Sleep is a complex physiological process of great significance to physical and mental health, and its research scope involves multiple disciplines. At present, the quantitative analysis of sleep mainly relies on the “gold standard” of polysomnography (PSG). However, PSG has great interference to the human body and cannot reflect the hemodynamic status of the brain. Functional near infrared spectroscopy (fNIRS) is used in sleep research, which can not only meet the demand of low interference to human body, but also reflect the hemodynamics of brain. Therefore, this paper has collected and sorted out the related literatures about fNIRS used in sleep research, concluding sleep staging research, clinical sleep monitoring research, fatigue detection research, etc. This paper provides a theoretical reference for scholars who will use fNIRS for fatigue and sleep related research in the future. Moreover, this article concludes the limitation of existing studies and points out the possible development direction of fNIRS for sleep research, in the hope of providing reference for the study of sleep and cerebral hemodynamics.
The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.
Hemodynamics plays a vital role in the development and progression of cardiovascular diseases, and is closely associated with changes in morphology and function. Reliable detection of hemodynamic changes is essential to improve treatment strategies and enhance patient prognosis. The combination of computational fluid dynamics with cardiovascular imaging technology has extended the accessibility of hemodynamics. This review provides a comprehensive summary of recent developments in the application of computational fluid dynamics for cardiovascular hemodynamic assessment and a succinct discussion for potential future development.
ObjectiveTo explore the hemodynamic effects of inhaled nitric oxide (iNO) on postoperative hemodynamic in patients with cyanotic congenital heart disease (CHD) combined with decreased pulmonary blood flow.MethodsFrom 2014 to 2018, there were 1 764 patients who received corrective repair of cyanotic CHD with decreased pulmonary blood flow in the Department of Pediatric Cardiac Surgery of Fuwai Hospital. We included 61 patients with the ratio of right ventricular systolic pressure to systolic blood pressure (SBP) ≥75% after weaning from cardiopulmonary bypass. There were 41 males and 20 females, with the age of 20.5 (9.0, 39.0) months and weight of 12.5±7.8 kg. The patients were divided into two groups: a conventional group (33 patients, conventional therapy only) and a combined therapy group (28 patients, iNO combined with conventional therapy). The hemodynamics during the first 24 hours after iNO therapy and the in-hospital outcomes of the two groups were investigated and compared.ResultsThere was no statistical difference between the two groups in demographic characteristics and surgical parameters (P>0.05). The hemodynamic effects of iNO within 24 hours included the decrease in the vasoactive inotropic score (VIS, 21.6±6.6 vs. 17.3±7.2, P=0.020) along with the increase in blood pressure (SBP: 73.7±9.7 mm Hg vs. 90.8±9.1 mm Hg, P<0.001) , the decrease in central venous pressure (10.0±3.1 mm Hg vs. 7.9±2.1 mm Hg, P=0.020), the decrease in lactate (2.2±1.7 mmol/L vs. 1.2±0.5 mmol/L, P<0.001) and increase in urine output [2.8±1.7 mL/(kg·h) vs. 4.9±2.2 mL/(kg·h), P<0.001]. The decrease of VIS at 24 h after the surgery in the conventional therapy group was not statistically significant (22.1±7.9 vs. 20.0±8.5, P=0.232). Besides, we discovered that the need for renal replacement therapy (RRT) was less in the combined therapy group than that in the conventional therapy group, especially in the moderate complicated surgery [risk adjustment in congenital heart surgery (RACHS-1) ≤3] subgroup (9.5% vs. 40.7%, P=0.016).ConclusionIn pediatric patients after corrective repair of cyanotic and pulmonary blood follow decreased CHD with increased pulmonary vascular resistance, iNO combined with conventional therapy can improve the hemodynamics effectively. Compared with the conventional therapy, the combined therapy with iNO can decrease the VIS and the need for RRT, which is beneficial to the postoperative recovery of patients.
Intravascular optical coherence tomography (IVOCT) has emerged as a high-resolution and minimal-invasive imaging technique that provides high-speed visualization of coronary arterial vessel walls and clearly displays the vessel lumen and lesions under the intima. However, morphological gray-scale images cannot provide enough information about the tissue components to accurately characterize the plaque tissues including calcified, fibrous, lipidic and mixed plaques. Quantitative IVOCT (qIVOCT) is necessary to provide the physiological contrast mechanisms and obtain the characteristic parameters of tissues with clinical diagnostic value. In this paper, the progress of qIVOCT is reviewed. The current methods for quantitatively measuring optical, elastic and hemodynamic parameters of vessel wall and plaque tissues using IVOCT gray-scale images and raw backscattered signals are introduced and potential development is forecast.
[Abstract]The number of lung transplantation is gradually increasing worldwide, which brings new challenges to the multi-disciplinary team of lung transplantation. The prognosis of lung transplant recipients is seriously affected by the pathophysiological state of specific lung diseases and perioperative risk factors. It is of great significance for these patients to optimize perioperative management according to these factors. Recently, several expert consensus have been published regarding anesthesia management of lung transplantation. Based on the current evidence and clinical practice of West China Hospital, this review summarizes the key points of anesthesia management for lung transplant recipients to guide anesthesiologists' clinical practice.
Objective To investigate the clinical efficacy of mitral valve repair technique in the treatment of rheumatic mitral valve lesions. Methods The clinical data of patients diagnosed with rheumatic mitral valve lesions and undergoing mitral valve repair under extracorporeal circulation in our department from 2021 to 2022 were retrospectively analyzed. Results A total of 100 patients were collected, including 78 females and 22 males with an average age of 52 years. There were no secondary open heart or death in the whole group. Extracorporeal circulation time was 136.3±33.1 min, aortic cross-clamping time was 107.6±27.5 min, ventilator use time was 12.9±5.9 h, ICU stay was 2.6±1.4 d, and vasoactive medication use was 823.4±584.4 mg. Before and after the surgery, there were statistical differences in the left ventricular end diastolic diameter, left atrial end systolic diameter, effective mitral valve orifice area, shortening rate of left ventricular short axis, mitral E-peak blood flow velocity, mean mitral transvalvular pressure difference, mitral pressure half-time, and cardiac function graded by New York Heart Association (P＜0.05). While there was no statistical difference in left ventricular ejection fraction or left ventricular end-diastolic volume (P>0.05). Conclusion Overall repair of rheumatic mitral valve lesions can significantly improve the cardiac function and hemodynamics of the patients, and is a good choice for patients with rheumatic mitral valve lesions.
As an important means of treating heart failure (HF), cardiac assist device has been widely used in clinic. This paper reviews the application status, existing problems and future development trend of cardiac assist devices, including the classification of cardiac assist devices, representative research achievements and indications of the assist devices. It also summarizes the biomechanical indexes of the heart and the new approaches and methods for treating heart failure, as well as the hemodynamic studies of cardiac assist devices in recent years. The research findings provide references for further optimization of cardiac assist device structure and clinical application of the device.
Objective To evaluate the early clinical outcomes of the Renatus® balloon-expandable valve in the treatment of severe aortic stenosis. MethodsFrom November 2021 to April 2022, a total of 38 patients who received Renatus® balloon-expandable valve for severe aortic stenosis in Guangdong Provincial People's Hospital were included. There were 22 males and 16 females, with an average age of 73.7±5.3 years. Mean aortic gradient and peak aortic jet velocity at baseline, post-procedure, and follow-up were compared. Clinical outcomes including all-cause mortality, perivalvular leakage, serious adverse cardiovascular events and the occurrence of permanent pacemaker implantation were assessed. ResultsAll patients completed the procedure successfully without conversion to thoracotomy or perioperative death. The post-implant mean aortic pressure gradient was decreased from 41.5 (27.8, 58.8) mm Hg to 6.0 (3.0, 8.0) mm Hg, and the peak aortic jet velocity was also decreased from 4.1±0.9 m/s to 1.7±0.4 m/s (P<0.001). Pacemakers were required in 2 (5.3%) patients. The median follow-up time was 27.5 (23.0, 87.5) d, with a follow-up rate of 100.0%. The mean aortic gradient was 8.0 (7.0, 10.8) mm Hg and peak aortic jet velocity was 2.0±0.3 m/s, showing significant improvement compared with those in the preoperative period (P<0.001). No severe aortic regurgitation or paravalvular leak was observed. There was no serious cardiovascular adverse event or reoperative event during the study period. ConclusionTranscatheter aortic valve replacement with the domestic Renatus® balloon-expandable valve system is a safe and effective procedure for selected patients with severe aortic stenosis who are at high risk or not candidates for surgical aortic valve replacement.
This paper aims to analyze the impact of splenic vein thrombosis (SVT) on the hemodynamic parameters in hepatic portal vein system. Based on computed tomography (CT) images of a patient with portal hypertension and commercial software MIMICS, the patient's portal venous system model was reconstructed. Color Doppler ultrasound method was used to measure the blood flow velocity in portal vein system and then the blood flow velocities were used as the inlet boundary conditions of simulation. By using the computational fluid dynamics (CFD) method, we simulated the changes of hemodynamic parameters in portal venous system with and without splenic vein thrombosis and analyzed the influence of physiological processes. The simulation results reproduced the blood flow process in portal venous system and the results showed that the splenic vein thrombosis caused serious impacts on hemodynamics. When blood flowed through the thrombosis, blood pressure reduced, flow velocity and wall shear stress increased. Flow resistance increased, blood flow velocity slowed down, the pressure gradient and wall shear stress distribution were more uniform in portal vein. The blood supply to liver decreased. Splenic vein thrombosis led to the possibility of forming new thrombosis in portal vein and surroundings.