The Experts below are selected from a list of 9519 Experts worldwide ranked by ideXlab platform
Matthias G Friedrich - One of the best experts on this subject based on the ideXlab platform.
-
why edema is a matter of the heart
Circulation-cardiovascular Imaging, 2017Co-Authors: Matthias G FriedrichAbstract:> I did then what I knew how to do. Now that I know better, I do better. > > —Maya Angelou Myocardial tissue characterization using cardiovascular magnetic resonance (CMR) has become an essential tool for diagnostic and therapeutic decision-making in patients with acute or chronic myocardial disease because it provides unique and relevant information. This is most evident in patients with suspected cardiomyopathy or myocardial involvement in systemic disease, such as amyloidosis, iron overload, or sarcoidosis. Suspected myocarditis is one of the most frequent indications for CMR scans and helps not only by confirming or refuting the disease but can also avoid other, more costly, or invasive diagnostic procedures.1 The established set of CMR criteria for the presence of myocardial inflammation, also known as the Lake Louise Criteria, yield a good diagnostic accuracy with a high negative predictive value.2 Their diagnostic targets are myocardial edema (T2-weighted images), hyperemia/capillary leak (early gadolinium enhancement), and Irreversible Injury (necrosis, scar; late gadolinium enhancement). Table 1 shows the likelihood of CMR criteria in various settings. View this table: Table 1. Typical Presence of CMR Findings in Patients With Different Forms and Stages of Myocarditis See Article by von Knobelsdorff-Brenkenhoff et al Recently, novel CMR criteria have gained significant interest, especially native T2, native T1, postcontrast T1, and the extracellular volume, the latter being calculated from native and postcontrast T1 mapping results. All these use mapping to measure myocardial proton relaxation times, which reflect tissue pathology and are less sensitive to several problems of signal intensity analyses of single images.3 Myocardial T1 has been found to be altered by …
-
edema as a very early marker for acute myocardial ischemia a cardiovascular magnetic resonance study
Journal of the American College of Cardiology, 2009Co-Authors: Hassan Abdelaty, Myra S Cocker, Cheryl Meek, John V Tyberg, Matthias G FriedrichAbstract:Objectives This study was designed to determine whether imaging myocardial edema would identify acute myocardial ischemia before Irreversible Injury takes place. Background Early identification of acute myocardial ischemia is a diagnostic challenge. Methods We studied 15 dogs with serial T2-weighted and cine imaging at baseline, during transient coronary occlusion of up to 35 min, and after reperfusion in a 1.5-T magnetic resonance imaging system. Late gadolinium enhancement and troponin measurements were used to assess for the presence of Irreversible Injury. Myocardial water content was measured to assess myocardial edema. Results We consistently observed a transmural area of high T2signal intensity matching areas with new onset regional akinesia 28 ± 4 min after experimental coronary artery occlusion. At this time, the contrast-to-noise ratio between the ischemic and remote myocardium had significantly increased from 1.0 ± 2.0 to 12.8 ± 9.6 (p Conclusions We provide the first evidence that T2-weighted cardiovascular magnetic resonance imaging of edema detects acute ischemic myocyte Injury before the onset of Irreversible Injury. T2-weighted cardiovascular magnetic resonance imaging may serve as a very useful diagnostic marker in clinical settings such as unstable angina or evolving infarction.
-
the salvaged area at risk in reperfused acute myocardial infarction as visualized by cardiovascular magnetic resonance
Journal of the American College of Cardiology, 2008Co-Authors: Matthias G Friedrich, Jeanette Schulzmenger, Hassan Abdelaty, Daniel Messroghli, Andrew J Taylor, Rainer DietzAbstract:Objectives We aimed to characterize the tissue changes within the perfusion bed of infarct-related vessels in patients with acutely reperfused myocardial infarction (MI) using cardiovascular magnetic resonance (CMR). Background Even in successful early revascularization, intermittent coronary artery occlusion affects the entire perfusion bed, also referred to as the area at risk. The extent of the salvaged area at risk contains prognostic information and may serve as a therapeutic target. Cardiovascular magnetic resonance can visualize the area at risk; yet, clinical data have been lacking. Methods We studied 92 patients with acute MI and successful reperfusion 3 ± 3 days after the event and 18 healthy control subjects. Breath-hold T2-weighted and contrast-enhanced (“late enhancement”) CMR were used to visualize the reversible and the Irreversible myocardial Injury, respectively. Results All reperfused infarcts consistently revealed a pattern with both reversibly and irreversibly injured tissue. In contrast to the infarcted area, reversible damage was always transmural, exceeding the infarct in its maximal extent by 16 ± 11% (absolute difference of the area of maximal infarct expansion 38 ± 15% vs. 22 ± 10%; p Conclusions In patients with reperfused MI, CMR visualizes both reversible and Irreversible Injury. This allows for quantifying the extent of the salvaged area after revascularization as an important parameter for clinical decision-making and research.
Hassan Abdelaty - One of the best experts on this subject based on the ideXlab platform.
-
edema as a very early marker for acute myocardial ischemia a cardiovascular magnetic resonance study
Journal of the American College of Cardiology, 2009Co-Authors: Hassan Abdelaty, Myra S Cocker, Cheryl Meek, John V Tyberg, Matthias G FriedrichAbstract:Objectives This study was designed to determine whether imaging myocardial edema would identify acute myocardial ischemia before Irreversible Injury takes place. Background Early identification of acute myocardial ischemia is a diagnostic challenge. Methods We studied 15 dogs with serial T2-weighted and cine imaging at baseline, during transient coronary occlusion of up to 35 min, and after reperfusion in a 1.5-T magnetic resonance imaging system. Late gadolinium enhancement and troponin measurements were used to assess for the presence of Irreversible Injury. Myocardial water content was measured to assess myocardial edema. Results We consistently observed a transmural area of high T2signal intensity matching areas with new onset regional akinesia 28 ± 4 min after experimental coronary artery occlusion. At this time, the contrast-to-noise ratio between the ischemic and remote myocardium had significantly increased from 1.0 ± 2.0 to 12.8 ± 9.6 (p Conclusions We provide the first evidence that T2-weighted cardiovascular magnetic resonance imaging of edema detects acute ischemic myocyte Injury before the onset of Irreversible Injury. T2-weighted cardiovascular magnetic resonance imaging may serve as a very useful diagnostic marker in clinical settings such as unstable angina or evolving infarction.
-
cardiac magnetic resonance monitors reversible and Irreversible myocardial Injury in myocarditis
Jacc-cardiovascular Imaging, 2009Co-Authors: Anja Zagrosek, Hassan Abdelaty, Daniel Messroghli, Rainer Dietz, Philipp Boye, Ralf Wassmuth, Wolfgang Utz, Andre Rudolph, Steffen Bohl, Jeanette SchulzmengerAbstract:Objectives We sought to assess the value of cardiac magnetic resonance (CMR) to monitor the spectrum of myocarditis-related injuries over the course of the disease. Background Myocarditis is associated with a wide range of myocardial tissue injuries, both reversible and Irreversible. Differentiating these types of injuries is a clinical demand. Methods We studied 36 patients (31 males, age 33 ± 14 years) hospitalized with myocarditis during the acute phase and 18 ± 10 months thereafter. CMR was performed on 2 1.5T scanners and included the following techniques: steady-state free precession (to assess left ventricular function and volumes), T2-weighted (myocardial edema), early (global relative enhancement [gRE], reflecting increased capillary leakage) and late T1-weighted after gadolinium-DTPA injection (late gadolinium enhancement [LGE], reflecting Irreversible Injury). Results In the acute phase, T2 ratio was elevated in 86%, gRE in 80%, and LGE was present in 63%. At follow-up, ejection fraction increased from 56 ± 8% to 62 ± 7% (p Conclusions A comprehensive CMR approach is a useful tool to monitor the reversible and Irreversible myocardial tissue injuries over the course of myocarditis and to differentiate acute from healed myocarditis in patients with still-preserved ejection fraction.
-
the salvaged area at risk in reperfused acute myocardial infarction as visualized by cardiovascular magnetic resonance
Journal of the American College of Cardiology, 2008Co-Authors: Matthias G Friedrich, Jeanette Schulzmenger, Hassan Abdelaty, Daniel Messroghli, Andrew J Taylor, Rainer DietzAbstract:Objectives We aimed to characterize the tissue changes within the perfusion bed of infarct-related vessels in patients with acutely reperfused myocardial infarction (MI) using cardiovascular magnetic resonance (CMR). Background Even in successful early revascularization, intermittent coronary artery occlusion affects the entire perfusion bed, also referred to as the area at risk. The extent of the salvaged area at risk contains prognostic information and may serve as a therapeutic target. Cardiovascular magnetic resonance can visualize the area at risk; yet, clinical data have been lacking. Methods We studied 92 patients with acute MI and successful reperfusion 3 ± 3 days after the event and 18 healthy control subjects. Breath-hold T2-weighted and contrast-enhanced (“late enhancement”) CMR were used to visualize the reversible and the Irreversible myocardial Injury, respectively. Results All reperfused infarcts consistently revealed a pattern with both reversibly and irreversibly injured tissue. In contrast to the infarcted area, reversible damage was always transmural, exceeding the infarct in its maximal extent by 16 ± 11% (absolute difference of the area of maximal infarct expansion 38 ± 15% vs. 22 ± 10%; p Conclusions In patients with reperfused MI, CMR visualizes both reversible and Irreversible Injury. This allows for quantifying the extent of the salvaged area after revascularization as an important parameter for clinical decision-making and research.
Kibong Kim - One of the best experts on this subject based on the ideXlab platform.
-
serial ultrastructural evaluation of myocardial ischemic Injury after infusion of del nido cardioplegia in the human heart
The Journal of Thoracic and Cardiovascular Surgery, 2020Co-Authors: Joon Chul Jung, Seongik Kim, Ho Young Hwang, Suk Ho Sohn, Jae Woong Choi, Jinhaeng Chung, Jeongwook Seo, Kibong KimAbstract:OBJECTIVES The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic Injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope. METHODS Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = Irreversible). RESULTS At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic Injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and Irreversible Injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic Injury score of mitochondria and ischemic time (P < .001). Most nuclei showed moderate to severe ischemic Injury at every time point (61.0%-85.2%). A significant linear correlation was also found between the average ischemic Injury score of nuclei and ischemic time (P < .001). CONCLUSIONS Myocardial ischemic Injury progresses gradually, and Irreversible ischemic Injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.
-
serial ultrastructural evaluation of myocardial ischemic Injury after infusion of del nido cardioplegia in the human heart
The Journal of Thoracic and Cardiovascular Surgery, 2020Co-Authors: Joon Chul Jung, Seongik Kim, Ho Young Hwang, Suk Ho Sohn, Jae Woong Choi, Jinhaeng Chung, Jeongwook Seo, Kibong KimAbstract:Abstract Objectives The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic Injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope. Methods Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = Irreversible). Results At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic Injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and Irreversible Injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic Injury score of mitochondria and ischemic time (P Conclusions Myocardial ischemic Injury progresses gradually, and Irreversible ischemic Injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.
Robert M Judd - One of the best experts on this subject based on the ideXlab platform.
-
myocardial magnetic resonance imaging contrast agent concentrations after reversible and Irreversible ischemic Injury
Circulation, 2002Co-Authors: Wolfgang G Rehwald, David S Fieno, Ennling Chen, Robert M JuddAbstract:Background— Discrepant reports have been published recently regarding the relationship of contrast-enhanced magnetic resonance image intensities to reversible and Irreversible ischemic Injury. Unlike image intensities, contrast agent concentrations provide data independent of the MRI technique. We used electron probe x-ray microanalysis (EPXMA) to simultaneously examine concentrations of Gd, Na, P, S, Cl, K, and Ca over a range of myocardial injuries. Methods and Results— Reversible and Irreversible Injury were studied in 38 rabbits divided into 4 groups defined by occlusion and reperfusion time, as well as time the animals were euthanized. Gd-DTPA was administered, and the hearts were excised and rapidly frozen, cryosectioned, freeze-dried, and examined by EPXMA in up to 3 regions: remote, infarcted, and at risk but not infarcted. Infarcted regions were defined by anti-myoglobin antibody or triphenyltetrazolium chloride staining. Regions at risk were defined by fluorescent microparticles administered dur...
-
contrast enhanced magnetic resonance imaging of myocardium at risk distinction between reversible and Irreversible Injury throughout infarct healing
Journal of the American College of Cardiology, 2000Co-Authors: David S Fieno, Ennling Chen, Francis J Klocke, Jon W Lomasney, Robert M JuddAbstract:Abstract OBJECTIVES We sought to determine the relationship of delayed hyperenhancement by contrast magnetic resonance imaging (MRI) to viable and nonviable myocardium within the region at risk throughout infarct healing. BACKGROUND The relationship of delayed MRI contrast enhancement patterns to injured but viable myocardium within the ischemic bed at risk has not been established. METHODS We compared in vivo and ex vivo MRI contrast enhancement to histopathologic tissue sections encompassing the entire left ventricle in dogs (n = 24) subjected to infarction with (n = 12) and without (n = 12) reperfusion at 4 h, 1 day, 3 days, 10 days, 4 weeks and 8 weeks. In vivo MR imaging was performed 30 min after contrast injection. RESULTS The sizes and shapes of in vivo myocardial regions of elevated image intensity (828 ± 132% of remote) were the same as those observed ex vivo (241 slices, r = 0.99, bias = 0.05 ± 1.6% of left ventricle [LV]). Comparison of ex vivo MRI to triphenyltetrazolim chloride–stained sections demonstrated that the spatial extent of hyperenhancement was the same as the spatial extent of infarction at every stage of healing (510 slices, lowest r = 0.95, largest bias = 1.7 ± 2.9% of LV). Conversely, hyperenhanced regions were smaller than the ischemic bed at risk defined by fluorescent microparticles at every stage of healing (239 slices, 35 ± 24% of risk region, p CONCLUSIONS Delayed contrast enhancement by MRI distinguishes between viable and nonviable regions within the myocardium at risk throughout infarct healing.
-
relationship of mri delayed contrast enhancement to Irreversible Injury infarct age and contractile function
Circulation, 1999Co-Authors: Raymond J Kim, David S Fieno, Ennling Chen, Todd B Parrish, Kathleen E Harris, Orlando P Simonetti, Jeffrey M Bundy, Paul J Finn, Francis J Klocke, Robert M JuddAbstract:Background—Contrast MRI enhancement patterns in several pathophysiologies resulting from ischemic myocardial Injury are controversial or have not been investigated. We compared contrast enhancement in acute infarction (AI), after severe but reversible ischemic Injury (RII), and in chronic infarction. Methods and Results—In dogs, a large coronary artery was occluded to study AI and/or chronic infarction (n=18), and a second coronary artery was chronically instrumented with a reversible hydraulic occluder and Doppler flowmeter to study RII (n=8). At 3 days after surgery, cine MRI revealed reduced wall thickening in AI (5±6% versus 33±6% in normal, P<0.001). In RII, wall thickening before, during, and after inflation of the occluder for 15 minutes was 35±5%, 1±8%, and 21±10% and Doppler flow was 19.8±5.3, 0.2±0.5, and 56.3±17.7 (peak hyperemia) cm/s, respectively, confirming occlusion, transient ischemia, and reperfusion. Gd-DTPA–enhanced MR images acquired 30 minutes after contrast revealed hyperenhancement...
Joon Chul Jung - One of the best experts on this subject based on the ideXlab platform.
-
serial ultrastructural evaluation of myocardial ischemic Injury after infusion of del nido cardioplegia in the human heart
The Journal of Thoracic and Cardiovascular Surgery, 2020Co-Authors: Joon Chul Jung, Seongik Kim, Ho Young Hwang, Suk Ho Sohn, Jae Woong Choi, Jinhaeng Chung, Jeongwook Seo, Kibong KimAbstract:OBJECTIVES The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic Injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope. METHODS Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = Irreversible). RESULTS At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic Injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and Irreversible Injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic Injury score of mitochondria and ischemic time (P < .001). Most nuclei showed moderate to severe ischemic Injury at every time point (61.0%-85.2%). A significant linear correlation was also found between the average ischemic Injury score of nuclei and ischemic time (P < .001). CONCLUSIONS Myocardial ischemic Injury progresses gradually, and Irreversible ischemic Injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.
-
serial ultrastructural evaluation of myocardial ischemic Injury after infusion of del nido cardioplegia in the human heart
The Journal of Thoracic and Cardiovascular Surgery, 2020Co-Authors: Joon Chul Jung, Seongik Kim, Ho Young Hwang, Suk Ho Sohn, Jae Woong Choi, Jinhaeng Chung, Jeongwook Seo, Kibong KimAbstract:Abstract Objectives The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic Injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope. Methods Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = Irreversible). Results At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic Injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and Irreversible Injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic Injury score of mitochondria and ischemic time (P Conclusions Myocardial ischemic Injury progresses gradually, and Irreversible ischemic Injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.
