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https://www.readbyqxmd.com/read/28206721/does-pre-pci-ffr-predict-post-pci-blood-flow-increase-do-we-need-imr-too
#1
EDITORIAL
Morton J Kern, Arnold H Seto
No abstract text is available yet for this article.
February 1, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28202246/analysis-of-myocardial-perfusion-parameters-in-an-ex-vivo-porcine-heart-model-using-third-generation-dual-source-ct
#2
Gert Jan Pelgrim, Taylor M Duguay, J Marco A Stijnen, Akos Varga-Szemes, Sjoerd Van Tuijl, U Joseph Schoepf, Matthijs Oudkerk, Rozemarijn Vliegenthart
PURPOSE: To evaluate the relationship between fractional flow reserve (FFR)-determined coronary artery stenosis severity and myocardial perfusion parameters derived from dynamic myocardial CT perfusion imaging (CTP) in an ex-vivo porcine heart model. METHODS: Six porcine hearts were perfused according to Langendorff. Circulatory parameters such as arterial blood flow (ABF) (L/min), mean arterial pressure (MAP) (mmHg) and heart rate (bpm) were monitored. Using an inflatable cuff and monitored via a pressure wire, coronary artery stenoses of different FFR grades were created (no stenosis, FFR = 0...
February 3, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28196527/assessment-of-increasing-intravenous-adenosine-dose-in-fractional-flow-reserve
#3
David Sparv, Matthias Götberg, Jan Harnek, Tobias Persson, Bjarne Madsen Hardig, David Erlinge
BACKGROUND: Effects of increased adenosine dose in the assessment of fractional flow reserve (FFR) were studied in relation to FFR results, hemodynamic effects and patient discomfort. FFR require maximal hyperemia mediated by adenosine. Standard dose is 140 μg/kg/min administrated intravenously. Higher doses are commonly used in clinical practice, but an extensive comparison between standard intravenous dose and a high dose (220 μg/kg/min) has previously not been performed. METHODS: Seventy-five patients undergoing FFR received standard dose adenosine, followed by high dose adenosine...
February 14, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28191876/clinical-and-angiographic-predictors-of-hemodynamically-significant-angiographic-lesions-development-and-validation-of-a-risk-score-to-predict-positive-fractional-flow-reserve
#4
Nishtha Sareen, Usman Baber, Safwan Kezbor, Sonny Sayseng, Melissa Aquino, Roxana Mehran, Joseph Sweeny, Nitin Barman, Annapoorna Kini, Samin K Sharma
AIMS: Coronary revascularization based upon physiological evaluation of lesions improves clinical outcomes. Angiographic or visual stenosis assessment alone is insufficient in predicting hemodynamic stenosis severity by Fractional Flow reserve (FFR) and therefore cannot be used to guide revascularization, particularly in the lesion subset (<70%). Accordingly, we sought to identify independent determinants of angiographic intermediate lesions with hemodynamic significance. METHODS AND RESULTS: We assessed consecutive intermediate lesions for patients from January 2014-April 2015 at our institution...
February 14, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28191874/instantaneous-wave-free-ratio-to-guide-coronary-revascularization-physiological-framework-validation-and-differences-with-fractional-flow-reserve
#5
Guus A de Waard, Carlo Di Mario, Amir Lerman, Patrick W Serruys, Niels van Royen
Determining the optimal treatment strategy for revascularization of coronary artery stenosis involves the use of fractional flow reserve (FFR). To improve the low clinical uptake of physiological lesion assessment to guide revascularization, the instantaneous wave-free period (iFR) was proposed as a simpler alternative to FFR that does not require adenosine administration. iFR is calculated as the ratio of blood pressure distal and proximal to a coronary artery stenosis during the diastolic wave- free period...
February 14, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28185890/-recording-the-human-brainstem-frequency-following-response-in-the-free-field
#6
Nuno Gama, Isabelle Peretz, Alexandre Lehmann
BACKGROUND: The human auditory brainstem frequency-following response (FFR) is an objective measure used to investigate the brainstem's encoding ability of sounds. Traditionally, FFRs are recorded under close-field conditions (earphones), but free-field stimulations (loudspeaker) have yet to be attempted, which would increase the applications of FFRs by making this technique accessible to those who cannot wear inserted transducers. Here we test the feasibility and reliability of measuring speech ABRs across free and close-field...
February 6, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28168977/diffuse-coronary-artery-disease-among-other-atherosclerotic-plaque-characteristics-by-coronary-computed-tomography-angiography-for-predicting-coronary-vessel-specific-ischemia-by-fractional-flow-reserve
#7
Asim Rizvi, Bríain Ó Hartaigh, Ibrahim Danad, Donghee Han, Ji Hyun Lee, Heidi Gransar, Jackie Szymonifka, Fay Y Lin, James K Min
BACKGROUND AND AIMS: Coronary computed tomography angiography (CCTA) permits effective identification of diffuse CAD and atherosclerotic plaque characteristics (APCs). We sought to examine the usefulness of diffuse CAD beyond luminal narrowing and APCs by CCTA to detect vessel-specific ischemia. METHODS: 407 vessels (n = 252 patients) from the DeFACTO diagnostic accuracy study were retrospectively analyzed for percent plaque diffuseness (PD). Percent plaque diffuseness (PD) was obtained on per-vessel level by summation of all contiguous lesion lengths and divided by total vessel length, and was logarithmically transformed (log percent PD)...
January 16, 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28164013/stenotic-flow-reserve-derived-from-quantitative-coronary-angiography-has-modest-but-incremental-value-in-predicting-functionally-significant-coronary-stenosis-as-evaluated-by-fractional-flow-reserve
#8
Elizabeth L Potter, Colin Machado, Yuvaraj Malaiapan, Om Narayan, Brian S H Ko, Peter J Psaltis, Kiran Munnur, James D Cameron, Ian T Meredith, Dennis Thiam Leong Wong
BACKGROUND: Stenotic flow reserve (SFR) derived from quantitative coronary angiography (QCA) has been correlated with myocardial ischaemia as determined by pharmacological stress echocardiography. However, the diagnostic accuracy of SFR in predicting functionally significant coronary stenosis as assessed by the gold standard, fractional flow reserve (FFR), has not been previously characterised. METHODS: Patients who underwent coronary angiography and FFR assessment between January 2010 and February 2012 in a single tertiary centre were retrospectively assessed...
February 2017: Cardiovascular Diagnosis and Therapy
https://www.readbyqxmd.com/read/28161129/navvus-ffr-to-reduce-contrast-cost-and-radiation-contract-insights-from-a-single-centre-clinical-and-economical-evaluation-with-the-rxi-rapid-exchange-ffr-device
#9
Kaneshka Masdjedi, Nicolas M Van Mieghem, Roberto Diletti, Robert-Jan van Geuns, Peter de Jaegere, Evelyn Regar, Felix Zijlstra, Ron T van Domburg, Joost Daemen
OBJECTIVES: To assess whether the RXi Navvus system compared to the use of standard Fractional Flow Reserve (FFR) wires reduces total contrast volume, radiation and overall study cost in a real world patient population referred for coronary angiography or percutaneous coronary intervention. BACKGROUND: FFR is the mainstay of functional hemodynamic assessment of coronary artery lesions. The RXi Navvus system (ACIST Medical Systems, Eden Prairie, MN) is a monorail microcatheter with FFR-measurement capability through optical pressure sensor technology...
January 4, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28160376/fractional-flow-reserve-and-resting-indices-for-coronary-physiologic-assessment-practical-guide-tips-and-tricks
#10
Fabien Picard, Michele Pighi, Hung Q Ly
Physiologic assessment using fractional flow reserve (FFR) to guide percutaneous coronary interventions (PCI) has been demonstrated to improve clinical outcomes, compared to angiography-guided PCI. Recently, resting indices such as resting Pd/Pa, "instantaneous wave-free ratio", and contrast medium induced FFR have been evaluated for the assessment of the functional consequences of coronary lesions. Herein, we review and discuss the use of FFR and other indices for the functional assessment of coronary lesions...
February 4, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28155688/mathematically-modeling-fluid-flow-and-fluid-shear-stress-in-the-canaliculi-of-a-loaded-osteon
#11
Xiaogang Wu, Ningning Wang, Zhaowei Wang, Weilun Yu, Yanqin Wang, Yuan Guo, Weiyi Chen
BACKGROUND: Mechanical load-induced intraosseous pressure gradients may result in some fluid stimuli effects, such as fluid flow and fluid shear stress (FSS), which may enable bone cells to detect external mechanical signals. Interstitial bone fluid flow is known to occur in lacunar-canalicular porosity (PLC). METHODS: In order to characterize lacunar-canalicular fluid flow behavior, a hierarchical osteon system is developed. The osteon is modeled as a poroelastic annular cylinder with two types of impermeable boundary cases considered on its outer wall: one is elastic restrained (Case I), whereas the other is displacement confined (Case II)...
December 28, 2016: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28154267/contrast-induced-hyperemia-as-an-alternative-to-drug-induced-hyperemia-in-the-evaluation-of-the-fractional-flow-reserve-in-coronary-lesions
#12
Nobuo Shiode, Tomokazu Okimoto, Hiromichi Tamekiyo, Tomoharu Kawase, Kenichi Yamane, Yuzo Kagawa, Yuto Fujii, Yusuke Ueda, Naoya Hironobe, Yasuko Kato, Yasuhiko Hayashi
Objective Measuring the fractional flow reserve (FFR) requires the induction of coronary hyperemia, usually with adenosine, adenosine triphosphate (ATP), or papaverine. However, adenosine can induce rhythmic complications, and intracoronary boluses of papaverine that prolong the QT interval can cause ventricular tachycardia. Injection of contrast media, which is routinely performed to validate the FFR guidewire placement, also induces hyperemia and may be an alternative method of measuring the FFR. We evaluated the diagnostic accuracy of the FFR after contrast hyperemia (FFRcont) compared to FFR evaluated after intracoronary papaverine (FFRpp)...
2017: Internal Medicine
https://www.readbyqxmd.com/read/28137699/frequency-dependent-fine-structure-in-the-frequency-following-response-the-byproduct-of-multiple-generators
#13
Parker Tichko, Erika Skoe
The frequency-following response (FFR) is an auditory-evoked response recorded at the scalp that captures the spectrotemporal properties of tonal stimuli. Previous investigations report that the amplitude of the FFR fluctuates as a function of stimulus frequency, a phenomenon thought to reflect multiple neural generators phase-locking to the stimulus with different response latencies. When phase-locked responses are offset by different latencies, constructive and destructive phase interferences emerge in the volume-conducted signals, culminating in an attenuation or amplification of the scalp-recorded response in a frequency-specific manner...
January 27, 2017: Hearing Research
https://www.readbyqxmd.com/read/28134124/the-impact-of-microvascular-resistance-on-the-discordance-between-anatomical-and-functional-evaluations-of-intermediate-coronary-disease
#14
Kyoung-Woo Seo, Hong-Seok Lim, Myeong-Ho Yoon, Seung-Jea Tahk, So-Yeon Choi, Byoung-Joo Choi, Hyoung-Mo Yang, Joon-Han Shin, Gyo-Seung Hwang, Jin-Sun Park, XiongJie Jin
AIMS: In intermediate coronary artery disease, discordance between anatomical and functional assessments persists and the diagnostic accuracy of an anatomical evaluation is not satisfactory for determining functional significance. We evaluated the impact of microvascular resistance on 'anatomical-functional discordance'. METHODS AND RESULTS: In 97 intermediate coronary lesions of 83 patients, minimum lumen area (MLA), fractional flow reserve (FFR), ∆(Pd/Pa-FFR), and hyperaemic microvascular resistance index (hMVRI) were measured using intravascular ultrasound and intracoronary dual pressure and Doppler sensor-tipped guidewire...
January 31, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28130886/classification-of-hemodynamically-significant-stenoses-from-dynamic-ct-perfusion-and-cta-myocardial-territories
#15
Marco Giordano, Dirk H J Poot, Adriaan Coenen, Theo van Walsum, Michela Tezza, Koen Nieman, Wiro J Niessen
PURPOSE: Myocardial blood flow (MBF) obtained by dynamic CT perfusion (CTP) has been recently introduced to assess hemodynamic significance of coronary stenosis in coronary artery disease. The diagnostic performance of dynamic CTP MBF is limited due to subjective interpretation of MBF maps and MBF variations caused by physiological, methodological and technical issues. In this paper we introduce a novel method to quantify the hypoperfused volume (HPV) in myocardial territories derived from CT angiography (CTA) in order to overcome the limitations of current dynamic CTP MBF analysis methods...
January 28, 2017: Medical Physics
https://www.readbyqxmd.com/read/28123019/cortical-correlates-of-the-auditory-frequency-following-and-onset-responses-eeg-and-fmri-evidence
#16
Emily B J Coffey, Gabriella Musacchia, Robert J Zatorre
: The frequency-following response (FFR) is a measure of the brain's periodic sound encoding. It is of increasing importance for studying the human auditory nervous system due to numerous associations with auditory cognition and dysfunction. Although the FFR is widely interpreted as originating from brainstem nuclei, a recent study using MEG suggested that there is also a right-lateralized contribution from the auditory cortex at the fundamental frequency (Coffey et al., 2016b). Our objectives in the present work were to validate and better localize this result using a completely different neuroimaging modality and to document the relationships between the FFR, the onset response, and cortical activity...
January 25, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28121952/instantaneous-wave-free-ratio-derived-from-coronary-computed-tomography-angiography-in-evaluation-of-ischemia-causing-coronary-stenosis-feasibility-and-initial-clinical-research
#17
Yue Ma, Hui Liu, Yang Hou, Aike Qiao, Yingying Hou, Qingqing Yang, Qiyong Guo
The instantaneous wave-free ratio (iFR) closely related to fractional flow reserve (FFR) is a adenosine-independent physiologic index of coronary stenosis severity. We sought to evaluate whether iFR derived from coronary computed tomographic angiography (iFRCT) can be used as a novel noninvasive method for diagnosis of ischemia-causing coronary stenosis.We retrospectively enrolled 33 patients (47 lesions) with coronary artery disease (CAD) and examined with coronary computed tomographic angiography (CTA), invasive coronary angiography (ICA), and FFR...
January 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28118185/comparison-of-plaque-morphology-between-peripheral-and-coronary-artery-disease-from-the-clarity-and-adapt-des-ivus-substudies
#18
Da Yin, Mitsuaki Matsumura, John Rundback, Jason A Yoho, Bernhard Witzenbichler, Gregg W Stone, Gary S Mintz, Akiko Maehara
OBJECTIVE: The aim of this study was to help understand the different outcomes when treating peripheral arterial disease (PAD) versus coronary artery disease (CAD). We compared plaque morphology between PAD and CAD using intravascular ultrasound. METHODS: Complete Lesion Assessment with ffR and IVUS TechnologY (CLARITY) was a prospective, multicenter trial that enrolled 50 PAD patients with a lower extremity wound fed by a tibial or a peroneal artery with diameter stenosis more than 50%...
January 21, 2017: Coronary Artery Disease
https://www.readbyqxmd.com/read/28117242/computed-tomography-angiography-versus-angiography-for-guiding-percutaneous-coronary-interventions-in-bifurcation-lesions-a-prospective-randomized-pilot-study
#19
Rafal Wolny, Jerzy Pregowski, Mariusz Kruk, Cezary Kepka, Gary S Mintz, Gabor G Toth, Artur Debski, Michal Ciszewski, Krzysztof Kukula, Maksymilian P Opolski, Zbigniew Chmielak, Adam Witkowski
BACKGROUND: There is no data on the impact of coronary computed tomography angiography (coronary CTA), as an addition to angiography, on the outcomes of percutaneous coronary interventions (PCI) in bifurcation lesions. METHODS: Patients with stable coronary artery disease scheduled for elective bifurcation PCI were randomized 1:1 to planning the procedure based on coronary CTA and angiography (CTA group) or angiography alone (CA group). The primary efficacy endpoint was the immediate angiographic result...
January 17, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28117101/the-relationship-between-fragmented-qrs-and-functional-significance-of-coronary-lesions
#20
Ahmet Korkmaz, Abdulkadir Yildiz, Mevlut Demir, Burcu Ozyazgan, Ekrem Sahan, Burak Acar, Umit Guray, Mehmet Ileri, Ozgul Ucar Elalmis
BACKGROUND: Recently fragmented QRS (fQRS) on electrocardiography (ECG) has been introduced as a predictor of myocardial scarring and myocardial ischemia in coronary artery disease (CAD). OBJECTIVE: The aim of this study was to investigate the relationship between fQRS and fractional flow reserve (FFR) results in patients with the intermediate degree of coronary artery stenosis. METHODS: A total of 301 consecutive patients who underwent coronary angiography (CAG) and FFR measurement for intermediate coronary artery stenosis were included in the study...
January 15, 2017: Journal of Electrocardiology
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