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Pacing Clin Electrophysiol ; 43(3): 297-307, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32045008


AIMS: In this study, we investigated the characteristics and underlying mechanisms of the electrocardiographic (ECG) morphology during left bundle branch area pacing (LBBAP), which have not been systematically described. METHODS: Patients with indications for permanent cardiac pacing underwent LBBAP attempts. The ECGs of patients with confirmed left bundle branch (LBB) capture were compared with those of individuals with right bundle branch block (RBBB) on 12-lead ECG. Intracardiac electrograms recorded during implantation were analyzed in all patients who underwent pacing. RESULTS: LBBAP was successfully achieved in 87.5% (56/64) of patients. The QRS morphologies in lead V1 during LBBAP, which typically demonstrated Qr (60.7%), qR (19.6%), rSR' (7.1%), or QS (12.5%) patterns, differed from those of native RBBB, which featured rsR' (57.5%), M shape (23.7%), or monophasic R patterns (18.7%). The terminal R' wave duration in lead V1 was significantly shorter during LBBAP than during native RBBB (51 ± 12 ms vs 85 ± 19 ms, p < 0.001). LBB potentials were recorded in 66.1% (37/56) of the LBBAP patients. No significant differences in ECG characteristics were found between LBBAP with and without recorded LBB potentials. The presence of bundle branch block during LBBAP significantly prolonged QRS duration, R wave peak time, and terminal R' wave duration in lead V1 . CONCLUSION: LBBAP-ECG patterns are characterized by a shorter terminal R' wave duration in lead V1 compared with that of native RBBB configurations. Bundle branch conduction integrity has an impact on ECG characteristics during LBBAP.

BMC Cardiovasc Disord ; 17(1): 120, 2017 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-28490354


BACKGROUND: Myocardial 18F-deoxyglucose (18F-FDG) uptake has been observed to be enhanced in patients with coronary artery disease (CAD) under fasting conditions. However, whether the increased 18F-FDG is induced by myocardial ischemia and how to discriminate ischemic from physiological 18F-FDG uptake have rarely been investigated. METHODS: Under fasting conditions, 18F-FDG PET imaging was performed in 52 patients with suspected CAD. Two 18F-FDG imaging sessions were conducted within two hours after a single administration of 18F-FDG (dual-time-point imaging), and with an intervention of an exercise test after the first imaging. Abnormal 18F-FDG uptake was determined by the classification of the 18F-FDG distribution pattern, and the changes of the 18F-FDG distribution between the two PET imaging sessions were analyzed. 99mTc-sestamibi was injected at peak exercise and myocardial perfusion imaging (MPI) was conducted after 18F-FDG imaging. Coronary angiography was considered the reference for diagnosing CAD. RESULTS: Overall, 54.8% (17/31) of CAD patients and 36.2% (21/58) of stenotic coronaries showed exercise-induced abnormal uptake of 18F-FDG. Based on the classification of the 18F-FDG distribution pattern, the sensitivity and specificity of exercise 18F-FDG imaging to diagnose CAD was 80.6% and 95.2% by patient analysis, 56.9% and 98.0% by vascular analysis, respectively. Compared with MPI, 18F-FDG imaging had a tendency to have higher sensitivity (80.6% vs 64.5%, P = 0.06) on the patient level. CONCLUSION: Myocardial ischemia can induce 18F-FDG uptake. With the classification of the 18F-FDG distribution pattern, dual-time-point 18F-FDG imaging under fasting conditions is efficient in diagnosing CAD.

Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Fluordesoxiglucose F18/administração & dosagem , Imagem de Perfusão/métodos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/administração & dosagem , Adulto , Idoso , Angiografia Coronária , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Vasos Coronários/metabolismo , Vasos Coronários/fisiopatologia , Teste de Esforço , Jejum , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Valor Preditivo dos Testes , Estudos Prospectivos , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Tecnécio Tc 99m Sestamibi/administração & dosagem
Nucl Med Commun ; 36(10): 999-1006, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26225939


OBJECTIVE: Increased myocardial glucose metabolism occurs with the onset of myocardial ischemia and may persist even after the restoration of blood flow, termed as 'ischemic memory'. Previous studies have demonstrated that 18F-fluorodeoxyglucose (18F-FDG) is a sensitive marker of myocardial ischemia and may have potential utility in diagnosing unstable angina (UA). This study aimed to explore the value of F-FDG PET/CT in diagnosing UA. PATIENTS AND METHODS: Thirty-four patients (17 male patients; mean age, 59 ± 6 years) with suspected UA were prospectively recruited. Resting myocardial F-FDG PET/CT imaging was performed 21 ± 9 h (2-46 h) after the latest onset of angina pectoris. Resting or exercise myocardial perfusion imaging (MPI) and coronary angiography were performed. 'Focal' or 'focal on diffuse' myocardial F-FDG uptake was defined as abnormal, whereas other patterns of myocardial uptake, including 'focal' uptake on the basal segments, were considered as normal. The final diagnosis of UA was based on a comprehensive analysis of ECG, MPI, and coronary angiography. RESULTS: Of the 21 patients with a final diagnosis of UA, 18 had increased 18F-FDG uptake (sensitivity 85.7%), whereas, of the 13 patients without UA, only one had abnormal 18F-FDG uptake (specificity 92.3%). The sensitivity of resting 18F-FDG imaging was higher than that of resting MPI (85.7 vs. 52.4%, P=0.016). Moreover, six UA patients with only exercise-induced ischemia showed abnormal F-FDG uptake at rest. CONCLUSION: This pilot study demonstrated that resting 18F-FDG PET/CT imaging is an accurate and sensitive technique for the identification of UA.

Angina Instável/diagnóstico por imagem , Fluordesoxiglucose F18 , Coração/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Angina Instável/metabolismo , Angina Instável/fisiopatologia , Transporte Biológico , Estudos de Coortes , Feminino , Fluordesoxiglucose F18/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Miocárdio/metabolismo
PLoS One ; 9(5): e98381, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24852165


PURPOSE: Childhood post-infectious bronchiolitis obliterans (BO) is an infrequent lung disease leading to narrowing and/or complete obliteration of small airways. Ventilation and perfusion (V/Q) scan can provide both regional and global pulmonary information. However, only few retrospective researches investigating post-infectious BO involved V/Q scan, the clinical value of this method is unknown. This preliminary prospective study was aimed to evaluate the correlation of V/Q scan with disease severity, pulmonary function test results, and prognosis in children with post-infectious BO. METHODS: Twenty-five post-infectious BO children (18 boys and 7 girls; mean age, 41 months) underwent V/Q scan and pulmonary function tests. Patients were followed after their inclusion. Ventilation index and perfusion index obtained from V/Q scan were used to measure pulmonary abnormalities. Spearman's rank correlation test of ventilation index and perfusion index on disease severity, lung function tests indices, and follow-up results were performed. RESULTS: The median follow-up period was 4.6 years (range, 2.2 to 5.0 years). Ventilation index and perfusion index were both correlated with disease severity (r = 0.72, p<0.01 and r = 0.73, p<0.01), but only ventilation index was related to pulmonary function tests results (all p<0.05). In addition, Spearman test yielded significant correlations between perfusion index and prognosis (r = 0.77, p<0.01), and ventilation index and prognosis (r = 0.63, p = 0.01). CONCLUSIONS: For children with post-infectious BO, the present study preliminarily indicated that the degree of ventilation and perfusion abnormalities evaluated by V/Q scan may be used to assess disease severity, and may be predictive of patient's outcome.

Bronquiolite Obliterante/diagnóstico por imagem , Cintilografia/métodos , Bronquiolite Obliterante/fisiopatologia , Broncoscopia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Projetos Piloto , Testes de Função Respiratória
J Nucl Med ; 53(4): 584-91, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22393224


UNLABELLED: This prospective study evaluated the accuracy of electrocardiogram-gated blood-pool SPECT (GBPS) for the assessment of left ventricular (LV) and right ventricular (RV) ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) in patients with dilated cardiomyopathy (DCM), using cardiac magnetic resonance (CMR) imaging as the reference standard. METHODS: Thirty-two patients (24 men and 8 women; mean age, 51 y) with a diagnosis of idiopathic DCM underwent GBPS and CMR. LV and RV parameters including EDV, ESV, and EF from GBPS were calculated using fully automated gradient software and compared with those obtained by CMR. RESULTS: Biventricular volumes were underestimated by GBPS, compared with CMR (P < 0.001). We found no statistical difference between these 2 methods in the assessment of LV EF (P = 0.23), whereas RV EF was overestimated by GBPS (P < 0.001 vs. CMR). Regression analysis yielded significant correlations between GBPS and CMR in the assessments of biventricular parameters (r = 0.83 for LV EDV, 0.88 for LV ESV, 0.89 for LV EF, 0.86 for RV EDV, 0.86 for RV ESV, and 0.62 for RV EF; all P < 0.001). Comparison of the deviations of RV indices between GBPS and CMR with the ratio of RV EDV to LV EDV showed that there was a statistically significant trend for RV volumes to be underestimated and for RV EF to be overestimated as the biventricular volumetric ratio decreased (r = 0.61 for RV EDV, 0.68 for RV ESV, and -0.55 for RV EF; all P < 0.001). CONCLUSION: For patients with DCM, GBPS correlated well with CMR for the assessment of biventricular parameters, but RV indices should be cautiously interpreted.

Cardiomiopatia Dilatada/diagnóstico por imagem , Imagem do Acúmulo Cardíaco de Comporta/métodos , Imagem por Ressonância Magnética , Volume Sistólico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Direita/diagnóstico por imagem , Adolescente , Adulto , Idoso , Cardiomiopatia Dilatada/fisiopatologia , Feminino , Imagem do Acúmulo Cardíaco de Comporta/normas , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Reprodutibilidade dos Testes , Tomografia Computadorizada de Emissão de Fóton Único/normas , Adulto Jovem
Clin Nucl Med ; 37(1): 44-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22157027


PURPOSE: Although surgical treatments evolved, the short-term postoperative mortality is still high in children with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), and long-term survivors may suffer from restrained functional recovery. Therefore, an optimal means in predicting postoperative reversal is demanded. In this study, we assess the utility of myocardial perfusion/F-18 fluorodeoxyglucose (FDG) imaging in the evaluation of myocardial viability and postsurgery functional recovery in children with ALCAPA. MATERIALS AND METHODS: A retrospective study was performed in 7 children with diagnosed ALCAPA who underwent myocardial perfusion/F-18 FDG imaging preoperatively. Global viability index was used to evaluate myocardial viability and was compared with the preoperative deviations of left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD) from age-matched healthy children and with the postoperative durations of intensive care. RESULTS: Children with more viable myocardium had less severe clinical symptoms. The viability index was correlated well with the preoperative deviations of LVEF (r = -0.98, P = 0.001) and LVEDD (r = 0.87, P = 0.02) and postoperative durations of intensive care hospitalization (r = 0.77, P = 0.04) and mechanical ventilation (r = 0.83, P = 0.02). LVEF and LVEDD reached normal range within 5 months in viable children, whereas incomplete reversal was observed in partial- and nonviable children. CONCLUSIONS: In children with ALCAPA, myocardial viability evaluated by perfusion/F-18 FDG imaging is related to the preoperative clinical manifestations and cardiac function. Additionally, it may predict functional recovery after surgical repair.

Fístula Artério-Arterial/diagnóstico por imagem , Anomalias dos Vasos Coronários/diagnóstico por imagem , Fluordesoxiglucose F18 , Imagem de Perfusão do Miocárdio/métodos , Miocárdio Atordoado/diagnóstico por imagem , Artéria Pulmonar/anormalidades , Artéria Pulmonar/diagnóstico por imagem , Criança , Pré-Escolar , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Lactente , Masculino , Radiografia , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade