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The current study evaluated the potentially detrimental effects of daily resistance training on cardiovascular health using a longitudinal study design. This study also addressed the effects of resistance training on vascular endothelial function. Recent cross-sectional studies have shown resistance trained individuals have reduced whole-body arterial compliance compared to sedentary controls and that the age-associated reduction of arterial compliance is augmented in resistance trained athletes. The effect of resistance training on vascular endothelial function has not been addressed to date in the literature. Twenty-eight young healthy males (age: 23±3.9 [mean±SD]) were whole body resistance trained five times a week for twelve weeks, using a split body design. Measurements of supine resting arterial blood pressure at the brachial artery, carotid, brachial and femoral cross-sectional compliance, and brachial vascular endothelial function (using flow-mediated dilation) were acquired prior to, halfway through and following the exercise training protocol. Strength of various body segments increased significantly following the resistance training program. Shoulder press one repetition maximum (1RM) lifts increased from 141.4±7.6 lbs. to 185.2±8.8 lbs. and double leg press 1RM from 483.0±29.0 lbs. to 859.8±52.1 lbs. Resting diastolic blood pressure increased significantly from Mid to Post training (61.8±1.3 mmHg to 65.4±1.2 mmHg) yet was not significantly changed from Pre values (62.9±1.2 mmHg). Pulse pressure was reduced significantly with exercise training by the Post training time-point (Pre 63.3±1.9 mmHg; Mid 59.0±2.4 mmHg; Post 53.7±2.8 mmHg). Mean arterial carotid and femoral artery diameters were not changed with resistance training; however, mean brachial artery diameter increased by the Mid training time-point and remained elevated at the Post training time-point (Pre 3.81±0.10 mm; Mid 4.03±0.1 0 mm; Post 4.04±0.11 mm). Cross-sectional compliance did not change at the carotid or the brachial arteries, however the femoral artery experienced a reduction of compliance by the Mid time-point that remained to the Post training time-point (Pre 0.162±0.012 mm²/mmHg; 0.125±0.013 mm²/mmHg; Post 0.129±0.015 mm²/mmHg). Brachial vascular endothelial function measured using flow-mediated dilation did not show a significant change with resistance training. When normalized for shear rate (which was also unaltered with resistance training) there were no changes in endothelial function. Peak and 1 0-s average brachial post-occlusion blood flow was enhanced with resistance training (Pre 247.5±14.0 ml/min; Mid 331.1±18.5 ml/min; Post 290.5±21.0 ml/min) possibly revealing enhanced resistance vessel function. In conclusion, resistance exercise training results decreased PP, reduced femoral compliance, an increase in mean brachial artery diameter and enhanced post-ischemic blood flow. The exact mechanisms responsible for such changes remain unknown and require further investigation. / Thesis / Master of Science (MS)

Diagnostic radiation is typically avoided during pregnancy, as the effect of low-dose radiation exposure on the fetus is uncertain. The objective of this study was to determine if ionizing radiation exposure during late fetal development would cause an adverse intrauterine environment, and lead to growth restriction of offspring and a hypertensive phenotype later in life. To study this, pregnant BALB/cJ mice were exposed to ionizing radiation at 5, 10, 50, 100, 300 or 1000 mGy on gestational day 15. Offspring were weighed weekly from the age of weaning until a mature age of 16 weeks. Cardiovascular effects were assessed every other week via heart rate and blood pressure measurements using tail plethysmography. The expression of genetic markers for endothelial dysfunction, inflammation, mitochondrial capacity, and regulation of the oxidative stress response in the aorta and heart for the 1000 mGy was assessed from tissue collected at 17 weeks of age. We observed no effects of low to mid dose (5-300 mGy) radiation on offspring growth and blood pressure. Growth restriction was observed in male and female offspring exposed to high-dose radiation (1000 mGy). In the heart, there was no observed effect on mitochondrial capacity and oxidative stress response genes. In the aorta, we observed decreased TNF-α expression in male offspring, which may be linked to the growth restriction but was not considered a sign of cardiovascular dysfunction. There were no observed effects of exposure to 1000 mGy on cardiovascular function. This study provides knowledge on the possible effects of radiation on in utero development, which broadens the knowledge on the range of stressors capable of affecting offspring growth and development. / Thesis / Master of Science (MSc)

We have previously shown that short-term treatment (30 minutes) with follistatin (FST), a glycoprotein inhibitor of activins, reduced contraction caused by potassium (KCl) in vessels of the Spontaneously Hypertensive Rat (SHR) model of essential hypertension. This study specifically investigates the mechanisms through which FST inhibits KCl-induced vessel contraction in the SHR. Resistance mesenteric arteries taken from SHR or normotensive control WKY rats were tested in response to KCl using wire myography. Primary vascular smooth muscle cell (VSMC) cultures were established from WKY and SHR vessels. The fluorescent calcium sensor dye Fluo-4 AM and potassium tracking dye IPG-1 were then used to examine ion levels in the VSMCs. To determine whether FST effects were activin-mediated, neutralizing antibodies against activin A and B were used. Only activin A neutralization in the SHR reduced KCl-induced contraction as well as intracellular calcium rise, similarly to FST. Activin A (30 minute treatment) augmented KCl-induced contraction in both WKY and SHR vessels, but this was more pronounced in the SHR. There was an augmented KCl induced-intracellular calcium rise in SHR VSMC compared to WKY, which was decreased by FST. Inhibiting release of intracellular calcium stores did not attenuate KCl-induced calcium influx that was augmented by activin A or reduced by FST, but both of these effects were inhibited in calcium-free conditions. FST also significantly lowered the augmented KCl-induced intracellular potassium increase seen in SHR VSMC. Overall, FST reduces augmented KCl-induced contraction and rise in calcium and potassium levels in SHR vessels and VSMC. Taken together, these data suggest that FST may modulate L-type voltage gated Ca2+ channel (LTCC) or K-ATP channel activity. Neutralization studies support an important role for activin A, but not activin B, in mediating FST effects. Further studies will examine the mechanism by which FST modulates calcium influx. / Thesis / Master of Health Sciences (MSc) / We had shown that a protein called follistatin can reduce high blood pressure in rats. High blood pressure, or hypertension, is a condition that can lead to health problems such as heart failure, kidney disease and death, if not managed properly. We focused on a type of rat called the Spontaneously Hypertensive Rat (SHR), which has high blood pressure similar to what people experience. Our goal was to understand how follistatin works to lower blood pressure. To do this, we looked at how the blood vessels in these rats responded to a substance called potassium chloride (KCl), which causes blood vessels to contract as they do with high blood pressure. We found that follistatin reduced contraction of blood vessels caused by KCl. We also observed that calcium and potassium levels inside muscle cells of the blood vessels were lowered with follistatin, which could be one way follistatin prevents contraction and relaxes blood vessels. A better understanding of how drugs affect blood vessels will help us to create new treatments for high blood pressure.

Anxiety and its cognitive component of worry have been related to exaggerated cardiovascular reactivity and delayed recovery to laboratory stressors, and to increased risk of cardiovascular disease. Previous research on the anxiety-cardiovascular system relationship, including data from Knepp and Friedman (2008), are included to support this project. Two experiments were completed during the course of this study. The first consisted of two peripheral-based body positioning tasks. The second experiment used an active versus passive sympathetic stress task paradigm (mental arithmetic, hand cold pressor). Subjects were nonsmokers free of cardiovascular and neurological disease. Trait worry was examined through the Penn State Worry Questionnaire (PSWQ). Blood pressure recordings and cardiac recordings through ECG and ICG were done in each experiment during seven epochs: an anticipatory baseline with three baselines preceding and three recovery periods following each task. Repeated measures analysis was run on all cardiovascular measures. In the first experiment, high worriers had worsened blood pressure reactivity to task. The second experiment found that high worriers had increased stroke volume across all epochs. There were mixed findings in the studies relating to subjects acclimated to the laboratory experience. Future directions of research relating anxiety, worry, and cardiovascular risk factors are discussed. / Ph. D.

Records from treadmill maximal graded exercise tests (GXTs) for 61 patients from the Virginia Tech Intervention Center were screened for changes in systolic blood pressure. These blood pressure responses were standardized according to exercise demand (ΔSBP/MET) between three different levels of the exercise test. Subject records were chosen on the basis that they did not reflect a physician diagnosis of coronary artery disease (CAD) and were not taking antihypertensive medications. The ΔSBP/MET responses were stratified as follows: low to moderate (ΔBP/MET1) = difference between a systolic blood pressure at a moderate intensity stage minus the first stage systolic blood pressure, adjusted for the corresponding changes in metabolic demand (MET); moderate to high (ΔBP/MET2) = difference between systolic blood pressure at the maximal stage minus the moderate-intensity stage per MET change; and low to high (​​ΔBP/METS) = difference between systolic blood pressure at the maximal stage minus the first stage per MET change. Subjects were separated (STΔ and NoSTΔ) according to whether or not they had exercise-induced ST segment shift of 1 mm (≥ 0.1 mV) at maximal exercise. The two groups were similar in physical characteristics, except the NoSTA group had a significantly higher BMI (Body Mass Index), were a few years younger and exhibited a lower RPP at maximal effort. Discriminant Function Analysis was used to predict group classification of individual patients (STA or NoSTA). Based on predictions using physical characteristics alone, (age, BMI, TC), age, BMI and TC (Total Blood Cholesterol) could correctly predicted classification in 66% of the cases. The set of age, BMI, TC and ΔBP/METS3 (low to high) generated a prediction with 77% correct classification. Thus, ΔBP/MET level alone was not the primary variable to explain predictive accuracy for clinically important ST changes in exercise testing. However, in accordance with the Bayesian principle, this hemodynamic exercise response is adjusted for overall metabolic demand in the test and coupled to markers of pre-test coronary risk, the ability to predict ST response is improved. / Master of Science

International Telemetering Conference Proceedings / October 22-25, 1984 / Riviera Hotel, Las Vegas, Nevada / Blood pressure signals recorded continuously in ambulatory patients using the Oxford system were analyzed by an IBM 370 computer in order to obtain beat by beat systolic and diastolic blood pressure along 24 hour blood pressure recordings. The method of digitizing the signal and the analysis of the sphygmogram are presented and discussed. Synthesis of the several thousands data obtained in 24 hour recordings and plotting of the data for clinical purposes and pharmacological studies are also reported.

L'hypertension artérielle (HTA) est un problème de santé sérieux qui affecte 22% des canadiens et dont les complications sont nombreuses. Ces complications peuvent être diminuées par un diagnostic précoce et un traitement efficace et plusieurs auteurs affirment que l'exactitude de la mesure de la pression artérielle (PA) est la pierre angulaire pour établir le diagnostic et assurer un suivi adéquat. Quoique cette mesure soit réalisée très fréquemment, des études réalisées ailleurs qu'au Québec indiquent que les connaissances des infirmières à l'égard de la mesure de la PA sont insuffisantes pour des éléments reconnus comme ayant une influence significative sur les résultats de la mesure de la PA. À notre connaissance, aucune étude concernant les connaissances des infirmières n'a été publiée au Canada. Cette étude a donc pour but de décrire les connaissances théoriques et pratiques des infirmières pour la mesure de la PA en regard des recommandations du Programme éducatif canadien pour le contrôle de l'hypertension artérielle (2004) et comparer les relations entre ces variables. Une enquête par questionnaire auto administré pour décrire les connaissances théoriques ainsi qu'une observation directe par échantillonnage exhaustif pour décrire les connaissances pratiques ont été utilisées pour un premier échantillon de 50 infirmières. Une enquête postale transversale par échantillonnage aléatoire a été utilisée pour décrire les connaissances théoriques auprès d'un deuxième échantillon de 307 infirmières. Les outils ont été testés pour leur validité et leur fidélité dans le cadre de cette étude. L'étude a été approuvée par le comité d'éthique du centre de recherche clinique du CHUS. Les résultats quant aux données sociodémographiques démontrent que les infirmières ayant participé à l'une ou l'autre partie de l'étude sont semblables aux autres infirmières du Québec à l'égard du genre, de l'âge, du type d'emploi et de l'expérience. Elles sont toutefois statistiquement différentes pour le niveau de formation. Le score obtenu par les infirmières des deux échantillons pour le questionnaire sur les connaissances théoriques est de moins de 60%. On peut donc conclure qu'il existe des lacunes importantes en regard des connaissances théoriques acquises. Par ailleurs, ces infirmières croient dans de très fortes proportions posséder les connaissances théoriques et pratiques nécessaires à une mesure exacte de la PA. Pour les connaissances pratiques, le score global des infirmières est de 38%. Force est de croire que malgré le processus de mise à jour annuel et d'implantation des recommandations canadiennes, les connaissances pratiques des infirmières ne sont pas équivalentes au contenu de ces recommandations. Les infirmières qui détiennent un niveau de formation supérieur, celles qui ont lu les recommandations et celles qui ont suivi une formation continue sur la mesure de la PA obtiennent de résultats légèrement supérieurs aux autres infirmières. Considérant la fréquence avec laquelle les infirmières mesurent la PA et l'impact que peut avoir une mesure inexacte, il est important d'entreprendre dès maintenant des actions concrètes pour améliorer cette situation en mettant en place des formations continues régulières sur le sujet et en s'assurant que les programmes de formation initiale incluent une formation théorique et pratique fondée sur les recommandations en vigueur. Il semble également crucial de stimuler l'implantation des recommandations du PECH auprès des infirmières et d'évaluer l'impact de ces mesures par la suite.

Background: In patients with diabetes, high blood pressure is an established risk factor for cardiovascular disease. The aim of this thesis was to explore the associations between blood pressure levels measured with different techniques and during different circumstances, and the degree of cardiovascular organ damage and subsequent prognosis in patients with diabetes. Methods: We analysed baseline data from patients with type 2 diabetes who participated in the observational cohort study CARDIPP (Cardiovascular Risk factors in Patients with Diabetes – a Prospective study in Primary care), and longitudinal data from patients registered in the Swedish national quality registry RIKS-HIA (Register of Information and Knowledge about Swedish Heart Intensive care Admissions). Patients in CARDIPP underwent nurse-recorded, 24-hour ambulatory and non-invasive central blood pressure measurements. Patients in RIKS-HIA had their systolic blood pressure measured upon hospitalisation for acute chest pain. Results: In CARDIPP, nearly one in three patients with office normotension (<130/80 mmHg) were hypertensive during the night (≥120/70 mmHg). This phenomenon, masked nocturnal hypertension, was significantly associated with increased arterial stiffness and increased central blood pressure. Furthermore, nearly one in five CARDIPP patients with office normotension had high central pulse pressure (≥50 mmHg), and there was a significant association between high central pulse pressure and increased carotid intima-media thickness and increased arterial stiffness. Among CARDIPP patients who used at least one antihypertensive drug, those who used beta blockers had significantly higher central pulse pressure than those who used other antihypertensive drugs, but there were no significant between-group differences concerning office or ambulatory pulse pressures. In CARDIPP patients with or without antihypertensive treatment, ambulatory systolic blood pressure levels were significantly associated with left ventricular mass, independently of central systolic blood pressure levels. When RIKS-HIA patients, admitted to hospital for chest pain, were stratified in quartiles according to admission systolic blood pressure levels, the risk for all-cause one-year mortality was significantly lower in patients with admission systolic blood pressure in the highest quartile (≥163 mmHg) than in patients with admission systolic blood pressure in the reference quartile (128-144 mmHg). This finding remained unaltered when the analysis was restricted to include only patients with previously known diabetes. Conclusions: In patients with type 2 diabetes, ambulatory or central blood pressure measurements identified patients with residual risk factors despite excellent office blood pressure control or despite ongoing antihypertensive treatment. Ambulatory systolic blood pressure predicted left ventricular mass independently of central systolic blood pressure. In patients with previously known diabetes who were hospitalised for acute chest pain, there was an inverse relationship between systolic blood pressure measured at admission and the risk for one-year all-cause mortality.