keyword
MENU ▼
Read by QxMD icon Read
search

Cardiac perfusion

keyword
https://www.readbyqxmd.com/read/28231318/effects-of-na-channel-blockers-on-the-restitution-of-refractory-period-conduction-time-and-excitation-wavelength-in-perfused-guinea-pig-heart
#1
Oleg E Osadchii
Na+ channel blockers flecainide and quinidine can increase propensity to ventricular tachyarrhythmia, whereas lidocaine and mexiletine are recognized as safe antiarrhythmics. Clinically, ventricular fibrillation is often precipitated by transient tachycardia that reduces action potential duration, suggesting that a critical shortening of the excitation wavelength (EW) may contribute to the arrhythmic substrate. This study examined whether different INa blockers can produce contrasting effects on the rate adaptation of the EW, which would explain the difference in their safety profile...
2017: PloS One
https://www.readbyqxmd.com/read/28227463/hemodynamic-effects-of-synchronizing-an-intra-aortic-vad-in-reverse-rotation-control-with-left-ventricle-a-mock-loop-study
#2
Yaxin Wang, P Alex Smith, Daniel L Timms, Po-Lin Hsu, Richard A McMahon, Yaxin Wang, P Alex Smith, Daniel L Timms, Po-Lin Hsu, Richard A McMahon, Richard A McMahon, Daniel L Timms, Po-Lin Hsu, Yaxin Wang, P Alex Smith
The IntraVAD is an intra-aortic left ventricular assist device (LVAD) to be located in the ascending aorta. In order to enhance unloading and promote coronary flow for the left ventricle (LV), an operating mechanism, reverse-rotation control (RRc) mode, has been developed for the IntraVAD and tested in vitro in a mock circulation loop (MCL). The RRc mode consists of forward rotation (FR) and reverse rotation (RR). The synchronization between the IntraVAD and the LV was studied to offload the ventricle more effectively and to improve myocardial perfusion...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227282/development-of-matlab-software-to-control-data-acquisition-from-a-multichannel-systems-multi-electrode-array
#3
Erik Messier, Behnaz Ghoraani, Erik Messier, Erik Messier, Behnaz Ghoraani
A Multichannel Systems (MCS) microelectrode array data acquisition (DAQ) unit is used to collect multichannel electrograms (EGM) from a Langendorff perfused rabbit heart system to study sudden cardiac death (SCD). MCS provides software through which data being processed by the DAQ unit can be displayed and saved, but this software's combined utility with MATLAB is not very effective. MCSs software stores recorded EGM data in a MathCad (MCD) format, which is then converted to a text file format. These text files are very large, and it is therefore very time consuming to import the EGM data into MATLAB for real-time analysis...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227089/low-energy-defibrillation-research-using-a-rabbit-ventricular-model-optimizing-the-potential-gradient-distribution-using-multiple-epicardial-electrodes
#4
Jianfei Wang, Lian Jin, Xiaomei Wu, Biao Song, Li Qian, Weiqi Wang, Jianfei Wang, Lian Jin, Xiaomei Wu, Biao Song, Li Qian, Weiqi Wang, Xiaomei Wu, Li Qian, Biao Song, Jianfei Wang, Weiqi Wang, Lian Jin
Cardiac potential gradient distribution directly affects defibrillation efficacy, and the electrode configuration that ensures optimal distribution is yet to be determined. In this study, a rabbit ventricular finite element conductor model containing blood perfusion in ventricular cavities was developed. The electric field was solved on the model by using 95% myocardial volume potential gradient higher than 5 V/cm as the successful defibrillation threshold (DFT). Multiple epicardial electrodes (MEE) protocols and a SCAN protocol were used to identify the optimum defibrillation method...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227084/development-of-data-acquisition-components-for-simultaneous-recording-of-3d-epicardial-and-surface-ecg-signals-in-the-langendorff-perfusion-apparatus
#5
Ryan Wade Selby, Anup Jonchhe, Chen Kaplan, Coeli M Lopes, Behnaz Ghoraani, Ryan Wade Selby, Anup Jonchhe, Chen Kaplan, Coeli M Lopes, Behnaz Ghoraani, Chen Kaplan, Behnaz Ghoraani, Anup Jonchhe, Coeli M Lopes, Ryan Wade Selby
Sudden Cardiac Death (SCD) claims 7 million lives per year. The importance of myocardial electrogram (EGM) repolarization alternans and surface electrocardiogram (ECG) T-wave alternans is gaining traction for understanding the underlying SCD mechanisms. However, the relationship between the 3D spatial distribution of myocardial EGMs and surface ECG with respect to SCD has yet to be investigated. To make this happen, a modified data acquisition system has been developed and fabricated in conjunction with the Langendorff perfusion system to enable simultaneous recording and analysis of the 3D spatial distribution of myocardial EGMs and the surface ECG...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226460/pro-arrhythmic-effect-of-heart-rate-variability-during-periodic-pacing
#6
Kanchan Kulkarni, Steven W Lee, Elena G Tolkacheva, Kanchan Kulkarni, Steven W Lee, Elena G Tolkacheva, Elena G Tolkacheva, Steven W Lee, Kanchan Kulkarni
Clinically, healthy hearts have been associated with a high ventricular heart rate variability (HRV) while diseased hearts have been known to exhibit low ventricular HRV. Hence, low HRV is suggested to be a marker of cardiac ventricular arrhythmias. Over the past few years, there has been considerable amount of interest in incorporating HRV in pacing to emulate healthy heart conditions and re-stabilize the electrical activity in diseased hearts. Recently, we used single cell numerical simulations to demonstrate that HRV incorporated into periodic pacing promotes alternans formation and thus, can be pro-arrhythmic...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28222421/luteolin-enhances-sarcoplasmic-reticulum-ca2-atpase-activity-through-p38-mapk-signaling-thus-improving-rat-cardiac-function-after-ischemia-reperfusion
#7
Shasha Zhu, Tongda Xu, Yuanyuan Luo, Yingying Zhang, Haochen Xuan, Yanfeng Ma, Defeng Pan, Dongye Li, Hong Zhu
BACKGROUND/AIMS: A major challenge for current therapeutic strategies against ischemia/reperfusion (I/R) is the lack of effective drugs. Considering luteolin enhances the activity of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) to improve the systolic/diastolic function of rat hearts and cardiomyocytes during the I/R process, we studied the regulatory function of the p38 MAPK pathway in this protective mechanism. METHODS: Isolated cardiomyocytes and perfused hearts were separately divided into five groups and used to investigate I/R...
February 21, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28219921/predictive-value-of-dobutamine-stress-perfusion-echocardiography-in-contemporary-end-stage-liver-disease
#8
Bipul Baibhav, Chetaj A Mahabir, Feng Xie, Valerie K Shostrom, Timothy M McCashland, Thomas R Porter
BACKGROUND: The assessment of cardiac risk in contemporary liver transplantation (LT) has required more sensitive testing for the detection of occult coronary artery disease as well as microvascular and functional cardiac abnormalities. Because dobutamine stress perfusion echocardiography provides an assessment of both regional systolic and diastolic function as well as microvascular perfusion (MVP), we sought to examine its incremental value in this setting. METHODS AND RESULTS: We evaluated the predictive value of dobutamine stress perfusion echocardiography in 296 adult patients with end-stage liver disease and preserved systolic function who underwent LT between 2008 and 2014...
February 20, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28219356/bacopa-monnieri-extract-increases-rat-coronary-flow-and-protects-against-myocardial-ischemia-reperfusion-injury
#9
Sirintorn Srimachai, Sylvie Devaux, Celine Demougeot, Sarawut Kumphune, Nina D Ullrich, Ernst Niggli, Kornkanok Ingkaninan, Natakorn Kamkaew, C Norman Scholfield, Sompol Tapechum, Krongkarn Chootip
BACKGROUND: This study explored Bacopa monnieri, a medicinal Ayurvedic herb, as a cardioprotectant against ischemia/reperfusion injury using cardiac function and coronary flow as end-points. METHODS: In normal isolated rat hearts, coronary flow, left ventricular developed pressure, heart rate, and functional recovery were measured using the Langendorff preparation. Hearts were perfused with either (i) Krebs-Henseleit (normal) solution, (control), or with 30, 100 μg/ml B...
February 20, 2017: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/28217366/crizotinib-inhibits-hyperpolarization-activated-cyclic-nucleotide-gated-channel-4-activity
#10
Zhushan Zhang, Tai-Qin Huang, Igor Nepliouev, Hengtao Zhang, Adam S Barnett, Paul B Rosenberg, Sai-Hong I Ou, Jonathan A Stiber
BACKGROUND: Sinus bradycardia is frequently observed in patients treated with crizotinib, a receptor tyrosine kinase inhibitor used for the treatment of anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). We investigated whether crizotinib could influence heart rate (HR) through direct cardiac effects. METHODS: The direct effect of crizotinib on HR was studied using ECG analysis of Langendorff-perfused mouse hearts. The whole-cell patch clamp technique was used to measure the effects of crizotinib on the hyperpolarization-activated funny current, If, in mouse sinoatrial node cells (SANCs) and hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) activity in HEK-293 cells stably expressing human HCN4...
2017: Cardiooncology
https://www.readbyqxmd.com/read/28217316/subacute-right-heart-failure-revealing-three-simultaneous-causes-of-post-embolic-pulmonary-hypertension-in-metastatic-dissemination-of-breast-cancer
#11
Flavien Vincent, Nicolas Lamblin, Marion Classe, Guillaume Schurtz, Antoine Rauch, Marie Fertin, Pascal De Groote
A 72-year-old woman with history of breast cancer only treated surgically was referred to our department for pulmonary hypertension (PH) suspicion. Echocardiogram revealed elevated right ventricular systolic pressure. Computed tomography (CT) angiogram showed no pulmonary embolism (PE), but lung scan revealed two ventilation-perfusion mismatch areas. Right cardiac catheterization established precapillary PH. Despite treatment with PH specific therapy (sildenafil, ambrisentan, and epoprostenol), her condition worsened rapidly with acute right heart failure (RHF)...
February 2017: ESC Heart Failure
https://www.readbyqxmd.com/read/28217062/anesthetic-management-of-a-case-of-gilbert-s-syndrome-for-mitral-and-aortic-valve-replacement-role-of-transesophageal-echocardiography
#12
P S Nagaraja, Naveen G Singh, S Subash, N Manjunatha, C G Prabhushankar, N Sathish
Gilbert's syndrome (GS) is an autosomal inherited disorder characterized by relative deficiency of glucuronyl transferase and poor uptake of unconjugated bilirubin by hepatocytes. Cardiac surgery on cardiopulmonary bypass (CPB) in these patients triggers further hepatic dysfunction. Transesophageal echocardiography (TEE) and Doppler assessment of hepatic vein help in assessing hepatic blood flow (HBF) during cardiac surgery. Here, we discuss anesthetic management and role of TEE in maintaining HBF perioperatively in a 25-year-old male patient with GS undergoing double valve replacement with tricuspid valve plasty...
January 2017: Saudi Journal of Anaesthesia
https://www.readbyqxmd.com/read/28215591/the-effect-of-resuscitation-position-on-cerebral-and-coronary-perfusion-pressure-during-mechanical-cardiopulmonary-resuscitation-in-porcine-cardiac-arrest-model
#13
Taeyun Kim, Sang Do Shin, Kyoung Jun Song, Yong Joo Park, Hyun Ho Ryu, Guillaume Debaty, Keith Lurie, Ki Jeong Hong
OBJECTIVE: Automated cardiopulmonary resuscitation (CPR) devices can be used during transport in a small spaces (e.g. an elevator) to reduce the length of stretcher and via body position change. It is unknown whether patient position is associated with the optimal cerebral (CePP) and coronary (CoPP) perfusion pressure. METHODS: This study utilized a randomized experimental design and anesthetized, intubated and paralyzed female pigs (n=12) (mean 42, SD 3kg) on a customized tilt table...
February 16, 2017: Resuscitation
https://www.readbyqxmd.com/read/28215415/diagnostic-and-prognostic-value-of-lead-avr-during-exercise-testing-in-patients-suspected-of-having-myocardial-ischemia
#14
Max Wagener, Roger Abächerli, Ursina Honegger, Nicolas Schaerli, Gil Prêtre, Raphael Twerenbold, Christian Puelacher, Germaine Sunier, Philipp Reddiess, Maria Rubini Gimenez, Karin Wildi, Jasper Boeddinghaus, Thomas Nestelberger, Patrick Badertscher, Zaid Sabti, Ramun Schmid, Remo Leber, Dayana Flores Widmer, Samyut Shrestha, Ivo Strebel, Damian Wild, Stefan Osswald, Michael Zellweger, Christian Mueller, Tobias Reichlin
We aimed to assess the diagnostic and prognostic value of ST-segment deviation in aVR, a lead often ignored in clinical practice, during exercise testing and to compare it to the most widely used criterion of ST-segment depression in V5. We enrolled 1,596 patients with suspected myocardial ischemia referred for nuclear perfusion imaging undergoing bicycle stress testing. ST-segment amplitudes in leads aVR and V5 were automatically measured. The presence of inducible myocardial ischemia was the diagnostic end point and adjudicated based on nuclear perfusion imaging and coronary angiography...
January 5, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28214967/increased-atrial-%C3%AE-adrenergic-receptors-and-grk-2-gene-expression-can-play-a-fundamental-role-in-heart-failure-after-repair-of-congenital-heart-disease-with-cardiopulmonary-bypass
#15
Marcela Silva Oliveira, Fabio Carmona, Walter V A Vicente, Paulo H Manso, Karina M Mata, Mara Rúbia Celes, Erica C Campos, Simone G Ramos
Surgeries to correct congenital heart diseases are increasing in Brazil and worldwide. However, even with the advances in surgical techniques and perfusion, some cases, especially the more complex ones, can develop heart failure and death. A retrospective study of patients who underwent surgery for correction of congenital heart diseases with cardiopulmonary bypass (CPB) in a university tertiary-care hospital that died, showed infarction in different stages of evolution and scattered microcalcifications in the myocardium, even without coronary obstruction...
February 18, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28213770/myosin-heavy-chain-and-cardiac-troponin-t-damage-is-associated-with-impaired-myofibrillar-atpase-activity-contributing-to-sarcomeric-dysfunction-in-ca-2-paradox-rat-hearts
#16
Árpád Kovács, Judit Kalász, Enikő T Pásztor, Attila Tóth, Zoltán Papp, Naranjan S Dhalla, Judit Barta
This study aimed to explore the potential contribution of myofibrils to contractile dysfunction in Ca(2+)-paradox hearts. Isolated rat hearts were perfused with Krebs-Henseleit solution (Control), followed by Ca(2+)-depletion, and then Ca(2+)-repletion after Ca(2+)-depletion (Ca(2+)-paradox) by Langendorff method. During heart perfusion left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), rate of pressure development (+ dP/dt), and pressure decay (-dP/dt) were registered. Control LVDP (127...
February 17, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28210637/anomalous-origin-of-the-left-coronary-artery-from-the-pulmonary-artery-an-uncommon-coronary-anomaly-with-serious-implications-in-adulthood
#17
Venkat Gangadharan, Kamesh Sivagnanam, Ghulam Murtaza, Michael Ponders, Otto Teixeira, Timir Paul
A 36-year-old woman was seen with complaints of exertional chest pain and shortness of breath. Her medical history included atrial fibrillation and diabetes. Physical examination was unremarkable except for an irregular cardiac rhythm. Myocardial perfusion imaging revealed the presence of a large area of infarction involving the entire anterior and apical walls and part of the anteroseptal wall with minimal periinfarct ischemia. Computed tomography coronary angiogram revealed an anomalous left main coronary artery arising from the main pulmonary artery...
January 2017: Journal of Investigative Medicine High Impact Case Reports
https://www.readbyqxmd.com/read/28205347/robust-universal-nonrigid-motion-correction-framework-for-first-pass-cardiac-mr-perfusion-imaging
#18
Mitchel Benovoy, Matthew Jacobs, Farida Cheriet, Nagib Dahdah, Andrew E Arai, Li-Yueh Hsu
PURPOSE: To present and assess an automatic nonrigid image registration framework that compensates motion in cardiac magnetic resonance imaging (MRI) perfusion series and auxiliary images acquired under a wide range of conditions to facilitate myocardial perfusion quantification. MATERIALS AND METHODS: Our framework combines discrete feature matching for large displacement estimation with a dense variational optical flow formulation in a multithreaded architecture...
February 15, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28205113/cardiac-pet-ct-with-rb-82-optimization-of-image-acquisition-and-reconstruction-parameters
#19
P Chilra, S Gnesin, G Allenbach, M Monteiro, J O Prior, L Vieira, J A Pires Jorge
BACKGROUND: Our aim was to characterize the influence of time-of-flight (TOF) and point spread function (PSF) recovery corrections, as well as ordered subset expectation maximization (OSEM) reconstruction parameters, in (82)Rb PET/CT quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Rest and stress list-mode dynamic (82)Rb PET acquisition data from 10 patients without myocardial flow defects and 10 patients with myocardial blood flow defects were reconstructed retrospectively...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28202440/exposure-to-placental-ischemia-impairs-postpartum-maternal-renal-and-cardiac-function-in-rats
#20
Nina D Paauw, Jaap A Joles, Frank T Spradley, Bhavisha Bakrania, Zsuzsanna K Zellenger, Arie Franx, Marianne C Verhaar, Joey P Granger, A Titia Lely
INTRODUCTION: Women with a history of preeclampsia (PE) have an increased risk to develop cardiovascular and renal diseases later in life, but the mechanisms underlying this effect are unknown. In rats, we assessed whether placental ischemia results in long-term effects on the maternal cardiovascular and renal systems using the Reduced Uterine Perfusion Pressure (RUPP) model for PE. METHODS: Sprague-Dawley rats received either a SHAM or RUPP operation at gestational day 14...
February 15, 2017: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
keyword
keyword
20264
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"