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31.
32.
Thomas C. Crawford Alan Wimmer Sujoya Dey Nagib Chalfoun Darryl Wells Jean-Francois Sarrazin Michael Kuhne Melissa Frederick Krit Jongnarangsin Eric Good Aman Chugh Frank Bogun Frank Pelosi Jr. Fred Morady Hakan Oral 《Journal of interventional cardiac electrophysiology》2008,21(1):27-33
Background A better understanding of the mechanisms of recurrent atrial fibrillation (AF) after radiofrequency ablation of complex, fractionated
atrial electrograms (CFAEs) may be helpful for refining AF ablation strategies.
Methods and results Electrogram-guided ablation (EGA) was repeated in 30 consecutive patients (mean age = 59 ± 8 years) for recurrent paroxysmal
AF, 10 ± 4 months after the first ablation. During the first procedure, CFAEs were targeted without isolating all pulmonary
veins (PVs). During repeat ablation, all PVs and the superior vena cava (SVC) were mapped with a circular catheter and the
left atrium was mapped for CFAEs. EGA was performed until AF was rendered noninducible or all identified CFAEs were eliminated.
During repeat ablation, ≥1 PV tachycardia was found in 83 PVs in 29 of the 30 patients (97%). Among these 83 PVs, 63 (76%)
had not been completely isolated previously. During repeat ablation, drivers originating in a PV or PV antrum were identified
only after infusion of isoproterenol (20 μg/min) in 12 patients (40%). At 9 ± 4 months of follow-up after the repeat ablation
procedure, 21 of the 30 patients (70%) were free from recurrent AF and flutter without antiarrhythmic drugs.
Conclusions Recurrence of AF after EGA is usually due to PV tachycardias. Therefore, it may be preferable to systematically map and isolate
all PVs during the first procedure. High-dose isoproterenol may be helpful to identify AF drivers. 相似文献
33.
Purpose of Review
Multidetector row computed tomography (CT) allows noninvasive imaging of the heart and coronary arteries. The purpose of this review is to briefly summarize recent advances in CT hardware and software technology, and machine learning applications for cardiovascular imaging.Recent Findings
In the last decades, there have been significant improvements in CT hardware focusing on faster gantry rotation resulting in improved temporal resolution. Concurrent hardware improvements include improved spatial resolution and higher coverage of the patient, enabling faster acquisition. Advances in cardiac CT software include methods for measurement of noninvasive FFR, coronary plaque characterization, and adipose tissue characteristics around the heart. Machine learning approaches using cardiac CT have been shown to improve both risk of prognosis and lesion-specific ischemia.Summary
Recent advances in CT hardware and software have expanded the clinical utility of CT for cardiovascular imaging. In the next decades, continued advances can be anticipated in these areas, and in machine learning applications in cardiac CT, as they are incorporated into clinical routine for image acquisition, image analysis, and prediction of patient outcomes.34.
Vinod?K.?SharmaEmail author Chandresh?Chandel Raj?Kumar S.?S.?Dey Chander?Parkash Reeta?Bhatia M.?Mawliya 《Proceedings of the National Academy of Sciences, India. Section B.》2018,88(2):451-457
The present study reports the quantification of changes in the contents of plant pigments and ascorbic acid as influenced by the planting time and fruit picking stages in sweet pepper. The crop was planted on five different dates at 10 days interval in randomized block design under open field conditions in temperate area to quantify the changes which took place in the contents of plant pigments and ascorbic acid in green and red fruits. The results showed that the planting time and fruit picking stage had significant (p ≤ 0.05) influence on plant pigments and ascorbic acid contents in sweet pepper. The last week of May was observed as the optimal planting time when fruits exhibited higher contents of lycopene, β-carotene and ascorbic acid. The red fruit picking stage had significantly higher concentration of these phytonutrients than the green picking stage. In order to pick-up fruits at right stage and time with high plant pigments and ascorbic acid contents, these results would help meet out the increasing demand of sweet pepper quality fruits. 相似文献
35.
Eastin Jennifer Dey Dzifa Amissah-Arthur Maame-Boatemaa Chaudhuri Kaushik Jawad Ali 《Clinical rheumatology》2021,40(9):3439-3443
Clinical Rheumatology - A project aimed to develop and deliver a clinical training course in Accra, Ghana, to increase patient access to physicians trained in the diagnosis, treatment and... 相似文献
36.
Amir Ahmadi Jonathon Leipsic Kristian A. Øvrehus Sara Gaur Emilia Bagiella Brian Ko Damini Dey Gina LaRocca Jesper M. Jensen Hans Erik Bøtker Stephan Achenbach Bernard De Bruyne Bjarne L. Nørgaard Jagat Narula 《JACC: Cardiovascular Imaging》2018,11(4):521-530
Objectives
The aims of the present study were: 1) to investigate the contribution of the extent of luminal stenosis and other lesion composition-related factors in predicting invasive fractional flow reserve (FFR); and 2) to explore the distribution of various combinations of morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR.Background
In patients with stable ischemic heart disease, FFR-guided revascularization, as compared with medical therapy alone, is reported to improve outcomes. Because morphological characteristics are the basis of plaque rupture and acute coronary events, a relationship between FFR and lesion characteristics may exist.Methods
This is a subanalysis of NXT (HeartFlowNXT: HeartFlow Analysis of Coronary Blood Flow Using Coronary CT Angiography), a prospective, multicenter study of 254 patients (age 64 ± 10 years, 64% male) with suspected stable ischemic heart disease; coronary computed tomography angiography including plaque morphology assessment, invasive angiography, and FFR were obtained for 383 lesions. Ischemia was defined by invasive FFR ≤0.80. Computed tomography angiography–defined morphological characteristics of plaques and their vascular location were used in univariate and multivariate analyses to examine their predictive value for invasive FFR. The distribution of various combinations of plaque morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR were examined.Results
The percentage of luminal stenosis, low-attenuation plaque (LAP) or necrotic core volume, left anterior descending coronary artery territory, and the presence of multiple lesions per vessel were the predictors of FFR. When grouped on the basis of degree of luminal stenosis, FFR-negative lesions had consistently smaller LAP volumes compared with FFR-positive lesions. The distribution of plaque characteristics in lesions with normal and abnormal FFR demonstrated that whereas FFR-negative lesions excluded likelihood of stenotic plaques with moderate to high LAP volumes, only one-third of FFR-positive lesions demonstrated obstructive plaques with moderate to high LAP volumes.Conclusions
In addition to the severity of luminal stenosis, necrotic core volume is an independent predictor of FFR. The distribution of plaque characteristics among lesions with varying luminal stenosis and normal and abnormal FFR may explain the outcomes associated with FFR-guided therapy. 相似文献37.
A combination of techniques for in vivo transillumination, topical application of vasoactive agents, and direct microscopic observation of microcirculatory responses was utilized to evaluate the vasomotor actions of prostaglandins (PGs) E1, E2, F1α, F2α, A1, and A2 on rat urinary bladder arterioles and venules. The effects of PGE1 and histamine (HIS) on arteriolar responsiveness to norepinephrine (NE), serotonin (5-HT), and PGF2α were measured. Histochemical studies were completed to determine the primary site of prostaglandin (PG) metabolic deactivation in the urinary bladder. Arteriolar dilatation occurred with HIS, PGE1, PGE2, PGA1, PGA2, and PGF1α, all of which (with the exception of HIS) demonstrated significant dose-related responses. Overall, PGE1 and PGE2 were of greatest potency. Significant dose-related arteriolar constriction occurred with NE > PGF2α > 5-HT (in order of decreasing potency). HIS, PGE1, PGE2, and PGA1 produced significant venular dilatation; PGE1 and HIS were dose related. Only NE resulted in significant venoconstriction. Arteriolar responsiveness to NE and PGF2α decreased after pretreatment with PGE1 but was unchanged by HIS pretreatment, whereas application of 5-HT following pretreatment with PGE1 or HIS produced equivalent levels of arteriolar constriction. The primary site of deactivation of PGE1 was histochemically localized to bundles of smooth muscle fibers in the muscular coat of the rat urinary bladder wall. 相似文献
38.
Saha Soma Pal Dey Poushali Mitra Souvik 《Proceedings of the National Academy of Sciences, India. Section B.》2021,91(4):919-927
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Microbial association is considered as a significant innovation for land colonization of mosses. Plagiomnium... 相似文献
39.
Mohammed N. Meah Trisha Singh Michelle C. Williams Marc R. Dweck David E. Newby Piotr Slomka Philip D. Adamson Alastair J. Moss Damini Dey 《Journal of Cardiovascular Computed Tomography》2021,15(4):333-338
BackgroundThe ability to characterize and to quantify the extent of coronary artery disease has the potential to improve the prognostic capability of coronary computed tomography angiography. Although reproducible techniques have been described in those with mild coronary disease, this has yet to be assessed in patients with advanced disease.MethodsTwenty patients with known multivessel disease underwent repeated computed tomography coronary angiography, 2 weeks apart. Coronary artery segments were analysed using semi-automated software by two trained observers to determine intraobserver, interobserver and interscan reproducibility.ResultsOverall, 149 coronary arterial segments were analysed. There was excellent intraobserver and interobserver agreement for all plaque volume measurements (Lin’s coefficient 0.95 to 1.0). There were no substantial interscan differences (P ?> ?0.05 for all) for total (2063 ?± ?1246 ?mm3, mean of differences ?35.6 ?mm3), non-calcified (1795 ?± ?910 ?mm3, mean of differences ?4.3 ?mm3), calcified (298 ?± ?425 ?mm3, mean of differences ?31.3 ?mm3) and low-attenuation (13 ?± ?13 ?mm3, mean of differences ?2.6 ?mm3) plaque volumes. Interscan agreement was highest for total and noncalcified plaque volumes. Calcified and low-attenuation plaque (?236.6 to 174 ?mm3 and -15.8 to 10.5 ?mm3 respectively) had relatively wider 95% limits of agreement reflecting the lower absolute plaque volumes.ConclusionIn the presence of advanced coronary disease, semi-automated plaque quantification provides excellent reproducibility, particularly for total and non-calcified plaque volumes. This approach has major potential to assess change in disease over time and optimize risk stratification in patients with established coronary artery disease. 相似文献
40.
Todd C. Villines Subhi J. Al’Aref Daniele Andreini Marcus Y. Chen Andrew D. Choi Carlo N. De Cecco Damini Dey James P. Earls Maros Ferencik Heidi Gransar Harvey Hecht Jonathon A. Leipsic Michael T. Lu Mohamed Marwan Pál Maurovich-Horvat Edward Nicol Gianluca Pontone Jonathan Weir-McCall Gudrun M. Feuchtner 《Journal of Cardiovascular Computed Tomography》2021,15(2):180-189