scholarly journals An Implantable Pressure Sensor for Long-term Wireless Monitoring of Cardiac Function -First Study in Man

2016 ◽  
Vol 4 (4) ◽  
Author(s):  
Henrik Casimir Ahn ◽  
Baz Delshad
Keyword(s):  
Cardiac Function ◽  
Pressure Sensor ◽  
Wireless Monitoring ◽  
Implantable Pressure Sensor

scholarly journals Design, Fabrication, and Implementation of a Wireless, Passive Implantable Pressure Sensor Based on Magnetic Higher-Order Harmonic Fields

Biosensors ◽  
2011 ◽  
Vol 1 (4) ◽  
pp. 134-152 ◽  
Author(s):  
Ee Lim Tan ◽  
Andrew J. DeRouin ◽  
Brandon D. Pereles ◽  
Keat Ghee Ong
Keyword(s):  
Pressure Sensor ◽  
Higher Order ◽  
Implantable Pressure Sensor

Exercise cardiac MRI unmasks cardiac dysfunction in childhood and adolescent cancer survivors with reduced cardiopulmonary fitness

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Foulkes ◽  
B Costello ◽  
E.J Howden ◽  
K Janssens ◽  
H Dillon ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Function ◽  
Cancer Survivors ◽  
Pediatric Cancer ◽  
Cardiac Dysfunction ◽  
Cardiopulmonary Fitness ◽  
Cardiac Reserve ◽  
Pediatric Cancer Survivors ◽  
Increased Risk

Abstract Background Young cancer survivors are at increased risk of impaired cardiopulmonary fitness (VO2peak) and heart failure. Assessment of exercise cardiac reserve may reveal sub-clinical abnormalities that better explain impairments in fitness and long term heart failure risk. Purpose To investigate the presence of impaired VO2peak in pediatric cancer survivors with increased risk of heart failure, and to assess its relationship with resting cardiac function and cardiac reserve Methods Twenty pediatric cancer survivors (aged 8–24 years) treated with anthracycline chemotherapy underwent cardiopulmonary exercise testing to quantify VO2peak, with a value <85% of predicted defined as impaired VO2peak. Resting cardiac function was assessed using 3-dimensional echocardiography, with cardiac reserve quantified from resting and peak exercise heart rate (HR), stroke volume index (SVi) and cardiac index (CI) using exercise cardiac magnetic resonance imaging. Results 12 of 20 survivors (60%) had impaired VO2peak (97±14% vs. 70±16% of age and gender predicted). There were no differences in echocardiographic or CMR measurements of resting cardiac function between survivors with normal or impaired VO2peak. However, those with reduced VO2peak had diminished cardiac reserve, with a lesser increase in CI (Fig. 1A) and SVi (Fig. 1B) during exercise (Interaction P=0.001 for both), whilst the HR response was similar (Fig. 1C; P=0.71). Conclusions Resting measures of cardiac function are insensitive to significant cardiac dysfunction amongst pediatric cancer survivors with reduced VO2peak. Measures of cardiopulmonary fitness and cardiac reserve may aid in early identification of survivors with heightened risk of long-term heart failure. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Heart Foundation

scholarly journals Exposure to Δ9-tetrahydrocannabinol during rat pregnancy leads to impaired cardiac dysfunction in postnatal life

2021 ◽  
Author(s):  
Kendrick Lee ◽  
Steven R. Laviolette ◽  
Daniel B. Hardy
Keyword(s):  
Body Weight ◽  
Cardiac Function ◽  
Cardiac Dysfunction ◽  
Cardiac Remodelling ◽  
Long Term Effects ◽  
Catch Up ◽  
First Time ◽  
Impaired Cardiac Function ◽  
In Pregnancy

Abstract Background Cannabis use in pregnancy leads to fetal growth restriction (FGR), but the long-term effects on cardiac function in the offspring are unknown, despite the fact that fetal growth deficits are associated with an increased risk of developing postnatal cardiovascular disease. We hypothesize that maternal exposure to Δ9-tetrahydrocannabinol (Δ9-THC) during pregnancy will impair fetal development, leading to cardiac dysfunction in the offspring. Methods Pregnant Wistar rats were randomly selected and administered 3 mg/kg of Δ9-THC or saline as a vehicle daily via intraperitoneal injection from gestational days 6 to 22, followed by echocardiogram analysis of cardiac function on offspring at postnatal days 1 and 21. Heart tissue was harvested from the offspring at 3 weeks for molecular analysis of cardiac remodelling. Results Exposure to Δ9-THC during pregnancy led to FGR with a significant decrease in heart-to-body weight ratios at birth. By 3 weeks, pups exhibited catch-up growth associated with significantly greater left ventricle anterior wall thickness with a decrease in cardiac output. Moreover, these Δ9-THC-exposed offsprings exhibited increased expression of collagen I and III, decreased matrix metallopeptidase-2 expression, and increased inactivation of glycogen synthase kinase-3β, all associated with cardiac remodelling. Conclusions Collectively, these data suggest that Δ9-THC-exposed FGR offspring undergo postnatal catch-up growth concomitant with cardiac remodelling and impaired cardiac function early in life. Impact To date, the long-term effects of perinatal Δ9-THC (the main psychoactive component) exposure on the cardiac function in the offspring remain unknown. We demonstrated, for the first time, that exposure to Δ9-THC alone during rat pregnancy results in significantly smaller hearts relative to body weight. These Δ9-THC-exposed offsprings exhibited postnatal catch-up growth concomitant with cardiac remodelling and impaired cardiac function. Given the increased popularity of cannabis use in pregnancy along with rising Δ9-THC concentrations, this study, for the first time, identifies the risk of perinatal Δ9-THC exposure on early postnatal cardiovascular health.

A Low-Range Drift-Free Bio-compatible Pressure Sensor Based on P(VDF-TrFE) Piezoelectric Thin Film

2009 ◽  
Vol 1222 ◽  
Author(s):  
Xiaoyang Li ◽  
Timothy Reissman ◽  
Fan Yu ◽  
Edwin C. Kan
Keyword(s):  
Thin Film ◽  
Blood Pressure ◽  
Pressure Sensor ◽  
Equivalent Circuit Model ◽  
Swelling Pressure ◽  
Pressure Monitoring ◽  
Sensing Element ◽  
Piezoelectric Resonance ◽  
Piezoelectric Thin Film

AbstractA low-range pressure sensor (0-100kPa) based on the P(VDF-TrFE) piezoelectric thin film is proposed, where the long-term drift is eliminated by operating near the piezoelectric resonance. The pressure sensor is designed for blood pressure and tissue swelling pressure monitoring. The poled 50μm±1μm P(VDF-TrFE) copolymer film is used as the sensing element, with all fabrication and assembly materials biocompatible. A modified Butterworth-Van Dyke (BVD) [1] equivalent circuit model is used to characterize the sensor behavior. The pressure sensor exhibits negligible drift in weeks of operation. The device shows a sensitivity of 0.038MHz/kPa resonance frequency shift under stress, which leads to a maximum readout change of 1.1%/kPa in the present setup.

Long-term levosimendan treatment improves systolic function and myocardial relaxation in mice with cardiomyocyte-specific disruption of the Serca2 gene

2013 ◽  
Vol 115 (10) ◽  
pp. 1572-1580 ◽  
Author(s):  
Vigdis Hillestad ◽  
Frank Kramer ◽  
Stefan Golz ◽  
Andreas Knorr ◽  
Kristin B. Andersson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Cardiac Function ◽  
Diastolic Dysfunction ◽  
Systolic Function ◽  
Cytosolic Calcium ◽  
Left Ventricular ◽  
Pressure Measurements ◽  
Human Heart Failure

In human heart failure (HF), reduced cardiac function has, at least partly, been ascribed to altered calcium homeostasis in cardiomyocytes. The effects of the calcium sensitizer levosimendan on diastolic dysfunction caused by reduced removal of calcium from cytosol in early diastole are not well known. In this study, we investigated the effect of long-term levosimendan treatment in a murine model of HF where the sarco(endo)plasmatic reticulum ATPase ( Serca) gene is specifically disrupted in the cardiomyocytes, leading to reduced removal of cytosolic calcium. After induction of Serca2 gene disruption, these mice develop marked diastolic dysfunction as well as impaired contractility. SERCA2 knockout (SERCA2KO) mice were treated with levosimendan or vehicle from the time of KO induction. At the 7-wk end point, cardiac function was assessed by echocardiography and pressure measurements. Vehicle-treated SERCA2KO mice showed significantly diminished left-ventricular (LV) contractility, as shown by decreased ejection fraction, stroke volume, and cardiac output. LV pressure measurements revealed a marked increase in the time constant (τ) of isovolumetric pressure decay, showing impaired relaxation. Levosimendan treatment significantly improved all three systolic parameters. Moreover, a significant reduction in τ toward normalization indicated improved relaxation. Gene-expression analysis, however, revealed an increase in genes related to production of the ECM in animals treated with levosimendan. In conclusion, long-term levosimendan treatment improves both contractility and relaxation in a heart-failure model with marked diastolic dysfunction due to reduced calcium transients. However, altered gene expression related to fibrosis was observed.

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