Echocardiography in the flight program

Observations on American and Soviet astronauts have documented the association of changes in cardiovascular function during orthostasis with space flight. A basic understanding of the cardiovascular changes occurring in astronauts requires the determination of cardiac output and total peripheral vascular resistance as a minimum. In 1982, we selected ultrasound echocardiography as our means of acquiring this information. Ultrasound offers a quick, non-invasive and accurate means of determining stroke volume which, when combined with the blood pressure and heart rate measurements of the stand test, allows calculation of changes in peripheral vascular resistance, the body's major response to orthostatic stress. The history of echocardiography in the Space Shuttle Program is discussed and the results are briefly presented

752-6 Visualization of Coronary Arteries and Measurement of Coronary Blood Flow with Transthoracic Echocardiography After Intravenous Administration of a New Echocardlographic Contrast Agent

Imagent®US (AF0145, Alliance Pharmaceutical Corp.), a new hemodynamically inert perfluorochemical echocardiographic contrast agent, produces excellent left ventricular and blood pool contrast effect after intravenous administration when imaged with conventional (2-D) ultrasound. We evaluated the potential of Contrast Specific Imaging (Acuson) employing second harmonic principles to further enhance the visualization of structures containing contrast agents. Transthoracic images were obtained during injections of 10–40mg of the agent into the left femoral vein of seven closed chest dogs. Coronary Dopplerflow was simultaneously measured using an intracoronary Doppler wire. No alterations in flow velocities were observed with contrast administration. There was heterogenous opacification of the myocardium following contrast injection: a striking finding was of contrast-enhanced linear, branching structures in the myocardium consistent with coronary vessels. Further exploration of the largest structures (2–3mm diameter) in the region of the basal ventricular septum was technically possible with pulsed wave Doppler in two dogs. A characteristic coronary Doppler flow pattern was observed (Fig 1a). Transthoracic Doppler flow velocities transiently increased after intracoronary adenosine (Fig 1b). The calculated coronary flow reserve ratio was similar to simultaneous intracoronary Doppler measurements.ConclusionsIntramyocardial coronaryvasculature was observed and coronary flow velocites were measured during transthoracic Contrast Specific Imaging with an intravenously administered contrast agent. These findings suggest that noninvasive assessment of coronary blood flow is possible with echocardiographic contrast enhancement

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Background. In stress echocardiography, contrast agents are used selectively to improve endocardial border definition. Early identification of candidates may facilitate use of these agents in small and medium volume laboratories where resources are limited. Methods. We studied 15232 patients who underwent stress echocardiography. Contrast agent was used if 2 or more ventricular segments were not adequately visualized without contrast. Logistic regression models were used to evaluate the association between individual characteristics and contrast use. An 11-point score was derived from the significant characteristics. Results. Variables associated with microbubble use were age, sex, smoking, presence of multiple risk factors, bodymass index (BMI), referral for dobutamine stress echocardiography, history of coronary artery disease, and abnormal baseline electrocardiogram. All variables except BMI were given a score of 1 if present and 0 if absent; BMI was given a score of 0 to 4 according to its value. An increased score was directly proportional to increased likelihood of contrast use. The score cutoff value to optimize sensitivity and specificity was 5. Conclusions. A pretest score can be computed from information available before imaging. It may facilitate contrast agent use through early identification of patients who are likely to benefit from improved endocardial border definition

Pretest Score for Predicting Microbubble Contrast Agent Use in Stress Echocardiography: A Method to Increase Efficiency in the Echo Laboratory

Background. In stress echocardiography, contrast agents are used selectively to improve endocardial border definition. Early identification of candidates may facilitate use of these agents in small and medium volume laboratories where resources are limited. Methods. We studied 15232 patients who underwent stress echocardiography. Contrast agent was used if 2 or more ventricular segments were not adequately visualized without contrast. Logistic regression models were used to evaluate the association between individual characteristics and contrast use. An 11-point score was derived from the significant characteristics. Results. Variables associated with microbubble use were age, sex, smoking, presence of multiple risk factors, bodymass index (BMI), referral for dobutamine stress echocardiography, history of coronary artery disease, and abnormal baseline electrocardiogram. All variables except BMI were given a score of 1 if present and 0 if absent; BMI was given a score of 0 to 4 according to its value. An increased score was directly proportional to increased likelihood of contrast use. The score cutoff value to optimize sensitivity and specificity was 5. Conclusions. A pretest score can be computed from information available before imaging. It may facilitate contrast agent use through early identification of patients who are likely to benefit from improved endocardial border definition

Alterations in Platelet Function and Cell-Derived Microvesicles in Recently Menopausal Women: Relationship to Metabolic Syndrome and Atherogenic Risk

A woman’s risk for metabolic syndrome (MS) increases at menopause, with an associated increase in risk for cardiovascular disease. We hypothesized that early menopause-related changes in platelet activity and concentrations of microvesicles derived from activated blood and vascular cells provide a mechanistic link to the early atherothrombotic process. Thus, platelet functions and cellular origin of blood-borne microvesicles in recently menopausal women (n = 118) enrolled in the Kronos Early Estrogen Prevention Study were correlated with components of MS and noninvasive measures of cardiovascular disease [carotid artery intima medial thickness (CIMT), coronary artery calcium (CAC) score, and endothelial reactive hyperemic index (RHI)]. Specific to individual components of the MS pentad, platelet number increased with increasing waist circumference, and platelet secretion of ATP and expression of P-selectin decreased with increasing blood glucose (p = 0.005) and blood pressure (p < 0.05), respectively. Waist circumference and systolic blood pressure were independently associated with monocyte- and endothelium-derived microvesicles (p < 0.05). Platelet-derived and total procoagulant phosphatidylserine-positive microvesicles, and systolic blood pressure correlated with CIMT (p < 0.05), but not with CAC or RHI. In summary, among recently menopausal women, specific platelet functions and concentrations of circulating activated cell membrane-derived procoagulant microvesicles change with individual components of MS. These cellular changes may explain in part how menopause contributes to MS and, eventually, to cardiovascular disease

The Canadian Women's Heart Health Alliance Atlas on the epidemiology, diagnosis, and management of cardiovascular disease in women - Chapter 5 : sex- and gender-unique manifestations of cardiovascular disease.

This Atlas chapter summarizes sex- and some gender-associated, and unique aspects and manifestations of cardiovascular disease (CVD) in women. CVD is the primary cause of premature death in women in Canada and numerous sex-specific differences related to symptoms and pathophysiology exist. A review of the literature was done to identify sex-specific differences in symptoms, pathophysiology, and unique manifestations of CVD in women. Although women with ischemic heart disease might present with chest pain, the description of symptoms, delay between symptom onset and seeking medical attention, and prodromal symptoms are often different in women, compared with men. Nonatherosclerotic causes of angina and myocardial infarction, such as spontaneous coronary artery dissection are predominantly identified in women. Obstructive and nonobstructive coronary artery disease, aortic aneurysmal disease, and peripheral artery disease have worse outcomes in women compared with men. Sex differences exist in valvular heart disease and cardiomyopathies. Heart failure with preserved ejection fraction is more often diagnosed in women, who experience better survival after a heart failure diagnosis. Stroke might occur across the lifespan in women, who are at higher risk of stroke-related disability and age-specific mortality. Sex- and gender-unique differences exist in symptoms and pathophysiology of CVD in women. These differences must be considered when evaluating CVD manifestations, because they affect management and prognosis of cardiovascular conditions in women.Dans le présent chapitre d’Atlas sont récapitulés les aspects et les manifestations uniques, associés au sexe et certains associés au genre, des maladies cardiovasculaires (MCV) chez les femmes. Les MCV sont la cause principale de décès prématurés chez les femmes au Canada. De nombreuses différences quant aux symptômes et à la physiopathologie existent entre les sexes. Nous avons réalisé une revue de la littérature pour déterminer les différences entre les sexes dans les symptômes et la physiopathologie, et les manifestations uniques des MCV chez les femmes. Bien que les femmes atteintes d’une cardiopathie ischémique puissent éprouver des douleurs thoraciques, la description des symptômes, le délai entre l’apparition des symptômes et l’obtention de soins médicaux, et les symptômes prodromiques sont souvent différents de ceux des hommes. Les causes de l’angine et de l’infarctus du myocarde non liées à l’athérosclérose telles que la dissection spontanée de l’artère coronaire sont principalement observées chez les femmes. La coronaropathie obstructive et non obstructive, l’anévrisme aortique et la maladie artérielle périphérique montrent de plus mauvaises issues chez les femmes que chez les hommes. Des différences entre les sexes sont observées dans la cardiopathie valvulaire et les cardiomyopathies. Le diagnostic d’insuffisance cardiaque avec fraction d’éjection préservée est plus souvent posé chez les femmes qui présentent un meilleur taux de survie après un diagnostic d’insuffisance cardiaque. L’accident vasculaire cérébral (AVC) pourrait survenir tout au long de la vie des femmes, qui sont exposées à un risque plus élevé d’incapacités liées à l’AVC et de mortalité par âge. Il existe des différences uniques entre les sexes et les genres pour ce qui est des symptômes et de la physiopathologie des MCV chez les femmes. Lors de l’évaluation des manifestations des MCV, il faut tenir compte de ces différences puisqu’elles influencent la prise en charge et le pronostic des maladies cardiovasculaires chez les femmes

The Canadian Women's Heart Health Alliance atlas on the epidemiology, diagnosis, and management of cardiovascular disease in women - Chapter 6 : sex- and gender-specific diagnosis and treatment

This chapter summarizes the sex- and gender-specific diagnosis and treatment of acute/unstable presentations and nacute/stable presentations of cardiovascular disease in women. Guidelines, scientific statements, systematic reviews/meta-analyses, and primary research studies related to diagnosis and treatment of coronary artery disease, cerebrovascular disease (stroke), valvular heart disease, and heart failure in women were reviewed. The evidence is summarized as a narrative, and when available, sex- and gender-specific practice and research recommendations are provided. Acute coronary syndrome presentations and emergency department delays are different in women than they are in men. Coronary angiography remains the gold-standard test for diagnosis of obstructive coronary artery disease. Other diagnostic imaging modalities for ischemic heart disease detection (eg, positron emission tomography, echocardiography, single-photon emission computed tomography, cardiovascular magnetic resonance, coronary computed tomography angiography) have been shown to be useful in women, with their selection dependent upon both the goal of the individualized assessment and the testing resources available. Noncontrast computed tomography and computed tomography angiography are used to diagnose stroke in women. Although sex-specific differences appear to exist in the efficacy of standard treatments for diverse presentations of acute coronary syndrome, many cardiovascular drugs and interventions tested in clinical trials were not powered to detect sex-specific differences, and knowledge gaps remain. Similarly, although knowledge is evolving about sex-specific difference in the management of valvular heart disease, and heart failure with both reduced and preserved ejection fraction, current guidelines are lacking in sex-specific recommendations, and more research is needed.Ce chapitre présente un résumé sur le diagnostic et le traitement des tableaux cliniques aigus/instables et non aigus/stables des maladies cardiovasculaires chez les femmes, et les différences propres à chacun des deux sexes. Les lignes directrices, les énoncés scientifiques, les revues systématiques/méta-analyses et les études de recherche originale sur le diagnostic et le traitement des coronaropathies, des maladies vasculaires cérébrales (AVC), des valvulopathies cardiaques et de l’insuffisance cardiaque chez les femmes ont été examinés. Les données probantes sont résumées sous forme narrative et, lorsqu’elles sont disponibles, des recommandations en matière de pratique et de recherche pour chacun des deux sexes sont présentées. Les tableaux cliniques du syndrome coronarien aigu et les délais d’attente à l’urgence sont différents selon qu’une femme ou un homme en est atteint. L’angiographie coronarienne reste l’examen de référence pour le diagnostic des coronaropathies obstructives. D’autres examens d’imagerie diagnostique (p. ex. la tomographie par émission de positons, l’échocardiographie, la tomographie d'émission à photon unique, la résonance magnétique cardiovasculaire, l’angiographie coronarienne par tomodensitométrie) se sont avérés utiles pour la détection des cardiopathies ischémiques chez les femmes. Le recours à ces modalités dépend de l’objectif de l’évaluation personnalisée et des ressources disponibles. La tomodensitométrie sans agent de contraste et l’angiographie par tomodensitométrie sont utilisées pour le diagnostic des AVC chez les femmes. Malgré les différences entre les sexes quant à l’efficacité des traitements de référence des divers tableaux cliniques du syndrome coronarien aigu, bon nombre des médicaments et des interventions cardiovasculaires qui ont fait l’objet d’essais cliniques n’avaient pas la puissance statistique nécessaire pour détecter des différences selon les sexes, de sorte que les connaissances restent fragmentaires sur ce sujet. De même, malgré l’évolution des connaissances sur les différences sexuelles quant à la prise en charge des valvulopathies cardiaques et de l’insuffisance cardiaque avec fraction d’éjection réduite ou préservée, on ne trouve pas de recommandations pour chaque sexe dans les lignes directrices actuelles, d’où la pertinence d’études supplémentaires portant sur cette question

Cardio-oncology: what you need to know now for clinical practice and echocardiography

Cardio-oncology is a rapidly growing field aimed at minimizing the effects of cardiovascular morbidity and mortality in cancer survivors. To meet this aim, patients are assessed at baseline to define their risk of cardiotoxicity and then followed closely during and after chemotherapy to assess for early signs or symptoms of cardiovascular disease. Cardiac imaging, and in particular, transthoracic echocardiography, plays an essential role in the baseline assessment and serial follow-up of cardio-oncology patients. The objectives of this paper are to review the mechanisms of cardiotoxicity of several common chemotherapeutic agents associated with an increased risk for left ventricular systolic dysfunction and to outline recommendations regarding the baseline assessment and serial follow-up of cardio-oncology patients with a focus on the role of echocardiography

Relationship between HgbA1c and Myocardial Blood Flow Reserve in Patients with Type 2 Diabetes Mellitus: Noninvasive Assessment Using Real-Time Myocardial Perfusion Echocardiography

To study the relationship between glycosylated hemoglobin (HgbA1c) and myocardial perfusion in type 2 diabetes mellitus (T2DM) patients, we prospectively enrolled 24 patients with known or suspected coronary artery disease (CAD) who underwent adenosine stress by real-time myocardial perfusion echocardiography (RTMPE). HgbA1c was measured at time of RTMPE. Microbubble velocity (β min−1), myocardial blood flow (MBF, mL/min/g), and myocardial blood flow reserve (MBFR) were quantified. Quantitative MCE analysis was feasible in all patients (272/384 segments, 71%). Those with HgbA1c > 7.1% had significantly lower βreserve and MBFR than those with HgbA1c ≤ 7.1% (P 2 as normal, HgbA1c > 7.1% significantly increased the risk for abnormal MBFR, (adjusted odds ratio: 1.92, 95% CI: 1.12–3.35, P=0.02). Optimal glycemic control is associated with preservation of MBFR as determined by RTMPE, in T2DM patients at risk for CAD