Left Ventricular Form and Function

Buckberg, Gerald D.; Weisfeldt, Myron L.; Ballester, Manel; Beyar, Rafael; Burkhoff, Daniel; Coghlan, H. Cecil; Doyle, Mark; Epstein, Neal D.; Gharib, Morteza; Ideker, Ray; Ingels, Neil B.; LeWinter, Martin M.; McCulloch, Andrew D.; Pohost, Gerald M.; Reinlib, Leslie; Sahn, David J.; Sopko, George; Spinale, Francis G.; Spotnitz, Henry M.; Torrent-Guasp, Francisco; Shapiro, Edward P.

doi:10.1161/01.cir.0000143625.56882.5c

Cited by 112 publications

(39 citation statements)

References 14 publications

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“…1 Left ventricular twist may be related to the helical fiber orientation of the LV, which results in opposing rotational directions of the apex and the base and which determines the magnitude of this torsional deformation. 2,3 It has been proposed that LV twist is a sensitive marker of changes in both regional and global LV function.…”

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Three-Dimensional Speckle-Tracking Imaging for Left Ventricular Rotation Measurement

Zhou

Ashraf

et al. 2010

Journal of Ultrasound in Medicine

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Objective. Left ventricular (LV) twist is manifested in oppositely directed apical and basal rotation. We studied a new 3-dimensional (3D) echocardiography program (wall motion tracking; Toshiba America Medical Systems, Inc, Tustin, CA) for left ventricular rotation. Methods. We used a rotation model with a variable-speed motor to rotate hearts in a water bath. We studied 10 freshly harvested pig hearts, which were mounted on the rotary actuator of our twist phantom with the heart base rotating and the apex held fixed to avoid translational motion, at rotations of 0°, 15°, 20°, and 25°. Full-volume 3D image loops were acquired on a Toshiba Aplio Artida ultrasound system at a maximized frame rate. Results. As the actual heart rotation increased, computed segmental and global rotation also increased accordingly, with the measured rotations of the basal and middle segments greater than that of the apex (both P < .001). Segmental and global rotation at all 3 levels correlated well with the actual rotation (base: r = 0.93; middle: r = 0.92; apex: r = 0.82; global: r = 0.95; all P < .001). Conclusions. The new 3D program tracked LV rotation accurately. Key words: left ventricular rotation; speckle tracking; 3-dimensional imaging. esearch in clinical deformation cardiac mechanics has recently been focused on 2-dimensional (2D) left ventricular (LV) deformation studies, including LV twist and LV rotation (LVrot). 1 Left ventricular twist may be related to the helical fiber orientation of the LV, which results in opposing rotational directions of the apex and the base and which determines the magnitude of this torsional deformation. 2,3 It has been proposed that LV twist is a sensitive marker of changes in both regional and global LV function. [4][5][6] Recently, efforts have focused on 2D speckle-tracking imaging (STI) to assess LVrot. [7][8][9] Several studies have shown that 2D STI gives equivalent results when compared to magnetic resonance imaging (MRI) or Doppler tissue imaging (DTI) for measuring LVrot. 9 However, because of the 3-dimensional (3D) nature of cardiac deformation, 2D STI based on 2D imaging may not be robust enough for LVrot measurement because of speckle decorrelation or the loss of some speckles due to elevational

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confidence: 99%

Three-Dimensional Speckle-Tracking Imaging for Left Ventricular Rotation Measurement

Zhou

Ashraf

et al. 2010

Journal of Ultrasound in Medicine

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“…Both structural and functional assessments are important in our understanding of myocardial contraction and relaxation in normal and pathologic states (1,2). It has been long known that left ventricular (LV) myocardial microstructure or fiber structure plays a critical role in determining mechanical properties, such as ventricular torsion, strain, and stress (3,4).…”

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“…It has been long known that left ventricular (LV) myocardial microstructure or fiber structure plays a critical role in determining mechanical properties, such as ventricular torsion, strain, and stress (3,4). Owing to the recent advances in cardiac MR and ultrasound imaging, there is an increasing interest in investigating LV by directly associating the LV myocardial fiber geometry to the complex spatial-temporal sequence of electrical activation and mechanical contraction/relaxation in beating hearts (1,2,5). LV is known to electrically activate first at the exits of Purkinje system, close to apical endocardium.…”

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confidence: 99%

“…LV is known to electrically activate first at the exits of Purkinje system, close to apical endocardium. The electrical activation then propagates from apex to base via depolarization and repolarization in both septum and free wall (1,6). This is accompanied by successive mechanical shortenings and intracavitary blood flow along the parallel apex-to-base direction, although highly transient and localized myocardial deformations exist.…”

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MR diffusion tensor imaging study of postinfarct myocardium structural remodeling in a porcine model

Nicholls

et al. 2007

Magnetic Resonance in Med

117

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This study aimed to investigate postinfarct left ventricular (LV) fiber structural alterations by ex vivo diffusion tensor imaging (DTI) in a porcine heart model. In vivo cardiac MR imaging was first performed to measure ventricular function in six adult pigs with septal infarction near apex induced by the LAD ligation 13 weeks earlier. Hearts were then excised from the infarct pigs (n ‫؍‬ 6) and six intact controls (n ‫؍‬ 6) and fixed in formalin. High-resolution DTI was employed to examine changes in fractional anisotropy (FA), apparent diffusion coefficient (ADC), and transmural helix angle distribution in the infarct, adjacent and remote regions as compared to the sham regions in the controls. FA values were found to decrease in the infarct and differ between the adjacent and remote regions. ADC increase in the infarct region was substantial, while changes in the adjacent and remote regions were insignificant. Structurally, the doublehelix myocardial structure shifted toward more left-handed around the infarcted myocardium. Accordingly, the histological analysis revealed clear fiber structural degradation in the adjacent region. These findings confirmed the subtle alterations in the myocardial fiber quality and structure not only in the in- Key words: myocardium infarction; borderzone; diffusion tensor imaging; fiber architecture Both structural and functional assessments are important in our understanding of myocardial contraction and relaxation in normal and pathologic states (1,2). It has been long known that left ventricular (LV) myocardial microstructure or fiber structure plays a critical role in determining mechanical properties, such as ventricular torsion, strain, and stress (3,4). Owing to the recent advances in cardiac MR and ultrasound imaging, there is an increasing interest in investigating LV by directly associating the LV myocardial fiber geometry to the complex spatial-temporal sequence of electrical activation and mechanical contraction/relaxation in beating hearts (1,2,5). LV is known to electrically activate first at the exits of Purkinje system, close to apical endocardium. The electrical activation then propagates from apex to base via depolarization and repolarization in both septum and free wall (1,6). This is accompanied by successive mechanical shortenings and intracavitary blood flow along the parallel apex-to-base direction, although highly transient and localized myocardial deformations exist.In infarcted myocardium, remodeling involves both structural and functional changes. Such changes have been found to occur in both infarcted myocardium and adjacent and remote myocardium (7-11). The effects of myocardial infarction (MI) on LV function have been investigated in numerous studies. In recent years, cardiac MR (CMR) imaging has become the accepted reference standard to assess LV function since CMR methods are both accurate and highly reproducible (12). These CMR techniques can be used to detect, localize, and quantify both MI and LV functions. Patten et al. (13) found that hearts...

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“…Tissue Doppler imaging (TDI) and strain/strain rate (SRs) imaging (SRI) are novel techniques that have been shown to be reliable and accurate for evaluating global and regional ventricular functions (9,10). TDI is preload and afterload dependent, SRI is also affected by afterload changes but less-load dependent than conventional parameter (11)(12)(13). Velocity Vector Imaging (VVI) is a novel two-dimensional strain imaging technique, which provides more accurate data on regional cardiac functions and is angle-independent (14,15).…”

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confidence: 99%

Subclinical left ventricular systolic dysfunction in patients with mild-to-moderate rheumatic mitral stenosis and normal left ventricular ejection fraction: an observational study

Yıldırımtürk

Helvacıoğlu²,

Tayyareci³

et al. 2013

Anadolu Kardiyol Derg

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Subclinical left ventricular systolic dysfunction in patients with mild-to-moderate rheumatic mitral stenosis and normal left ventricular ejection fraction: an observational studyHafif orta derecede romatizmal mitral kapak darlığı ve normal sol ventrikül ejeksiyon fraksiyonu olan hastalarda subklinik sol ventrikül sistolik disfonksiyonu: Bir gözlemsel çalışma Original Investigation Özgün Araşt›rma 328ÖZET Amaç: Tanı ve tedavideki gelişmelere rağmen mitral kapak darlığı (MD) genç erişkinlerde morbiditenin önemli bir sebebidir. Genellikle, MD olan hastalarda sol ventrikül (SV) fonksiyonları iyi korunmuştur. Ancak bazı çalışmalarda saf MD olan hastalarda SV sistolik fonksiyonlarının bozulduğu gösterilmiştir. Bu çalışmanın amacı; izole hafif-orta MD olan, normal SV ejeksiyon fraksiyonlu hasta kohortunda doku Doppler görüntüleme (DDG) ve hız vektör görüntüleme (HVG) yöntemlerini kullanarak, bu hastalarda subklinik sol ventrikül sistolik disfonksiyon varlığını araştırmaktır. Yöntemler: İzole hafif-orta MD olan 50 hasta (%84 kadın, ortalama yaş 49.1±10.0 yıl) ve 60 sağlıklı kişi (%76.7 kadın, ortalama yaş 49.1±10.5 yıl) göz-lemsel kesitsel çalışmaya dahil edildi. Tüm hastalara konvansiyonel ekokardiyografi, DDG ve HVG ile strain (S) ve strain oranı (SR) analizi yapıldı. Bulgular: MD olan hastalarda ortalama transmitral gradient 6.4±3.0 mmHg ve ortalama mitral kapak alanı 1.45±0.36 cm 2 olarak bulundu. MD olan hastalarda hem longitüdinal hem de sirkümferensiyal S ve SR değerleri belirgin olarak düşük bulundu (p<0.001). DDG ile elde edilen izovolümik akselerasyon (IVA) ve sistolik dalga hızı (Sa) da izole MD olan hastalarda düşük olarak ölçüldü (p<0.001). SV ejeksiyon fraksiyonu deformasyon indeksleri ile korelasyon göstermemekte idi. Deformasyon indeksleri transmitral gradiyent ya da mitral kapak alanı ile ilişkili değildi. Sonuç: Normal ejeksiyon fraksiyonu olan izole MD olan hastalarda HVG ile elde edilen deformasyon parametreleri subklinik sistolik disfonksiyonu gös-terebilir. Bu bulgular mitral kapak cerrahisi için optimal zamanlamanın belirlenmesinde faydalı olabilir. (Anadolu Kardiyol Derg 2013; 13: 328-36) Anahtar kelimeler: Sol ventrikül, sistolik fonksiyon, deformasyon görüntüleme, mitral kapak darlığı, hız vektör görüntüleme

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Left Ventricular Form and Function

Cited by 112 publications

References 14 publications

Three-Dimensional Speckle-Tracking Imaging for Left Ventricular Rotation Measurement

Three-Dimensional Speckle-Tracking Imaging for Left Ventricular Rotation Measurement

MR diffusion tensor imaging study of postinfarct myocardium structural remodeling in a porcine model

Subclinical left ventricular systolic dysfunction in patients with mild-to-moderate rheumatic mitral stenosis and normal left ventricular ejection fraction: an observational study

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