4 results on '"left ventricular remodeling"'
Search Results
2. Einfluss der Aortenklappenstenose auf die Hämodynamik in der Aorta ascendens und deren Wechselspiel mit myokardialen Veränderungen
- Author
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Karunaharamoorthy, Achudhan
- Subjects
4D flow MRI ,left ventricular remodeling ,aorta ,magnetic resonance imaging ,aortic valve stenosis ,hemodynamics ,600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit::610 Medizin und Gesundheit ,cardiac magnetic resonance - Abstract
Hintergrund: Die Aortenklappenstenose (AS) führt durch die chronische Linksherzbelastung zu einer Hypertrophie und verschiedenen Formen des Remodelings des linken Ventrikels (LV). Das Ziel dieser Studie war es, die Blutflussmuster in der Aorta ascendens bei AS-Patienten zu charakterisieren und Zusammenhänge zwischen ihnen und dem Remodeling zu untersuchen. Methodik: Bei 37 Patienten mit AS (14 leichte, 8 mittlere und 15 schwere; Alter 63±13 Jahre) und 37 gesunden Probanden (Alter 60±10 Jahre) wurde eine vierdimensionale flusssensitive Magnetresonanztomographie (4D-Fluss-MRT) im 3-Tesla-Scanner ohne Kontrastmittel durchgeführt. Nach dem Preprocessing der Daten wurden die Helices, Vortices und Exzentrizität in der Aorta ascendens analysiert. Das Normalized flow displacement von der Gefäßmitte und die maximale Wandscherkraft in der Aorta ascendens wurden quantifiziert. Das LV-Remodeling wurde anhand des LV-Massenindex und dem Verhältnis zwischen der LV-Masse und enddiastolischen Volumen (relative Wandmasse) bestimmt. Die Herzdimensionen (Volumetrie, Funktionsparameter) wurden berechnet und eine Planimetrie der Aortenklappe durchgeführt. Ergebnisse: Schwere Helices und Vortices sowie Exzentrizität waren häufiger bei Patienten mit AS als bei gesunden Probanden; die Patienten zeigten eine höhere und asymmetrisch verteilte maximale Wandscherkraft. Vortices (p=0,0274), Exzentrizität (p=0,0070) und Normalized flow displacement (p=0,0021) korrelierten negativ zur Klappenöffnungsfläche bei Patienten. Eine bikuspide Aortenklappe ging mit stärkeren Helices (p=0,0098), Vortices (p=0,0536), Exzentrizität (p=0,11) und höherer maximalen Wandscherkraft (p=0,0926) einher. Der LV-Massenindex und die relative Wandmasse waren signifikant zur Klappenöffnungsfläche (p=0,0611, p=0,0058) und Normalized flow displacement (p=0,0058, p=0,00283) assoziiert. Fazit: Diese Pilotstudie zeigte, dass AS zu einer Veränderung des Blutflussmusters und einer höheren maximalen Wandscherkraft in der Aorta ascendens führt. Die Klappenöffnungsfläche und das Normalized flow displacement korrelierten mit dem LV-Remodeling. Die 4D-Fluss-MRT könnte in der Zukunft bei der AS zur Risikostratifizierung beitragen., Background: Aortic stenosis (AS) leads to chronic stress for the left ventricle (LV) and consequently LV hypertrophy and a broad range of LV remodeling. The aim of this study was to describe blood flow patterns in the ascending aorta of patients with AS and determine their association with remodeling. Methods: Thirty-seven patients with AS (14 mild, 8 moderate, 15 severe; age, 63±13 years) and 37 healthy controls (age, 60±10 years) underwent 4-dimensional-flow magnetic resonance imaging (4D flow MRI) in a 3-T scanner without contrast agent. After preprocessing the flow data, helical and vortical flow formations and flow eccentricity were assessed in the ascending aorta. Normalized flow displacement from the vessel center and peak systolic wall shear stress in the ascending aorta were quantified. LV remodeling was assessed based on LV mass index and the ratio of LV mass:end-diastolic volume (relative wall mass). Cardiac dimensions (volumetric indices, functional parameters) were measured and an aortic valve area planimetry performed. Results: Marked helical and vortical flow formation and eccentricity were more prevalent in patients with AS than in healthy subjects, and patients with AS exhibited an asymmetrical and elevated distribution of peak wall shear stress. In AS, aortic orifice area was strongly negatively associated with vortical flow formation (P=0.0274), eccentricity (P=0.0070), and flow displacement (P=0.0021). Bicuspid aortic valve was associated with more intense helical (P=0.0098) and vortical flow formation (P=0.0536), higher flow displacement (P=0.11), and higher peak wall shear stress (P=0.0926). LV mass index and relative wall mass were significantly associated with aortic orifice area (P=0.0611, P=0.0058) and flow displacement (P=0.0058, P=0.0283). Conclusion: In this pilot study, AS leads to abnormal blood flow pattern and peak wall shear stress in the ascending aorta. In addition to aortic orifice area, normalized flow displacement was significantly associated with LV remodeling. 4D flow MRI could contribute to the risk stratification of AS in the future.
- Published
- 2020
3. Diagnostik und Indikation zum Klappenersatz bei asymptomatischer und symptomatischer Aorteninsuffizienz.
- Author
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Mandinov, Lazar, Kaufmann, Philipp, and Hess, Otto
- Abstract
Copyright of Herz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 1998
- Full Text
- View/download PDF
4. [Chronic cervical vagal stimulation. Mechanisms of action and clinical relevance for heart failure].
- Author
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Kuschyk J, Doesch C, Akin I, Borggrefe M, and Roeger S
- Subjects
- Chronic Disease, Evidence-Based Medicine, Heart Failure diagnosis, Humans, Implantable Neurostimulators, Technology Assessment, Biomedical, Treatment Outcome, Ventricular Dysfunction, Left diagnosis, Heart Failure complications, Heart Failure prevention & control, Vagus Nerve Stimulation methods, Ventricular Dysfunction, Left complications, Ventricular Dysfunction, Left prevention & control
- Abstract
Increased sympathetic nerve activity and reduced vagal activity are associated with increased mortality in patients after myocardial infarction and patients with chronic heart failure; furthermore, vagal withdrawal has been documented to precede acute decompensation. Experimental studies have indicated that increased parasympathetic activity by means of vagal stimulation may reduce mortality in animal models of postinfarction sudden cardiac death and of chronic heart failure. First clinical results have demonstrated that chronic vagus nerve stimulation in heart failure patients with severe systolic dysfunction appears to be safe and tolerable and may improve the quality of life and left ventricular (LV) function. Vagus nerve stimulation gives rise to these potential clinical benefits by multiple mechanisms of action, including reduced heart rate, restoration of heart rate variability and baroreflex sensitivity, suppression of proinflammatory cytokines and antiarrhythmic effects. First clinical results suggest that vagal nerve stimulation is safe and tolerable and could lead to a marked clinical improvement but discrepancies in the findings due to different study designs warrant further discussion.
- Published
- 2015
- Full Text
- View/download PDF
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