Patient Specific Numerical Modeling for Renal Blood Monitoring Using Electrical Bio-Impedance

Knowledge of renal blood circulation is considered as an important physiological value, particularly for fast detection of acute allograft rejection as well as the management of critically ill patients with acute renal failure. The electrical impedance signal obtained from kidney with an appropriate electrode system and optimal electrode system position regarding to the kidney projection on skin surface reflects the nature of renal blood circulation and tone of renal blood vessels. This paper proposes a specific numerical modelling based on prior information from MRI-data. The numerical modelling was conducted for electrical impedance change estimation due to renal blood distribution. The proposed model takes into the account the geometrical and electrophysiological parameters of tissues around the kidney as well as the actual blood distribution within the kidney. The numerical modelling had shown that it is possible to register the electrical impedance signal caused by renal blood circulation with an electrode system commensurate with the size of kidney, which makes it possible to reduce the influence of surrounding tissues and organs. Experimental studies were obtained to prove the numerical modelling and the effectiveness of developed electrode systems based on the obtained simulation results. The obtained electrical impedance signal with the appropriate electrode system shows very good agreement with the renal blood change estimated using Doppler ultrasound. For the measured electrical impedance signal, it is possible to obtain the amplitude-time parameters, which reflect the hemodynamic characteristics of the kidneys and used in diagnostics, which is the subject of further research.

Analysis of Predictive Model of Coronary Vulnerable Plaque under Hemodynamic Numerical Simulation

Objective. Vulnerable plaque is considered to be the cause of most clinical coronary arteries, and linear cytokines are an important factor causing plaque instability. Early prediction of vulnerable plaque is of great significance in the treatment of cardiovascular diseases. Methods. Computational fluid dynamics (CFD) was used to simulate the hemodynamics around plaques, and the serum biochemical markers in 224 patients with low-risk acute coronary syndrome (ACS) were analyzed. Vulnerable plaques were predicted according to the distribution of biochemical markers in serum. Results. CFD can accurately capture the hemodynamic characteristics around the plaque. The patient’s age, history of hyperlipidemia, apolipoprotein B (apoB), adiponectin (ADP), and sE-Selection were risk factors for vulnerable plaque. Area under curve (AUC) values corresponding to the five biochemical markers were 0.601, 0.523, 0.562, 0.519, 0.539, and the AUC value after the combination of the five indicators was 0.826. Conclusion. The combination of multiple biochemical markers to predict vulnerable plaque was of high diagnostic value, and this method was convenient and noninvasive, which was worthy of clinical promotion.

Alterations in plantar vessel blood flow in patients with mild diabetic peripheral neuropathy

IntroductionEarly identification and treatment of diabetic peripheral neuropathy (DPN) are crucial. Presently, the mechanism of DPN is not very clear, and there are inconclusive conclusions about the influencing factors of vascular dynamic characteristics in DPN. This study aims to detect and compare the hemodynamic characteristics of plantar blood vessels in patients with mild DPN and healthy participants to explore a simple and reliable new idea and a potential method for early assessment of DPN and to investigate the influence of gender and age on hemodynamic characteristics.Research design and methodsSixty age-matched and gender-matched patients with mild DPN (30 men and 30 women) and 60 healthy participants were randomly recruited. Color Doppler ultrasound was used to measure and analyze the hemodynamic characteristics of plantar-related vessels.ResultsUltrasonic measurements had good test–retest reliability. There may be no statistically significant differences in the blood flow velocity and blood flow in the plantar-related blood vessels of participants, irrespective of their gender and age. For patients with mild DPN, color Doppler ultrasound may indicate early hemodynamic abnormalities when there are no obvious abnormalities in the large arteries of the lower limbs, which are specifically manifested as increased blood flow velocity and blood flow in the distal small vessels.ConclusionsOur study provides in vivo data support for the dynamic characteristics of the plantar blood vessel biomechanical model and provides a new idea of in vivo and non-invasive early diagnosis of DPN.

Periprocedural hemodynamic assessment of percutaneous balloon mitral valvuloplasty

Besides the standart echcardiografic parameters for mitral stenosis assessment it is necessary to inquire the hemodynamic characteristics as well. The following article describes and illustrates step-by-step the invasive parameters and their significance in the assessment of mitral stenosis in patients who underwent percutaneous balloon mitral valvuloplasty.

P.192 Arterial Hemodynamics and the Clinical Presentation of Cerebral Arteriovenous Malformations

Background: Arterial Hemodynamics have been implicated in hemorrhage from cerebral arteriovenous malformations (AVMs). The correlation between hemodynamic characteristics and the tendency of AVMs to rupture has been explored in the past, and various theories have been proposed to explain the clinical presentation of AVMs as a hemorrhage vs. seizure. Methods: We monitored feeder artery pressures in 45 patients with AVMS (16 presenting with hemorrhage, 29 without) during super selective angiography and AVM embolization. Results: Mean feeder artery pressure (FP) was found to be 49mm Hg. The mean FP in patients presenting with hemorrhage was somewhat higher than in those without hemorrhage, but the difference was not statistically significant (53.8 mm Hg vs 47.0 mm Hg, p=0.13). Systemic mean pressure was found to correlate with AVM size (r=-0.31, p=0.037). Significant predictors of feeder artery pressure were systemic pressure, AVM size, and the distance of microcatheter from the circle of Willis. Meanwhile, the presence or absence of venous outflow stenosis and the position of the AVM nidus (superficial or deep to the cortical surface) were the most significant predictors of AVM hemorrhage vs seizures. Conclusions: Anatomic factors may be more important than arterial hemodynamic factors in determining the clinical presentation of cerebral AVMs.

Сlinical and hemodynamic characteristics and coronary blood flow in patients with chronic coronary artery disease and type 2 diabetes

Aim. To assess the features of clinical and hemodynamic characteristics and the severity of coronary involvement in patients with chronic coronary artery disease (CAD) with and without diabetes.Material and methods. The study included 100 patients with stable CAD, which were divided into two groups: group I (mean age, 57,9-1,04 years, male/female 35/14) — 49 patients with CAD and type 2 diabetes, II — (60,2-0,9 years, 34/17) — 51 patients without SD. Along with behavioral and biological risk factors, clinical and hemodynamic characteristics were analyzed. All patients underwent coronary angiography.Results. The presence of diabetes in patients with CAD was associated with abdominal obesity and comorbidity of somatic diseases. Among group I patients, electrocardiographic signs of left ventricular hypertrophy, conduction abnormalities, accompanied by a decrease in the left ventricular ejection fraction, impaired diastolic function, and high mean pulmonary artery pressure were significantly more often detected. In patients with CAD and type 2 diabetes, significant right coronary artery (CA) stenoses were more often recorded (39%), while in patients without diabetes, the anterior descending artery was the most susceptible to atherosclerosis. In group I, stenosis of the distal CA third was detected 1,5 times more often (p<0,001), and their diffuse multivessel lesion prevailed by 28% (73% and 45%, respectively, p<0,005). The average SYNTAX score in patients with and without diabetes was 29,2±0,8 vs 22±0,7, respectively (p<0,0005).Conclusion. In patients with CAD and diabetes, more pronounced atherosclerotic coronary involvement (diffuse multivessel CAD) was revealed, which should be taken into account when planning further treatment. The risk of adverse cardiovascular events will always be present with percutaneous coronary interventions.