Cardiac amyloidosis: non-invasive diagnosis.

Cardiac amyloidosis is an infiltrative disease which requires a high degree of clinical suspicion for appropriate diagnosis. Early diagnosis and the definition of the type of amyloidosis play a key role in the early treatment and prognosis of this disease. In this context, the use of cardiac biomarkers such as troponins and NT-proBNT associated with analysis by multimodality imaging methods like echocardiographic techniques such as strain, nuclear medicine, and cardiovascular resonance imaging have an increasing role in patients with cardiac amyloidosis. This article details the role of non-invasive diagnostic methods in patients with cardiac amyloidosis.

Cardiac amyloidosis: non-invasive diagnosis

SUMMARY Cardiac amyloidosis is an infiltrative disease which requires a high degree of clinical suspicion for appropriate diagnosis. Early diagnosis and the definition of the type of amyloidosis play a key role in the early treatment and prognosis of this disease. In this context, the use of cardiac biomarkers such as troponins and NT-proBNT associated with analysis by multimodality imaging methods like echocardiographic techniques such as strain, nuclear medicine, and cardiovascular resonance imaging have an increasing role in patients with cardiac amyloidosis. This article details the role of non-invasive diagnostic methods in patients with cardiac amyloidosis.

RESUMO A amiloidose cardíaca é uma doença infiltrativa que exige um alto grau de suspeição clínica para o diagnóstico apropriado. O diagnóstico precoce e a definição do subtipo de amiloidose têm um papel fundamental para a terapêutica e prognóstico desta doença. Nesse contexto, o emprego de biomarcadores cardíacos como as troponinas e NT-proBNT associados à análise por métodos de imagem multimodalidade por técnicas ecocardiográficas atuais como o strain, medicina nuclear e a ressonância magnética cardíaca têm papel crescente em pacientes com amiloidose. Este artigo detalha a utilização dos métodos não invasivos para a avaliação de pacientes com amiloidose cardíaca.

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

OBJECTIVES: Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (82RbPET) MPI. Thus, this study aimed to evaluate agreement between 82RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. METHODS: Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. RESULTS: There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). CONCLUSIONS: There was a significant agreement between dipyridamole stress 320-CT MPI and 82RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. KEY POINTS: • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Decreased glycolytic metabolism in non-compaction cardiomyopathy by 18F-fluoro-2-deoxyglucose positron emission tomography: new insights into pathophysiological mechanisms and clinical implications.

AIMS: The pathophysiological mechanisms of left ventricular non-compaction cardiomyopathy (LVNC) remain controversial. This study performed combined 18F-fluoro-2-deoxyglucose dynamic positron emission tomography (FDG-PET) and 99mTc-sestamibi single-photon emission computed tomography (SPECT) studies to evaluate myocardial glucose metabolism and perfusion in patients with LVNC and their clinical implications. METHODS AND RESULTS: Thirty patients (41 ± 12 years, 53% male) with LVNC, diagnosed by cardiovascular magnetic resonance (CMR) criteria, and eight age-matched healthy controls (42 ± 12 years, 50% male) were prospectively recruited to undergo FDG-PET with measurement of the myocardial glucose uptake rate (MGU) and SPECT to investigate perfusion-metabolism patterns. Patients with LVNC had lower global MGU compared with that in controls (36.9 ± 8.8 vs. 44.6 ± 5.4 µmol/min/100 g, respectively, P = 0.02). Of 17 LV segments, MGU levels were significantly reduced in 8, and also a reduction was observed when compacted segments from LVNC were compared with the segments from control subjects (P < 0.001). Perfusion defects were also found in 15 (50%) patients (45 LV segments: 64.4% match, and 35.6% mismatch perfusion-metabolism pattern). Univariate and multivariate analyses showed that beta-blocker therapy was associated with increased MGU (beta coefficient = 10.1, P = 0.008). Moreover, a gradual increase occurred in MGU across the beta-blocker dose groups (P for trend = 0.01). CONCLUSION: The reduction of MGU documented by FDG-PET in LVNC supports the hypothesis that a cellular metabolic pathway may play a role in the pathophysiology of LVNC. The beneficial effect of beta-blocker mediating myocardial metabolism in the clinical course of LVNC requires further investigation.

Influence of the arm position in myocardial perfusion imaging acquisition.

OBJECTIVE: despite the technologic advances in myocardial perfusion imaging, we keep using an uncomfortable and sometimes impracticable patient position - supine with arms raised above the head (U). The purpose of this study was to investigate whether perfusion and functional cardiac gated SPECT scan results of acquisition U are equivalent to another position modality: supine with arms down at the sides of the trunk (D). METHODS AND RESULTS: we performed U acquisition and in sequence D acquisition in 120 patients (pts) using a one-day MPI (rest-gated/stress), with 99mTc-sestamibi (370 MBq and 1110 MBq). Images were processed by the iterative reconstruction method (OSEM). Rest (R) and stress (S) studies were scored using 17-segments model. Functional parameters (left ventricular ejection fraction, and volumes) were automatically obtained by the quantitative gated SPECT (QGS) program. According to the degree of stress defects observed in U study, the patients were categorized in two subgroups: normal (SSS ≤ 3 or < 5%) and abnormal (SSS>3 or ≥ 5%). Shoulder/back pain occurred in 23.3% of U patients and in 5% of D. No significant differences between U and D were found for SSS (p = 0.82) and SRS (p = 0.74) in normal group. In abnormal group, good correlation was found between U and D modes for SSS (Rho = 0.95, p = 0.0001) and SRS (Rho = 0.96 p = 0.0001), but the mean SSS (12.53 ± 7.54) and SRS (10.60 ± 7.08) values of D were significantly lower (p < 0.05) than SSS (13.43 ± 6.81) and SRS (11.33 ± 6.97) of U mode. Function measurements presented good correlations, except for end-diastolic volume (p = 0.0001). CONCLUSION: although D mode appears to be more comfortable and presented a good correlation with U values of SSS and SRS, in abnormal pts, the extent and severity of defects can be underestimated. Considering clinical implications of an accurate perfusion measurement, the acquisition with the arms down should be avoided.

Influence of the arm position in myocardial perfusion imaging acquisition / Influência da posição dos braços na aquisição da cintilografia do miocárdio

Objective: despite the technologic advances in myocardial perfusion imaging, we keep using an uncomfortable and sometimes impracticable patient position - supine with arms raised above the head (U). The purpose of this study was to investigate whether perfusion and functional cardiac gated SPECT scan results of acquisition U are equivalent to another position modality: supine with arms down at the sides of the trunk (D). Methods and Results: we performed U acquisition and in sequence D acquisition in 120 patients (pts) using a one-day MPI (rest-gated/stress), with 99mTc-sestamibi (370 MBq and 1110 MBq). Images were processed by the iterative reconstruction method (OSEM). Rest (R) and stress (S) studies were scored using 17-segments model. Functional parameters (left ventricular ejection fraction, and volumes) were automatically obtained by the quantitative gated SPECT (QGS) program. According to the degree of stress defects observed in U study, the patients were categorized in two subgroups: normal (SSS ≤ 3 or < 5%) and abnormal (SSS>3 or ≥ 5%). Shoulder/back pain occurred in 23.3% of U patients and in 5% of D. No significant differences between U and D were found for SSS (p = 0.82) and SRS (p = 0.74) in normal group. In abnormal group, good correlation was found between U and D modes for SSS (Rho = 0.95, p = 0.0001) and SRS (Rho = 0.96 p = 0.0001), but the mean SSS (12.53 ± 7.54) and SRS (10.60 ± 7.08) values of D were significantly lower (p < 0.05) than SSS (13.43 ± 6.81) and SRS (11.33 ± 6.97) of U mode. Function measurements presented good correlations, except for end-diastolic volume (p = 0.0001). Conclusion: although D mode appears to be more comfortable and presented a good correlation with U values of SSS and SRS, in abnormal pts, the extent and severity of defects can be underestimated. Considering clinical implications of an accurate perfusion measurement, the acquisition with the ...

Objetivo: no estudo de perfusão miocárdica, apesar dos avanços tecnológicos, continuamos utilizando o desconfortável e às vezes impraticável posicionamento em decúbito dorsal com braços acima da cabeça (U). O objetivo do estudo foi investigar se os resultados da perfusão e da função cardíacas obtidos com a aquisição U são equivalentes ao de outra modalidade de posição: com braços para baixo nas laterais do tronco (D). Métodos e resultados: adquirida a aquisição U, na sequência foi realizada a aquisição D em 120 pacientes (pts) em um único dia (repouso e estresse sincronizado ao ECG), com 99mTc-sestamibi (370 MBq e 1110 MBq). As imagens foram processadas usando reconstrução iterativa (OSEM). Cada estudo foi quantificado usando o modelo de 17-segmentos ao repouso (R) e ao estresse (S). Os parâmetros funcionais (fração de ejeção do ventrículo esquerdo e volumes) foram obtidas automaticamente pelo programa gated SPECT quantitativa (QGS). De acordo com a dimensão da alteração perfusional no estresse na aquisição U, os pacientes foram classificados em dois subgrupos: 80 pts normais (SSS ≤ 3 ou < 5%) e 40 pts anormais (SSS > 3 ou ≥ 5%). Dor no ombro e/ou nas costas ocorreu em 23,3% dos pacientes de U e em 5% de D. Não houve diferenças significativas entre U e D quanto ao SSS (p = 0,82) e SRS (p = 0,74) no grupo normal. No grupo anormal, boa correlação foi encontrada entre U e D para SSS (Rho = 0,95, p = 0,0001) e SRS (Rho = 0,96 p = 0,0001), entretanto a média dos valores de SSS (12,53 ± 7,54) e SRS (10,60 ± 7,08 ) de D foram significativamente menores (p < 0,05) que o SSS (13,43 ± 6,81) e SRS (11,33 ± 6,97) de U. As medidas de função apresentaram boas correlações, ...

Comparação entre a razão de viabilidade subendocárdica obtida por tonometria de aplanação e alterações de perfusão miocárdica pela cintilografia / Comparison between the subendocardial viability ratio obtained by applanation tonometry and myocardial perfusion defects by scintigraphy

Introdução: Estudos recentes correlacionam índices obtidos por análise do contorno da onda de pulso pela tonometria de aplanação com fatores de risco cardiovascular, rigidez arterial e aterosclerose. Destes índices, a razão de viabilidade subendocárdica (RVSE), obtida pela razão da área diastólica e a área sistólica da onda de pulso, é considerada uma estimativa de perfusão coronariana. No entanto, não há estudo da correlação da RVSE com provas de perfusão, como a cintilografia. Métodos: Foram avaliados 52 pacientes com indicação de cintilografia de perfusão miocárdica para avaliação de suspeita de doença coronariana, dos quais foram obtidas as medidas de tonometria de aplanação pelo aparelho SphygmoCor®. Após a coleta dos dados, foi realizada a análise estatística para avaliar correlações entre os índices tonométricos e os achados cintilográficos. Resultados: O exame de cintilografia de perfusão miocárdica revelou alteração em 23 indivíduos (44,2%), sendo mais frequente em homens e naqueles com mais de 4 fatores de risco associados. A RVSE foi estatisticamente semelhante nos pacientes com (162,4±22,7%) ou sem alteração (164,7±32,2%) na cintilografia de perfusão miocárdica, mesmo considerando apenas as alterações isquêmicas transitórias. Os demais índices obtidos pela tonometria também não mostraram diferença entre os grupos com ou sem alteração na cintilografia. Conclusões: Em pacientes com suspeita de doença arterial coronariana observou-se mais alterações de perfusão na cintilografia miocárdica em homens e em pacientes com múltiplos fatores de risco. A RVSE assim como os demais índices obtidos pela análise da onda de pulso não se correlacionaram com alterações de perfusão miocárdica da cintilografia.

Introduction: Recent research correlates indices acquired by pulse wave analysis with cardiovascular risk factors, arterial stiffness and atherosclerosis. One of them, the subendocardial viability ratio (SEVR), obtained from the ratio between the diastolic and systolic area of the pulse wave, has been considered as an estimative of coronary perfusion. However, there is no record of comparison between SEVR and other tools of myocardial perfusion as the scintigraphy. Methods: We evaluated 52 patients referred for myocardial perfusion imaging to assess the suspicion of coronary artery disease, followed by the applanation tonometry which was performed in these attendees by SphygmoCor® device. After collecting the data, it was performed a statistical analysis to evaluate whether there was a correlation between tonometrical indices and scintigraphic findings. Results: Myocardial perfusion imaging revealed defects in 23 individuals studied (44.2%), being more frequent in men and those with more than four associated risk factors. The SEVR was statistically similar between the patients with (162.4±22.7%) or without (164.7± 32.2%) a defect in myocardial perfusion scintigraphy. Other indices measured by tonometry have not also presented correlation between the groups with or without defects in scintigraphy. Conclusion: In patients with suspicion of coronary artery disease, it was observed more changes in perfusion on myocardial scintigraphy in men and in patients with multiple risk factors. SEVR as well as others arterial stiffness indices obtained by pulse wave analysis from applanation tonometry have not correlated with myocardial perfusion imaging defect.

Left cardiac sympathetic denervation for treatment of symptomatic systolic heart failure patients: a pilot study.

AIMS: To evaluate the feasibility, safety, and potential beneficial effects of left cardiac sympathetic denervation (LCSD) in systolic heart failure (HF) patients. METHODS AND RESULTS: In this prospective, randomized pilot study, inclusion criteria were New York Heart Association (NYHA) functional class II or III, left ventricular ejection fraction (LVEF) ≤40%, sinus rhythm, and resting heart rate >65 b.p.m., despite optimal medical therapy (MT). Fifteen patients were randomly assigned either to MT alone or MT plus LCSD. The primary endpoint was safety, measured by mortality in the first month of follow-up and morbidity according to pre-specified criteria. Secondary endpoints were exercise capacity, quality of life, LVEF, muscle sympathetic nerve activity (MSNA), brain natriuretic peptide (BNP) levels and 24 h Holter mean heart rate before and after 6 months. We studied clinical effects in long-term follow-up. Ten patients underwent LCSD. There were no adverse events attributable to surgery. In the LCSD group, LVEF improved from 25 ± 6.6 to 33 ± 5.2 (P = 0.03); 6 min walking distance improved from 167 ± 35 to 198 ± 47 m (P = 0.02). Minnesota Living with Heart Failure Questionnaire (MLWHFQ) score physical dimension changed from 21 ± 5 to 15 ± 7 (P = 0.06). The remaining analysed variables were unchanged. During 848 ± 549 days of follow-up, in the MT group, three patients either died or underwent cardiac transplantation (CT), while in the LCSD group six were alive without CT. CONCLUSIONS: LCSD was feasible and seemed to be safe in systolic HF patients. Its beneficial effects warrant the development of a larger randomized trial. Trail registration: NCT01224899.

Papel da medicina nuclear na terapia de ressincronização cardíaca: [revisão] / Role of nuclear medicine in the cardiac resinchronization therapy: [review]

A terapia de ressincronização cardíaca (TRC) surgiu como a mais promissora abordagem no tratamento da dissincronia cardíaca, em pacientes com insuficiência cardíaca refratária ao tratamento medicamentoso. Embora seus resultados clínicos e funcionais sejam de fato promissores, as análises das respostas individuais revelam que uma significativa parcela dos pacientes não responde ao tratamento. Nesta revisão, foi discutido o papel da medicina nuclear e imagem molecular na seleção de candidatos à TRC, por meio do estudo da dissincronia cardíaca, avaliação de viabilidade, perfusão e fluxo sanguíneo miocárdicos e atividade simpática cardíaca. O potencial uso dessa técnica, no aprimoramento da compreensão dos efeitos deletérios da dissincronia, sobre a função cardíaca e na avaliação e monitorização de resposta à TRC, foram também abordados. Outros alvos moleculares que caracterizam metabolismo glicolítico e de ácido graxo, apoptose, atividade da enzima conversora da angiotensina e angiogênese, que podem seravaliados e medidos por essa técnica, foram descritos.

Cardiac resynchronization therapy (CRT) emerged as one of the most promising approaches in the treatment of cardiac dyssynchrony in heart failure patients’ refractory to medical treatment. However, despite very promising clinical and functional results, individual response analyses show that a significant number of patients do not respond to treatment. The role of nuclear medicine and molecular imaging in the selection of CRT candidates by the assessment of cardiac dyssynchrony, myocardial viability, myocardial perfusion and blood flow and sympathetic cardiac activity has been discussed in this review. The potential utilization of this tool to improve the comprehension of detrimental effects of dyssynchrony on cardiac function and the evaluation and monitoring of the response to CRT were also considered. Other molecular targets that characterize glucose and fatty acid metabolism, apoptosis, angiotensin converting enzyme activity and angiogenesis that can be evaluated with this technique were described.

Medicina nuclear nas doenças não-coronárias / Role of nuclear medicine in noncoronary diseases

Diferentes exames de medicina nuclear podem ser utilizados para a avaliação de doenças cardiovasculares não-coronárias. Neste artigo foram discutidos a ventriculografia radioisotópica (gated blood pool), a cintilografia cardíaca com gálio-67 e a cintilografia com MIBG (meta-iodo-benzil-guanidina). A ventriculografia radioisotópica permite a avaliação funcional dos ventrículos esquerdo e direito, com obtenção de valores precisos e reprodutivos de fração de ejeção, importante para decisões terapêuticas e acompanhamento evolutivo em diversas afecções cardiovsculares, como nas cardiomiopatias e cardiopatias congênitas. A cintilografia com gálio-67 constitui um método não-invasivo importante para a avaliação de processos inflamatórios cardíacos e da cavidade de arcabouço torácicos. A técnica permite...

[Valve replacement with chordal preservation and valvuloplasty for chronic mitral insufficiency]. / Troca valvar com preservação de cordas e plástica na cirurgia da insuficiência mitral crônica.

OBJECTIVE: To compare, from the clinical and laboratory points of view, 3 groups of patients undergoing surgical treatment for isolated chronic mitral insufficiency. One group underwent valvuloplasty, and the other 2 groups underwent mitral valve replacement with different techniques for chordal preservation. METHODS: Twenty-eight patients with a mean age of 54.1 years, no coronary or multivalvular disease, and no reoperation, underwent surgery as follows: 9 underwent valvuloplasty; 10 underwent mitral valve replacement with chordal preservation in both leaflets; and 9 underwent mitral valve replacement with chordal preservation only in the posterior leaflet. Clinical, Doppler echocardiographic, and radionuclide ventriculographic assessments were performed until the 6th month of follow-up. RESULTS: At the end, 88.8% of the patients were in functional class I. One died due to intracranial hemorrhage during anticoagulant treatment. The left ventricular diastolic diameter (P<0.0001) and end-diastolic volume (P<0.0001) decreased in the 3 groups. Only the patients undergoing valvuloplasty had a decrease in systolic diameter (P=0.0003) and in end-systolic volume (P=0.0040), with no change in the ejection fraction (P=0.5586). The patients undergoing mitral valve replacement had a similar drop in ejection fraction (P=0.0001 and P=0.0296). CONCLUSION: The 3 surgical techniques used provided clinical improvement. Patients undergoing valvuloplasty had better preservation of ventricular function. No significant difference was observed in cardiac performance between the 2 groups undergoing mitral valve replacement with chordal preservation within a 6-month follow-up.

Troca valvar com preservação de cordas e plástica na cirurgia da insuficiência mitral crônica / Valve replacement with chordal preservation and valvuloplasty for chronic mitral insufficiency

OBJETIVO: Comparar, clinica e laboratorialmente, três grupos de pacientes submetidos ao tratamento cirúrgico da insuficiência mitral crônica isolada; um grupo submetido à plástica valvar e dois à troca da valva mitral com diferentes técnicas de preservação das cordas. MÉTODOS: Operados 28 pacientes com idade média de 54,1 anos, sem doença coronariana, multivalvar ou reoperações: 9 tiveram plástica valvar, 10 troca valvar mitral com preservação das cordas de ambas as cúspides, e 9 apenas da cúspide posterior. Avaliações clínicas, ecodopplercardiográfica e radioisotópica foram realizadas até o 6º mês de seguimento. RESULTADOS: Ao final, 88,8 por cento encontravam-se em classe funcional I. Um faleceu por hemorragia intracraniana durante tratamento anticoagulante. Houve queda no diâmetro diastólico (p<0,0001) e volume diastólico final do ventrículo esquerdo (p<0,0001) nos três grupos. Apenas os pacientes submetidos à plástica tiveram queda no diâmetro sistólico (p=0,0003) e no volume sistólico final (p=0,0040), sem alterações na fração de ejeção (p=0,5586). Os submetidos à troca valvar mitral tiveram queda similar na fração de ejeção (p=0,0001 e p=0,0296). CONCLUSAO: Houve melhora clínica com as três técnicas empregadas. Os pacientes submetidos à plástica valvar tiveram melhor preservação da função ventricular. Não houve diferença significativa no desempenho cardíaco entre os dois grupos submetidos à troca valvar mitral com preservação das cordas até o 6º mês de seguimento.

Tumor intratorácico detectado em estudo de perfusão miocárdica com 99mTc-sestamibi: relato de um caso / Intrathoracic tumor detected by myocardial perfusion scintigraphy: a case report

Relatamos o caso de paciente submetida a cintilografia do miocárdio com 99mTc-sestamibi para a investigação de possível doença coronariana, que apresentou lesão hipercaptante na projeção supracardíaca, junto ao hilo pulmonar esquerdo. O estudo de perfusão cardíaca foi normal. A paciente foi encaminhada para estudos de tomografia computadorizada e ressonância magnética, a fim de complementar o diagnóstico. Foi realizada biópsia guiada por tomografia, que identificou tumor carcinóide. Salientamos a importância de aprofundar a investigação sempre que houver áreas hipercaptantes extracardíacas em pacientes submetidos a investigação de doença arterial coronariana com 99mTc-sestamibi. Este radiofármaco tem-se mostrado excelente marcador tumoral, sendo muito sensível mas pouco específico.

Estudo de perfusão miocárdica em portadores de bloqueio de ramo direito / Myocardial perfusion study in patients with right bundle branch block

PURPOSE: To evaluate the sensitivity and specificity of myocardial perfusion scintigraphy in the detection of coronary artery disease in patients with right bundle branch block (RBBB). METHODS: Thirty one patients (24 male, 62.3 +/- 10.5 years) with RBBB, submitted to myocardial perfusion scintigraphy associated with exercise (n = 7) or dipyridamole (n = 24) and previous cinecoronariography were studied retrospectively. Left ventricle scintigraphic image was divided in three segments corresponding to the three main epicardic coronary territories in a total of 93 segments. Cineangiographic and scintigraphic data were then compared according to the different artery territories. RESULTS: Twenty three patients had significant lesions (> or = 60) in one or more coronary arteries and eight had no obstruction. Forty nine segments were irrigated by normal coronary arteries and 44 were related to arteries that had significant lesions. Twenty out of twenty three patients showed alterations in perfusion (sensitivity = 87). All patients without coronary obstructions showed normal perfusion scintigraphy (specificity = 100). One of the segments perfused by normal coronaries showed abnormal scintigraphy. Scintigraphy showed perfusion defects in 29 out of 44 segments with coronary obstructions. Sensitivity and specificity of the method for each arterial territory were 72and 100(left descending coronary artery), 67and 94(right coronary artery), 55and 100(circunflex coronary artery), respectively. CONCLUSION: The presence of RBBB does not modify the sensitivity and specificity of the method in the detection of coronary artery disease.

Avaliação da reserva funcional miocárdica em portadores de aneurisma de ventrículo esquerdo por ventriculografia radioisotópica. Resposta ao exercício isotônico / Radionuclide Ventriculography Assessment of Myocardial Functional Reserve in Patients With Left Ventricular Aneurysm. Response to Isotonic Exercise

PURPOSE: To evaluate global and regional left ventricular (LV) ejection fractions (EF) by radionuclide ventriculography in patients with LV aneurysm at rest and during isotonic exercise. METHODS: Twenty patients were studied by radionuclide ventriculography at rest and during exercise. All patients had been submitted to cineangiography and showed LV aneurysm post myocardial infarction. RESULTS: Patients were divided according to LV EF in two groups: one with EF > or = 40 and the other with < 40 EF. Both groups showed normal response of global EF to exercise: mean rest EF was 40 +/- 14 and mean exercise EF was 45 +/- 14 (p < 0.01). When groups were considered separately, EF values showed the same behavior. Half of the patients showed normal response to exercise and the other half showed abnormal response. These changes were not associated with resting EF values, but were due to regional EF of lateral wall, that changed from 44 +/- 7 to 48 +/- 7 in the group of patients with normal LV EF response to stress and from 50 +/- 5 to 46 +/- 5 in those with abnormal response (p < 0.01). CONCLUSION: The evaluation of regional ventricular EF by radionuclide ventriculography during exercise better discriminates functional reserve in patients with LV aneurysm than resting global EF. These findings could help the decision making of the therapeutic approach in this specific group of patients.

Objetivo - Avaliar a fração de ejeção (FE) global e segmentar do ventrículo esquerdo (VE), em portadores de aneurisma ventricular pelo uso da ventriculografia radioisotópica no repouso e ao exercício isotônico. Métodos - Foram estudados 20 pacientes através da ventriculografia radioisotópica em repouso e na vigência de exercício isotônico. Os pacientes tinham dingnóstico de aneurisma de VE pós-infarto do miocárdio à cineangiografia contrastada. Resultados - Os pacientes foram divididos em 2 grupos segundo a FE global de VE no repouso: grupo com FE >40% e outro com FE <40%. Quando analisados os dois grupos em conjunto, a resposta da FE global ao esforço foi normal: média de FE no repouso 4014% e no esforço 4514% (p<0,01). Observou-se o mesmo comportamento das FE no esforço quando os 2 grupos foram analisados separadamente. Metade dos pacientes apresentou resposta normal da FE global de VE e na outra metade a resposta foi anormal. Este comportamento nao estava associado ao valor de repouso da FE global e deveu-se à resposta da FE regional da parede lateral ao exercício que passou de 447para 487% (p<0,01) no grupo com resposta normul e de 505 para 465% naqueles com resposta anormal (p<0,01). Conclusão - A avaliação da fração regional ventricular no esforço pela ventriculografia radioisotópica discrimina melhor a reserva funcional de portadores de aneurisma de VE do que a FE global de repouso e pode auxiliar na decisão terapêutica deste grupo de pacientes

Cintilografia mamária com tecnecio-99m-Sestamibi: fundamentos do método e experiência clínica inicial / Mamary scintigraphy Technetium-99m-Sestamibi: fundamentals of the method and initial clinical experience

A cintilografia mamária com Tecnecio-99m-Sestamibi e um novo método empregado para estudo por imagem da mama, que se baseia na propriedade que tem as células malignas da mama de captar este radio-farmaco. Neste estudo é apresentada a primeira experiência brasileira com o método utilizado em 50 pacientes com nódulos palpaveis de mama. Estes casos correspondem a 32 casos de carcinoma 64 por cento), 10m alteraçöes fibrocisticas (20 por cento), 6 fibroadenomas (12 por cento), 1 tumor filodes (2 por cento) e 1 papiloma (2 por cento)...

Cintilografia de perfusäo miocárdica associada ao estresse farmacológico com dipiridamol / Scintigraphy of myocardial perfusion combined with pharmacologic stress with dipyridamole

PURPOSE--To analyze adverse reactions (AR), hemodynamic and electrocardiographic changes and thallium scintigraphy (TS) results, during pharmacological stress with dipyridamole (SD), correlating these data to the presence and extension of coronary artery disease (CAD). METHODS--We studied 126 patients, 66 had no evidence of cardiovascular disease (G1) and 60 had critical occlusive CAD > or = 70 per cent stenosis (G2). Most of them were male, mean age 56.5 +/- 10.9 years old. All patients were submitted to TS after receiving 0.56 mg/kg of dipyridamole intravenously (0.14 mg/min during 4 min) followed by 111MBq of thallium-chloride-201. Conventional ECG was recorded before and after SD; heart rate (HR) and arterial pressure (AP) were monitored during dipyridamole infusion. All signals and/or symptoms were observed. RESULTS--Cine-coronarography showed 22 patients (37 per cent ) with one vessel disease (VD) (G2a), 26 (46 per cent ) with two VD (G2b) and 12 (20 per cent ) with three VD (G2c). Of the 126 patients 63 per cent did not present symptoms. Flushing (25 per cent ) and sick-headache (12 per cent ) were most frequent AR. Typical angina was reported by one G1 patient (1.5 per cent ) and six G2 patients (10 per cent ) (p < 0.05). HR increased 18.09 +/- 12.27 per cent and 12.40 +/- 4.90 per cent , systolic blood pressure varied -5.2 +/- 7.5 per cent and -4.3 +/- 6.5 per cent in G1 and G2, respectively. These parameters are not correlated to CAD presence and extension. ST depression and ectopic beats occurred in 5 per cent and 11 per cent of G1 patients, in 15 per cent and 30 per cent of G2 patients, respectively (p < 0.05). Typical angina was more common in G2a and G2b; ST changes in G2b and G2c; and arrhythmia in G2c (not significant). Sensitivity of TS associated to SD was 84 per cent , comparable to stress exercise thallium test. CONCLUSION--TS associated to SD, a noninvasive, safe with low morbidity and few collateral effects method is an option to patients with limitations to physical exercise tests

Radioisotopos na avaliacao de cardiopatias congenitas / Radionuclide scintigraphy in the assessment of congenital heart disease

Varios procedimentos de cardiologia nuclear foram desenvolvidos para diagnostico e avaliacao de cardiopatias congenitas. Os autores descrevem 4 procedimentos radioisotopicos particularmente uteis na avaliacao destes pacientes: angiocardiografia radioisotopica, ventriculografia sincronizada das camaras cardiacas, cintilografia com particulas radiomarcadas e cintilografia de perfusao miocardica. A angiocardiografia e a ventriculografia radioisotopica permitem o calculo de varios parametros funcionais, entre eles: tempos de transito pulmonares, quantificacao do fluxo direita-esquerda e fracao de ejecao dos ventriculos direito e esquerdo. A injecao de macroagregados de albumina-Tc99m, seguida da cintilografia pulmonar e de corpo total, fornece informacoes sobre a magnitude da comunicacao direita-esquerda e a distribuicao do fluxo sanguineo arterial pulmonar. Os estudos com talio-201 permitem a avaliacao da perfusao miocardica, sendo utilizados fundamentalmente na avaliacao coronaria anomala