Application of Tornado-flow Fundamental Hydro- dynamic Theory to the Study of Blood Flow in the Heart -Further Development of Tornado-like Jet Technology

ABSTRACT It has been proved previously that the Tornado-like swirling flows have strictly ordered hydrodynamic structure which can be exhaustively described by using the exact solution of non-stationary Navier-Stokes and continuity equations for this class of flows The current study proposes a method of measurement and calculation of the flow structural parameters derived from the exact solution, using LV cavity casts morphometry in humans and dogs and Multislice computed tomography (MSCT) of LV in two patients without severe cardiac pathology. It has been shown that the dynamic expression of intracardiac trabeculae and instant shape of LV cavity within a complete cardiac cycle correspond closely to the stages of single Tornado-like jet evolution. Since the intraventricular trabeculae profile is streamlined continuously by the blood flow, it should determine the hydrodynamic flow structure as an ensemble of guiding vanes. Therefore it has been concluded that the intraventricular flow dynamics can be analyzed and quantified using the exact solution. Application of this analysis to the MSCT visualization of LV cavity dynamics has shown the validity of this approach, which may be used for clinical diagnostic purpose. A realistic mathematical model of intraventricular blood flow has been proposed and evaluated. The results showed a good agreement between the model and known cardiac anatomy and function

Detection of Functional Significance of Coronary Stenoses Using Dynamic 13N-Ammonia Stress-PET/CT with Absolute Values of Myocardial Blood Flow and Coronary Flow Reserve

Objectives. The aim of the study was to compare the values of myocardial blood flow (MBF) at stress, MBF at rest and coronary flow reserve (CFR) obtained by 13Nammonia stress-PET/CT in patients with various degrees of coronary stenosis and in healthy patients. And thus to estimate the possible contribution of the stress-PET/CT quantitative data to the detection of functionally significant coronary stenoses in patients with coronary artery disease (CAD). Materials and methods. 63 patients (mean age 64±9 years) with known CAD underwent dynamic 13N-ammonia stress-PET/CT followed by calculation of MBF both at stress and at rest in absolute units and CFR. We compared quantitative values in two groups of patients with coronary artery stenosis: 1) ≥75% (n = 36) and 2) <75% (n = 27) confirmed by invasive coronary angiography and in group of healthy patients (n = 11). Results. MBF at stress was significantly lower in group with ≥75% diameter stenoses (median 1,44 [1,21; 1,85] mL/min per g) compared with group with <75% diameter stenoses (2,42 [1,75; 2,89] mL/min/g) and the normal group (2,54 [2,31; 2,86] mL/min/g), (p <0,001). There was no reliable difference in MBF at rest between the three groups (p = NS). CFR was significantly lower in the group of patients with severe ≥75% stenoses (1,85 [1,54; 2,31]) in comparison with patients group with stenoses of intermediate <75% severity (2,73 [2,19; 3,21]), and also in comparison with the normal group (3,12 [2,75; 3,23]), (p <0,001). Conclusion. The values of MBF at stress and CFR are significantly lower in patients with severe coronary arteries stenoses comparing with the group of patients with mild and moderate stenoses. The value of MBF at rest used independently has no diagnostic utility for detection of functional significance of coronary artery stenoses. Keywords: myocardial blood flow, coronary flow reserve, PET/CT, 13N-ammonia, coronary stenosis

Применение рекомбинантного активированного протеина С в терапии сепсиса у детей после кардиохирургических вмешательств

Sepsis is the principal cause of hospital death among children and ranks fourth among all causes of death in infants under 1 year of age and second in 1-to-14-year-old children. Objective: to assess whether activated protein C (APC) infusion may be incorporated into the complex intensive therapy for sepsis in babies of the first year of life. Subjects and methods. In January 2005 to April 2007, APC was used in the complex intensive therapy for sepsis in 36 infants of the first year of life. APC therapy was initiated in the first 24 hours after the occurrence of organ dysfunction in 29 (80%) patients and in the first 48 hours in others cases. Results. Status stabilization and multiple organ dysfunction (MOD) regression were noted in most patients during APC infusion. Ten (28%) patients died; mortality rates in the groups of patients with early and late infusion were 17 and 71%, respectively. The baseline APC level failed to affect 28-day survival. By the end of infusion, the mean level of protein C was much higher in the group of survivors than that in the deceased. Conclusion. APC as a part of the complex intensive therapy for sepsis should be given to infants of the first year of life who had multiple organ dysfunctions within the first 24 hours after the occurrence of organ dysfunction. Key words: pediatric sepsis, activated a-drotrecogin, multiple organ dysfunction.Сепсис является основной причиной госпитальной летальности среди детей и занимает четвертое место среди всех причин смерти детей до 1 года, второе — среди причин смерти детей от 1 года до 14 лет. Цель работы . Оценить возможность включения инфузии активированного протеина С (АПС) в комплексную интенсивную терапию сепсиса у детей первого года жизни после кардиохирургических вмешательств. Материал и методы. С января 2005 по апрель 2007 года АПС применен в комплексной интенсивной терапии сепсиса у 36 детей 1-го года жизни. Терапия АПС была начата в первые 24 часа после появления органной дисфункции у 29 (80%) пациентов; в остальных случаях в течение первых 48 часов. Результаты. У большинства пациентов на фоне инфузии АПС отмечена стабилизация состояния и регресс синдрома полиорганной недостаточности (СПОН). Умерли 10 (28%) больных, смертность в группе больных с ранним началом инфузии составила 17%, с поздним — 71%. Исходный уровень АПС не влиял на 28-дневную выживаемость. В группе выживших больных в среднем уровень протеина С к концу инфузии был значительно выше, чем у умерших. Заключение. АПС в комплексной интенсивной терапии сепсиса детей 1-го года жизни с полиорганной недостаточностью должен быть назначен в первые 24 часа после появления органной дисфункции. Ключевые слова: педиатрический сепсис, дротрекогин a-активированный, полиорганная недостаточность

4D FLOW МРТ в оценке диастолического кровотока в левом желудочке у пациентов с гипертрофической кардиомиопатией

Objective. To assess phase-contrast MRI in the evaluation of left ventricular hemodynamics changes in various forms of hypertrophic cardiomyopathy.Materials and methods. 11 patients were examined: without pathology of the cardiovascular system (n = 3), with apical (n = 3), diffuse-septal (n = 2) and focal-basal (n = 3) types of hypertrophic cardiomyopathy. All patients underwent MRI of the heart with an additional phase-contrast sequence of the left ventricular area. Postprocessing carried out in the 4D FLOW application (Siemens).Results. Data were obtained on the geometry and dynamics of vortex diastolic flows in the left ventricular of all patients. In patients with hypertrophic cardiomyopathy, an increase in the distance to the center of the vortex and a decrease in the normalized area and peak velocity of the vortex is determined. The diffuse-septal type is characterized by a minimal vortex peak velocity; apical type - by the maximum vortex sphericity index. For patients with a focalbasal type of hypertrophic cardiomyopathy the maximum changes in blood flow are determined in late diastole (absence of vortexes).Conclusion. 4D FLOW Phase-contrast MRI allows identifying and assessing LV vortical flow. Quantitative analysis can be used to characterize the remodeling of LV blood flow of various types of hypertrophic cardiomyopathy.Цель исследования: оценить изменения гемодинамики левого желудочка с помощью фазово-контрастной МРТ у пациентов с различными формами гипертрофической кардиомиопатии.Материал и методы. Обследовано 11 пациентов: без патологии сердечно-сосудистой системы (n = 3), с апикальной (n = 3), диффузно-септальной (n = 2) и фокально-базальной (n = 3) формами гипертрофической кардиомиопатии. Всем пациентам выполнено МРТ-исследование сердца с дополнительной фазовоконтрастной последовательностью области левого желудочка. Постпроцессорная обработка проведена в приложении 4D FLOW (Siemens).Результаты. Получены данные о геометрии и динамике вихревых диастолических потоков в левом желудочке у всех пациентов. У пациентов определяется апикальное смещение вортекса, уменьшение нормализованной площади и пиковой скорости вортекса. Диффузно-септальная форма характеризуется минимальной скоростью вихревого потока, апикальная форма – максимальным индексом сферичности вортекса. Для пациентов с фокально-базальной формой максимальные изменения кровотока определяются в позднюю диастолу (отсутствие вортексов)Заключение. Метод 4D FLOW фазово-контрастной МРТ позволяет выявить и оценивать изменения диастолических вихревых потоков в левом желудочке. Количественный анализ данных можно использовать для характеристики ремоделирования кровотока в левом желудочке при различных типах гипертрофической кардиомиопатии

2020 Clinical guidelines for Atrial fibrillation and atrial flutter

Russian Society of Cardiology (RSC).With the participation of Russian Scientific Society of Clinical Electrophysiology, Arrhythmology and Cardiac Pacing, Russian Association of Cardiovascular Surgeons.Approved by the Scientific and Practical Council of the Russian Ministry of Health