Background: To assess whether the standardized recommendation of patients with heart failure (HF), left-ventricular assist device (LVAD) and heart transplantation (HTx) to visit their dentist leads to improved oral conditions after 12 months. Methods: Patients from the Department of Cardiothoracic Surgery, Leipzig Heart Centre, Germany were examined at baseline and after 12 months. A dental (decayed-, missing-, and filled-teeth index (DMF-T)) and periodontal examination (periodontal probing depth, clinical attachment loss) was performed. At baseline, patients received a standardized recommendation to visit their dentist. At follow-up, a standardized questionnaire regarding the dental consultation was applied. Results: Eighty-eight participants (HTx: 31, LVAD: 43, HF: 14) were included. The majority of patients (79.5%) followed the recommendation to visit their dentist. Within the total cohort, periodontal treatment need was significantly reduced from 91% (baseline) to 75% (follow-up; p < 0.01). Only 10% of total cohort stated that they received periodontal treatment. The outcome in periodontal and dental treatment need at follow-up appointment revealed no statistically significant associations to the questionnaire regarding dentist consultation (p > 0.05). Conclusions: The simple recommendation to visit the dentist appears not enough to obtain sufficient dental and periodontal conditions in patients with severe heart diseases. Thereby, a lack in periodontal treatment of patients with HF, HTx and LVAD was identified, making interdisciplinary dental special care programs recommendable.

Ventricle Assist Devices (VADs), which are typically either axial or centrifugal flow pumps implanted on the aortic arch, have been used to support patients who are awaiting cardiac transplantation. Success of the apparatus in the short term has led to long term use. Despite anticoagulation measures, blood clots (thrombi) have been known to form in the device itself or inside of the heart. The Ventricle Assist Devices supply blood flow via a conduit (cannula) implanted on the ascending aorta. Currently, the implantation angle of the VAD cannula is not taken into consideration. Since the VADs supply a significant amount of blood flow to the aorta, the implantation angle can greatly affect the trajectory of the formed thrombi as well as the cardiac flow field inside of the aortic arch. This study aims to vary the implantation angle of a pediatric Left Ventricle Assist Device (LVAD) through a series of computational fluid dynamics (CFD) software simulations focusing on the aortic arch and its branching arteries of a 20 kg pediatric patient in order to reduce the occurrence of stroke.

Mancais são elementos importantes para o funcionamento adequado de muitos conjuntos mecânicos. Sendo assim, o contínuo desenvolvimento de novos tipos de mancais permite melhorar as condições atuais de funcionamento de dispositivos com necessidades específicas. Além disso, novos mancais proporcionam novos recursos para novos projetos. Este trabalho visa investigar a funcionalidade de um novo tipo de mancal rotativo híbrido resultante da combinação de um par de mancais magnéticos radiais passivos com um par de mancais de escora. Na direção radial, o eixo é mantido em posição central graças a dois mancais magnéticos compostos por imãs permanentes. Na direção axial, a restrição do movimento é devido a um par de mancais de escora localizados nas extremidades do eixo. Pelo ajuste do entreferro de cada par magnético é possível minimizar a carga axial que age em cada mancal de escora. Por meio de estudos baseados no método dos elementos finitos e experimentações, pretende-se esclarecer a relação entre os parâmetros construtivos e o desempenho do mancal. Os experimentos envolvem a verificação do desempenho do mancal por meio de um conjunto para testes, bem como um estudo de caso. O conjunto para testes possibilitou um ensaio de desgaste acelerado, onde uma esfera de aço, utilizada como pivô, manteve contato com uma superfície de PVC rígido. Tal ensaio resultou em um desgaste desprezível da superfície de contato devido à aplicação do novo conceito proposto, validando o mancal híbrido. Em relação ao estudo de caso, o mancal proposto foi empregado em uma bomba centrífuga representando um dispositivo de assistência ventricular, sendo seu desempenho discutido. Através da comparação entre algumas configurações possíveis para este tipo mancal, a rigidez radial é apresentada e discutida. Embora não constitua objeto principal deste trabalho, são discutidos os aspectos ligados ao desgaste causado pelo contato decorrente do uso dos mancais de escora, analisando o benefício do uso conjunto do mancal magnético com o mancal de escora. A expectativa é a de que este tipo de mancal possa ser utilizado em aplicações onde a existência de uma força resultante na direção radial seja muito pequena se comparada com os esforços presentes na direção axial. / Bearings are important elements for the proper working of many mechanical assemblies. Thus, the continuous development of new types of bearings improves the current operating conditions of devices with specific needs. In addition, new bearings provide new resources for new projects. This research aims to investigate the functionality of a new type of hybrid rotational bearing that combines a pair of radial magnetic bearing with a pair of thrust bearings. In the radial direction, the central axis is kept in position due to two magnetic bearings comprising permanent magnets. In the axial direction, the movement is constrained due to a pair of thrust bearings located at the shaft ends. By adjusting the air gap of each magnetic pair, it is possible to minimize the axial load that acts on each thrust bearing. Through studies based on finite elements methods and experiments, the relationship between the constructive parameters and the performance of the bearing are clarified. The experiments involve the performance checking of the proposed bearing through a test bed and a case study. The test bed allows an accelerated wear test, using a steel sphere as pivot against a rigid PVC surface. This test showed that the wear of PVC contact surface was negligible due to the applications of the proposed bearing concept, validating the hybrid bearing. Regarding the case study, the bearing was used in a centrifugal pump representing a ventricular assist device, and so the performance was discussed. By comparing some possible settings for this bearing type, the radial stiffness is presented and discussed. Although it is not the main goal of this paper, it was discussed the aspects related to the wear caused by contact from the use of thrust bearings in order to analyze the benefits of using magnetic bearing with the thrust bearing. The expectation is that this type of bearing can be used in applications where there is a very small net force acting in the radial direction compared with forces acting in the axial direction.

The number of patients that are waiting for heart transplants far exceed the number of available donor hearts. Left Ventricular Assist Devices are mechanical alternatives that can help and are helping several patients. They work by taking blood from the left ventricle and ejecting that blood into the aorta. In the University of Louisville they are developing a similar device that will take the blood from the aorta instead of the ventricle. This new device is called an Artificial Vasculature Device. In this thesis the arterial system and AVD are modeled and a simple control algorithm for the AVD proposed. The arteries are modeled as a tube with linear resistance and inertia followed by a chamber with linear compliance and last a tube with linear resistance. The model is identical to the 4-element Windkessel model. The values for the resistances, inertia and compliance are identified using pressure and flow measurements from the ventricle and aortic root from a healthy patient. In addition to the Windkessel model the aortic valve is also modeled. The valve is modeled as a drum that closes the aorta and the parameters identified like before. The measurements are also used to model the left ventricle by assuming it has a constant compliance profile. The AVD is modeled using common modeling structures for servo motors and simple structures for tubes and pistons. The values for the AVD could not be measured and identified so they are fetched from preliminary motor and part specifications. The control algorithm for the AVD uses a wanted load to create a reference aortic flow. This wanted aortic flow is then achieved by using a PI controller. With these models and controller the interaction between the arterial system and AVD is investigated. With this preliminary understanding of the interaction further research can be made in the future to improve the understanding and improve the AVD itself.

<p>The number of patients that are waiting for heart transplants far exceed the number of available donor hearts. Left Ventricular Assist Devices are mechanical alternatives that can help and are helping several patients. They work by taking blood from the left ventricle and ejecting that blood into the aorta. In the University of Louisville they are developing a similar device that will take the blood from the aorta instead of the ventricle. This new device is called an Artificial Vasculature Device. In this thesis the arterial system and AVD are modeled and a simple control algorithm for the AVD proposed. </p><p>The arteries are modeled as a tube with linear resistance and inertia followed by a chamber with linear compliance and last a tube with linear resistance. The model is identical to the 4-element Windkessel model. The values for the resistances, inertia and compliance are identified using pressure and flow measurements from the ventricle and aortic root from a healthy patient. In addition to the Windkessel model the aortic valve is also modeled. The valve is modeled as a drum that closes the aorta and the parameters identified like before. The measurements are also used to model the left ventricle by assuming it has a constant compliance profile. </p><p>The AVD is modeled using common modeling structures for servo motors and simple structures for tubes and pistons. The values for the AVD could not be measured and identified so they are fetched from preliminary motor and part specifications. </p><p>The control algorithm for the AVD uses a wanted load to create a reference aortic flow. This wanted aortic flow is then achieved by using a PI controller. With these models and controller the interaction between the arterial system and AVD is investigated. </p><p>With this preliminary understanding of the interaction further research can be made in the future to improve the understanding and improve the AVD itself.</p>

Mancais são elementos importantes para o funcionamento adequado de muitos conjuntos mecânicos. Sendo assim, o contínuo desenvolvimento de novos tipos de mancais permite melhorar as condições atuais de funcionamento de dispositivos com necessidades específicas. Além disso, novos mancais proporcionam novos recursos para novos projetos. Este trabalho visa investigar a funcionalidade de um novo tipo de mancal rotativo híbrido resultante da combinação de um par de mancais magnéticos radiais passivos com um par de mancais de escora. Na direção radial, o eixo é mantido em posição central graças a dois mancais magnéticos compostos por imãs permanentes. Na direção axial, a restrição do movimento é devido a um par de mancais de escora localizados nas extremidades do eixo. Pelo ajuste do entreferro de cada par magnético é possível minimizar a carga axial que age em cada mancal de escora. Por meio de estudos baseados no método dos elementos finitos e experimentações, pretende-se esclarecer a relação entre os parâmetros construtivos e o desempenho do mancal. Os experimentos envolvem a verificação do desempenho do mancal por meio de um conjunto para testes, bem como um estudo de caso. O conjunto para testes possibilitou um ensaio de desgaste acelerado, onde uma esfera de aço, utilizada como pivô, manteve contato com uma superfície de PVC rígido. Tal ensaio resultou em um desgaste desprezível da superfície de contato devido à aplicação do novo conceito proposto, validando o mancal híbrido. Em relação ao estudo de caso, o mancal proposto foi empregado em uma bomba centrífuga representando um dispositivo de assistência ventricular, sendo seu desempenho discutido. Através da comparação entre algumas configurações possíveis para este tipo mancal, a rigidez radial é apresentada e discutida. Embora não constitua objeto principal deste trabalho, são discutidos os aspectos ligados ao desgaste causado pelo contato decorrente do uso dos mancais de escora, analisando o benefício do uso conjunto do mancal magnético com o mancal de escora. A expectativa é a de que este tipo de mancal possa ser utilizado em aplicações onde a existência de uma força resultante na direção radial seja muito pequena se comparada com os esforços presentes na direção axial. / Bearings are important elements for the proper working of many mechanical assemblies. Thus, the continuous development of new types of bearings improves the current operating conditions of devices with specific needs. In addition, new bearings provide new resources for new projects. This research aims to investigate the functionality of a new type of hybrid rotational bearing that combines a pair of radial magnetic bearing with a pair of thrust bearings. In the radial direction, the central axis is kept in position due to two magnetic bearings comprising permanent magnets. In the axial direction, the movement is constrained due to a pair of thrust bearings located at the shaft ends. By adjusting the air gap of each magnetic pair, it is possible to minimize the axial load that acts on each thrust bearing. Through studies based on finite elements methods and experiments, the relationship between the constructive parameters and the performance of the bearing are clarified. The experiments involve the performance checking of the proposed bearing through a test bed and a case study. The test bed allows an accelerated wear test, using a steel sphere as pivot against a rigid PVC surface. This test showed that the wear of PVC contact surface was negligible due to the applications of the proposed bearing concept, validating the hybrid bearing. Regarding the case study, the bearing was used in a centrifugal pump representing a ventricular assist device, and so the performance was discussed. By comparing some possible settings for this bearing type, the radial stiffness is presented and discussed. Although it is not the main goal of this paper, it was discussed the aspects related to the wear caused by contact from the use of thrust bearings in order to analyze the benefits of using magnetic bearing with the thrust bearing. The expectation is that this type of bearing can be used in applications where there is a very small net force acting in the radial direction compared with forces acting in the axial direction.

Objectifs: Malgré beaucoup de progrès dans la gestion médico-électrique, certains problèmes demeurent et plusieurs patients souffrant d'insuffisance cardiaque sont encore dans l'impasse. Ainsi, les dispositifs d'assistance ventriculaire gauche (LVAD) ont été développés pour réduire les conséquences de l'insuffisance cardiaque et améliorer la qualité de vie. Malgré les avantages évidents, plusieurs complications : thrombo-embolie, infection dû au câble d'alimentation externe, dépendance aux batteries demeurent. L'ICOMS est un nouveau concept de LVAD mélangeant une pompe entièrement intraventriculaire, synchronisé avec le cœur et relié à une batterie interne. Méthodes et résultats : L'intervalle de fonctionnement prévu est un débit de 0.8 to 6.7 10-5 m3/s à une vitesse de rotation de 733 to 942 rad/s, avec des pressions physiologiques. Le point de fonctionnement choisi pour la conception est un débit de 3.3 10-5 m3/s et 10.6 103 Pa . Dans cette étude, Une simulation numérique est réalisée avec des profils de lames différents pour chaque région de fluide étudié. Les performances telles que l'efficacité, la contrainte de cisaillement sont analysée pour vérifier l'efficacité pour les patients atteints d'insuffisance cardiaque. Afin d'obtenir le meilleur résultat avec le logiciel ANSYS, le modèle k-ε turbulent a été appliquée pour obtenir des caractéristiques d'écoulement entre l'entrée et à la sortie de l'évacuateur du redresseur de la pompe. Les résultats numériques montrent une performance acceptable pour les adultes pour délivrer des pressions physiologiques avec une efficacité hydraulique de 10 à 37% ainsi qu'un niveau acceptable de stress de cisaillement maximale le long de la surface de la partie mobile de la pompe. La deuxième partie de l'étude est une étude expérimentale où un prototype a été testé sur banc d'essai. Les résultats ont montré que la pompe pourrait fonctionner et améliorer le débit cardiaque de 1.7 à 6.7 10-5 m3/s. Les résultats in vitro convergent vers les résultats numériques. Pour les tests in vivo, 6 moutons ont été opérés pour l'implantation du LVAD. L'ICOMS a été implanté dans l'apex du ventricule gauche. Plusieurs paramètres hémodynamiques et échocardiographiques ont été stockés dans des conditions normales ou pathologiques. Conclusion: Nous avons montré que l'ICOMS pourrait présenter un effet potentiel pour réduire les conséquences de l'insuffisance cardiaque. De nouvelles expérimentations sont nécessaires pour confirmer notre résultat et optimiser ce nouveau LVAD / Objectives: Despite much progress in medical-electrical management, some problems remain and several heart failure patients are still in a no option solution. In this way, artificial hearts as Left Ventricular Assist Device (LVAD) have been developed. Despite evident benefits, several complications as thromboembolism, driveline infection, batteries dependency remain. ICOMS is a new LVAD concept mixing a fully intraventricular pump, heat rate-synchronized and connected with intracorporeal batteries. Methods and Results : It is expected to deliver 0.8 to 6.7 10-5 m3/s at rotational speeds of 733 to 942 rad/s over physiologic pressures and has a selected design point of 3.3 10-5 m3/s and 10.6 103 Pa . In this study, the axial blood pump with motor connected to impeller has been selected to numerical simulation. This selection is based on axial flow pump with different blade profile for each fluid region and studied on its performance such as efficiency, wall shear stress and considering effective operation for cardiac failure patients. In order to achieve the best result with the ANSYS software, k-ε turbulent model has been applied to obtain the flow characteristics from inducer inlet to straightener outlet of the pump. Numerical results show acceptable performance to deliver physiologic pressures with hydraulic efficiency of 10 to 37 % as well as acceptable maximum shear stress level along the blade tip surface of the impeller. The second part of the study is an experimental investigation where a prototype device was tested in a test bench circulation loop have shown that the pump could operate and improve the cardiac output of 1.7 to 6.7 10-5 m3/s. In vitro results converge to numerical results. For test vivo 6 sheep were operated for the LVAD implantation with the support of cardiopulmonary by-pass. The ICOMS was implanted into the LV apex. Several hemodynamic and echocardiographic parameters were stored as well as in normal or pathological conditions and analyzed. Conclusion: We showed that the ICOMS could present a potential effect in the LV support reducing the heart failure criteria. As evidence, further experimentations are necessary to confirm our result and to optimize this new LVAD

Patienten mit Herzinsuffizienz im Endstadium erhalten zunehmend linksventrikuläre Unterstützungssysteme (LVAD) als Dauertherapiemittel oder zur Überbrückung bis zu einer möglichen Herztransplantation. Diese Patientenklientel ist grundsätzlich durch die Driveline, als potenzielle Eintrittsstelle für Mikroorganismen, einem Infektionsrisiko ausgesetzt. Die Mundhöhle beinhaltet diverse Bakterien, die sich auch systemisch verbreiten können und so eine mögliche Quelle für Driveline-Infektionen darstellen. Es ist jedoch unklar, ob bei LVAD-Patienten Erkrankungen der Mundhöhle durch Bakteriämien zu systemischen Komplikationen und Driveline-Infektionen führen können. Aktuell fehlt es an Studien zum Mundgesundheitszustand bei diesen Patienten und über einen möglichen Zusammenhang von oralen Erkrankungen und Driveline-Infektionen. Ziel dieser Studie war daher die Beurteilung des Mundgesundheitsverhaltens, des Mundgesundheitszustands sowie der mundgesundheitsbezogenen Lebensqualität von LVAD-Patienten. Bei den in dieser Studie untersuchten LVAD-Patienten traten vermehrt schwere Parodontitiden auf. Da Parodontitis das Risiko und das Ausmaß einer systemischen Bakteriämie erhöht und möglicherweise zu kardiovaskulären Komplikationen führen könnte, kann dieser Zustand als potenziell problematisch betrachtet werden. Die aktuelle Studie konnte jedoch keinen Zusammenhang zwischen Driveline-Infektionen und dem vorliegenden zahnärztlichen Behandlungsbedarf bestätigen, sodass der Einfluss der Mundgesundheit auf systemische, krankheits- und gerätebezogene Parameter unklar bleibt. Insgesamt scheint die Erarbeitung eines interdisziplinären zahnärztlichen Versorgungskonzeptes nötig, um die unzureichende Mundgesundheitssituation von LVAD-Patienten zu verbessern.:1 Einführung 1.1 Herzinsuffizienz 1.1.1 Definition und Klassifikation 1.1.2 Ätiologie und Epidemiologie 1.1.3 Therapie 1.2 Ventrikuläre Unterstützungssysteme 1.2.1 Einteilung, Funktionsprinzipien und Aufbau 1.2.2 Indikation und Therapiekonzepte 1.2.3 Komplikationen und Überlebensraten 1.3 Mundgesundheit bei Herzinsuffizienzpatienten 1.3.1 Mundgesundheit 1.3.2 Karies 1.3.3 Parodontitis 1.3.4 Bedeutung der Mundgesundheit bei Herzinsuffizienzpatienten und zahnärztliche Therapiekonzepte 1.4 Zielsetzung und Fragestellung 2 Publikationsmanuskript 3 Zusammenfassung der Arbeit 4 Ausblick 5 Literaturverzeichnis 6 Wissenschaftliche Präsentationen 7 Darstellung des eigenen Beitrages 8 Erklärung über die eigenständige Abfassung der Arbeit 9 Danksagung

Background: The use of percutaneous left ventricular assist devices in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS) is evolving. The aim of the study was to assess the long-term outcome of patients with AMICS depending on early initiation of Impella CP® support prior to a percutaneous coronary intervention (PCI). Methods: We retrospectively reviewed all patients who underwent PCI and Impella CP® support between 2014 and 2016 for AMICS at our institution. We compared survival to discharge between those with support initiation before (pre-PCI) and after (post-PCI) PCI. Results: A total of 73 consecutive patients (69±12 years old, 27.4% female) were supported with Impella CP® and underwent PCI for AMICS (34 pre-PCI vs. 39 post-PCI). All patients were admitted with cardiogenic shock, and 58.9% sustained cardiac arrest. Survival at discharge was 35.6%. Compared with the post-PCI group, patients in the pre-PCI group had more lesions treated (p=0.03), a higher device weaning rate (p=0.005) and higher survival to discharge as well as to 30 and 90 days after device implantation, respectively (50.0% vs. 23.1%, 48.5% vs. 23.1%, 46.9 vs. 20.5%, p < 0.05). Kaplan–Meier analysis showed a higher survival at one year (31.3% vs. 17.6%, log-rank p-value=0.03) in the pre-PCI group. Impella support initiation before PCI was an independent predictor of survival up to 180 days after device implantation. Conclusions: In this small, single-centre, non-randomized study Impella CP® initiation prior to PCI was associated with higher survival rates at discharge and up to one year in AMICS patients presenting with high risk for in-hospital mortality.

No description available.