keyword
MENU ▼
Read by QxMD icon Read
search

Darrel Francis

keyword
https://www.readbyqxmd.com/read/27885752/biventricular-paced-qrs-area-predicts-acute-hemodynamic-crt-response-better-than-qrs-duration-or-qrs-amplitudes
#1
Jan DE Pooter, Milad El Haddad, Marc DE Buyzere, Hernandez Alfonso Aranda, Richard Cornelussen, Berthold Stegemann, Christopher A Rinaldi, Maciej Sterlinski, Adam Sokal, Darrel P Francis, Luc Jordaens, Roland X Stroobandt, Frederic VAN Heuverswyn, Frank Timmermans
INTRODUCTION: Vectorcardiographic (VCG) QRS area of left bundle branch block (LBBB) predicts acute hemodynamic response in cardiac resynchronization therapy (CRT) patients. We hypothesized that changes in QRS area occurring with biventricular pacing (BV) might predict acute hemodynamic CRT response (AHR). METHODS AND RESULTS: VCGs of 624 BV paced electrocardiograms (25 LBBB patients with 35 different pacing configurations) were calculated according to Frank's orthogonal lead system...
November 25, 2016: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/27712778/mechanisms-of-myocardial-ischemia-in-hypertrophic-cardiomyopathy-insights-from-wave-intensity-analysis-and-magnetic-resonance
#2
Claire E Raphael, Robert Cooper, Kim H Parker, Julian Collinson, Vassilis Vassiliou, Dudley J Pennell, Ranil de Silva, Li Yueh Hsu, Anders M Greve, Sukh Nijjer, Chris Broyd, Aamir Ali, Jennifer Keegan, Darrel P Francis, Justin E Davies, Alun D Hughes, Andrew Arai, Michael Frenneaux, Rod H Stables, Carlo Di Mario, Sanjay K Prasad
BACKGROUND: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia. OBJECTIVES: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM. METHODS: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity...
October 11, 2016: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/27708281/the-fractal-heart-embracing-mathematics-in-the-cardiology-clinic
#3
REVIEW
Gabriella Captur, Audrey L Karperien, Alun D Hughes, Darrel P Francis, James C Moon
For clinicians grappling with quantifying the complex spatial and temporal patterns of cardiac structure and function (such as myocardial trabeculae, coronary microvascular anatomy, tissue perfusion, myocyte histology, electrical conduction, heart rate, and blood-pressure variability), fractal analysis is a powerful, but still underused, mathematical tool. In this Perspectives article, we explain some fundamental principles of fractal geometry and place it in a familiar medical setting. We summarize studies in the cardiovascular sciences in which fractal methods have successfully been used to investigate disease mechanisms, and suggest potential future clinical roles in cardiac imaging and time series measurements...
October 6, 2016: Nature Reviews. Cardiology
https://www.readbyqxmd.com/read/27599296/a-dock8-wip-wasp-complex-links-t-cell-receptors-to-the-actin-cytoskeleton
#4
Erin Janssen, Mira Tohme, Mona Hedayat, Marion Leick, Sudha Kumari, Narayanaswamy Ramesh, Michel J Massaad, Sumana Ullas, Veronica Azcutia, Christopher C Goodnow, Katrina L Randall, Qi Qiao, Hao Wu, Waleed Al-Herz, Dianne Cox, John Hartwig, Darrell J Irvine, Francis W Luscinskas, Raif S Geha
Wiskott-Aldrich syndrome (WAS) is associated with mutations in the WAS protein (WASp), which plays a critical role in the initiation of T cell receptor-driven (TCR-driven) actin polymerization. The clinical phenotype of WAS includes susceptibility to infection, allergy, autoimmunity, and malignancy and overlaps with the symptoms of dedicator of cytokinesis 8 (DOCK8) deficiency, suggesting that the 2 syndromes share common pathogenic mechanisms. Here, we demonstrated that the WASp-interacting protein (WIP) bridges DOCK8 to WASp and actin in T cells...
October 3, 2016: Journal of Clinical Investigation
https://www.readbyqxmd.com/read/27559818/resonance-as-the-mechanism-of-daytime-periodic-breathing-in-patients-with-heart-failure
#5
Scott A Sands, Yoseph Mebrate, Bradley A Edwards, Shamim Nemati, Charlotte H Manisty, Akshay S Desai, Andrew Wellman, Keith Willson, Darrel P Francis, James P Butler, Atul Malhotra
RATIONALE: In patients with chronic heart failure, daytime oscillatory breathing at rest is associated with high mortality risk. Experimental evidence, including exaggerated ventilatory responses to carbon dioxide (CO2) and prolonged circulation time, implicates the ventilatory control system and suggests feedback instability (loop gain>1) is responsible. However, daytime oscillatory patterns often appear remarkably irregular versus classical instability (Cheyne-Stokes respiration), suggesting our mechanistic understanding is limited...
August 25, 2016: American Journal of Respiratory and Critical Care Medicine
https://www.readbyqxmd.com/read/27448698/resolving-the-paradox-of-randomised-controlled-trials-and-observational-studies-comparing-multi-vessel-angioplasty-and-culprit-only-angioplasty-at-the-time-of-stemi
#6
Yousif Ahmad, Christopher Cook, Matthew Shun-Shin, Ashwin Balu, Daniel Keene, Sukhjinder Nijjer, Ricardo Petraco, Christopher S Baker, Iqbal S Malik, Michael F Bellamy, Amarjit Sethi, Ghada W Mikhail, Mahmud Al-Bustami, Masood Khan, Raffi Kaprielian, Rodney A Foale, Jamil Mayet, Justin E Davies, Darrel P Francis, Sayan Sen
BACKGROUND: Patients presenting with ST-elevation myocardial infarction commonly have multi-vessel coronary artery disease. After the culprit artery is treated, the optimal treatment strategy for the residual disease is not yet defined. Large observational studies suggest that treatment of residual disease should be deferred but smaller randomised controlled trials (RCTs) suggest multi-vessel primary percutaneous coronary intervention (MV-PPCI) at the time of STEMI is safe. We examine if allocation bias of high-risk patients could explain the conflicting results between observational studies and RCTs and aim to resolve the paradox between the two...
November 1, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27411361/cardiac-resynchronization-therapy-mechanisms-of-action-and-scope-for-further-improvement-in-cardiac-function
#7
Siana Jones, Joost Lumens, S M Afzal Sohaib, Judith A Finegold, Prapa Kanagaratnam, Mark Tanner, Edward Duncan, Philip Moore, Francisco Leyva, Mike Frenneaux, Mark Mason, Alun D Hughes, Darrel P Francis, Zachary I Whinnett
AIMS: Cardiac resynchronization therapy (CRT) may exert its beneficial haemodynamic effect by improving ventricular synchrony and improving atrioventricular (AV) timing. The aim of this study was to establish the relative importance of the mechanisms through which CRT improves cardiac function and explore the potential for additional improvements with improved ventricular resynchronization. METHODS AND RESULTS: We performed simulations using the CircAdapt haemodynamic model and performed haemodynamic measurements while adjusting AV delay, at low and high heart rates, in 87 patients with CRT devices...
July 13, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27389109/tyrosine-sulfated-v2-peptides-inhibit-hiv-1-infection-via-coreceptor-mimicry
#8
Raffaello Cimbro, Francis C Peterson, Qingbo Liu, Christina Guzzo, Peng Zhang, Huiyi Miao, Donald Van Ryk, Xavier Ambroggio, Darrell E Hurt, Luca De Gioia, Brian F Volkman, Michael A Dolan, Paolo Lusso
Tyrosine sulfation is a post-translational modification that facilitates protein-protein interaction. Two sulfated tyrosines (Tys173 and Tys177) were recently identified within the second variable (V2) loop of the major HIV-1 envelope glycoprotein, gp120, and shown to contribute to stabilizing the intramolecular interaction between V2 and the third variable (V3) loop. Here, we report that tyrosine-sulfated peptides derived from V2 act as structural and functional mimics of the CCR5 N-terminus and potently block HIV-1 infection...
August 2016: EBioMedicine
https://www.readbyqxmd.com/read/27294103/cardiovascular-risk-factors-from-early-life-predict-future-adult-cardiac-structural-and-functional-abnormalities-a-systematic-review-of-the-published-literature
#9
Arjun K Ghosh, Darrel P Francis, Nishi Chaturvedi, Diana Kuh, Jamil Mayet, Alun D Hughes, Rebecca J Hardy
BACKGROUND: Clinical practice evaluates cardiovascular risk based on current risk factor (RF) levels [Blood pressure (BP), body mass index (BMI) and glycaemic control] largely disregarding previous risk-factor history over the totality of the life course. RFs are related to contemporaneous echocardiographic measures of cardiac structure and function which in turn are independently related to cardiovascular morbidity and mortality in cross-sectional studies. However, the effect of lifetime or earlier RF history on future echocardiographic changes has never been systematically examined...
July 2014: Journal of Cardiology and Therapeutics
https://www.readbyqxmd.com/read/27232908/frame-rate-required-for-speckle-tracking-echocardiography-a-quantitative-clinical-study-with-open-source-vendor-independent-software
#10
Madalina Negoita, Massoud Zolgharni, Elham Dadkho, Matteo Pernigo, Michael Mielewczik, Graham D Cole, Niti M Dhutia, Darrel P Francis
OBJECTIVES: To determine the optimal frame rate at which reliable heart walls velocities can be assessed by speckle tracking. BACKGROUND: Assessing left ventricular function with speckle tracking is useful in patient diagnosis but requires a temporal resolution that can follow myocardial motion. In this study we investigated the effect of different frame rates on the accuracy of speckle tracking results, highlighting the temporal resolution where reliable results can be obtained...
September 1, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27124724/in-heart-failure-patients-with-left-bundle-branch-block-single-lead-multispot-left-ventricular-pacing-does-not-improve-acute-hemodynamic-response-to-conventional-biventricular-pacing-a-multicenter-prospective-interventional-non-randomized-study
#11
Maciej Sterliński, Adam Sokal, Radosław Lenarczyk, Frederic Van Heuverswyn, C Aldo Rinaldi, Marc Vanderheyden, Vladimir Khalameizer, Darrel Francis, Joeri Heynens, Berthold Stegemann, Richard Cornelussen
INTRODUCTION: Recent efforts to increase CRT response by multiSPOT pacing (MSP) from multiple bipols on the same left ventricular lead are still inconclusive. AIM: The Left Ventricular (LV) MultiSPOTpacing for CRT (iSPOT) study compared the acute hemodynamic response of MSP pacing by using 3 electrodes on a quadripolar lead compared with conventional biventricular pacing (BiV). METHODS: Patients with left bundle branch block (LBBB) underwent an acute hemodynamic study to determine the %change in LV+dP/dtmax from baseline atrial pacing compared to the following configurations: BiV pacing with the LV lead in a one of lateral veins, while pacing from the distal, mid, or proximal electrode and all 3 electrodes together (i...
2016: PloS One
https://www.readbyqxmd.com/read/27079914/ovarian-sparing-surgery-in-pediatric-benign-ovarian-tumors
#12
Paulette I Abbas, Jennifer E Dietrich, Jessica A Francis, Mary L Brandt, Darrell L Cass, Monica E Lopez
STUDY OBJECTIVE: To evaluate outcomes of children after ovarian-sparing surgery (OSS) for non-neoplastic and benign neoplastic ovarian lesions. DESIGN: Retrospective cohort study from January 2003 to January 2012. SETTING: Single, high-volume, tertiary care hospital. PARTICIPANTS: Children 18 years of age and younger. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Postoperative complications and tumor recurrence after OSS...
October 2016: Journal of Pediatric and Adolescent Gynecology
https://www.readbyqxmd.com/read/27076571/quantification-of-the-effect-of-pressure-wire-drift-on-the-diagnostic-performance-of-fractional-flow-reserve-instantaneous-wave-free-ratio-and-whole-cycle-pd-pa
#13
Christopher M Cook, Yousif Ahmad, Matthew J Shun-Shin, Sukhjinder Nijjer, Ricardo Petraco, Rasha Al-Lamee, Jamil Mayet, Darrel P Francis, Sayan Sen, Justin E Davies
BACKGROUND: Small drifts in intracoronary pressure measurements (±2 mm Hg) can affect stenosis categorization using pressure indices. This has not previously been assessed for fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and whole-cycle distal pressure/proximal pressure (Pd/Pa) indices. METHODS AND RESULTS: Four hundred forty-seven stenoses were assessed with FFR, iFR, and whole-cycle Pd/Pa. Cut point values for significance were predefined as ≤0...
April 2016: Circulation. Cardiovascular Interventions
https://www.readbyqxmd.com/read/27056972/midlife-blood-pressure-predicts-future-diastolic-dysfunction-independently-of-blood-pressure
#14
Arjun Kumar Ghosh, Alun David Hughes, Darrel Francis, Nishi Chaturvedi, Denis Pellerin, John Deanfield, Diana Kuh, Jamil Mayet, Rebecca Hardy
OBJECTIVES: High blood pressure (BP) is associated with diastolic dysfunction, but the consequence of elevated BP over the adult life course on diastolic function is unknown. We hypothesised that high BP in earlier adulthood would be associated with impaired diastolic function independent of current BP. METHODS: Participants in the Medical Research Council National Survey of Health and Development birth cohort (n=1653) underwent investigations including echocardiography at age 60-64 years...
September 1, 2016: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/27042321/distribution-of-lifespan-gain-from-primary-prevention-intervention
#15
Judith A Finegold, Matthew J Shun-Shin, Graham D Cole, Saman Zaman, Annette Maznyczka, Sameer Zaman, Rasha Al-Lamee, Siqin Ye, Darrel P Francis
OBJECTIVE: When advising patients about possible initiation of primary prevention treatment, clinicians currently do not have information on expected impact on lifespan, nor how much this increment differs between individuals. METHODS: First, UK cardiovascular and non-cardiovascular mortality data were used to calculate the mean lifespan gain from an intervention (such as a statin) that reduces cardiovascular mortality by 30%. Second, a new method was developed to calculate the probability distribution of lifespan gain...
2016: Open Heart
https://www.readbyqxmd.com/read/26987757/coronary-artery-disease-screen-or-treat
#16
EDITORIAL
Darrel P Francis, Graham D Cole
No abstract text is available yet for this article.
March 17, 2016: BMJ: British Medical Journal
https://www.readbyqxmd.com/read/26874378/oxygen-uptake-efficiency-slope-and-breathing-reserve-not-anaerobic-threshold-discriminate-between-patients-with-cardiovascular-disease-over-chronic-obstructive-pulmonary-disease
#17
Anthony Barron, Darrel P Francis, Jamil Mayet, Ralf Ewert, Anne Obst, Mark Mason, Sarah Elkin, Alun D Hughes, Roland Wensel
OBJECTIVES: The study sought to compare the relative discrimination of various cardiopulmonary exercise testing (CPX) variables between cardiac and respiratory disease. BACKGROUND: CPX testing is used in many cardiorespiratory diseases. However, discrimination of cardiac and respiratory dysfunction can be problematic. Anaerobic threshold (AT) and oxygen-uptake to work-rate relationship (VO2/WR slope) have been proposed as diagnostic of cardiac dysfunction, but multiple variables have not been compared...
April 2016: JACC. Heart Failure
https://www.readbyqxmd.com/read/26787669/diagnostic-role-of-head-up-tilt-test-in-patients-with-cough-syncope
#18
Roberto Mereu, Patricia Taraborrelli, Arunashis Sau, Alessandro Di Toro, Sandra Halim, Sajad Hayat, Luciano Bernardi, Darrel P Francis, Richard Sutton, Phang Boon Lim
AIMS: The aim of this study was to describe the head-up tilt (HUT) test and carotid sinus massage (CSM) responses, and the occurrence of syncope with coughing during HUT in a large cohort of patients. METHODS AND RESULTS: A total of 5133 HUT were retrospectively analysed to identify patients with cough syncope. Head-up tilt followed by CSM were performed. Patients were made to cough on two separate occasions in an attempt to reproduce typical clinical symptoms on HUT...
August 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/26758193/quantifying-the-3-biases-that-lead-to-unintentional-overestimation-of-the-blood-pressure-lowering-effect-of-renal-denervation
#19
REVIEW
James P Howard, Matthew J Shun-Shin, Adam Hartley, Deepak L Bhatt, Henry Krum, Darrel P Francis
BACKGROUND: Studies of renal denervation report disparate results. Meta-analysis by trial design may allow quantitative estimation of sources and magnitude of biases in denervation studies. METHODS AND RESULTS: One hundred forty nonrandomized, 6 randomized open-label, and 2 randomized blinded studies were analyzed for 2 outcomes: (1) blood pressure changes for nonrandomized, open-label randomized, and blinded studies; and (2) quantification of 3 biases potentially contributing to apparent antihypertensive effects: (a) regression to the mean, (b) asymmetrical data handling, and (c) true blood pressure drops caused by something other than the tested therapy (confounding)...
January 2016: Circulation. Cardiovascular Quality and Outcomes
https://www.readbyqxmd.com/read/26683900/estimation-of-coronary-wave-intensity-analysis-using-noninvasive-techniques-and-its-application-to-exercise-physiology
#20
COMPARATIVE STUDY
Christopher J Broyd, Sukhjinder Nijjer, Sayan Sen, Ricardo Petraco, Siana Jones, Rasha Al-Lamee, Nicolas Foin, Mahmud Al-Bustami, Amarjit Sethi, Raffi Kaprielian, Punit Ramrakha, Masood Khan, Iqbal S Malik, Darrel P Francis, Kim Parker, Alun D Hughes, Ghada W Mikhail, Jamil Mayet, Justin E Davies
Wave intensity analysis (WIA) has found particular applicability in the coronary circulation where it can quantify traveling waves that accelerate and decelerate blood flow. The most important wave for the regulation of flow is the backward-traveling decompression wave (BDW). Coronary WIA has hitherto always been calculated from invasive measures of pressure and flow. However, recently it has become feasible to obtain estimates of these waveforms noninvasively. In this study we set out to assess the agreement between invasive and noninvasive coronary WIA at rest and measure the effect of exercise...
March 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
keyword
keyword
108094
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"