The physiological and psychosocial benefits of sustained exercise adherence among individuals with coronary artery disease (CAD) have been well-documented (e.g., Blumenthal et al., 1997; Rozanski et al., 1999; Wenger et al., 1995). Despite these known benefits, approximately 80% of patients who enter the maintenance phase of cardiac rehabilitation drop out after one year (Balady et al., 1994; Hedback, Perk, Wodlin, 1993 ). Among this 80%, less than 25% continue to exercise at levels that will maintain or improve cardiorespiratory fitness (Daltroy, 1985; Radtke, 1989). Self-efficacy has been identified as a significant predictor of adherence to exercise beyond the initial 6 months of participation. In addition to self-efficacy, outcome satisfaction has been suggested as a potentially significant predictor of adherence to exercise beyond the initiation phase (i.e., beyond the first 6 months). Unfortunately, most research examining these predictors of adherence has been conducted among asymptomatic populations. Thus, little is known about the predictive utility of self-efficacy and outcome satisfaction in relation to sustained exercise adherence among the CAD population. The purpose of the present study was to examine self-efficacy (Bandura, 1986) and outcome satisfaction (Rothman, 2000) in the prediction of adherence to maintenance cardiac rehabilitation in 101 men (M age= 68.15 ± 8.03) with coronary artery disease (CAD). A series of three hierarchical multiple regression analyses were conducted to predict onsite, offsite and total adherence to the maintenance cardiac rehabilitation exercise prescription. Interestingly, Exercise Beliefs (i.e., days of aerobic exercise per week believed necessary to maintain cardiovascular health), one of the study covariates, emerged as an important predictor of both offsite and total exercise adherence and explained a significant amount of variance in these variables (R2 = .25 [offsite], .23 [total],ps < .01). As predicted, self-regulatory efficacy was a significant predictor and explained a significant amount of variance in onsite exercise adherence (R2 = .17 [scheduling],p < .001). Task self-efficacy was not a significant predictor and did not account for a significant amount of variance in onsite exercise adherence. Also as predicted, task self-efficacy was a significant predictor and explained a significant amount of variance in offsite exercise adherence (R2= .10,p < .05). Self-regulatory efficacy was not a significant predictor and did not account for a significant amount of variance in offsite exercise adherence. In addition, consistent with hypothesis, both task self-efficacy and self-regulatory efficacy were significant predictors of total exercise adherence and explained a significant amount of the variance in this variable (R2 = .12 [task], .07 [scheduling],ps < .05). Contrary to hypothesis, outcome satisfaction did not explain a significant amount of variance in exercise adherence (onsite, offsite, and total) beyond that explained by self-efficacy (task and self-regulatory) alone. Taken together, this research has enhanced our knowledge of the psychosocial predictors of adherence to the maintenance cardiac rehabilitation exercise prescription among men with CAD. These findings also have important implications for health care professionals working in the area of cardiac rehabilitation. Specifically, it is up to health care professionals to ensure that patient beliefs regarding the maintenance cardiac rehabilitation exercise prescription are accurate, and that patients are efficacious in their ability to engage in the elemental physical aspects of exercise and to effectively schedule exercise into their daily lives. / Thesis / Master of Science (MS)

The development of atherosclerotic lesions and endothelial cell damage can originate during early childhood. Endothelial cells produce and release vasodilatory chemicals, which dictate the artery’s ability to vasodilate or vasoconstrict. Brachial artery FMD is a non-invasive, reproducible and a sensitive technique used to detect changes in arterial diameter and is correlated with coronary artery endothelial function. Cross-sectional studies have indicated increases in arterial diameter in children between the ages of 6-18 years however, a longitudinal, observational design study has not been conducted to understand how arterial diameters and FMD change over time in children, with considerations for the influences of physical activity and sex. The purpose of this study was to understand the impact of age and sex on arterial diameter and FMD and investigate the effects of habitual moderate-to-vigorous physical activity (MVPA) during both the school-age and preschool years on endothelial function trajectories during the school-age years. Over three years, 418 children between 3-5 years old participated in the HOPP study annually, and 279 of these children attended the lab when they were between 6-12 years old for an additional 3 annual visits in the SKIP study. Habitual MVPA was measured for 7 days in both the HOPP and SKIP studies each year, and FMD was measured each year during SKIP. Linear mixed-effects modeling was implemented to study the trend in FMD and the influence of chronological and biological age, sex and MVPA on arterial function; effects are reported as unstandardized estimates (Est). Boys had larger baseline and peak brachial artery diameters compared to girls (p<0.001). Girls had larger brachial artery FMD compared to boys (6.82±3.39 vs. 6.23±3.50 %, p<0.001). There was an effect of MVPA in the SKIP study on allometrically scaled FMD (Est. -0.017, p=0.03), but not on relative FMD (Est. -0.01, p=0.17). MVPA in the preschool years did not predict school-aged scaled FMD (Est. 0.11, p=0.24) or FMD (Est. -0.003, p=0.64). The observed trends in brachial artery diameter and FMD are in-line with expected changes in growth and maturation in children. Children who engaged in more habitual MVPA during the childhood years, but not the preschool years, demonstrated changes endothelial function during the school-age years. / Thesis / Master of Science (MSc) / It is clear that preliminary signs of atherosclerosis begin during the early years of childhood, and typically precede the development of future cardiovascular disease. Engaging in habitual physical activity at higher intensities, has been shown to positively influence cardiovascular health, specifically in central and peripheral arteries. This study sought to investigate the trends in vascular heath over time in children and examine the effect of moderate-to-vigorous physical activity engagement during the preschool years on vascular health during the school-age years. Our results suggest that as children age, their arteries get bigger in size and that school-aged girls have elevated vascular function when compared to boys. Children who engage in greater amounts of moderate-to-vigorous physical activity during their school-age years does not influence measures of vascular health. Additionally, engagement in habitual moderate to vigorous physical activity during the preschool years does not impact these vascular health relationships during the school-age years.

This thesis investigates the integration of vehicles with differing levels of automation and connectivity within suburban traffic systems, focusing on their impact on road safety, traffic efficiency, and risk, particularly concerning vulnerable road users. By employing a Cooperative and Connected Automotive Mobility (CCAM) framework, the study examines how vehicles that share real-time information and intentions under different CCAM configurations influence the dynamics of suburban mobility. Utilizing simulation tools like SUMO and Artery, this research conducts multiple traffic scenario simulations to capture the interactions between automated, connected, and conventional vehicles. The simulations specifically target the implementation of Intelligent Transport Systems (ITS) protocols such as ETSI ITS-G5, directed by the European standard, assessing their efficacy in fostering safer and more efficient suburban environments. The parameters used to determine the performance of a scenario are number of emergency brakes, collisions, average vehicle speed, average relative speed and ratio of departed speed. The findings aim to provide actionable insights into deploying advanced vehicular technologies, ensuring their beneficial integration into increasingly complex suburban traffic networks, thus supporting global road safety initiatives like Vision Zero. This project shows that safety-wise, the general mix of vehicles that provide the safest traffic conditions are the heterogenous mix of 50% automated, with higher levels of connectivity contributing to better metric scores from an efficiency standpoint.

published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Introduction: Coronary artery bypass grafting surgery is an effective treatment for coronary heart disease for many patients; however, evidence suggests that there are some patients who do not report a good post-operative recovery. Although several studies have begun investigating possible reasons for these observations, little is known about the impact of CABG on quality of life and there still remains a lack of information that can help clinicians identify those people more likely to experience poorer recovery so that interventions can be targeted appropriately. Aims: The overall aim was to investigate barriers to and facilitators of recovery after CABG. Method: Phase 1 was a retrospective qualitative study involving semi-structured interviews with eleven patients who had undergone CABG and with ten health professionals experienced in caring for these patients. Data were analysed using thematic analysis. Phase 2 was a prospective study comprising two components, questionnaire and interview. The questionnaire included measures of quality of life, perceived recovery, demographic and psychosocial variables and was administered prior to surgery and at six and twelve months post-surgery. A sample of ten people who completed questionnaires were interviewed at the same time points and data analysed using framework analysis. Results: Interview data described the patient experience of undergoing CABG and identified components of a good recovery from the patient perspective. Patient and health professional participants identified numerous barriers and facilitators to recovery at three key time points - prior to surgery, during the hospital inpatient stay and post-CABG - and noted the complex inter-relationships between them, thus emphasising the need for a holistic approach to investigating recovery. Questionnaire data described the pattern of psychosocial functioning, quality of life and perceived recovery across the surgical pathway and identified depression and self-efficacy as the main predictors of post-CABG quality of life and perceived recovery. Using interview and questionnaire data a model of recovery is proposed. Conclusions: Findings from this research have identified a complex inter-related network of barriers and facilitators to recovery, suggested the possible mechanisms by which they impact on post-CABG outcome and identified recommendations for clinical practice.

INTRODUCTION: The risk factors for cardiovascular disease (CVD) are associated with coronary atherosclerosis and having multiple risk factors potentiates atherosclerosis. This study examined the prevalence of multiple biological and lifestyle/behavioral risk factors and their association with coronary artery calcium (CAC), a marker for subclinical coronary atherosclerosis. METHODS: This is a cross-sectional study of 1607 community-dwelling asymptomatic individuals from central Appalachia who participated in CAC screening between January 2011 and December 2012. Data on demographics (sex and age) and 7 traditional risk factors for coronary artery disease (CAD) were collected and categorized into 5 groups (0-1, 2, 3, 4, and ≥5). Prevalence of these risk factors and CAC scores (0, 1-99, 100-399, ≥400) were assessed, and the impact of the number of risk factors on CAC scores were delineated using multiple logistic regression. RESULTS: Over 98% of participants had ≥1 risk factor. While obesity, diabetes, hypertension, and family history of CAD significantly increased the odds of having CAC, CAC scores significantly increased with number of risk factors. After adjusting for demographic factors, having 3, 4, and ≥5 risk factors was significantly associated with increased odds of having higher CAC scores when compared to zero CAC score by more than one and half times [OR=1.65, CI (1.20-2.25)], two times [OR=2.32, CI (1.67-3.23)] and three times [OR=3.45, CI (2.42-4.92)], respectively. CONCLUSION: The high prevalence of multiple risk factors in the study population suggests the need for aggressive multiple risk factors interventions for primary prevention of CAD, which could address CVD health disparities.

Aim: To examine the association of cardiovascular disease risk factors with and their cumulative effect on coronary artery calcium in hard-to-reach asymptomatic patients with diabetes. Methods: : A total of 2563 community-dwelling asymptomatic subjects from Central Appalachia participated in coronary artery calcium screening at a heart centre. Binary variable was used to indicate that coronary artery calcium was either present or absent. Independent variables consisted of demographic and modifiable risk factors and medical conditions. Descriptive statistics and multinomial logistic regression analyses were conducted. Results: : In total, 55.8% and 13.7% of study participants had subclinical atherosclerosis (coronary artery calcium ⩾1) and diabetes, respectively. The presence of coronary artery calcium was higher in subjects with diabetes (68.5%) than those without (53.8%). Compared to subjects without diabetes with coronary artery calcium = 0, obesity, hypertension, hypercholesterolaemia and smoking increased the odds of the presence of coronary artery calcium (coronary artery calcium score ⩾1) regardless of diabetes status; however, with larger odds ratios in subjects with diabetes. Compared to subjects without diabetes with coronary artery calcium score = 0, having 3, 4 and ⩾5 risk factors increased the odds of presence of coronary artery calcium in subjects with diabetes by 14.06 (confidence interval = 3.26–62.69), 32.30 (confidence interval = 7.41–140.82) and 47.12 (confidence interval = 10.35–214.66) times, respectively. Conclusion: : There is a need for awareness about subclinical atherosclerosis in patients with diabetes and more research about coronary artery calcium in subpopulations of patients.

Η ασβέστωση των στεφανιαίων αρτηριών αποτελεί αξιόπιστο δείκτη της στεφανιαίας αθηρωμάτωσης. Η ψηφιακή ακτινοσκόπηση/ακτινογράφηση είναι μία ακριβής μη αιματηρή μέθοδος ανάδειξης της στεφανιαίας ασβέστωσης, εύκολα διαθέσιμη, χαμηλού κόστους, γρήγορη και με χαμηλή δόση ακτινοβολίας. Μέχρι τώρα δεν έχει ερευνηθεί πολύπλευρα η αξία της για την ανίχνευση της ασβέστωσης των στεφανιαίων αρτηριών. / Coronary artery calcification is a reliable indicator of coronary artery atherosclerosis. Digital subtraction cinefluoroscopy is an accurate, noninvasive, rapid, widely available method for coronary calcium detection, with low average skin penetration dose. Until now, digital cinefluoroscopy value for coronary calcium detection has not been fully elucidated.

Contents 1. Introduction 7 1.1. The aim of the study 8 1.2. Tasks of the study 9 1.3. The scientific novelty and originality of the study 9 1.4. Practical importance of the study 9 2. Material and methods 11 2.1. The contingent of studied patients 11 2.2. Methods 12 2.2.1.Coronary artery bypass grafting 12 2.2.2. The used equipment 12 2.2.3. The method of myocardial SPECT performance 12 2.2.4. Evaluation of myocardial SPECT 13 2.3. Statistical analysis of data 15 3. Results 16 3.1. The evaluation of influence of left ventricular ejection fraction on postoperative changes of perfusion of revascularized myocardium 16 3.2. The evaluation of influence of left ventricle ejection fraction on postoperative changes of contraction of revascularized myocardium 18 3.3. The evaluation of influence of collaterals on postoperative changes of perfusion of revasculized myocardium 19 3.4. The evaluation of influence of collaterals on postoperative changes of contraction of revasculized myocardium 21 3.5. The prediction of postoperative myocardial perfusion and contraction 23 3.6. The identification of period of the maximal recovery of myocardial perfusion and contraction after surgical revascularization 27 4. Conclusions 29 5. List of publications 30 6. Summary in Lithuanian 31 7. Autobiography 34 1. Introduction Heart and blood vessels diseases, the most common of which is coronary artery disease (CAD), are the leading causes of death and disability of middle-aged and elderly... [to full text]

ABBREVIATIONS A – amniocentesis DA – deceleration angle FMH – fetomaternal haemorrhage MCA – middle cerebral artery MoM – multiples of median PI – pulsatility index PSV – peak systolic velocity RI – resistance index SA – splenic artery SGA – small for gestational age HDN – haemolytic disease of newborn 1. INTRODUCTION Rhesus alloimmunization occurs when a rhesus negative woman has an immunologic response to a paternally derived red-cell antigen that is foreign to the mother and inherited by the fetus. Rhesus alloimmunization and haemolytic disease of the newborn continues to occur as a serious complication of pregnancy despite well-organized antenatal antiD prophylaxis programs. At the Perinatal Center of Kaunas University of Medicine the incidence has remained stable at around 60 cases of alloimmunized pregnancies and from 30 to 40 cases of haemolytic disease of newborn annually. Perinatal mortality in cases of rhesus alloimmunization has been estimated to be at around 1 to 3.5 percent. Due to failure to apply or comply with antiD prophylaxis guidelines and limitations of the prophylaxis rhesus sensitization continues to occur. Rhesus alloimmunization is diagnosed when the test of a rhesus negative woman for red cell alloantibodies is positive. Prognosis for the fetus and perinatal outcomes depends much on how severely the fetus is affected by the disease at the time of diagnosis. The main pathological entity of the disease is fetal red blood cell destruction and... [to full text]