Papers by niloufar samiei
European Heart Journal - Cardiovascular Imaging, 2014
Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the... more Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the poor spatial resolution of the PET system. Moreover, cardiac PET images are further degraded by the blur caused by the breathing and beating motions, thus hampering diagnosis and evaluation of myocardial pathologies. Anatomy-enhanced PET reconstruction, using a high-resolution CT, has proven useful in brain imaging. In cardiac datasets however, due to the motion artefacts, the application of any restoring technique on datasets affected by motion blur needs to be preceded by the validation of the proposed method on realistic static datasets. In this work, the validation is performed using static cardiac ex vivo datasets obtained from a number of sacrificed sheep, scanned on a clinical PET/CTscanner. The aim of this work is to assess the effectiveness of reconstructions of the acquired datasets with different CTbased anatomical priors, in comparison to reconstructions currently applied in clinical practise. The gold standard to which all reconstructions are compared consists of images of the same hearts scanned on a small-animal PET scanner, whose high spatial resolution allows for almost artefact-free images. Encouraging results were obtained so far, with improvements in volume delineation and uniformity of activity values when anatomical information was used. Fig 1 shows the gold standard image (left) compared to a regular clinical reconstruction (middle) and to a reconstruction using the high-resolution CT as anatomical information (right).
Acta Cardiologica Sinica, 2022
Nuclear Medicine Communications, 2021
Objective Myocardial perfusion imaging (MPI) by gated single-photon emission computed tomography ... more Objective Myocardial perfusion imaging (MPI) by gated single-photon emission computed tomography (SPECT) is a feasible method in the evaluation of left ventricular perfusion and function. The purpose of this study was to determine the threshold and grading of left ventricular (LV) diastolic dysfunction (LVDD) using gated SPECT MPI. Methods A total of 149 patients were recruited in the study. All of the patients underwent a standard 2-day stress/rest gated MPI study and transthoracic echocardiography within 2 weeks. The reconstructed rest-only images were analyzed by Cedar-Sinai’s quantitative gated SPECT and the LV diastolic parameters, including peak filling rate (PFR), time to PFR (TTPF) and secondary PFR (PFR2) to PFR ratio were provided and compared to echocardiographic data. Results 68 (45.6%) and 81 (54.4%) of patients were categorized in LVDD-absent and LVDD-present groups on the basis of LVDD evidence in echocardiography, respectively. receiver-operating-characteristic analysis for PFR and TTPF was performed, resulting in diagnostic sensitivities of 70 and 57% and specificities of 60 and 75% for PFR <2.6 end-diastolic volumes (EDV)/s and TTPF>160.5 ms, respectively. Applying our previously used thresholds of <1.70 EDV/s for PFR, >208 ms for TTPF and >1 for PFR2/PFR, sensitivities and specificities of 9.9 and 96.6%, 9.9 and 95.6% and 13.8 and 88% were resulted, respectively. Grading of LVDD on the basis of MPI-obtained diastolic parameters showed considerable overlapping data by interquartile range. Conclusion Gated SPECT MPI can be used as a highly specific means for detection of LV diastolic dysfunction when compared to echocardiography. However, grading of severity of diastolic heart failure appears to be impracticable.
CVD Prevention and Control, 2009
Background: Right ventricular (RV) restrictive physiology is a condition caused by the chronic el... more Background: Right ventricular (RV) restrictive physiology is a condition caused by the chronic elevation of systolic pressure in the RV, which is typically found in patients with tetralogy of Fallot (ToF) who had undergone total surgical correction and can be diagnosed either via cardiac magnetic resonance imaging (CMR) or finding the RV enddiastolic forward flow (EDFF) via echocardiography. We aimed to assess the relationship between RV restrictive physiology with myocardial fibrosis and functional indices on CMR, along with exercise capacity and diastolic dysfunction indicators measured by transthoracic echocardiography (TTE). Methods: All patients with a history of the total correction of ToF at childhood who referred to our center for the evaluation of postoperative severe pulmonary regurgitation were included. All the patients were examined using electrocardiography, the exercise test, TTE, and late gadolinium enhancement (LGE) CMR. Results: Among the study population, 17 (56.7...
ARYA Atherosclerosis, 2017
BACKGROUND Double-orifice mitral valve (DOMV) is an extremely rare cardiac malformation. It has b... more BACKGROUND Double-orifice mitral valve (DOMV) is an extremely rare cardiac malformation. It has been found to be accompanied by congenital anomalies (CAs), however, it can be detected as an isolated anomaly. The clinical findings of a DOMV are variable and depend predominantly on the associated cardiac abnormalities, particularly atrioventricular septal defects or mitral valve (MV) regurgitation and/or stenosis. CASE REPORT In this regard, we describe an isolated DOMV in an 18-year-old young girl who complained of a short-term nonspecific chest pain. She underwent transthoracic and transesophageal echocardiographic examinations. The examinations revealed a DOMV without any valvular or structural malformations. Other examinations were unremarkable. The patient did need neither medical nor surgical interventions. CONCLUSION The isolated cases of DOMV do not need therapy and might be only followed up using echocardiographic examinations. However, a careful echocardiographic examination...
JACC: Cardiovascular Interventions
Journal of Heart Valve Disease, 2015
Cardiac surgery during pregnancy is rarely required and potentially increases feto-maternal morta... more Cardiac surgery during pregnancy is rarely required and potentially increases feto-maternal mortality. The study aim was to evaluate pregnancy outcomes in females who underwent open-heart surgery with cardiopulmonary bypass (CPB) during pregnancy. Between 1999 and 2014, a total of 16 pregnant women (mean age 27 ± 7 years; mean gestational age 13 ± 7.7 weeks) underwent urgent cardiac surgery using CPB. The preoperative diagnosis included prosthetic valve dysfunction in 12 women (five aortic, seven mitral), native valve endocarditis and critical aortic stenosis each in one woman, and intracardiac masses in two women. Eleven patients were in the first trimester, three in the second trimester, and two in the third trimester. A retrospective analysis was conducted that included maternal variables of age, gestational age, cardiac diagnosis, prior operations, surgical details, maternal morbidity and mortality and type of delivery, while fetal variables included incidence of low birth weigh...
Background: Identifying End-Diastole (ED) and End-Systole (ES) frames is highly important in the ... more Background: Identifying End-Diastole (ED) and End-Systole (ES) frames is highly important in the process of evaluating cardiac function and measuring global parameters accurately, such as Ejection Fraction (EF), Cardiac Output (CO) and Stroke Volume. Objectives: The current study aimed to develop a new method based on measuring volume changes in Left Ventricle (LV) during cardiac cycle. Material and Methods: For this purpose, the Level Set method was used both in detecting endocardium border and quantifying cardiac function of all frames. Results: Demonstrating LV volumes displays ED and ES frames and the volumes used in calculating the required parameters. Conclusions: Since ES and ED frames exist in iso-volumic phases of the cardiac cycle with minimum and maximum values of LV volume signals, such peaks can be utilized in finding related frames.
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BackgroundFilamentous fibrin strands (FSs) attached to valve prostheses have been well described ... more BackgroundFilamentous fibrin strands (FSs) attached to valve prostheses have been well described in patients undergoing transesophageal echocardiography (TEE), but the frequency and clinical significance of these strands remain poorly defined. We aimed to determine the frequency of prosthetic valve strands and to assess their association with anticoagulant status, location, type, and number of prosthetic heart valves. MethodsIn total, 300 consecutive patients with prosthetic heart valves, who were referred for clinically indicated TEE, were evaluated for the presence of FSs (defined as highly mobile, fine, filamentous masses with less than 1 mm thickness). ResultsFSs were found in 141 (47%) patients. Significant associations were observed between the presence of FSs and anticoagulant status (P-value < 0.001). The location and number of the prosthetic valves had no statistically significant associations with the strands. The FSs were found more frequently on mechanical than on bio...
ObjectivesAs an invaluable surgical tool, autologous pericardium has been successfully used to re... more ObjectivesAs an invaluable surgical tool, autologous pericardium has been successfully used to repair many cardiac lesions. The encouraging results from its use in repairing heart valves have been applied to repair tricuspid valve regurgitation (TR). In the present study, we report our preliminary results using autologous pericardium as an alternative surgical technique in repairing tricuspid valve insufficiency. MethodsFrom June 2002 to November 2006, 22 patients (mean age 39.7 years) with heart valve disease underwent tricuspid valve repair by anterior leaflet augmentation with glutaraldehydetreated autologous pericardium. Nineteen patients (86.4%) had pure tricuspid valve regurgitation (TR), while the remaining three patients (13.6%) had significant associated tricuspid valve stenosis in whom commissurotomy was carried out. TR was considered severe in 18 patients and moderate to severe in four cases. All had associated left-sided heart valve surgery, except two patients. Concomit...
Archives of Medical Research
BACKGROUND Inflammatory is one of the main cause of aortic valve stenosis (AS), so discovering no... more BACKGROUND Inflammatory is one of the main cause of aortic valve stenosis (AS), so discovering novel biomarkers for the targeted therapy of inflammation could be an attractive strategy in AS prevention. The objectives of our study were to clarify the modulatory role of resistin and silent information regulator 1 (SIRT1) before and after surgery and also to evaluate the therapeutic effects of resveratrol. METHODS Nineteen AS patients and 15 healthy subjects were studied as the case and control groups, respectively. Peripheral blood mononuclear cells (PBMCs) were isolated and cultured to determine the levels of resistin and SIRT1 and the effects of resveratrol on them. RESULTS Significant increase in resistin expression was observed in the patients compare to the control (p ≤0.01), and this upregulation was augmented 72 h following surgery (p ≤0.01). The SIRT1 expression decreased in the AS group compare to the control but this reduction was not significant. Aortic valve replacement caused a higher decrease in the protein (p ≤0.01) and mRNA level (p ≤0.05) of SIRT1. Resveratrol in the AS group significantly diminished the resistin level (p ≤0.05) but increased the SIRT1 level (p ≤0.001). CONCLUSIONS In our patients with AS, the resistin level was increased, whereas the expression of SIRT1 was reduced and surgery augmented these alterations. Resveratrol improved inflammation in the PBMCs of the patients through the SIRT1/resistin pathway. These findings suggest that pharmacological therapy with resveratrol might be a novel approach to alleviating inflammation in patients with AS.
Research in Cardiovascular Medicine, 2013
Background: According to previous studies on the deformation properties of the left atrium, the s... more Background: According to previous studies on the deformation properties of the left atrium, the systolic strain and strain rates represent the atrial reservoir function and the early and late diastolic strain rates show the conduit and booster functions, respectively. Objectives: We sought to evaluate the intra and interatrial asynchrony using strain/strain rate imaging in systolic heart failure patients. Patients and Methods: Twenty five patients with systolic heart failure (LVEF ≤ 40%) were enrolled into the study. Asynchrony quantifications were performed according to the standard deviation of time-to peak (TP-SD) of deformation of three segments manually located along the perimeter of the left atrium free wall, right atrium free wall and interatrial septum, as imaged in an apical four-chamber view. We also calculated classic echocardiography parameters such as LV end-diastolic dimension index, LA volume index, RA area, as well as deceleration time (DT) on transmitral pulsed wave Doppler and E/E' ratio on mitral annular tissue Doppler imaging. Results: In heart failure patients either inter or intra-atrial asynchrony were far more common in comparison with normal subjects (P=0.008 and P=0.007 respectively). Conclusions: Left ventricular systolic heart failure, may result in inter and intra-atrial asynchrony even in clinically stable patients without significant pulmonary hypertension and diastolic dysfunction.
European Journal of Echocardiography, 2006
Advances in Respiratory Medicine
Introduction: Right ventricular (RV) function in the setting of pulmonary hypertension based on d... more Introduction: Right ventricular (RV) function in the setting of pulmonary hypertension based on different etiologies has not been well studied. In this study, we evaluated the RV function in patients with idiopathic pulmonary hypertension (IPH) versus secondary pulmonary hypertension (SPH) due to congestive heart failure. Material and method: Forty-five patients with pulmonary hypertension and New York Heart Association (NYHA) functional class II or III were enrolled. Of these, 22 were diagnosed with IPH and 23 with SPH. Echocardiographic data, including Doppler and Doppler based strain, were assessed according to the American Society of Echocardiography (ASE) guidelines for detailed evaluation of RV function in these two groups. Results: Mean PAP was 60 ± 14.5 mm Hg in patients with IPH versus 43 ± 11.5 mm Hg in patients with SPH (p = 0.001). Considering conventional indexes of RV function, only Sm and dp/dt were significantly better in the first group compared with the second group (p-value for Sm = 0.042 and for dp/dt = 0.039). RV end diastolic dimension was significantly higher in the IPH group (p = 0.013). Using deformation indexes of RV function, the basal and mid portion of RV free wall strain and basal RV strain rates were significantly worse in the chronic systolic heart failure (PH-HF) group in comparison to the IPH group (p < 0.001 in basal RV strain, p = 0.034 in mid RV strain and p = 0.046 in basal RV strain rate respectively). Conclusion: IPH has less impact on RV function in comparison to PH-HF. Considering both entities are in the category of RV pressure overload, we conclude that the etiology of pulmonary hypertension also plays an important role in RV function in addition to pressure overload.
Although people with less critical symptoms should not visit hospitals in order to reduce exposur... more Although people with less critical symptoms should not visit hospitals in order to reduce exposure during a pandemic, it is of utmost importance that those experiencing risky symptoms visit in early stages to prevent delayed consequences. In this article, we reported three ST-segment Elevation Myocardial Infarction (STEMI) patients who would have benefited from visiting the hospital earlier while they were experiencing low threshold angina.
Background: The superior type of sinus venosus atrial septal defect (SVASD) is a rare form of the... more Background: The superior type of sinus venosus atrial septal defect (SVASD) is a rare form of the atrial septal defect (ASD) in which the upper part of the atrial septum does not exist. The presence of other cardiac anomalies such as anomalous pulmonary venous connections has been reported in this type of congenital heart disease. This study aimed to assess the presence of the patent foramen ovale (PFO) in patients with the superior type of SVASD. Methods: This retrospective case-control study on 387 patients, consisting of 187 patients with a definite SVASD and 200 patients with problems other than the ASD, was conducted in Rajaie Cardiovascular Medical and Research Center between February 2005 and July 2014. Seven patients with inadequate data were excluded from the analysis. The presence/absence of the PFO was also evaluated in the case and control groups. Results: The analyses were performed on 182 male and 198 female patients at a mean age of 39.07±14.41 and 51.01±15.80 years i...
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Papers by niloufar samiei