Influence of Heart Rate and Epicardial Stenosis Severity on Cardiac Contractility Under Concomitant Microvascular Disease in a Porcine Model

2011 ◽  
Author(s):  
Srikara V. Peelukhana ◽  
Kranthi K. Kolli ◽  
William Gottliebson ◽  
Massoud Leesar ◽  
Tarek Helmy ◽  
...  
Keyword(s):  
Heart Rate ◽  
Guide Wire ◽  
Cardiac Contractility ◽  
Microvascular Disease ◽  
In Vivo Experiments ◽  
Stenosis Severity ◽  
Yorkshire Pigs ◽  
Epicardial Stenosis ◽  
Dynamic Variables

Invasive guide wire methods to assess functional severity of coronary stenosis are affected by dynamic variables like heart rate (HR), contractility, epicardial stenosis (AS) and blood pressure. The interdependence of these factors is also influenced by the presence of concomitant microvascular disease (CMVD). The purpose of this study is to assess the variation in contractility under varying HR and AS in the presence of CMVD. In vivo experiments were performed on seven Yorkshire pigs. It was found that, in the presence of concomitant microvascular disease (CMVD), for lower AS (<50%) contractility increases for HR<120 bpm while it marginally decreases for HR>120 bpm. However, for higher AS (>50%), contractility decreases for both HR<120 bpm and HR>120 bpm.

Influence of Heart Rate and Contractility on Coronary Diagnostic Parameters With Normal Microvasculature in Porcine Model

2010 ◽  
Author(s):  
Kranthi K. Kolli ◽  
Mohamed Effat ◽  
Tarek Helmy ◽  
Massoud Leesar ◽  
Arif Imran ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pressure Drop ◽  
Guide Wire ◽  
Dynamic Pressure ◽  
Fractional Flow ◽  
Diagnostic Parameters ◽  
In Vivo Experiments ◽  
Flow Reserve ◽  
Yorkshire Pigs

Invasive guide-wire measurements are used to assess coronary lesion severity under clinical settings. The objective of the present research is to determine the influence of heart rate (HR) and contractility (CY) on fractional flow reserve (FFR; the ratio of distal pressure to proximal pressure at a stenotic section) and pressure drop coefficient (CDPe; the ratio of trans-stenotic pressure drop to distal dynamic pressure). In-vivo experiments were performed on eight Yorkshire pigs, to evaluate the diagnostic parameters for the conditions “CY<1100 mmHg/sec” and “CY>1100 mmHg/sec,” and for the conditions “HR<110 bpm” and “HR>110 bpm”. It was found that in the presence of normal microvasculature the measured coronary diagnostic parameters (FFR and CDPe) have a significant mean difference for variation in contractility (0.59±0.04 to 0.89±0.045 for FFR and 121.63±18 to 23.53±18 for CDPe). The variation in HR has no significant effect on FFR and CDPe (0.72±0.048 to 0.74±0.048 and 54±20 to 53±20 respectively).

Influence of Heart Rate and Area Stenosis on Coronary Diagnostic Parameters in a Porcine Model

2009 ◽  
Author(s):  
Kranthi Kumar Kolli ◽  
Srikara V. Peelukhana ◽  
Mohamed Effat ◽  
Tarek Helmy ◽  
Massoud Leesar ◽  
...  
Keyword(s):  
Heart Rate ◽  
Dynamic Pressure ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Diagnostic Parameters ◽  
In Vivo Experiments ◽  
Flow Reserve ◽  
Mean Pressure ◽  
Yorkshire Pigs

Several parameters have been proposed to assess the physiologic significance of coronary lesions invasively. The purpose of the present study is to determine the effect of heart rate and percentage area stenosis on Fractional Flow Reserve (FFR), which is the ratio of mean pressure distal to stenosis over the mean proximal (aortic) pressure and Pressure Drop Coefficient (CDP), ratio of trans-stenotic pressure gradient to distal dynamic pressure. In-vivo experiments were performed on three Yorkshire pigs, to achieve the objective. It was found that increase in heart rate does have a significant effect on the coronary diagnostic parameters with increase in area stenosis.

scholarly journals Single breath-hold saturation recovery 3D cardiac T1 mapping via compressed SENSE at 3T

2020 ◽  
Vol 33 (6) ◽  
pp. 865-876
Author(s):  
Tiago Ferreira da Silva ◽  
Carlos Galan-Arriola ◽  
Paula Montesinos ◽  
Gonzalo Javier López-Martín ◽  
Manuel Desco ◽  
...  
Keyword(s):  
Heart Rate ◽  
Saturation Recovery ◽  
Acquisition Time ◽  
Breath Hold ◽  
Post Contrast ◽  
In Vivo Experiments ◽  
Single Breath ◽  
Single Breath Hold ◽  
Phantom Experiments

Abstract Objectives To propose and validate a novel imaging sequence that uses a single breath-hold whole-heart 3D T1 saturation recovery compressed SENSE rapid acquisition (SACORA) at 3T. Methods The proposed sequence combines flexible saturation time sampling, compressed SENSE, and sharing of saturation pulses between two readouts acquired at different RR intervals. The sequence was compared with a 3D saturation recovery single-shot acquisition (SASHA) implementation with phantom and in vivo experiments (pre and post contrast; 7 pigs) and was validated against the reference inversion recovery spin echo (IR-SE) sequence in phantom experiments. Results Phantom experiments showed that the T1 maps acquired by 3D SACORA and 3D SASHA agree well with IR-SE. In vivo experiments showed that the pre-contrast and post-contrast T1 maps acquired by 3D SACORA are comparable to the corresponding 3D SASHA maps, despite the shorter acquisition time (15s vs. 188s, for a heart rate of 60 bpm). Mean septal pre-contrast T1 was 1453 ± 44 ms with 3D SACORA and 1460 ± 60 ms with 3D SASHA. Mean septal post-contrast T1 was 824 ± 66 ms and 824 ± 60 ms. Conclusion 3D SACORA acquires 3D T1 maps in 15 heart beats (heart rate, 60 bpm) at 3T. In addition to its short acquisition time, the sequence achieves good T1 estimation precision and accuracy.

scholarly journals Optical measurement of tissue perfusion changes as an alternative to electrocardiography for heart rate monitoring in Atlantic salmon (Salmo salar)

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Eirik Svendsen ◽  
Finn Økland ◽  
Martin Føre ◽  
Lise L. Randeberg ◽  
Bengt Finstad ◽  
...  
Keyword(s):  
Heart Rate ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Optical Measurement ◽  
Anterior Part ◽  
Physiological Responses ◽  
Tissue Perfusion ◽  
Heart Rate Monitoring ◽  
In Vivo Experiments

Abstract Background Welfare challenges in salmon farming highlights the need to improve understanding of the fish’s response to its environment and rearing operations. This can be achieved by monitoring physiological responses such as heart rate (HR) for individual fish. Existing solutions for heart rate monitoring are typically based on Electrocardiography (ECG) which is sensitive to placement and electrode orientation. These factors are difficult to control and affects the reliability of the principle, prompting the desire to find an alternative to ECG for heart rate monitoring in fish. This study was aimed at adapting an optical photoplethysmography (PPG) sensor for this purpose. An embedded sensor unit measuring both PPG and ECG was developed and tested using anesthetized Atlantic salmon in a series of in-vivo experiments. HR was derived from PPG and compared to the ECG baseline to evaluate its efficacy in estimating heart rate. Results The results show that PPG HR was estimated with an accuracy of 0.7 ± 1.0% for 660 nm and 1.1 ± 1.2% for 880 nm wavelengths, respectively, relative to the ECG HR baseline. The results also indicate that PPG should be measured in the anterior part of the peritoneal cavity in the direction of the heart. Conclusion A PPG/ECG module was successfully adapted to measure both ECG and PPG in-vivo for anesthetized Atlantic salmon. Using ECG as baseline, PPG analysis results show that that HR can be accurately estimated from PPG. Thus, PPG has the potential to become an alternative to ECG HR measurements in fish.

scholarly journals Acknowledging Sex Differences in In vivo Experiments: Dilemma

2021 ◽  
Vol 4 (1) ◽  
pp. 1-3
Author(s):  
Pavol Svorc ◽  
Keyword(s):  
Heart Rate ◽  
Clinical Applications ◽  
In Vivo Experiments ◽  
Cardiac Control ◽  
Control Heart ◽  
Organ Specific ◽  
Hrv Analysis ◽  
Cardiovascular Autonomic Regulation

The role of the Autonomic Nervous System (ANS) and its organ-specific functions are largely elucidated. Heart Rate Variability (HRV) analysis is a popular tool for the assessment of autonomic cardiac control. Heart rate and its changes are a sensitive indicator of ANS function, therefore cardiovascular autonomic regulation is considered to be the most reliable indicator of ANS activity and status. HRV refers to beat to beat variation in the heart rate that quantifies the interplay between sympathetic and parasympathetic activity of the ANS. Although patterns of HRV hold considerable promise for clarifying issues in clinical applications,

scholarly journals Overexpression of p53 due to excess protein O-GlcNAcylation is associated with coronary microvascular disease in type 2 diabetes

2019 ◽  
Vol 116 (6) ◽  
pp. 1186-1198
Author(s):  
Rui Si ◽  
Qian Zhang ◽  
Atsumi Tsuji-Hosokawa ◽  
Makiko Watanabe ◽  
Conor Willson ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Protein Level ◽  
P53 Protein ◽  
Cardiac Contractility ◽  
Microvascular Disease ◽  
Wild Type ◽  
Type 2 Diabetic

Abstract Aims We previously reported that increased protein O-GlcNAcylation in diabetic mice led to vascular rarefaction in the heart. In this study, we aimed to investigate whether and how coronary endothelial cell (EC) apoptosis is enhanced by protein O-GlcNAcylation and thus induces coronary microvascular disease (CMD) and subsequent cardiac dysfunction in diabetes. We hypothesize that excessive protein O-GlcNAcylation increases p53 that leads to CMD and reduced cardiac contractility. Methods and results We conducted in vivo functional experiments in control mice, TALLYHO/Jng (TH) mice, a polygenic type 2 diabetic (T2D) model, and EC-specific O-GlcNAcase (OGA, an enzyme that catalyzes the removal of O-GlcNAc from proteins)-overexpressing TH mice, as well as in vitro experiments in isolated ECs from these mice. TH mice exhibited a significant increase in coronary EC apoptosis and reduction of coronary flow velocity reserve (CFVR), an assessment of coronary microvascular function, in comparison to wild-type mice. The decreased CFVR, due at least partially to EC apoptosis, was associated with decreased cardiac contractility in TH mice. Western blot experiments showed that p53 protein level was significantly higher in coronary ECs from TH mice and T2D patients than in control ECs. High glucose treatment also increased p53 protein level in control ECs. Furthermore, overexpression of OGA decreased protein O-GlcNAcylation and down-regulated p53 in coronary ECs, and conferred a protective effect on cardiac function in TH mice. Inhibition of p53 with pifithrin-α attenuated coronary EC apoptosis and restored CFVR and cardiac contractility in TH mice. Conclusions The data from this study indicate that inhibition of p53 or down-regulation of p53 by OGA overexpression attenuates coronary EC apoptosis and improves CFVR and cardiac function in diabetes. Lowering coronary endothelial p53 levels via OGA overexpression could be a potential therapeutic approach for CMD in diabetes.

Effect of heart rate on hemodynamic endpoints under concomitant microvascular disease in a porcine model

2012 ◽  
Vol 302 (8) ◽  
pp. H1563-H1573 ◽  
Author(s):  
S. V. Peelukhana ◽  
R. K. Banerjee ◽  
K. K. Kolli ◽  
M. A. Effat ◽  
T. A. Helmy ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pressure Drop ◽  
Dynamic Pressure ◽  
Microvascular Disease ◽  
Flow Coefficient ◽  
Fractional Flow ◽  
Anova Analysis ◽  
Throat Region ◽  
Flow Reserve ◽  
Yorkshire Pigs

Diagnosis of the ischemic power of epicardial stenosis with concomitant microvascular disease (MVD) is challenging during coronary interventions, especially under variable hemodynamic factors like heart rate (HR). The goal of this study is to assess the influence of variable HR and percent area stenosis (%AS) in the presence of MVD on pressure drop coefficient (CDP; ratio of transstenotic pressure drop to the distal dynamic pressure) and lesion flow coefficient (LFC; ratio of %AS to the CDP at the throat region). We hypothesize that CDP and LFC are independent of HR. %AS and MVD were created using angioplasty balloons and 90-μm microspheres, respectively. Simultaneous measurements of pressure drop (DP) and velocity were done in 11 Yorkshire pigs. Fractional flow reserve (FFR), CDP, and LFC were calculated for the groups HR < 120 and HR > 120 beats/min, %AS < 50 and %AS > 50, and additionally for DP < 14 and DP > 14 mmHg, and analyzed using regression and ANOVA analysis. Regression analysis showed independence between HR and the FFR, CDP, and LFC while it showed dependence between %AS and the FFR, CDP, and LFC. In the ANOVA analysis, for the HR < 120 beats/min and HR > 120 beats/min groups, the values of FFR (0.82 ± 0.02 and 0.82 ± 0.02), CDP (83.15 ± 26.19 and 98.62 ± 26.04), and LFC (0.16 ± 0.03 and 0.15 ± 0.03) were not significantly different ( P > 0.05). However, for %AS < 50 and %AS > 50, the FFR (0.89 ± 0.02 and 0.75 ± 0.02), CDP (35.97 ± 25.79.10 and 143.80 ± 25.41), and LFC (0.09 ± 0.03 and 0.22 ± 0.03) were significantly different ( P < 0.05). A similar trend was observed between the DP groups. Under MVD conditions, FFR, CDP, and LFC were not significantly influenced by changes in HR, while they can significantly distinguish %AS and DP groups.

Stem Cell Cure for Kidney Injury: Therapy to Solve Most Complex Issues in Renal System

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Kidney Injury ◽  
Cell Types ◽  
Tissue Remodelling ◽  
Major Health Problem ◽  
In Vivo Experiments ◽  
Renal Regeneration ◽  
Induced Pluripotent

Renal failure is a major health problem. The mortality rate remain high despite of several therapies. The most complex of the renal issues are solved through stem cells. In this review, different mechanism for cure of chronic kidney injury along with cell engraftment incorporated into renal structures will be analysed. Paracrine activities of embryonic or induced Pluripotent stem cells are explored on the basis of stem cell-induced kidney regeneration. Several experiments have been conducted to advance stem cells to ensure the restoration of renal functions. More vigour and organised protocols for delivering stem cells is a possibility for advancement in treatment of renal disease. Also there is a need for pressing therapies to replicate the tissue remodelling and cellular repair processes suitable for renal organs. Stem cells are the undifferentiated cells that have the ability to multiply into several cell types. In vivo experiments on animal’s stem cells have shown significant improvements in the renal regeneration and functions of organs. Nevertheless more studies show several improvements in the kidney repair due to stem cell regeneration.

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