| 1. |
- Allencherril, Joseph, et al.
(författare)
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Appropriateness of anteroseptal myocardial infarction nomenclature evaluated by late gadolinium enhancement cardiovascular magnetic resonance imaging
- 2018
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736. ; 51:2, s. 218-223
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Tidskriftsartikel (refereegranskat)abstract
- Background: In traditional literature, it appears that "anteroseptal" MIs with Q waves in V1-V3 involve basal anteroseptal segments although studies have questioned this belief. Methods: We studied patients with first acute anterior Q-wave (>. 30. ms) MI. All underwent late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI). Results: Those with Q waves in V1-V2 (n = 7) evidenced LGE >. 50% in 0%, 43%, 43%, 57%, and 29% of the basal anteroseptal, mid anteroseptal, apical anterior, apical septal segments, and apex, respectively. Patients with Q waves in V1-V3 (n = 14), evidenced involvement was 14%, 43%, 43%, 50%, and 7% of the same respective segments. In those with extensive anterior Q waves (n = 7), involvement was 0%, 71%, 57%, 86%, and 86%. Conclusions: Q-wave MI in V1-V2/V3 primarily involves mid- and apical anterior and anteroseptal segments rather than basal segments. Data do not support existence of isolated basal anteroseptal or septal infarction. "Anteroapical infarction" is a more appropriate term than "anteroseptal infarction.".
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| 2. |
- Allencherril, Joseph, et al.
(författare)
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Correlation of anteroseptal ST elevation with myocardial infarction territories through cardiovascular magnetic resonance imaging
- 2018
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736. ; 51:4, s. 563-568
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Tidskriftsartikel (refereegranskat)abstract
- Background: Anteroseptal ST elevation myocardial infarction (STEMI) is traditionally defined on the electrocardiogram (ECG) by ST elevation (STE) in leads V1-V3, with or without involvement of lead V4. It is commonly taught that such infarcts affect the basal anteroseptal myocardial segment. While there are suggestions in the literature that Q waves limited to V1-V4 represent predominantly apical infarction, none have evaluated anteroseptal ST elevation territories. We compared the distribution of the myocardium at risk (MaR) in STEMI patients presenting with STE limited to V1-V4 and those with more extensive STE (V1-V6). Methods: We identified patients in the MITOCARE study presenting with a first acute STEMI and new STE in at least two contiguous anterior leads from V1 to V6. Patients underwent cardiac magnetic resonance (CMR) imaging three to five days after acute infarction. Results: Thirty-two patients met inclusion criteria. In patients with STE in V1-V4 (n = 20), myocardium at risk (MaR) > 50% was seen in 0%, 85%, 75%, 100%, and 90% in the basal anteroseptal, mid anteroseptal, apical anterior, apical septal segments, and apex, respectively. The group with STE in V1-V6 (n = 12), MaR > 50% was seen in 8%, 83%, 83%, 92%, and 83% of the same segments. Conclusions: Patients with acute STEMI and STE in leads V1-V4, exhibit MaR in predominantly apical territories and rarely in the basal anteroseptum. We found no evidence to support existence of isolated basal anteroseptal or septal STEMI. “Anteroapical” infarction is a more precise description than “anteroseptal” infarction for acute STEMI patients exhibiting STE in V1-V4.
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| 3. |
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| 4. |
- Atar, Dan, et al.
(författare)
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Rationale and Design of the 'MITOCARE' Study: A Phase II, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety and Efficacy of TRO40303 for the Reduction of Reperfusion Injury in Patients Undergoing Percutaneous Coronary Intervention for Acute Myocardial Infarction
- 2012
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Ingår i: Cardiology. - : S. Karger AG. - 1421-9751 .- 0008-6312. ; 123:4, s. 201-207
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Tidskriftsartikel (refereegranskat)abstract
- Treatment of acute ST-elevation myocardial infarction (STEMI) by reperfusion using percutaneous coronary intervention (PCI) or thrombolysis has provided clinical benefits; however, it also induces considerable cell death. This process is called reperfusion injury. The continuing high rates of mortality and heart failure after acute myocardial infarction (AMI) emphasize the need for improved strategies to limit reperfusion injury and improve clinical outcomes. The objective of this study is to assess safety and efficacy of TRO40303 in limiting reperfusion injury in patients treated for STEMI. TRO40303 targets the mitochondrial permeability transition pore, a promising target for the prevention of reperfusion injury. This multicenter, double-blind study will randomize patients with STEMI to TRO40303 or placebo administered just before balloon inflation or thromboaspiration during PCI. The primary outcome measure will be reduction in infarct size (assessed as plasma creatine kinase and troponin I area under the curve over 3 days). The main secondary endpoint will be infarct size normalized to the myocardium at risk (expressed by the myocardial salvage index assessed by cardiac magnetic resonance). The study is being financed under an EU-FP7 grant and conducted under the auspices of the MITOCARE research consortium, which includes experts from clinical and basic research centers, as well as commercial enterprises, throughout Europe. Results from this study will contribute to a better understanding of the complex pathophysiology underlying myocardial injury after STEMI. The present paper describes the rationale, design and the methods of the trial. Copyright (c) 2012 S. Karger AG, Basel
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| 5. |
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| 6. |
- Fakhri, Yama, et al.
(författare)
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Electrocardiographic scores of severity and acuteness of myocardial ischemia predict myocardial salvage in patients with anterior ST-segment elevation myocardial infarction
- 2018
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736. ; 51:2, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- Background: Terminal "QRS distortion" on the electrocardiogram (ECG) (based on Sclarovsky-Birnbaum's Grades of Ischemia Score) is a sign of severe ischemia, associated with adverse cardiovascular outcome in ST-segment elevation myocardial infarction (STEMI). In addition, ECG indices of the acuteness of ischemia (based on Anderson-Wilkins Acuteness Score) indicate myocardial salvage potential. We assessed whether severe ischemia with or without acute ischemia is predictive of infarct size (IS), myocardial salvage index (MSI) and left ventricular ejection fraction (LVEF) in anterior versus inferior infarct locations. Methods: In STEMI patients, the severity and acuteness scores were obtained from the admission ECG. Based on the ECG patients were assigned with severe or non-severe ischemia and acute or non-acute ischemia. Cardiac magnetic resonance (CMR) was performed 2-6. days after primary percutaneous coronary intervention (pPCI). LVEF was measured by echocardiography 30. days after pPCI. Results: ECG analysis of 85 patients with available CMR resulted in 20 (23%) cases with severe and non-acute ischemia, 43 (51%) with non-severe and non-acute ischemia, 17 (20%) with non-severe and acute ischemia, and 5 (6%) patients with severe and acute ischemia. In patients with anterior STEMI (n = 35), ECG measures of severity and acuteness of ischemia identified significant and stepwise differences in myocardial damage and function. Patients with severe and non-acute ischemia had the largest IS, smallest MSI and lowest LVEF. In contrast, no difference was observed in patients with inferior STEMI (n = 50). Conclusions: The applicability of ECG indices of severity and acuteness of myocardial ischemia to estimate myocardial damage and salvage potential in STEMI patients treated with pPCI, is confined to anterior myocardial infarction.
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| 7. |
- Jakobsson, Martin, et al.
(författare)
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Arctic Ocean glacial history
- 2014
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 92, s. 40-67
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Forskningsöversikt (refereegranskat)abstract
- While there are numerous hypotheses concerning glacial interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the present state-of-the-art knowledge gained from field work and chronological studies, and with a specific focus on ice-sheet extent and environmental conditions during the Last Glacial Maximum (LGM). The maximum Quaternary extension of ice sheets is discussed and compared to LGM. We bring together recent results from the circum-Arctic continental margins and the deep central basin; extent of ice sheets and ice streams bordering the Arctic Ocean as well as evidence for ice shelves extending into the central deep basin. Discrepancies between new results and published LGM ice-sheet reconstructions in the high Arctic are highlighted and outstanding questions are identified. Finally, we address the ability to simulate the Arctic Ocean ice sheet complexes and their dynamics, including ice streams and ice shelves, using presently available ice-sheet models. Our review shows that while we are able to firmly reject some of the earlier hypotheses formulated to describe Arctic Ocean glacial conditions, we still lack information from key areas to compile the holistic Arctic Ocean glacial history.
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| 8. |
- Kjaer, Kurt, et al.
(författare)
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Eurasian ice-sheet interaction in northwestern Russia throughout the late Quaternary
- 2006
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Ingår i: Boreas. - : Wiley. - 1502-3885 .- 0300-9483. ; 35:3, s. 444-475
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Tidskriftsartikel (refereegranskat)abstract
- Sediment successions from the Kanin Peninsula and Chyoshskaya Bay in northwestern Russia contain information on the marginal behaviour of all major ice sheets centred in Scandinavia, the Barents Sea and the Kara Sea during the Eemian - Weichselian. Extensive luminescence dating of regional lithostratigraphical units, supported by biostratigraphical evidence, identifies four major ice advances at 100 - 90, 70 - 65, 55 - 45 and 20 - 18 kyr ago interbedded with lacustrine, glaciolacustrine and marine sediments. The widespread occurrence of marine tidal sediments deposited c. 65 - 60 kyr ago allows a stratigraphical division of the Middle Weichselian Barents Sea and Kara Sea ice sheets into two shelf-based glaciations separated by almost complete deglaciation. The first ice dispersal centre was in the Barents Sea and thereafter in the Kara Sea. It is possible to extract both flow patterns from ice marginal landforms inside the southward termination. Accordingly, it is proposed that the Markhida line and its western continuation are asynchronous and originate from two separate glaciations before and after the marine transgression. The marine sedimentation occurred during a eustatic sea-level rise of up to 20 m/1000 yr, i. e. the Mezen Transgression. We speculate that the rapid eustatic sea-level rise triggered a collapse of the Barents Sea Ice Sheet at the MIS ( Marine Isotope Stage) 4 to 3 transition. This is motivated by lack of an early marine highstand, the timing of events, and the marginal position of Arkhangelsk relative to open marine conditions.
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| 9. |
- Kjær, Kurt H., et al.
(författare)
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Glacier response to the Little Ice Age during the Neoglacial cooling in Greenland
- 2022
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Ingår i: Earth-Science Reviews. - : Elsevier. - 0012-8252 .- 1872-6828. ; 227
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Tidskriftsartikel (refereegranskat)abstract
- In the Northern Hemisphere, an insolation driven Early to Middle Holocene Thermal Maximum was followed by a Neoglacial cooling that culminated during the Little Ice Age (LIA). Here, we review the glacier response to this Neoglacial cooling in Greenland. Changes in the ice margins of outlet glaciers from the Greenland Ice Sheet as well as local glaciers and ice caps are synthesized Greenland-wide. In addition, we compare temperature reconstructions from ice cores, elevation changes of the ice sheet across Greenland and oceanographic reconstructions from marine sediment cores over the past 5,000 years. The data are derived from a comprehensive review of the literature supplemented with unpublished reports. Our review provides a synthesis of the sensitivity of the Greenland ice margins and their variability, which is critical to understanding how Neoglacial glacier activity was interrupted by the current anthropogenic warming. We have reconstructed three distinct periods of glacier expansion from our compilation: two older Neoglacial advances at 2,500 – 1,700 yrs. BP (Before Present = 1950 CE, Common Era) and 1,250 – 950 yrs. BP; followed by a general advance during the younger Neoglacial between 700-50 yrs. BP, which represents the LIA. There is still insufficient data to outline the detailed spatio-temporal relationships between these periods of glacier expansion. Many glaciers advanced early in the Neoglacial and persisted in close proximity to their present-day position until the end of the LIA. Thus, the LIA response to Northern Hemisphere cooling must be seen within the wider context of the entire Neoglacial period of the past 5,000 years. Ice expansion appears to be closely linked to changes in ice sheet elevation, accumulation, and temperature as well as surface-water cooling in the surrounding oceans. At least for the two youngest Neoglacial advances, volcanic forcing triggering a sea-ice /ocean feedback, could explain their initiation. There are probably several LIA glacier fluctuations since the first culmination close to 1250 CE (Common Era) and available data suggests ice culminations in the 1400s, early to mid-1700s and early to mid-1800s CE. The last LIA maxima lasted until the present deglaciation commenced around 50 yrs. BP (1900 CE). The constraints provided here on the timing and magnitude of LIA glacier fluctuations delivers a more realistic background validation for modelling future ice sheet stability.
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| 10. |
- Lambeck, Kurt, et al.
(författare)
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Constraints on the Late Saalian to early Middle Weichselian ice sheet of Eurasia from field data and rebound modelling
- 2006
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Ingår i: Boreas. - : Wiley. - 1502-3885 .- 0300-9483. ; 35:3, s. 539-575
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Tidskriftsartikel (refereegranskat)abstract
- Using glacial rebound models we have inverted observations of crustal rebound and shoreline locations to estimate the ice thickness for the major glaciations over northern Eurasia and to predict the palaeo-topography from late MIS-6 ( the Late Saalian at c. 140 kyr BP) to MIS-4e ( early Middle Weichselian at c. 64 kyr BP). During the Late Saalian, the ice extended across northern Europe and Russia with a broad dome centred from the Kara Sea to Karelia that reached a maximum thickness of c. 4500 m and ice surface elevation of c. 3500 m above sea level. A secondary dome occurred over Finland with ice thickness and surface elevation of 4000 m and 3000 m, respectively. When ice retreat commenced, and before the onset of the warm phase of the early Eemian, extensive marine flooding occurred from the Atlantic to the Urals and, once the ice retreated from the Urals, to the Taymyr Peninsula. The Baltic - White Sea connection is predicted to have closed at about 129 kyr BP, although large areas of arctic Russia remained submerged until the end of the Eemian. During the stadials (MIS-5d, 5b, 4) the maximum ice was centred over the Kara - Barents Seas with a thickness not exceeding c. 1200 m. Ice-dammed lakes and the elevations of sills are predicted for the major glacial phases and used to test the ice models. Large lakes are predicted for west Siberia at the end of the Saalian and during MIS-5d, 5b and 4, with the lake levels, margin locations and outlets depending inter alia on ice thickness and isostatic adjustment. During the Saalian and MIS-5d, 5b these lakes overflowed through the Turgay pass into the Aral Sea, but during MIS-4 the overflow is predicted to have occurred north of the Urals. West of the Urals the palaeo-lake predictions are strongly controlled by whether the Kara Ice Sheet dammed the White Sea. If it did, then the lake levels are controlled by the topography of the Dvina basin with overflow directed into the Kama-Volga river system. Comparisons of predicted with observed MIS-5b lake levels of Komi Lake favour models in which the White Sea was in contact with the Barents Sea.
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