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https://www.readbyqxmd.com/read/28202246/analysis-of-myocardial-perfusion-parameters-in-an-ex-vivo-porcine-heart-model-using-third-generation-dual-source-ct
#1
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
#2
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/28185890/-recording-the-human-brainstem-frequency-following-response-in-the-free-field
#3
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
#4
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/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
#5
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/28154267/contrast-induced-hyperemia-as-an-alternative-to-drug-induced-hyperemia-in-the-evaluation-of-the-fractional-flow-reserve-in-coronary-lesions
#6
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/28134124/the-impact-of-microvascular-resistance-on-the-discordance-between-anatomical-and-functional-evaluations-of-intermediate-coronary-disease
#7
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/28123019/cortical-correlates-of-the-auditory-frequency-following-and-onset-responses-eeg-and-fmri-evidence
#8
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/28118185/comparison-of-plaque-morphology-between-peripheral-and-coronary-artery-disease-from-the-clarity-and-adapt-des-ivus-substudies
#9
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/28117101/the-relationship-between-fragmented-qrs-and-functional-significance-of-coronary-lesions
#10
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
https://www.readbyqxmd.com/read/28112409/improving-ccta-based-lesions-hemodynamic-significance-assessment-by-accounting-for-partial-volume-modeling-in-automatic-coronary-lumen-segmentation
#11
Moti Freiman, Hannes Nickisch, Sven Prevrhal, Holger Schmitt, Mani Vembar, Pál Maurovich-Horvat, Patrick Donnelly, Liran Goshen
PURPOSE: The goal of this study was to assess the potential added benefit of accounting for partial volume effects (PVE) in an automatic coronary lumen segmentation algorithm that is used to determine the hemodynamic significance of a coronary artery stenosis from coronary computed tomography angiography (CCTA). MATERIALS AND METHODS: Two sets of data were used in our work: (1) multi-vendor CCTA datasets of 18 subjects from the MICCAI 2012 challenge with automatically generated centerlines and 3 reference segmentations of 78 coronary segments and (2) additional CCTA datasets of 97 subjects with132 coronary lesions, that had invasive reference standard FFR measurements...
January 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28110424/effects-of-caffeine-on-fractional-flow-reserve-values-measured-using-intravenous-adenosine-triphosphate
#12
Masafumi Nakayama, Taishiro Chikamori, Takashi Uchiyama, Yo Kimura, Nobuhiro Hijikata, Ryosuke Ito, Mikio Yuhara, Hideaki Sato, Yuichi Kobori, Akira Yamashina
We investigated the effects of caffeine intake on fractional flow reserve (FFR) values measured using intravenous adenosine triphosphate (ATP) before cardiac catheterization. Caffeine is a competitive antagonist for adenosine receptors; however, it is unclear whether this antagonism affects FFR values. Patients were evenly randomized into 2 groups preceding the FFR study. In the caffeine group (n = 15), participants were given coffee containing 222 mg of caffeine 2 h before the catheterization. In the non-caffeine group (n = 15), participants were instructed not to take any caffeine-containing drinks or foods for at least 12 h before the catheterization...
January 21, 2017: Cardiovascular Intervention and Therapeutics
https://www.readbyqxmd.com/read/28109933/integrating-ct-myocardial-perfusion-and-ct-ffr-in-the-work-up-of-coronary-artery%C3%A2-disease
#13
Adriaan Coenen, Alexia Rossi, Marisa M Lubbers, Akira Kurata, Atsushi K Kono, Raluca G Chelu, Sabrina Segreto, Marcel L Dijkshoorn, Andrew Wragg, Robert-Jan M van Geuns, Francesca Pugliese, Koen Nieman
OBJECTIVES: The aim of this study was to investigate the individual and combined accuracy of dynamic computed tomography (CT) myocardial perfusion imaging (MPI) and computed tomography angiography (CTA) fractional flow reserve (FFR) for the identification of functionally relevant coronary artery disease (CAD). BACKGROUND: Coronary CTA has become an established diagnostic test for ruling out CAD, but it does not allow interpretation of the hemodynamic severity of stenotic lesions...
January 12, 2017: JACC. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28086778/diabetes-does-not-impact-the-diagnostic-performance-of-contrast-based-fractional-flow-reserve-insights-from-the-contrast-study
#14
Giuseppe Gargiulo, Eugenio Stabile, Marco Ferrone, Emanuele Barbato, Frederik M Zimmermann, Julien Adjedj, Barry Hennigan, Mitsuaki Matsumura, Nils P Johnson, William F Fearon, Allen Jeremias, Bruno Trimarco, Giovanni Esposito
BACKGROUND: Adenosine-free coronary pressure wire metrics have been proposed to test the functional significance of coronary artery lesions, but it is unexplored whether their diagnostic performance might be altered in patients with diabetes. METHODS: We performed a post-hoc analysis of the CONTRAST study, which prospectively enrolled an international cohort of patients undergoing routine fractional flow reserve (FFR) assessment for standard indications. Paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, contrast-based FFR, and FFR) were made...
January 13, 2017: Cardiovascular Diabetology
https://www.readbyqxmd.com/read/28047187/tu-h-campus-iep2-03-development-of-3d-printed-coronary-phantoms-for-in-vitro-ct-ffr-validation-using-data-from-320-detector-row-coronary-ct-angiography
#15
C Ionita, E Angel, D Mitsouras, S Rudin, D Bednarek, S Zaid, M Wilson, F Rybicki
PURPOSE: To validate Computed Tomography Fractional Flow Reserve (CT-FFR) measurements with accurate 3D printed coronary phantoms. METHODS: DICOM data from four phases in two patients imaged with a standard 320 × 0.5mm coronary CT acquisition (70-80% cardiac cycle) underwent semi-automated segmentation using a research workstation. Both patients had a >50% stenosis from the clinical image interpretation. Each volume was saved as a Stereo Lithographic (STL) file with 250 micron resolution...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28043881/simultaneously-evoked-auditory-potentials-seap-a-new-method-for-concurrent-measurement-of-cortical-and-subcortical-auditory-evoked-activity
#16
Christopher Slugocki, Daniel Bosnyak, Laurel J Trainor
Recent electrophysiological work has evinced a capacity for plasticity in subcortical auditory nuclei in human listeners. Similar plastic effects have been measured in cortically-generated auditory potentials but it is unclear how the two interact. Here we present Simultaneously-Evoked Auditory Potentials (SEAP), a method designed to concurrently elicit electrophysiological brain potentials from inferior colliculus, thalamus, and primary and secondary auditory cortices. Twenty-six normal-hearing adult subjects (mean 19...
December 31, 2016: Hearing Research
https://www.readbyqxmd.com/read/28013282/fractional-flow-reserve-derived-from-coronary-computed-tomography-angiography-diagnostic-performance-in-hypertensive-and-diabetic-patients
#17
Ashkan Eftekhari, James Min, Stephan Achenbach, Mohamed Marwan, Matthew Budoff, Jonathon Leipsic, Sara Gaur, Jesper Møller Jensen, Brian S Ko, Evald Høj Christiansen, Anne Kaltoft, Hans Erik Bøtker, Jens Flensted Jensen, Bjarne Linde Nørgaard
AIMS: Fractional flow reserve (FFR) derived from coronary computed tomography (FFRCT) has high diagnostic performance in stable coronary artery disease (CAD). The diagnostic performance of FFRCT in patients with hypertension (HTN) and diabetes (DM), who are at risk of microvascular impairment, is not known. METHODS AND RESULTS: We analysed the diagnostic performance of FFRCT, in patients (vessels) with DM (n = 16), HTN (n = 186), DM + HTN (n = 58) vs...
December 24, 2016: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28007742/invasive-minimal-microvascular-resistance-is-a-new-index-to-assess-microcirculatory-function-independent-of-obstructive-coronary-artery-disease
#18
Guus A de Waard, Sukhjinder S Nijjer, Martijn A van Lavieren, Nina W van der Hoeven, Ricardo Petraco, Tim P van de Hoef, Mauro Echavarría-Pinto, Sayan Sen, Peter M van de Ven, Paul Knaapen, Javier Escaned, Jan J Piek, Justin E Davies, Niels van Royen
BACKGROUND: Coronary microcirculatory dysfunction portends a poor cardiovascular outcome. Invasive assessment of microcirculatory dysfunction by coronary flow reserve (CFR) and hyperemic microvascular resistance (HMR) is affected by coronary artery disease (CAD). In this study we propose minimal microvascular resistance (mMR) as a new measure of microcirculatory dysfunction and aim to determine whether mMR is influenced by CAD. METHODS AND RESULTS: We obtained 482 simultaneous measurements of intracoronary Doppler flow velocity and pressure...
December 22, 2016: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28004229/patient-specific-3d-hemodynamics-modelling-of-left-coronary-artery-under-hyperemic-conditions
#19
Sarfaraz Kamangar, Irfan Anjum Badruddin, Kalimuthu Govindaraju, N Nik-Ghazali, A Badarudin, Girish N Viswanathan, N J Salman Ahmed, T M Yunus Khan
The purpose of this study is to investigate the effect of various degrees of percentage stenosis on hemodynamic parameters during the hyperemic flow condition. 3D patient-specific coronary artery models were generated based on the CT scan data using MIMICS-18. Numerical simulation was performed for normal and stenosed coronary artery models of 70, 80 and 90% AS (area stenosis). Pressure, velocity, wall shear stress and fractional flow reserve (FFR) were measured and compared with the normal coronary artery model during the cardiac cycle...
December 21, 2016: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/27998839/ffr-result-post-pci-is-suboptimal-in-long-diffuse-coronary-artery-disease
#20
Arvydas Baranauskas, Aaron Peace, Aleksandras Kibarskis, Joanne Shannon, Vytautas Abraitis, Vilhelmas Bajoras, Valdas Bilkis, Audrius Aidietis, Aleksandras Laucevicius, Giedrius Davidavicius
AIMS: The aim of this study was to evaluate the functional result immediately post PCI and at nine-month follow-up, and to ascertain how often a functionally optimal result of >0.95 can be achieved in long coronary lesions treated with long second- or newer-generation DES. METHODS AND RESULTS: Patients receiving DES measuring ≥30 mm with FFR value ≤0.8 were included in the study. Stent length was defined as long (30 to 49 mm; L-DES) and ultra-long (≥50 mm; UL-DES)...
December 20, 2016: EuroIntervention
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