médicos nucleares sem prévio conhecimento do resultado da cine. RESULTADOS: Dos pacientes, 64 (92,8 por cento) apresentaram alteração nas imagens de perfusão e 4 (7,2 por cento) apresentaram perfusão normal, sendo que, destes, três apresentaram alterações funcionais na análise do gated-SPECT. CONCLUSÃO: A CPM mostrou-se de grande valor na identificação de pacientes portadores de doença coronária multiarterial, já que a maioria dos pacientes apresentou alterações perfusionais sugestivas de isquemia.

BACKGROUND: Myocardial perfusion radionuclide imaging (MPRI) is a noninvasive method extremely useful for evaluating ischemia in patients with coronary disease. However, the idea that this method would not be effective for patients with multivessel coronary disease is still entertained. OBJECTIVE: Assess the value of MPRI with gated-SPECT for tracing pharmacological stress-induced ischemia in patients with multivessel obstructive coronary disease. METHODS: We evaluated 68 patients with multivessel obstructive coronary disease applying coronary angiography for performing MPRI under pharmacologic stress with dipyridamole. The tests were analyzed by two nuclear medicine physicians without prior knowledge of the result of the coronary angiography. RESULTS: Gated-SPECT revealed that, out of the patients, 64 (92.8 percent) showed images of perfusion abnormalities and 4 (7.2 percent) showed normal perfusion, given that three of the latter showed functional changes. CONCLUSION: MPRI has shown high value for identifying patients with multivessel coronary disease, since most patients had perfusion abnormalities indicative of ischemia.

Avaliação da perfusão e função miocárdicas em vítimas de escorpionismo utilizando o Gated-SPECT / Assessment of myocardial perfusion and function in victims of scorpion envenomation using Gated-SPECT

FUNDAMENTO: O choque cardiogênico e o edema agudo de pulmão são as principais causas de óbito em pacientes com escorpionismo, cujo mecanismo fisiopatológico ainda é controverso. OBJETIVOS: Investigar a correlação entre os distúrbios da perfusão miocárdica e a função contrátil do ventrículo esquerdo, em vítimas de escorpionismo. MÉTODOS: Quinze pacientes submeteram-se à cintilografia de perfusão miocárdica sincronizada com ECG (Gated SPECT), dentro de 72 horas e 15 dias após o acidente escorpiônico. As imagens foram analisadas visualmente por escore semiquantitativo de perfusão (0 = normal, 4 = ausente) e mobilidade (0 = normal, 4 = acinético), utilizando modelo de 17 segmentos. Para cada paciente foram calculados escores somados de perfusão (ESP) e mobilidade (ESM). A fração de ejeção (FEVE) foi calculada por software comercialmente disponível. RESULTADOS: Na avaliação inicial, 12 dos 15 pacientes apresentaram alterações da contratilidade e da perfusão miocárdica. O ESP foi de 12,5 ± 7,3, o ESM de 17,0 ± 12, 8 e a FEVE de 44,6 ± 16,0 por cento. Houve correlação positiva entre o ESP e o ESM (r = 0,68; p = 0,005) e negativa entre o ESP e a FEVE (r = -0,75; p = 0,0021). Os estudos de seguimento mostraram recuperação da contratilidade global (FEVE de 68,9 ± 9,5, p = 0,0002), segmentar (ESM 2,6 ± 3,1, p = 0,0009) e da perfusão (ESP 3,7 ± 3,3, p = 0,0003). A melhora da FEVE correlacionou-se positivamente com a melhora do ESP (r = 0,72; p = 0,0035). CONCLUSÕES: Alterações perfusionais miocárdicas são comuns no envenenamento escorpiônico e correlacionam-se topograficamente com a disfunção contrátil. A recuperação da contratilidade correlaciona-se com a reversibilidade dos defeitos perfusionais. Estes achados sugerem a participação de alterações perfusionais miocárdicas na fisiopatologia desta forma de insuficiência ventricular aguda. (Arq Bras Cardiol 2010;94(4): 444-451)

BACKGROUND: Cardiogenic shock and acute pulmonary edema are the major causes of death of patients with scorpion envenomation, whose pathophysiological mechanism remains controversial. OBJECTIVE: To investigate the correlation between myocardial perfusion abnormalities and left ventricular contractile function in victims of scorpion envenomation. METHODS: Fifteen patients underwent ECG-gated myocardial perfusion scintigraphy (gated SPECT) within 72 hours of, and 15 days after scorpion envenomation. Images were analyzed by means of a semi-quantitative visual perfusion score (0 = normal, 4 = absent) and motion score (0 = normal, 4 = akinesia), using the 17-segment model. Summed perfusion (SPS) and summed motion (SMS) scores were calculated for each patient. Ejection fraction (LVEF) was calculated by a commercially available software. RESULTS: At baseline, 12 out of the 15 patients presented abnormal myocardial perfusion and contractility. Mean values of SPS, SMS and LVEF were 12.5 ± 7.3, 17.0 ± 12.8, and 44.6 ± 16.0 percent, respectively. A positive correlation between SPS and SMS (r = 0.68; p = 0.005) and negative correlation between SPS and LVEF (r = -0.75; p = 0.0021) were found. The follow-up studies showed recovery of global contractility (LVEF of 68.9 ± 9.5, p = 0.0002), segmental contractility (SMS of 2.6 ± 3.1, p = 0.0009) and perfusion (SPS of 3.7 ± 3.3, p = 0.0003). Improvement of LVEF correlated positively with improvement of SPS (r = 0.72; p = 0.0035). CONCLUSIONS: Myocardial perfusion abnormalities are common in scorpion envenomation and correlate topographically with the contractile dysfunction. Recovery of contractility correlates with reversibility of perfusion defects. These findings suggest the participation of myocardial perfusion abnormalities in the pathophysiology of this form of acute ventricular failure. (Arq Bras Cardiol 2010;94(4): 418-425)