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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Brustschmerzambulanz - Chest Pain Unit am Herzzentrum der Universität Leipzig Eine retrospektive Analyse für das Jahr 2009

Heumesser, Christian Eugen 15 October 2015 (has links) (PDF)
Brustschmerz ist ein häufiges Symptom. Er bedarf einer schnellen Differenzierung zum Ausschluss lebensbedrohlicher Erkrankungen wie zum Beispiel eines Myokardinfarktes oder einer Aortendissektion. Hierzu wurden Chest Pain Units (CPU) und Brustschmerzambulanzen (BSA) gegründet. Im Jahr 2008 führte die Deutsche Gesellschaft für Kardiologie Mindeststandards für deren Ausstattung und Struktur ein. 2009 wurde die zwei Jahre zuvor gegründete BSA am Herzzentrum Leipzig (HZL) zertifiziert. In dieser Arbeit wurde eine retrospektive Analyse von 2.220 Patientendaten aus dem Jahr 2009 durchgeführt. Bei steigenden Patientenzahlen wurde die BSA am häufigsten montags sowie in den Mittagsstunden aufgesucht. Dabei zeigte die Symptomdauer eine Spannweite von wenigen Minuten bis zu mehreren Jahren. Der größte Anteil mit 19,1 % der Patienten kam mit einer Symptomdauer zwischen einer Woche und einem Monat, 11,6 % der Patienten innerhalb von sechs Stunden. Symptome und Begleiterkrankungen boten eine große Variabilität. 24,7 % der Patienten stellten sich ohne Schmerzen vor. 66,4 % der Patienten verblieben ambulant und durchschnittlich verbrachten die Patienten 4,8 Stunden in der BSA. 59,9 % der Patienten ohne primär ersichtliche, kardiale Symptomkonstellation zeigten eine kardiale Erkrankung. Selbsteinweiser und ärztlich eingewiesene Patienten sowie stationäre und ambulante Verläufe zeigten Unterschiede in Symptomen, Begleiterkrankungen, Untersuchungen, Interventionen und Entlassungsdiagnosen. 26,9 % der Patienten erhielten eine Herzkatheteruntersuchung. Davon erfolgte bei 31,4 % eine Intervention, in 62,4 % der Fälle eine medikamentöse Therapie. Eine KHK war bei 19,1 % der Patienten die Entlassungsdiagnose. In der Hälfte der Fälle wurde damit erstmals diese Diagnose gestellt. Aus Symptomen, Symptomdauer und kardiovaskulären Risikofaktoren wurde der Symptome-30-2-CRF-Score abgeleitet, welcher bei ≤ 9 Punkten eine KHK ablehnt und bei Werten ≥ 14 Punkten den Verdacht auf eine KHK bekräftigt.
12

Brustschmerzambulanz - Chest Pain Unit am Herzzentrum der Universität Leipzig Eine retrospektive Analyse für das Jahr 2009: Brustschmerzambulanz - Chest Pain Unitam Herzzentrum der Universität LeipzigEine retrospektive Analyse für das Jahr 2009

Heumesser, Christian Eugen 24 September 2015 (has links)
Brustschmerz ist ein häufiges Symptom. Er bedarf einer schnellen Differenzierung zum Ausschluss lebensbedrohlicher Erkrankungen wie zum Beispiel eines Myokardinfarktes oder einer Aortendissektion. Hierzu wurden Chest Pain Units (CPU) und Brustschmerzambulanzen (BSA) gegründet. Im Jahr 2008 führte die Deutsche Gesellschaft für Kardiologie Mindeststandards für deren Ausstattung und Struktur ein. 2009 wurde die zwei Jahre zuvor gegründete BSA am Herzzentrum Leipzig (HZL) zertifiziert. In dieser Arbeit wurde eine retrospektive Analyse von 2.220 Patientendaten aus dem Jahr 2009 durchgeführt. Bei steigenden Patientenzahlen wurde die BSA am häufigsten montags sowie in den Mittagsstunden aufgesucht. Dabei zeigte die Symptomdauer eine Spannweite von wenigen Minuten bis zu mehreren Jahren. Der größte Anteil mit 19,1 % der Patienten kam mit einer Symptomdauer zwischen einer Woche und einem Monat, 11,6 % der Patienten innerhalb von sechs Stunden. Symptome und Begleiterkrankungen boten eine große Variabilität. 24,7 % der Patienten stellten sich ohne Schmerzen vor. 66,4 % der Patienten verblieben ambulant und durchschnittlich verbrachten die Patienten 4,8 Stunden in der BSA. 59,9 % der Patienten ohne primär ersichtliche, kardiale Symptomkonstellation zeigten eine kardiale Erkrankung. Selbsteinweiser und ärztlich eingewiesene Patienten sowie stationäre und ambulante Verläufe zeigten Unterschiede in Symptomen, Begleiterkrankungen, Untersuchungen, Interventionen und Entlassungsdiagnosen. 26,9 % der Patienten erhielten eine Herzkatheteruntersuchung. Davon erfolgte bei 31,4 % eine Intervention, in 62,4 % der Fälle eine medikamentöse Therapie. Eine KHK war bei 19,1 % der Patienten die Entlassungsdiagnose. In der Hälfte der Fälle wurde damit erstmals diese Diagnose gestellt. Aus Symptomen, Symptomdauer und kardiovaskulären Risikofaktoren wurde der Symptome-30-2-CRF-Score abgeleitet, welcher bei ≤ 9 Punkten eine KHK ablehnt und bei Werten ≥ 14 Punkten den Verdacht auf eine KHK bekräftigt.
13

Cognitive behavioural therapy for non-cardiac chest pain

Brown, Shona Lynsey January 2013 (has links)
Objectives: This thesis aims to explore evidence for the effectiveness of cognitive behavioural therapy (CBT) for non-cardiac chest pain (NCCP). Design: The systematic review aimed to evaluate evidence for CBT as an effective intervention for anxiety in the NCCP population. Study one describes the chest pain characteristics, illness beliefs and prevalence of anxiety in a NCCP sample in a cross-sectional design. Study two explores the acceptability and clinical effectiveness of a CBT-based self-help intervention for NCCP patients, using a between subjects, repeated measures design. Methods: A systematic review was completed via a comprehensive literature search for comparative studies examining CBT-based interventions for NCCP including a measure of anxiety. In the empirical study, participants completed measures of anxiety, illness beliefs and indices of chest pain (self-reported frequency, severity and impact on activities) at baseline. Comparisons between illness beliefs and anxiety were undertaken using descriptive statistics and Pearson correlations. Participants were randomised to receive a CBT-based self-help intervention booklet or treatment as usual, with questionnaires re-administered at three-month follow-up. ANOVAs were used to evaluate whether the intervention led to improvements in anxiety levels, or increased belief in participants’ personal control of symptoms. Results: Ten studies met inclusion criteria for the systematic review, with four studies showing evidence regarding the effectiveness of CBT for anxiety. Approximately two thirds of the thesis research sample reported on-going pain following clinic attendance, for the majority this was ‘very mild’ or ‘mild’ pain. Almost half (47%) reported experiencing clinically significant anxiety. Stress was the most common causal attribution advocated by the sample to explain their chest pain. Anxiety scores were significantly associated with psychological attribution scores, but not with personal control or illness coherence beliefs. In study two, 87 participants completed the study and ITT analyses were completed on 119. There were no significant differences between the groups in terms of reduced anxiety or self-reported belief in personal control of symptoms. The intervention booklet was evaluated largely positively by those who reported reading it. Conclusions: CBT-based self-help appears an acceptable intervention for those diagnosed with NCCP. Further research is needed to identify those who are most likely to benefit from such self-help intervention.
14

Bedside echo for chest pain: an algorithm for education and assessment

Amini, Richard, Stolz, Lori, Kartchner, Jeffrey, Thompson, Matthew, Stea, Nicolas, Joshi, Raj, Adhikari, Srikar, Hawbaker, Nicolaus 05 1900 (has links)
Background: Goal-directed ultrasound protocols have been developed to facilitate efficiency, throughput, and patient care. Hands-on instruction and training workshops have been shown to positively impact ultrasound training. Objectives: We describe a novel undifferentiated chest pain goal-directed ultrasound algorithm-focused education workshop for the purpose of enhancing emergency medicine resident training in ultrasound milestones competencies. Methods: This was a cross-sectional study performed at an academic medical center. A novel goal-directed ultrasound algorithm was developed and implemented as a model for teaching and learning the sonographic approach to a patient with undifferentiated chest pain. This algorithm was incorporated into all components of the 1-day workshop: asynchronous learning, didactic lecture, case-based learning, and hands-on stations. Performance comparisons were made between postgraduate year (PGY) levels. Results: A total of 38 of the 40 (95%) residents who attended the event participated in the chest pain objective standardized clinical exam, and 26 of the 40 (65%) completed the entire questionnaire. The average number of ultrasounds performed by resident class year at the time of our study was as follows: 19 (standard deviation [SD]=19) PGY-1, 238 (SD=37) PGY-2, and 289 (SD=73) PGY-3. Performance on the knowledge-based questions improved between PGY-1 and PGY-3. The application of the novel algorithm was noted to be more prevalent among the PGY-1 class. Conclusion: The 1-day algorithm-based ultrasound educational workshop was an engaging learning technique at our institution.
15

Chest pain in general practice

Frese, Thomas, Mahlmeister, Jarmila, Heitzer, Maximilian, Sandholzer, Hagen 30 June 2016 (has links) (PDF)
Objective: Chest pain is a common reason for an encounter in general practice. The present investigation was set out to characterize the consultation rate of chest pain, accompanying symptoms, frequency of diagnostic and therapeutic interventions, and results of the encounter. Materials and Methods: Cross‑sectional data were collected from randomly selected patients in the German Sächsische Epidemiologische Studie in der Allgemeinmedizin 2 (SESAM 2) and analyzed from the Dutch Transition Project. Results: Overall, 270 patients from the SESAM 2 study consulted a general practitioner due to chest pain (3% of all consultations). Chest pain was more frequent in people aged over 45 years. The most common diagnostic interventions were physical examination, electrocardiogram at rest and analysis of blood parameters. For the majority of cases, the physicians arranged a follow‑up consultation or prescribed drugs. The transition project documented 8117 patients reporting chest pain with a frequency of 44.5/1000 patient years (1.7% of all consultations). Physical examination was also the most common diagnostic intervention, and physician’s advice the most relevant therapeutic one. Conclusion: The most common causes for chest pain were musculoskeletal problems followed by cardiovascular diseases. Ischemic heart disease, psychogenic problems, and respiratory diseases each account for about 10% of the cases. However, acutely dangerous causes are rare in general practice.
16

Responses to chest pain : development and initial evaluation of an evidence-based information resource

Woods, Alexander J. January 2009 (has links)
Coronary heart disease is the leading cause of premature death in the UK. Chest pain, the most common symptoms associated with this disease, accounts for 1% of all primary care consultations, 5% of visits to emergency departments, and up to 40% of emergency admissions to hospital. When people experience acute coronary symptoms such as chest pain, or other symptoms such as pain in the arms, back or shoulder pain and pain in the jaw and neck, we know that prompt diagnosis and treatment of heart disease can significantly reduce mortality. However, we also know that when people experience these symptoms they can wait sometime before seeking medical help. Part of the problem may be that people do not attribute their symptoms a serious problem such as heart disease. Whilst several campaigns have been aimed at the general population there is no information resource targeted at people who may be at risk of heart disease to help them understand and evaluate their symptoms and take prompt action. The overall aim of this thesis is to fill this gap by producing a piloted draft information resource which aims to help people to respond effectively to symptoms that might be attributable to heart disease for people at high risk of heart disease. Using focus group discussions and individual interviews with people who had experienced symptoms that might be attributable to heart disease or might be at high risk of heart disease experiential data about their response to symptoms were gathered. Participants were also asked their views on what an information resource should be like and their experiences and views formed the basis of the content of the first draft of the information resource. In making sense of their symptom the participants drew upon a range of past experiences and the experiences of others to help them; participants who experienced severe symptoms sought help quickly; those whose symptoms were mild or transient waited, in some cases a considerable time, before seeking help. Previous personal experience may be the factor that helped those who acted quickly. Whereas the experience of others, evident in many of the accounts of those who waited, may not be sufficient to help people interpret and make sense of their own symptom experiences. The information resource incorporated the experiences of people with symptoms that ended up being attributable to heart disease and included examples of the range of symptoms that can be encountered to illustrate the different ways in which heart disease can be manifested as well as information drawn from best practice resources in the management of heart disease. Participants in the original focus group discussions and interviews were asked to be involved in the development of the resource and seventeen agreed. The information resource went through three drafts; at each stage changes were made to incorporate respondent views; at the penultimate draft health professionals’ views were also sought and used to inform the final draft which is now ready for further evaluation.
17

INVESTIGATION OF INOSINE AND HYPOXANTHINE AS BIOMARKERS OF CARDIAC ISCHEMIA IN PLASMA OF NON-TRAUMATIC CHEST PAIN PATIENTS AND A RAPID ANALYTICAL SYSTEM FOR ASSESSMENT

Farthing, Don E 01 January 2008 (has links)
Each year in the U.S., approximately 7-8 million patients with non-traumatic chest pain visit hospital emergency departments (ED) for medical evaluation. It is estimated that approximately 2-5% of these patients are experiencing acute cardiac ischemia, but due to the shortcomings of current test methods, they are incorrectly diagnosed and discharged without appropriate treatment provided, thus leading to poor patient outcome and potential medical malpractice litigation.The goals of this research were to evaluate plasma samples for potential biomarker(s) of acute cardiac ischemia prior to heart tissue necrosis, and to ultimately develop a rapid method for detection of the potential biomarker(s) in human plasma. Initial experiments were performed using the mouse model, with subsequent evaluations on human plasma samples using high performance liquid chromatographic ultraviolet detection (HPLC-UV). The final phase of this research involved the development of a rapid luminometer test method (An HPLC-UV detection method was developed and utilized for inosine, hypoxanthine and other adenosine triphosphate (ATP) catabolic by-products in Krebs-Henseleit (Krebs) buffer solution, with analysis on perfusate samples from isolated mouse hearts undergoing 20 min acute global ischemia. The HPLC-UV method was modified for subsequent use on human plasma samples, obtained from hospital emergency department (ED) patients presenting with non-traumatic chest pain (potential acute cardiac ischemia) and from healthy normal individuals. The HPLC-UV (component quantification) and HPLC-MS (component identification) test methods utilized C18 column technology, mobile phases consisting of aqueous trifluoroacetic acid (0.05% TFA in deionized water pH 2.2, v/v) and methanol gradient to achieve component separation, with both utilizing simple sample preparations (e.g. direct injection of Krebs perfusate samples and centrifugal membrane filtration on plasma samples).Results of the animal experiments using isolated mouse hearts undergoing 20 min acute global ischemia demonstrated significant levels of endogenous inosine effluxed from the heart tissue, indicating its use as a potential candidate biomarker of acute cardiac ischemia. The HPLC results from human plasma representing ED non-traumatic chest pain patients demonstrated elevated levels of inosine (hypoxanthine precursor) and significant levels of hypoxanthine, which provided additional support for the use of these candidate biomarker(s) as a potential diagnostic tool for the initial acute cardiac ischemic event, prior to heart tissue necrosis.The final phase of this research focused on the development of a rapid, simple and sensitive chemiluminescence test method. Using a microplate luminometer with direct injectors and continuous mixing, the measurement of inosine and hypoxanthine in human plasma was achieved for healthy normal individuals and on patients with confirmed acute MI, with an analysis time of less than 5 minutes. The utility of this rapid luminescence technique would be the potential use at point-of-care (POC) services (e.g. hospital clinical laboratory or emergency medical services) as part of the initial ED treatment protocol on patients presenting with non-traumatic chest pain and signs/symptoms of acute myocardial ischemia or acute MI.
18

Cintilografia planar de perfusão miocárdica em pacientes com dor torácica e eletrocardiograma sem alterações sugestivas de isquemia / Planar scintigraphy myocardial perfusion in patients with chest pain and ECG changes without suggestive of ischemia

Yamada, Alice Tatsuko 05 July 2002 (has links)
O objetivo deste estudo foi avaliar o uso da cintilografia de perfusão miocárdica planar de repouso para o diagnóstico de insuficiência coronariana aguda em pacientes com dor torácica e eletrocardiograma sem alterações sugestivas de isquemia. Foram estudados 71 pacientes com idades entre 34 e 87 (média 58, desvio-padrão 12) anos; 44 (62%) eram do sexo masculino e 27 (38%) do feminino. Os pacientes com dor torácica foram avaliados na unidade de emergência com anamnese, exame físico e eletrocardroqrarna de 12 derivações. Pacientes com dor torácica de duração superior a 20 minutos, em vigência da dor ou sem dor, mas que sofreram dor torácica até seis horas anies do atendimento e com eletrocardioqrarna sem alterações sugestivas de isquemia miocárdica, foram submetidos à cintilografia planar de perfusão miocárdica de repouso quando solicitada pelo médico assistente. O tempo médio entre o início da dor toràcica e a Injeção do radiotraçador foi de três horas e seis minutos. Treze pacientes apresentavam dor torácica no momento da injeção. Foram colhidas amostras sanguineas para dosagens de atividade da creatinoquinase-MB (CK-MB), CK-MB massa, troponina I e mioglobina, seis horas após o início da dor torácica. O diagnóstico de insuficiência coronariana aguda foi feito em pacientes com angina de repouso, infarto agudo do miocárdio, pacientes submetidos à revascularização miocárdica, presença de lesões coronarianas significativas na angiografia (>- 70% estenose em artérias coronárias ou seus ramos ou .- 50% em tronco de artéria coronária esquerda) realizada durante a inernação e morte cardíaca foram considerados eventos cardíacos maiores. As cintilografias com defeito de captação foram consideradas sugestivas de isquemia miocárdica e foram comparadas com o diagnóstico clínico e com a ocorrência de eventos cardíacos maiores até três meses após a alta.Pacientes sem insuficiência coronariana aguda, dispensados da unidade de emergência, foram encaminhados para realização ambulatorial de cintilografia de perfusão miocárdica tomográfica de esforço ou com dipiridamol. Vinte e um pacientes (29,6%) tiveram o diagnóstico de insuficiência coronariana aguda e em 15 (21,1%) ocorreram eventos cardíacos maiores (oito com infarto agudo do miocárdio e sete foram submetidos à revascularização miocárdica). A cintilografia planar de perfusão miocárdica demonstrou defeitos de captação em 21 (29,6%) pacientes, dos quais 16 (76,2%) tiveram o diagnóstico de insuficiência coronariana aguda, 12 (80%) apresentaram eventos cardíacos maiores e 7 (87,5%) infarto agudo do miocárdio. O valor preditivo negativo da cintilografia planar de perfusão miocárdica foi de 90% para o diagnóstico de insuficiência coronariana aguda e de 94% para detecção de eventos cardíacos maiores. Portanto a cintilografia planar de perfusão miocárdica foi eficaz para o diagnóstico de insuficiência coronariana aguda em pacientes com dor torácica e electrocardiograma sem alterações sugestivas de isquemia / The objective of the study was to evaluate the usefulness of rest scintigraphic planar myocardial perfusion imaging in patients with acute chest pain suspected of myocardial ischemia and nondiagnostic ECG in the diagnosis of acute coronary syndromes and to predict adverse cardiac outcomes. Patients within 6 hours of chest pain onset and nondiagnostic ECGs underwent planar myocardial perfusion imaging with Technetium-99m sestamibi and measurements of serum creatine kinase-MB, creatine kinase-MB mass. troponin and myoglobin 6 hours after the onset of symptoms. Studies showing perfusion defects were considered suggestive of acute coronary syndromes and were compared to the diagnosis made by the attending cardiologist. Clinical diagnosis of acute coronary syndromes was made In patients with rest angina admitted to the hospital, acute myocardial Infarction, myocardial revascularization, demonstration of significant coronary artery disease on angiography or cardiac death. Acute myocardial revascularization and cardiac death were considered major cardiac events. Patients discharged without acute coronary syndromes were scheduled for outpatient stress myocardial perfusion imaging. A total of 71 patients underwent planar myocardial perfusion imaging. The mean age was 58 +- 12 years, 44 (62%) were male and 27 (38%) female. The mean time between chest pain onset and radiotracer injection was 3 hours and 6 minutes, thirteen patients had chest pain at the moment of iniection. Twenty-one (29,6%) patients had acute coronary syndromes, 15 (21,1 %) had major cardiac events (8 myocardial infarction and 7 underwent myocardial revascularization). Planar perfusion imaging demonstrated perfusion defects in 21 patients, 16 (76,2%) patients with acute coronary syndromes, 12 (80%) patients who had major cardiac events and in 7 (87,5%) patients with myocardial infarction. The negative predictive value of planar perfusion image was 90% for diagnosis of acute coronary syndromes and 94% for detecting major cardiac events. In conclusion, early planar perfusion imaging allowed for a rapid and accurate risk stratification of emergency departments patients with possible myocardial ischemia and nondiagnostic ECGs
19

Optimisation des paramètres d'acquisition et de reconstruction pour une reduction de dose en tomodensitométrie dans le bilan diagnostique de douleurs thoraciques aux urgences / Optimization of acquisition and reconstruction parameters in chest CT aiming a dose reduction in emergency settings for chest pain

Macri, Francesco 22 November 2016 (has links)
Le scanner a révolutionné la médecine permettant une accélération et une meilleure prise en charge du patient. La tomodensitométrie (TDM) s’accompagne d’un désavantage qui est l’augmentation du risque de cancer radio-induit des patients qui en bénéficient. La question se pose notamment aux urgences où l’emploi du scanner est de plus en plus prédominant, souvent après la réalisation d’une radiographie. Cette attitude, malgré tout justifiée dans la plupart des cas, peut s'avérer délétère. De ce fait les principes de radioprotection obligent à l’optimisation de la dose délivrée aux patients. L’inquiétude principale réside dans l’irradiation du thorax qui est la région la plus radiosensible du corps humain. Cela se traduit par une recherche continue d’un compromis entre l’obtention de la dose la plus basse possible tout en gardant une qualité d’image satisfaisante pour le diagnostic. Les dernières années des innovations technologiques ont été développées pour optimiser la dose au scanner ; la plus importante et la plus récente étant la reconstruction itérative (RI). La RI permet d’améliorer les index de qualité image avec une dose abaissée ou à dose équivalente reconstruite avec la classique rétroprojection filtrée, mais restituant enfin une qualité d’image modifiée. L’objectif de cette thèse était d’établir un protocole TDM du thorax délivrant une dose similaire à celle d’une radiographie du thorax de face et une de profil (ULD-CT_Ultra-low-dose-Computed Tomography) pour des indications de douleurs thoraciques en urgence sans injection de produit de contraste. La réaction des radiologues non habitués a été investiguée pour considérer la modification de l’image liée à la réduction de la dose et de l’emploi de la RI. Pour atteindre cet objectif les travaux de cette thèse se sont déroulés selon trois phases. La première phase représente une approche globale à la RI, testée sur fantômes pour optimiser les protocoles TDM de notre département. À partir des résultats obtenus, la deuxième phase a débuté. Des protocoles TDM thorax standard, à basse dose (LD-CT_Low-dose) et à très basse dose (ULD-CT) ont été testés sur des cadavres humains. La troisième phase a été caractérisée par l’application du protocole ULD-CT en pratique clinique aux urgences. Quatre articles scientifiques ont été rédigés pour représenter les trois phases de cette thèse. En conclusion, le protocole ULD-CT reconstruit avec des hauts niveaux de RI a délivré une dose inférieure à celle du niveau de référence diagnostique national pour une radiographie du thorax de face et une de profil. Ce type de protocole à très faible dose reconstruit avec RI est une alternative valable à la radiographie pour certaines indications sélectionnées pour l’exploration du thorax en urgence. En outre les radiologues malgré des remarques critiques sur la qualité d’image de l’ULD-CT ont toujours déclaré un niveau de confiance diagnostique élevé. / Computed Tomography (CT) improved patients' health care. However CT has a major drawback, which is the ionizing irradiation of the patient with an ensuing radiation-induced cancer risk. This issue is particularly observed in emergency settings, where the CT is increasingly becoming a dominant tool for the care decision-making, often after a radiographic study. Although this attitude is justified in the majority of the cases, it could be deleterious. Thus the principles of radiation safety obligate to the optimization of radiation dose delivered to the patients. The main problem is that the chest is the most radiation sensitive region of the human body. Hence the research of the better trade-off between the dose reduction and a diagnostic image quality is mandatory. Recently, several technological improvements have been developed to optimize the radiation dose at CT. The newest and most important innovation is the iterative reconstruction (IR). IR improves the quality image indexes of a CT image generated with a lowered dose or equivalent to that reconstructed with filtered back projection. Finally this reconstruction method renders a modified CT image. The goals of this PhD thesis were: i) to establish an unenhanced CT protocol, delivering a dose in the range of a radiographic study (ULD_ultra-low-dose-CT), for chest pain indications with no need of contrast media administration and ii) to investigate the reaction of unaccustomed radiologists to ULD-CT imaging. To accomplish these tasks the work of this thesis has been split in three phases. In the first phase a study approaching globally the IR was carried out testing several CT protocols on phantoms, in order to optimize the CT protocols of our institution. The outcomes of this study opened the second phase. A standard dose CT, a low-dose-CT and an ULD-CT protocols were acquired on the chest of human cadavers. The third phase was characterized by the application of ULD-CT in clinical practice in emergency settings. Four scientific articles were produced to communicate the results of this doctorate work. In conclusion, the ULD-CT protocol, reconstructed with high strengths of IR, conveyed a dose lower than the one of the national diagnostic reference level for a double projections chest X-ray. This ULD-CT protocol with IR is a valid alternative to the radiography for the study of the chest, for selected indications in emergency settings. Moreover, despite the radiologists were censorious about the ULD-CT image quality, they demonstrated always a high diagnostic confidence level.
20

Cintilografia planar de perfusão miocárdica em pacientes com dor torácica e eletrocardiograma sem alterações sugestivas de isquemia / Planar scintigraphy myocardial perfusion in patients with chest pain and ECG changes without suggestive of ischemia

Alice Tatsuko Yamada 05 July 2002 (has links)
O objetivo deste estudo foi avaliar o uso da cintilografia de perfusão miocárdica planar de repouso para o diagnóstico de insuficiência coronariana aguda em pacientes com dor torácica e eletrocardiograma sem alterações sugestivas de isquemia. Foram estudados 71 pacientes com idades entre 34 e 87 (média 58, desvio-padrão 12) anos; 44 (62%) eram do sexo masculino e 27 (38%) do feminino. Os pacientes com dor torácica foram avaliados na unidade de emergência com anamnese, exame físico e eletrocardroqrarna de 12 derivações. Pacientes com dor torácica de duração superior a 20 minutos, em vigência da dor ou sem dor, mas que sofreram dor torácica até seis horas anies do atendimento e com eletrocardioqrarna sem alterações sugestivas de isquemia miocárdica, foram submetidos à cintilografia planar de perfusão miocárdica de repouso quando solicitada pelo médico assistente. O tempo médio entre o início da dor toràcica e a Injeção do radiotraçador foi de três horas e seis minutos. Treze pacientes apresentavam dor torácica no momento da injeção. Foram colhidas amostras sanguineas para dosagens de atividade da creatinoquinase-MB (CK-MB), CK-MB massa, troponina I e mioglobina, seis horas após o início da dor torácica. O diagnóstico de insuficiência coronariana aguda foi feito em pacientes com angina de repouso, infarto agudo do miocárdio, pacientes submetidos à revascularização miocárdica, presença de lesões coronarianas significativas na angiografia (>- 70% estenose em artérias coronárias ou seus ramos ou .- 50% em tronco de artéria coronária esquerda) realizada durante a inernação e morte cardíaca foram considerados eventos cardíacos maiores. As cintilografias com defeito de captação foram consideradas sugestivas de isquemia miocárdica e foram comparadas com o diagnóstico clínico e com a ocorrência de eventos cardíacos maiores até três meses após a alta.Pacientes sem insuficiência coronariana aguda, dispensados da unidade de emergência, foram encaminhados para realização ambulatorial de cintilografia de perfusão miocárdica tomográfica de esforço ou com dipiridamol. Vinte e um pacientes (29,6%) tiveram o diagnóstico de insuficiência coronariana aguda e em 15 (21,1%) ocorreram eventos cardíacos maiores (oito com infarto agudo do miocárdio e sete foram submetidos à revascularização miocárdica). A cintilografia planar de perfusão miocárdica demonstrou defeitos de captação em 21 (29,6%) pacientes, dos quais 16 (76,2%) tiveram o diagnóstico de insuficiência coronariana aguda, 12 (80%) apresentaram eventos cardíacos maiores e 7 (87,5%) infarto agudo do miocárdio. O valor preditivo negativo da cintilografia planar de perfusão miocárdica foi de 90% para o diagnóstico de insuficiência coronariana aguda e de 94% para detecção de eventos cardíacos maiores. Portanto a cintilografia planar de perfusão miocárdica foi eficaz para o diagnóstico de insuficiência coronariana aguda em pacientes com dor torácica e electrocardiograma sem alterações sugestivas de isquemia / The objective of the study was to evaluate the usefulness of rest scintigraphic planar myocardial perfusion imaging in patients with acute chest pain suspected of myocardial ischemia and nondiagnostic ECG in the diagnosis of acute coronary syndromes and to predict adverse cardiac outcomes. Patients within 6 hours of chest pain onset and nondiagnostic ECGs underwent planar myocardial perfusion imaging with Technetium-99m sestamibi and measurements of serum creatine kinase-MB, creatine kinase-MB mass. troponin and myoglobin 6 hours after the onset of symptoms. Studies showing perfusion defects were considered suggestive of acute coronary syndromes and were compared to the diagnosis made by the attending cardiologist. Clinical diagnosis of acute coronary syndromes was made In patients with rest angina admitted to the hospital, acute myocardial Infarction, myocardial revascularization, demonstration of significant coronary artery disease on angiography or cardiac death. Acute myocardial revascularization and cardiac death were considered major cardiac events. Patients discharged without acute coronary syndromes were scheduled for outpatient stress myocardial perfusion imaging. A total of 71 patients underwent planar myocardial perfusion imaging. The mean age was 58 +- 12 years, 44 (62%) were male and 27 (38%) female. The mean time between chest pain onset and radiotracer injection was 3 hours and 6 minutes, thirteen patients had chest pain at the moment of iniection. Twenty-one (29,6%) patients had acute coronary syndromes, 15 (21,1 %) had major cardiac events (8 myocardial infarction and 7 underwent myocardial revascularization). Planar perfusion imaging demonstrated perfusion defects in 21 patients, 16 (76,2%) patients with acute coronary syndromes, 12 (80%) patients who had major cardiac events and in 7 (87,5%) patients with myocardial infarction. The negative predictive value of planar perfusion image was 90% for diagnosis of acute coronary syndromes and 94% for detecting major cardiac events. In conclusion, early planar perfusion imaging allowed for a rapid and accurate risk stratification of emergency departments patients with possible myocardial ischemia and nondiagnostic ECGs

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