Cardiac Components Research Articles

Detection of cardiac sounds components: a pilot study

<span>This paper presents a preliminary study related to the detection and identification of cardiac sounds components including first sound (S1), second sound (S2) and murmurs. Detection and identification of cardiac sounds are an important process in automated cardiac sound analysis system in order to automatically diagnose people who are having cardiovascular disorder and determine the existence of murmurs. Sixteen of recorded cardiac sounds (eight normal cardiac sounds, four abnormal cardiac sounds with systole murmur, and four abnormal cardiac sounds with diastole murmur) from PASCAL Classifying Heart Sounds Challenge database were examined for analysis. This work is significant in studying the time and time-frequency based detection of cardiac sounds components characteristics. In time-based analysis, envelope of signal energy was used to do the peak detection of S1, S2 and murmur and also analysis of cardiac cycle, systole and diastole duration. While time-frequency based analysis was used to determine the S1, S2 and murmur frequency range. The findings yield the overall accuracy of envelope-based detection for normal cardiac sound signal at 60.85% while for abnormal cardiac sound signal at 57.24%.</span>

A rat model of enhanced glycation mimics cardiac phenotypic components of human type 2 diabetes : A translational study using MRI

BackgroundThe success of translational research depends on how well animal models mimic the pathophysiology of the human phenotype, and on the identification of disease mechanisms such as enhanced glycation. MethodsHere, we studied cardiac MRI and metabolic phenotypes in human type 2 diabetes (N = 106; 55 patients+51 controls) and animal models with distinct levels of fat diet and end glycation products, to model the role of these factors in the cardiac phenotype. We included four groups of rats, designed to evaluate the role of lipid load and glucotoxicity in cardiac function and to correlate these with the cardiac phenotype observed in humans. We also aimed to assess into which extent phenotypes were related to specific risk factors. ResultsStroke Volume (SV) and Peak Filling Rate (PFR) measures were similarly discriminative both in humans and animal models, particularly when enhanced glycation was present. Factorial analysis showed that reduction of multidimensionality into common main explanatory factors, in humans and animals, revealed components that equally explained the variance of cardiac phenotypes (87.62% and 83.75%, respectively). One of the components included, both in humans and animals, SV, PFR and peak ejection rate (PER). The other components included in both humans and animals are the following: ESV (end systolic volume), left ventricular mass (LVM) and ejection fraction (EF). These components were useful for between group discrimination. ConclusionsWe conclude that animal models of enhanced glycation and human type 2 diabetes share a striking similarity of cardiac phenotypic components and relation with metabolic changes, independently of fact content in the diet, which reinforces the role of glucose dysmetabolism in left ventricular dysfunction and provides a potentially useful approach for translational research in diabetes, in particular when testing new therapies early on during the natural history of this condition.

Cardiac and respiratory signal extraction methods from ballistocardiography signal sensed using fiber bragg grating sensor

This work presents a simple, efficient and an easy-to-build ballistocardiography sys-tem using Fiber Bragg Grating (FBG) sensor and a comprehensive assessment of relevant digital signal processing algorithms to simultaneously extract respiratory and cardiac frequency components from a cluttered mix Ballistocardiography (BCG) signal. The primary purpose of the current study is two-fold: first- to build an analog circuit for BCG signal amplification, and second to evaluate the performance of three state-of-the-art methods, namely: lowpass-highpass filter, weiner filter and ensemble empherical mode decomposition to simultaneously extract respiratory and cardiac frequency components from the BCG signal. BCG measurements from test subjects were used in this study and a commercial digital stethoscope was used to validate the performance of methods used in this study. In addition to the effective amplification of the BCG signal through proposed analog circuit configuration, we demonstrate that a simple low pass high pass filter configuration can be used for accurate measurement of cardiac and respiratory frequencies. Due to its simplicity, the proposed system can be suitably tailored to process BCG signal for simultaneous extraction of respiration and heart rate which can aid as an effective diagnostic tool for identifying critical disorders associated with lungs and heart dysfunction.

Matrix metalloproteinases regulate ECM accumulation but not larval heart growth in Drosophila melanogaster

The Drosophila heart provides a simple model to examine the remodelling of muscle insertions with growth, extracellular matrix (ECM) turnover, and fibrosis. Between hatching and pupation, the Drosophila heart increases in length five-fold. If major cardiac ECM components are secreted remotely, how is ECM “self assembly” regulated? We explored whether ECM proteases were required to maintain the morphology of a growing heart while the cardiac ECM expanded. An increase in expression of Drosophila's single tissue inhibitor of metalloproteinase (TIMP), or reduced function of metalloproteinase MMP2, resulted in fibrosis and ectopic deposition of two ECM Collagens; type-IV and fibrillar Pericardin. Significant accumulations of Collagen-IV (Viking) developed on the pericardium and in the lumen of the heart. Congenital defects in Pericardin deposition misdirected further assembly in the larva. Reduced metalloproteinase activity during growth also increased Pericardin fibre accumulation in ECM suspending the heart. Although MMP2 expression was required to remodel and position cardiomyocyte cell junctions, reduced MMP function did not impair expansion of the heart. A previous study revealed that MMP2 negatively regulates the size of the luminal cell surface in the embryonic heart. Cardiomyocytes align at the midline, but do not adhere to enclose a heart lumen in MMP2 mutant embryos. Nevertheless, these embryos hatch and produce viable larvae with bifurcated hearts, indicating a secondary pathway to lumen formation between ipsilateral cardiomyocytes. MMP-mediated remodelling of the ECM is required for organogenesis, and to prevent assembly of excess or ectopic ECM protein during growth. MMPs are not essential for normal growth of the Drosophila heart.

Development of the human heart.

In 2014, an extensive review discussing the major steps of cardiac development focusing on growth, formation of primary and chamber myocardium and the development of the cardiac electrical system, was published. Molecular genetic lineage analyses have since furthered our insight in the developmental origin of the various component parts of the heart, which currently can be unambiguously identified by their unique molecular phenotype. Moreover, genetic, molecular and cell biological analyses have driven insights into the mechanisms underlying the development of the different cardiac components. Here, we build on our previous review and provide an insight into the molecular mechanistic revelations that have forwarded the field of cardiac development. Despite the enormous advances in our knowledge over the last decade, the development of congenital cardiac malformations remains poorly understood. The challenge for the next decade will be to evaluate the different developmental processes using newly developed molecular genetic techniques to further unveil the gene regulatory networks operational during normal and abnormal cardiac development.

Cardiac Rehabilitation for Frail Older People.

Comprehensive cardiac rehabilitation programmes include multifactorial components to optimise cardiovascular risk reduction, promote healthy behaviours and an active lifestyle, reduce disability and improve health and wellbeing. There is compelling evidence that older people with certain cardiovascular conditions, such as heart failure, can benefit both physically and mentally from cardiac rehabilitation. This chapter discusses the evolution of cardiac rehabilitation, frailty assessment in cardiac rehabilitation and guideline recommendations in the context of ageing populations. Contemporary cardiac rehabilitation service models are presented along with potential solutions to meeting older people's preferences and improving access to effective treatment for those with frailty. Innovations in catheter-based surgical interventions mean that more people with frailty are undergoing cardiovascular surgery than ever before. Although traditionally, cardiac rehabilitation has been associated with secondary prevention after cardiac diagnoses, events and interventions, new models of preconditioning rehabilitation or 'prehab' are being offered to frail older people before surgery to improve functional outcomes and reduce hospital stay. Individual tailoring of cardiac rehabilitation programme components is a cornerstone of high-quality care. Importantly, participation in core components, such as exercise and nutritional interventions, can impact on both cardiac vascular disease and frailty, providing the potential to change the trajectory of both conditions.

Duloksetinin Kalp Üzerindeki Etkilerinin Araştırılması

Objevtive: The present study was designed to examine the effects of high dose and low dose duloxetine on Cx43, a gap junction (GJ) protein; on S100A, cardiac contractility component and on certain early cardiac impairment parameters as TnI and TnT. Material and Methods: The study was performed with 24 male Wistar Albino rats by generating control group (1 ml solvent), low-dose duloxetine (LDD) group (10 mg/kg) and high-dose duloxetine (HDD) group (100 mg/kg). After the experimental procedure, the results concerning blood pressure and heart rates of the anesthetized rats were recorded and HE staining and immunostaining of Cx43, S100A, TnI and TnT were applied to the heart tissue sections. Results: In the control group, Cx43 was stained as marked streaks between cardiomyocytes; TnI, TnT and S100A were stained as homogenous and dark brown in cytoplasm. Nevertheless, intensity of Cx43 immunostaining showed significant increase in duloxetine- treated groups (p0.05). Conclusion: Our study reveals that duloxetine induced an increase in the immunostaining of Cx43, and a decrease in the immunostaining of TnI, TnT and S100A, also known as early cardiac parameters. Furthermore, duloxetine was observed to show no effect on oxidant and antioxidant parameters. While heart rate remained unchanged, mean blood pressure decreased in high dose duloxetine group. In the light of the study outcomes, it has been concluded that antidepressants must be administered more advertently in depression patients with heart disorders.

The Intrapericardial Delivery of Extracellular Vesicles from Cardiosphere-Derived Cells Stimulates M2 Polarization during the Acute Phase of Porcine Myocardial Infarction

Acute myocardial infarction triggers a strong inflammatory response in the affected cardiac tissue. New therapeutic tools based on stem cell therapy may modulate the unbalanced inflammation in the damaged cardiac tissue, contributing to the resolution of this pathological condition. The main goal of this study was to analyze the immunomodulatory effects of cardiosphere-derived cells (CDCs) and their extracellular vesicles (EV-CDCs), delivered by intrapericardial administration in a clinically relevant animal model, during the initial pro-inflammatory phase of an induced myocardial infarction. This effect was assessed in peripheral blood and pericardial fluid leukocytes from infarcted animals. Additionally, cardiac functional parameters, troponin I, hematological and biochemical components were also analyzed to characterize myocardial infarction-induced changes, as well as the safety aspects of these procedures. Our preclinical study demonstrated a successful myocardial infarction induction in all animals, without any reported adverse effect related to the intrapericardial administration of CDCs or EV-CDCs. Significant changes were observed in biochemical and immunological parameters after myocardial infarction. The analysis of peripheral blood leukocytes revealed an increase of M2 monocytes in the EV-CDCs group, while no differences were reported in other lymphocyte subsets. Moreover, arginase-1 (M2-differentiation marker) was significantly increased in pericardial fluids 24 h after EV-CDCs administration. In summary, we demonstrate that, in our experimental conditions, intrapericardially administered EV-CDCs have an immunomodulatory effect on monocyte polarization, showing a beneficial effect for counteracting an unbalanced inflammatory reaction in the acute phase of myocardial infarction. These M2 monocytes have been defined as “pro-regenerative cells” with a pro-angiogenic and anti-inflammatory activity.

Insights from examination of hearts from adults dying suddenly to the understanding of congenital cardiac malformations.

Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the "morphological method" serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394-404, 2020. © 2019 Wiley Periodicals, Inc.

P3140Burden and the clinical significance of the retained cardiac implantable electronic device components after heart transplantation

Abstract Background Cardiovascular implantable electronic devices (CIEDs) are common in patients undergoing heart transplantation (HT), and complete removal is not always possible at the time of transplantation. Frequency and clinical significance of retained CIED components after HT is not well studied. Methods Adult heart failure patients whom had heart transplantation in our institution from date June 2000 to December 2018 were retrospectively evaluated. Pre-post operative chest x-rays and recorded fluoroscopy images of the previous coronary angiograms or endomyocardial biopsies were reviewed by a single observer for retained CIED components. All patients clinical records were also reviewed for adverse outcomes of retained components such as deep venous thrombosis of upper extremity, infection and mortality. Results A total of 226 patients had bicaval orthotopic heart transplantation during study time. 73 (32%) of the patients had CIED before transplantation and 24 (32.8%) of the patients had retained lead components after HT. (Table 1) All of the components were part of a superior vena cava coil of the right ventricular ICD lead. Mean follow up time was 46.6±49.8 months and only 1 (1.3%) adverse event (right subclavian DVT) occurred in a patient with retained lead. There were not any statistical significance for mortality and infection between patients with and without lead fragments. Patients were also compared for history of any cardiac surgery before HT, especially ventricular assist device procedures and no differences were observed between groups. For history of any cardiac surgery p=0.748, for assist device surgery, p=0.269). Patient's medical records reviewed for a history of magnetic resonance imaging (MRI). Two patients with retained lead fragments had non-thorocic (abdominal and cranial) MRI and any clinical pathology did not observed after MRI. Table 1 All Patients With Retained CIED comp. Without Retained CIED comp. p (n=226) (n=24) (n=49) Age ± sd 42.91±12.2 44.88±12.6 41.59±13 0.290 Ischemic etiology 65 (28.8%) 8 (33.3%) 13 (26.5%) 0.546 CIED type CRT-D 5 (20.8%) 5 (%10.2) 0.215 DR-ICD 5 (20.8%) 8 (16.3%) 0.636 VR-ICD 14 (58.3%) 35 (71.4%) 0.263 Dual coil ICD lead 24 (100%) 48 (97%) 1 Mortality (%) 96 (42.5) 7 (37%) 20 (40.8%) 0.463 Conclusion Retained CIED components were seen 32.8% of the HT patients with CIED prior to transplantation. According to our data retained leads are not associated with severe adverse clinical outcomes. Also non cardiac MRI could be safe in patients with retained lead fragments.

Effect of Once-Weekly Exenatide in Patients With Type 2 Diabetes Mellitus With and Without Heart Failure and Heart Failure-Related Outcomes: Insights From the EXSCEL Trial.

Once-weekly exenatide (EQW) had a neutral effect on hospitalization for heart failure (HHF) in the EXSCEL study (Exenatide Study of Cardiovascular Event Lowering), with no differential treatment effect on major adverse cardiac events by baseline heart failure (HF) status. EQW's effects on secondary end points based on HHF status have not been reported. The objective was to explore the effects of EQW on secondary end points in patients with and without baseline HF and test the effects of EQW on recurrent HHF events. The prespecified analysis of the randomized controlled EXSCEL trial, which enrolled patients with type 2 diabetes mellitus with and without additional cardiovascular disease, analyzed EQW effects on all-cause death, each major adverse cardiac event component, first HHF, and repeat HHF, by baseline HF status (regardless of ejection fraction). A subgroup analysis of the population stratified by preserved or reduced baseline ejection fraction was performed. Of 14 752 EXSCEL participants, 2389 (16.2%) had HF at baseline. Compared with those without HF at baseline, patients with preexisting HF were older, and more likely to be male and white, with a higher burden of other cardiovascular diseases. Overall, those assigned to EQW had a lower incidence of all-cause death (hazard ratio [HR], 0.86 [95% CI, 0.77-0.97]) and the composite outcome of all-cause death or HHF (HR, 0.89 [95% CI, 0.80-0.99]). When stratified by presence or absence of baseline HF, there was no observed reduction in all-cause death with EQW with baseline HF (HR, 1.05 [95% CI, 0.85-1.29]), while the risk of mortality was reduced with EQW in the no-HF group (HR, 0.79 [95% CI, 0.68-0.92]) with an interaction P value of 0.031. The reduction in all-cause death or HHF seen with EQW in patients without baseline HF (HR, 0.81 [95% CI, 0.71-0.93]) was not seen in patients with baseline HF (HR, 1.07 [95% CI, 0.89-1.29]; interaction P=0.015). First, plus recurrent, HHF was reduced in the exenatide group versus placebo (HR, 0.82 [95% CI, 0.68-0.99]; P=0.038). In EXSCEL, the use of EQW in patients with or without HF was well tolerated, but benefits of EQW on reduction in all-cause death and first hospitalization for HF were attenuated in patients with baseline HF. https://www.clinicaltrials.gov. Unique identifier: NCT01144338.

Learning Cardiac Embryology-Which Resources Do Students Use, and Why?

With increasing class sizes, small group activities for learning embryology are present in few institutions. How then do students supplement their lectures in order to ask and answer questions, or delve into concepts in detail? Arguably, animations and videos are ideal for visualizing four-dimensional anatomy, but how do students find and filter these? First-year medical students were surveyed with respect to the cardiac embryology component of their course and asked their opinions regarding the clinical relevance of this content and the resources they used to enhance learning. Students indicated that they considered cardiac embryology to be of relevance to clinical practice and that videos are a useful resource in helping them to learn this material. However, when seeking videos or resources, it emerged that students tended to Google information in preference to accessing online resources (or textbooks) specifically recommended by their instructor, despite students' recognition that "accuracy of information" was paramount when choosing what resource to use. While all students seemed reluctant to contact a staff member with questions, those with less proficiency in English were less likely to approach faculty for assistance. While acknowledging students as adult learners, self-regulated learning skills do not develop automatically and the development of these skills should be viewed as a "shared responsibility" between students and staff. Likewise, students also need to be taught critical appraisal of learning resources, especially in the complex online environment, with design of their bespoke institutional virtual learning environment facilitating easy identification and access of recommended resources.

Melatonin and the heart circadian clock of euglycemic and type 2 diabetic male rats: a transcriptional evaluation

Diabetes increases risk of various comorbidities, including retinopathy, neuropathy, and cardiovascular disease, comprising both ischemic and non-ischemic cardiomyopathy. Cardiac dysfunction during diabetes is associated with perturbations at histologic, metabolic, biochemical and molecular levels. The circadian clock is misaligned in multiple organs during diabetes, including the heart. Such alterations in clock function have been postulated to play a causal role in cardiac dysfunction even though the mechanisms leading to circadian misalignment are currently unknown. Melatonin has been reported to alter heart circadian clock components and its circulating levels are decreased during diabetes. These observations led to the hypothesis that decreased melatonin levels during diabetes could be related to mismanagement of the heart clock. To evaluate this hypothesis, in the current study male Wistar and non-obese type 2 diabetic Goto-Kakizaki (GK) rats were given melatonin supplementation in their drinking water during the dark phase (for 12-wks), followed by assessment of clock component and the mRNA expression of the clock-controlled genes in the hearts of these animals. Melatonin supplementation significantly altered mRNA expression of targeted genes in both euglycemic and diabetic rat hearts. Collectively, under the condition of diabetes, the jeopardized pineal melatonin synthesis with misalignment of cardiac circadian clock components may likely mediate heart metabolic dysfunction, and/or even cause cardiovascular diseases.

Performance evaluation and validation of the Animal Trauma Triage score and modified Glasgow Coma Scale in injured cats: A Veterinary Committee on Trauma registry study.

To examine the Animal Trauma Triage (ATT) and modified Glasgow Coma Scale (mGCS) scores as predictors of mortality in injured cats. Observational cohort study conducted September 2013 to March 2015. Nine Level I and II veterinary trauma centers. Consecutive sample of 711 cats reported on the Veterinary Committee on Trauma (VetCOT) case registry. None. We compared the predictive power (area under receiver operating characteristic curve; AUROC) and calibration of the ATT and mGCS scores to their components. Overall mortality risk was 16.5% (95% confidence interval [CI], 13.9-19.4). Head trauma prevalence was 11.8% (n = 84). The ATT score showed a linear relationship with mortality risk. Discriminatory performance of the ATT score was excellent (AUROC = 0.87 [95% CI, 0.84-0.90]). Each ATT score increase of 1 point was associated with an increase in mortality odds of 1.78 (95% CI, 1.61-1.97, P<0.001). The eye/muscle/integument category of the ATT showed the lowest discrimination (AUROC = 0.60). When this component, skeletal, and cardiac components were omitted from score calculation, there was no loss in discriminatory capacity compared with the full score (AUROC = 0.86 vs 0.87, respectively, P = 0.66). The mGCS showed fair performance overall for prediction of mortality, but the point estimate of performance improved when restricted to head trauma patients (AUROC = 0.75, 95% CI, 0.70-0.80 vs AUROC = 0.80, 95% CI, 0.70-0.90). The motor component of the mGCS showed the best predictive performance (AUROC = 0.71); however, the full score performed better than the motor component alone (P = 0.004). When assessment was restricted to patients with head injury (n = 84), there was no difference in performance between the ATT and mGCS scores (AUROC = 0.82 vs 0.80, P = 0.67). On a large, multicenter dataset of feline trauma patients, the ATT score showed excellent discrimination and calibration for predicting mortality; however, an abbreviated score calculated from the perfusion, respiratory, and neurologic categories showed equivalent performance.

Abstract 938: BET Bromodomain Protein 4 (BRD4) Governance of Cardiovascular Disease Stress-related Cardiomyocyte Remodeling

During the past decade, epigenetic control of cardiac remodeling has attracted attention as a major mechanism contributing to heart failure. The BET family of bromodomain proteins (BRD) functions as “readers” of acetylated chromatin. Pharmacological inhibition of BRD proteins prevents cardiac hypertrophy and heart failure in preclinical models, yet mechanistic studies elucidating the biology of BRD proteins in the heart are lacking. Here, we investigated the role(s) of BRD4 in cardiac physiology and pathophysiology. By engineering a cardiomyocyte-specific BRD4 knockout mouse, we discovered that loss of BRD4 triggered progressive decline in ventricular contractile function, culminating in dilated cardiomyopathy in both post-natal and adult hearts. To identify early transcriptomic changes in BRD4-ablated heart, we conducted a global transcriptome analysis in KO hearts prior to the onset of ventricular dysfunction. RNA sequencing analysis of BRD4 KO hearts revealed disruption of genes essential to mitochondrial energy production and homeostasis, as well as key cardiac sarcomeric components. Computational analysis identified key transcription factors involved in BRD4-mediated gene regulation, including MEF2 complex, ERR1, SRF, and Nkx2.5. By studying isolated cardiomyocytes maintained in primary culture, we confirmed that disruption of the candidate TF complexes by BRD4 ablation altered mitochondrial morphology and provoked progressive contractile dysfunction. In aggregate, we describe for the first time a critical role of BRD4 in regulating key cardiomyocyte gene networks, in particular genes involved in mitochondrial homeostasis and contractility, to maintain cardiac function. Moreover, our data suggest that BRD4 is a novel regulator of epigenetic events in dilated cardiomyopathy. Elucidating these novel roles of BRD4 in cardiomyocyte remodeling will provide critical insights into the epigenetic control of stress-related cardiac events with potential clinical relevance.

Biological Indices Evaluation of Various Treatment Techniques for Left-Sided Breast Treatment

PurposeTo compare dose to organs at risk (OARs) and biological evaluation using normal tissue complication probability (NTCP) for left-sided breast radiation therapy in 4 techniques: supine free breathing (SFB), supine deep inspiration breath hold (SDIBH), prone free breathing (PFB), and prone deep inspiration breath hold (PDIBH). Methods and MaterialsTwenty-five patients with left-sided breast cancer suitable for this study underwent a computed tomography scan using SFB, SDIBH, PFB, and PDIBH. One radiation oncologist contoured the planning target volume and OAR (cardiac components). Dose-volume histograms and NTCPs for the heart, left ventricle (LV), left anterior descending artery (LAD), and left lung were calculated for all 4 techniques. ResultsThe mean heart dose in PDIBH is 0.77 Gy, which is statistically significantly lower than in SFB (1.88 Gy, P < .0001), SDIBH (0.97 Gy, P < .001), and PFB (0.85 Gy, P < .001). The mean left lung dose is 0.69 Gy in PFB and 0.88 Gy in PDIBH. PFB and PDIBH have statistically significantly lower doses compared with SFB (6.09 Gy, P < .0001) and SDIBH (5.41 Gy, P < .0001). The mean NTCP in SFB for the heart, LV, and LAD is 0.27%, 0.62%, and 4.23%, respectively, and it is negligible for other techniques. ConclusionsWe found that PDIBH had a dosimetrically lower mean dose for the heart and LV compared with the other 3 techniques. In addition, SDIBH, PFB and PDIBH had statistically significantly lower NTCP for the heart, LV, and LAD compared with SFB. NTCP for the left lung was statistically significantly lower for prone techniques compared with supine techniques. Therefore we concluded that, compared with SDIBH, PDIBH provides the added benefit of sparing the heart while keeping the benefit of sparing the lung as in the prone technique.

Neuroinflammation in the NTS is associated with changes in cardiovascular reflexes during systemic inflammation

BackgroundLipopolysaccharide (LPS)-induced systemic inflammation (SI) is associated with neuroinflammation in the brain, hypotension, tachycardia, and multiple organs dysfunctions. Considering that during SI these important cardiovascular and inflammatory changes take place, we measured the sensitivity of the cardiovascular reflexes baroreflex, chemoreflex, and Bezold-Jarisch that are key regulators of hemodynamic function. We also evaluated neuroinflammation in the nucleus tractus solitarius (NTS), the first synaptic station that integrates peripheral signals arising from the cardiovascular and inflammatory status.MethodsWe combined cardiovascular recordings, immunofluorescence, and assays of inflammatory markers in male Wistar rats that receive iv administration of LPS (1.5 or 2.5 mg kg−1) to investigate putative interactions of the neuroinflammation in the NTS and in the anteroventral preoptic region of the hypothalamus (AVPO) with the short-term regulation of blood pressure and heart rate.ResultsLPS induced hypotension, tachycardia, autonomic disbalance, hypothermia followed by fever, and reduction in spontaneous baroreflex gain. On the other hand, during SI, the bradycardic component of Bezold-Jarisch and chemoreflex activation was increased. These changes were associated with a higher number of activated microglia and interleukin (IL)-1β levels in the NTS.ConclusionsThe present data are consistent with the notion that during SI and neuroinflammation in the NTS, rats have a reduced baroreflex gain, combined with an enhancement of the bradycardic component of Bezold-Jarisch and chemoreflex despite the important cardiovascular impairments (hypotension and tachycardia). These changes in the cardiac component of Bezold-Jarisch and chemoreflex may be beneficial during SI and indicate that the improvement of theses reflexes responsiveness though specific nerve stimulations may be useful in the management of sepsis.

Extracting Cardiac Information From Medical Radar Using Locally Projective Adaptive Signal Separation.

Electrocardiography is the gold standard for electrical heartbeat activity, but offers no direct measurement of mechanical activity. Mechanical cardiac activity can be assessed non-invasively using, e.g., ballistocardiography and recently, medical radar has emerged as a contactless alternative modality. However, all modalities for measuring the mechanical cardiac activity are affected by respiratory movements, requiring a signal separation step before higher-level analysis can be performed. This paper adapts a non-linear filter for separating the respiratory and cardiac signal components of radar recordings. In addition, we present an adaptive algorithm for estimating the parameters for the non-linear filter. The novelty of our method lies in the combination of the non-linear signal separation method with a novel, adaptive parameter estimation method specifically designed for the non-linear signal separation method, eliminating the need for manual intervention and resulting in a fully adaptive algorithm. Using the two benchmark applications of (i) cardiac template extraction from radar and (ii) peak timing analysis, we demonstrate that the non-linear filter combined with adaptive parameter estimation delivers superior results compared to linear filtering. The results show that using locally projective adaptive signal separation (LoPASS), we are able to reduce the mean standard deviation of the cardiac template by at least a factor of 2 across all subjects. In addition, using LoPASS, 9 out of 10 subjects show significant (at a confidence level of 2.5%) correlation between the R-T-interval and the R-radar-interval, while using linear filters this ratio drops to 6 out of 10. Our analysis suggests that the improvement is due to better preservation of the cardiac signal morphology by the non-linear signal separation method. Hence, we expect that the non-linear signal separation method introduced in this paper will mostly benefit analysis methods investigating the cardiac radar signal morphology on a beat-to-beat basis.

Comprehensive Analysis of Animal Models of Cardiovascular Disease using Multiscale X-Ray Phase Contrast Tomography

Cardiovascular diseases (CVDs) affect the myocardium and vasculature, inducing remodelling of the heart from cellular to whole organ level. To assess their impact at micro and macroscopic level, multi-resolution imaging techniques that provide high quality images without sample alteration and in 3D are necessary: requirements not fulfilled by most of current methods. In this paper, we take advantage of the non-destructive time-efficient 3D multiscale capabilities of synchrotron Propagation-based X-Ray Phase Contrast Imaging (PB-X-PCI) to study a wide range of cardiac tissue characteristics in one healthy and three different diseased rat models. With a dedicated image processing pipeline, PB-X-PCI images are analysed in order to show its capability to assess different cardiac tissue components at both macroscopic and microscopic levels. The presented technique evaluates in detail the overall cardiac morphology, myocyte aggregate orientation, vasculature changes, fibrosis formation and nearly single cell arrangement. Our results agree with conventional histology and literature. This study demonstrates that synchrotron PB-X-PCI, combined with image processing tools, is a powerful technique for multi-resolution structural investigation of the heart ex-vivo. Therefore, the proposed approach can improve the understanding of the multiscale remodelling processes occurring in CVDs, and the comprehensive and fast assessment of future interventional approaches.

Setup strategies and uncertainties in esophageal radiotherapy based on detailed intra- and interfractional tumor motion mapping

Background and purposeDetailed knowledge of target motion is important for improved accuracy and decreased toxicity of esophageal cancer radiotherapy. This study uses the 3D trajectories of implanted markers during setup CBCT scans to investigate the intra- and interfractional tumor motion in esophageal cancer radiotherapy. Material and methodsFor 21 esophageal cancer patients with implanted fiducial markers, 60-s 3D marker trajectories were estimated from the 2D marker positions in the projections of daily setup CBCT scans by a probability-based method. The motion was separated into respiratory and cardiac components by frequency analysis and motion magnitude (2nd–98th percentile) was extracted for each marker. The mean motion was calculated over all markers. The daily mean setup interfraction error for bony-anatomy and soft-tissue setup was used to estimate the margin accounting for interfractional motion. ResultsA total of 1036 marker trajectories were extracted using 427 CBCT scans and 63 markers. The mean motion magnitude over all markers was 2.9 mm (left–right (LR)), 8.8 mm (cranio-caudal (CC)) and 4.1 mm (anterior–posterior (AP)) for the full motion during CBCT acquisition with mean magnitudes of 2.7 mm (LR), 8.4 mm (CC) and 3.5 mm (AP) for respiratory motion and 1.0 mm (LR), 1.5 mm (CC) and 1.4 mm (AP) for cardiac motion. Substantial daily marker shifts relative to bones resulted in margins of 8.9 mm (LR), 9.5 mm (CC), and 7.3 mm (AP). Soft-tissue based setup in and near the CTV combined with rescanning of patients with anatomical changes reduced the margins to 6.9 mm (LR), 6.8 mm (CC), and 5.6 mm (AP). ConclusionsEsophageal tumor motion was mapped with unprecedented detail throughout the radiotherapy course. Respiratory motion dominated and was largest in the CC direction. Soft-tissue matching and an adaptive strategy reduced interfractional margins by 2–3 mm compared to bony-anatomy matching.