Objetivos: Determinar hallazgos estructurales o funcionales ecocardiográficos en pacientes recuperados de infección SARS-CoV-2. Materiales y métodos: Estudio observacional transversal, que incluyó pacientes trabajadores de un hospital nacional COVID, estudiados entre 3 a 6 meses luego del diagnostico de infección SARS-CoV-2. La exploración ecocardiográfica se desarrolló de forma sistemática e incluyó las modalidades convencionales. Resultados: Se incluyeron 65 casos con infección-CoV-2, la edad promedio fue 37.7 años, la obesidad resultó la comorbilidad mas frecuente (13.8%) y la presentación clínica leve fue la de mayor prevalencia (84.6%). Las medias del diámetro diastólico y la fracción de eyección ventrículo izquierdo fueron 42mm y 57% respectivamente. Así mismo la media del diámetro basal del ventrículo derecho fue de 31mm, de la fracción de acortamiento 44% y en todos los casos se reportó probabilidad de hipertensión pulmonar como baja. No se encontró efusión pericárdica en ninguno de los casos. Conclusiones Los pacientes recuperados de infección SARS-CoV-2, no presentan alteraciones estructurales ni funcionales en la exploración ecocardiográfica convencional.

Determinations of cardiac output (CO) by M-mode echocardio-graphy were compared with simultaneous determinations by thermodilution in 2 conscious and 5 anesthetized horses. A range of cardiac outputs was induced by use of a pharmacological protocol (dopamine, 4 ug/kg/min, dobutamine, 4 ug/kg/min, and 10 ug/kg detomidine plus 20 ug/kg butorphanol, in sequence). Changes from baseline CO in response to each drug were evaluated, and data was analyzed to determine whether there were any interactions between drug treatment and measurement method. The mathematical relationship between CO as determined by M-mode echocardio-graphy (COecho) and as determined by thermodilution (COTD) was described and used to predict COTD from COecho. The 2 methods were compared with respect to bias and variability in order to determine the suitability of COecho as a substitute for COTD . Sources of the variability for each method were determined. Determination of CO by either method in standing horses was prohibitively difficult due to patient movement. The pharmacologi-cal protocol was satisfactory for inducing a range of cardiac outputs for the purpose of method comparison; however, use of dopamine did not offer any additional benefit over the use of dobutamine and was generally less reliable for increasing CO. Inclusion of detomidine provided an additional change in CO but did not increase the overall range of CO over that produced by halothane and dobutamine. COecho and COTD were significantly related by the predictive equation COTD = (0.63 +/- 0.157) x COecho + (16.6 +/- 3.22). The relatively large standard errors associated with COecho measurements resulted in a broad 95% prediction interval such that COecho would have to change by more than 100% in order to be 95% confident that the determined value represents true hemodynamic change. COecho underestimated COTD by a mean of 10 +/- 6.3 l/min/450 kg. The large standard deviation of the bias resulted in broad limits of agreement (-22.3 to +2.3 l/min/450 kg). Measurement-to-measurement variability accounted for 28% of the total variation in COTD values and 64% of the total variation in COecho values. Results might be improved if the mean of 3-5 consecutive beats was used for each measurement, but as determined in this experiment, COecho is too variable to have confidence in its use for precise determinations of CO. / Master of Science

No description available.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成5年2月19日 竹中晃氏の博士論文として提出された

Background:  The right ventricle (RV) is multi-compartmental in orientation with a complex structural geometry. However, assessment of this part of the heart has remained an elusive clinical challenge. As a matter of fact, its importance has been underestimated in the past, especially its role as a determinant of cardiac symptoms, exercise capacity in chronic heart failure and survival in patients with valvular disease of the left heart. Evidence also exists that pulmonary hypertension (PH) affects primarily the right ventricular function. On the other hand, previous literature suggested that severe aortic stenosis (AS) affects left ventricular (LV) structure and function which partially recover after aortic valve replacement (AVR). However, the impact of that on RV global and segmental function remains undetermined.  Objectives: We sought to gain more insight into the RV physiology using 3D technology, Speckle tracking as well as already applicable echocardiographic measures. Our first aim was to assess the normal differential function of the RV inflow tract (IT), apical and outflow tract (OT) compartments, also their interrelations and the response to pulmonary hypertension. We also investigated the extent of RV dysfunction in severe AS and its response to AVR. Lastly, we studied the extent of global and regional right ventricular dysfunction in patients with pulmonary hypertension of different aetiologies and normal LV function. Methods: The studies were performed on three different groups; (1) left sided heart failure with (Group 1) and without (Group 2) secondary pulmonary hypertension, (2) severe aortic stenosis and six months post AVR and (3) pulmonary hypertension of different aetiologies and normal left ventricular function. We used 3D, speckle tracking echocardiography and conventionally available Doppler echocardiographic transthoracic techniques including M-mode, 2D and myocardial tissue Doppler. All patients’ measurements were compared with healthy subjects (controls). Statistics were performed using a commercially available SPSS software. Results: 1-  Our RV 3D tripartite model was validated with 2D measures and eventually showed strong correlations between RV inflow diameter (2D) and end diastolic volume (3D) (r=0.69, p<0.001) and between tricuspid annular systolic excursion (TAPSE) and RV ejection fraction (3D) (r=0.71, p<0.001). In patients (group 1 & 2) we found that the apical ejection fraction (EF) was less than the inflow and outflow (controls:  p<0.01 & p<0.01, Group 1:  p<0.05 & p<0.01 and Group 2: p<0.05 & p<0.01, respectively). Ejection fraction (EF) was reduced in both patient groups (p<0.05 for all compartments). Whilst in controls, the inflow compartment reached the minimum volume 20 ms before the outflow and apex, in Group 2 it was virtually simultaneous. Both patient groups showed prolonged isovolumic contraction (IVC) and relaxation (IVR) times (p<0.05 for all). Also, in controls, the outflow tract was the only compartment where the rate of volume fall correlated with the time to peak RV ejection (r = 0.62, p = 0.03). In Group 1, this relationship was lost and became with the inflow compartment (r = 0.61, p = 0.01). In Group 2, the highest correlation was with the apex (r=0.60, p<0.05), but not with the outflow tract. 2- In patients with severe aortic stenosis, time to peak RV ejection correlated with the basal cavity segment (r = 0.72, p<0.001) but not with the RVOT. The same pattern of disturbance remained after 6 months of AVR (r = 0.71, p<0.001). In contrast to the pre-operative and post-operative patients, time to RV peak ejection correlated with the time to peak outflow tract strain rate (r = 0.7, p<0.001), but not with basal cavity function. Finally in patients, RVOT strain rate (SR) did not change after AVR but basal cavity SR fell  (p=0.04). 3- In patients with pulmonary hypertension of different aetiologies and normal LV function, RV inflow and outflow tracts were dilated (p<0.001 for both). Furthermore, TAPSE (p<0.001), inflow velocities (p<0.001), basal and mid-cavity strain rate (SR) and longitudinal displacement (p<0.001 for all) were all reduced. The time to peak systolic SR at basal, mid-cavity (p<0.001 for both) and RVOT (p=0.007) was short as was that to peak displacement (p<0.001 for all). The time to peak pulmonary ejection correlated with time to peak SR at RVOT (r=0.7, p<0.001) in controls, but with that of the mid cavity in patients (r=0.71, p<0.001). Finally, pulmonary ejection acceleration (PAc) was faster (p=0.001) and RV filling time shorter in patients (p=0.03) with respect to controls. Conclusion: RV has distinct features for the inflow, apical and outflow tract compartments, with different extent of contribution to the overall systolic function. In PH, RV becomes one dyssynchronous compartment which itself may have perpetual effect on overall cardiac dysfunction. In addition, critical aortic stenosis results in RV configuration changes with the inflow tract, rather than outflow tract, determining peak ejection. This pattern of disturbance remains six month after valve replacement, which confirms that once RV physiology is disturbed it does not fully recover. The findings of this study suggest an organised RV remodelling which might explain the known limited exercise capacity in such patients. Furthermore, in patients with PH of different aetiologies and normal LV function, there is a similar pattern of RV disturbance. Therefore, we can conclude that early identification of such changes might help in identifying patients who need more aggressive therapy early on in the disease process.

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine Johannesburg, 2005 / ABSTRACT INTRODUCTION The risk of cardiovascular disease in patients with end stage renal disease (ESRD) is far greater than in the general population. Amongst patients with ESRD, the prevalence of coronary artery disease (CAD) and congestive heart failure is approximately 40% compared with 5-12% in the general population. The excess risk is caused by multiple traditional and non-traditional risk factors for ischaemic heart disease present in these patients. There is little information on CAD and its risk factors in black haemodialysis patients as most of these studies were carried out in the white population. This study is therefore aimed at determining the risk factors for atherosclerosis in Black and non-black (White and Indian) South African patients on haemodialysis. METHODS Fifty-eight black patients and twenty-six non-black patients on haemodialysis were recruited. Sixty-three age and sex matched controls (staff, students and kidney donors) were also recruited. Fasting venous blood samples were drawn for measurement of Creactive protein, homocysteine, Lp (a), serum lipids and adiponectin. Carotid intima-media thickness and plaque occurrence was measured by B-mode ultrasonography. Echocardiography was used to determine LVH. vi RESULTS Haemodialysis (HD) patients had significantly lower total cholesterol, LDL cholesterol and triglycerides compared with controls (p<0.001; p= 0.042). Hs-CRP, adiponectin and homocysteine levels were significantly higher in patients compared with controls (p< 0.001). The prevalence of plaques was significantly higher among HD patients (32%) compared with controls (7%) X2 = 60.72 p< 0.001. LVMI was significantly higher among HD patients (194.25± 7.69gm/m2) compared with controls (93.21 ± 3.27 gm/m2) p < 0.001. No significant difference between patients (Black or Asian/White) and controls with respect to CIMT was found. CVD risk factors in black haemodialysis patients and black controls showed a similar pattern to the whole study population combined. Risk factors associated with CIMT on regression analysis were total cholesterol, LDL-cholesterol, age, Hs-CRP, family history of CKD. Risk factors associated with plaque occurrence on logistic regression analysis were age, systolic blood pressure, male gender, smoking, calcium phosphate product and serum phosphate. CONCLUSION HD patients have a high prevalence of traditional and non-traditional risk factors for atherosclerosis and this is independent of race. Traditional risk factors like lipids were much lower in ESRD patients. HD patients showed a high prevalence of atherosclerosis as measured by increased carotid intima-media thickness and plaque occurrence in carotid arteries. Hs-CRP correlated significantly with a surrogate marker of atherosclerosis (CIMT).

No description available.

Master of Science / Department of Kinesiology / Carl Ade / Background: Cancer survivors treated with anthracycline-based chemotherapy have a high risk of developing anthracycline-induced cardiotoxicities, including cardiac abnormalities, endothelial dysfunction, and dilated cardiomyopathy. Notably, the imbalance of decreased nitric oxide (NO) production and increased reactive oxygen species has been shown to cause significant damage to cardiac tissue and mitochondria. Therefore, the aim of the current investigation was to determine if an inorganic dietary nitrate (NO3-) supplementation period could restore normal cardiac function in cancer survivors with a history of anthracycline chemotherapy. Methods: Ten cancer survivors, 9 with breast cancer and 1 with lymphoma, completed the experiment. Standard and Tissue Doppler echocardiography were used to assess LV and carotid artery function during systole and diastole at rest. Results: There were no differences in ventricular-arterial coupling (p=0.10), arterial stiffness (p=0.38) or strain of the LV (p=0.49). However, NO₃- supplementation improved strain rate in early filling, early mitral septal wall annular velocity, and mitral A-wave velocity or late diastolic filling. Conclusion: Following NO₃- supplementation, cancer survivors with a history of anthracycline chemotherapy showed significant improvements in diastolic function compared to placebo treatments. These findings add support to the literature of the therapeutic benefits of inorganic dietary NO₃- supplementation on cardiovascular function in clinical populations.

Background: The molecular and cellular mechanisms corresponding to the compensatory and maladaptive hypertrophy and remodeling of the left ventricle with chronic doxorubicin (DOX) treatment are currently unclear. Non-invasive methods of determining these changes are still deficient. To investigate these changes, 8 groups of rats in 4 different studies including a control saline group of the same age, gender and strain were evaluated for cardiac morphology and function including: (1) DOX dose response using a cumulative dose of 7.5mg/kg, and 15mg/kg in 8-10 week old female Sprague-Dawley (SD) rats, (2) strain differences were investigated in response to a cumulative dose of 15mg/kg in 8-10 week old female Fisher (F344) rats compared to the SD rats treated with same dose, (3) the role of gender and aging were studied in response to DOX at a cumulative dose of 3mg/kg in male and female neonates, and (4) combined losartan and a cumulative dose of 15mg/kg of DOX in 8-10 week old female SD rats compared to controls of saline and 15mg/kg treated SD rats. Method: Onset of cardiac toxicity was assessed by echocardiography and the rat model of heart failure was developed when the fractional shortening declined ≤ 40%. The mean arterial pressure and single-photon-emission computer tomography scanning and Tc-99m-HYNIC-Annexin V were performed at week 10 to analyze blood pressure and quantify apoptosis, respectively. All rats were euthanized at week 10 except for the neonates and two of the 7.5mg/kg-treated SD rats that were left alive for study of long -term cardiac side effects. The heart and kidney tissues were harvested for protein isolation and histopathological studies. Blood samples were collected for hematological and lipid profile analysis in all the rats. Results: A dose- and time-dependent increase in LVmass coincided with a parallel increase in MAP, kidney damage, expression of myocardial erbB2, heat shock protein 90 Akt, mTOR, GSK-3β, TGF-β, pSMAD2, and cardiomyocyte apoptosis in SD rats treated with 7.5mg/kg and 15mg/kg of DOX at week 10. The 7.5 kg/kg treatment showed adaptive hypertrophy whereas the 15mg/kg treatment group showed maladaptive hypertrophy. However decompensation was apparent by week 14 in other rats treated with 7.5mg/kg. LVmass, FS, MAP, kidney damage, red blood cells and blood lipid levels were not significantly altered in the F344 rats compared to the 15 mg/kg-treated SD rats. Losartan supplementation reduced the left ventricular hypertrophy, improved myocardial contractility, and reduced TGF-β expression compared to the DOX-treated SD rats. The 3mg/kg of DOX in neonates induced cardiac toxicity and deaths in about 60% of males 50 weeks after treatment; the females instead developed mammary tumors. Conclusion: The results of this study suggest that age, gender, and strain differences are risks factors for doxorubicin-induced harmful reno-cardiovascular toxicity. The inhibition of TGF-β expression by losartan can be used in prevention of chronic doxorubicin-induced cardiac toxicity without interfering with its anti-tumor activities.

Background: Decreased right ventricular function after coronary artery bypass graft surgery is a well-known phenomenon. The use of an artificial circuit and of cardioplegia during cardiopulmonary bypass (conventional coronary artery bypass graft surgery) has been evoked as possible reason for this dysfunction. With the availability of cardiac stabilisers (Octopus or Starfish®), bypass surgery on a beating heart is now possible without the use of cardioplegia and cardiopulmonary bypass (off-pump coronary artery bypass graft surgery). Avoiding the potential damaging effects of cardiopulmonary bypass and keeping a nearly continuous perfusion in the coronary arteries of the beating heart have been postulated to offer a better protection of the myocardium with a better outcome and to reduce the perioperative morbidity. Aims: If right ventricular dysfunction is known to occur after conventional coronary artery bypass graft surgery, nothing is known about right ventricular function after off-pump coronary artery bypass graft surgery. Therefore we performed two prospective, randomised, controlled trials to assess and compare the short-term and medium-term effects of conventional and off-pump coronary artery bypass graft surgery on the global and regional right ventricular function. We used transoesophageal and transthoracic echocardiography as investigating tools of right ventricular systolic and diastolic function. Materials and Methods: Fifty consecutive patients scheduled for elective coronary bypass graft surgery and for whom the surgeon regarded off-pump and on-pump techniques as equally suitable were randomised. We performed a transthoracic echocardiography the day before surgery and 3 months after surgery, and a transoesophageal echocardiography just before opening and just after closure of the sternum. Results: Just after closure of the sternum, we could not observe a better protection of the right ventricular function by the off-pump surgery. Cardiac index and right ventricular ejection fraction were equally preserved in the 2 groups. Systolic and diastolic myocardial function (investigated by Tissue Doppler imaging) was impaired only in the off-pump group, but the intergroup difference was not statistically significant. Three months after surgery, there were no differences between the 2 groups: global right ventricular systolic function was equally preserved and right ventricular systolic and diastolic myocardial function equally impaired. Conclusions: These 2 studies do not allow for concluding that off-pump coronary artery bypass graft surgery would better preserve right ventricular systolic and diastolic function than conventional coronary artery bypass graft surgery, just after surgery or 3 months later. In any event, our studies provided the opportunity to acquire experience in systematically evaluating the right ventricle using transoesophageal echocardiography. / Introduction: La dysfonction ventriculaire droite après chirurgie coronaire est un phénomène bien connu. L'utilisation d'un circuit artificiel ainsi que d'une solution de cardioplégie pendant la circulation extra-corporelle (CEC) (chirurgie coronaire classique) a été évoquée comme origine possible de cette dysfonction. Une chirurgie sur cœur battant (chirurgie coronaire sans CEC) est actuellement possible grâce à l'utilisation de stabilisateurs cardiaques (Octopus ou Starfish®). Ce type de chirurgie sans CEC permet d'éviter l'utilisation de la CEC et de solutions de cardioplégie et d'en supprimer ainsi les effets délétères. Elle permet également de maintenir une perfusion quasi continue des artères coronaires. Ces différents éléments ont été évoqués comme offrant une meilleure protection myocardique ainsi qu'un meilleur devenir des patients, et comme pouvant réduire la morbidité périopératoire. Buts : La survenue d'une dysfonction ventriculaire droite après chirurgie coronaire classique est un phénomène bien connu, par contre nous savons peu de chose sur la fonction ventriculaire droite après chirurgie coronaire sans CEC. Pour cette raison, nous avons entrepris deux études prospectives, randomisées et contrôlées afin d'étudier et de comparer les effets à court et moyen terme de la chirurgie coronaire classique et sans CEC. Nous avons utilisé l'échographie cardiaque transthoracique et transœsophagienne comme outil de mesure de la fonction systolique et diastolique du ventricule droit. Matériel et Méthode : Nous avons randomisé cinquante patients consécutifs, programmés pour une chirurgie coronaire élective et pour laquelle le chirurgien estimait qu'une chirurgie sans CEC était aussi appropriée qu'une chirurgie avec CEC. Une échographie cardiaque transthoracique était réalisée la veille de l'intervention ainsi que 3 mois plus tard, une échographie transoesophagienne était réalisée juste avant l'ouverture et après la fermeture du sternum. Résultats : Juste après la fermeture du sternum, la fonction ventriculaire droite dans le groupe sans CEC n'était pas mieux protégée que dans le groupe avec CEC. L'index cardiaque et la fraction d'éjection ventriculaire droite étaient préservés de manière équivalente dans les 2 groupes. La fonction régionale systolique et diastolique du ventricule droit (étudiée par Doppler tissulaire) n'était altérée de manière significative que dans le groupe sans CEC, mais la différence intergroup n'était pas statistiquement significative. A 3 mois également, les 2 groupes ne différaient pas : la fonction systolique globale du ventricule droit était préservée de manière équivalente ; la fonction régionale systolique et diastolique du ventricule droit était altérée de manière équivalente. Conclusions : Ces 2 études ne nous permettent pas de conclure à une meilleure protection de la fonction systolique et diastolique ventriculaire droite par la chirurgie coronaire sans CEC, que ce soit juste en fin de chirurgie ou 3 mois plus tard. D'autre part, ces études nous ont permis d'acquérir de l'expérience dans l'analyse systématique du ventricule droit par échographie cardiaque transoesophagienne.