Structure and function relationships of the helical ventricular myocardial band

Buckberg, Gerald D.; Mahajan, Aman; Saleh, Saleh; Hoffman, Julien I.E.; Coghlan, Cecil

doi:10.1016/j.jtcvs.2007.10.088

Cited by 77 publications

(86 citation statements)

References 55 publications

(30 reference statements)

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“…Presently, there is increasing consensus that both the septum and RV free wall play an important role in RV contraction. The septum consists of oblique longitudinal fibers with spiral architecture [29], resulting in the twisting motion required for efficient ejection against increased vascular resistance. In contrast, the predominant transverse fiber orientation of the RV free wall leads to circumferential compression or bellows action, which maintains RVEF with normal pulmonary artery pressure [28,30,31].…”

Section: Discussionmentioning

confidence: 99%

Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension

Kind

Mauritz

Marcus

et al. 2010

Journal of Cardiovascular Magnetic Resonance

188

148

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BackgroundLongitudinal wall motion of the right ventricle (RV), generally quantified as tricuspid annular systolic excursion (TAPSE), has been well studied in pulmonary hypertension (PH). In contrast, transverse wall motion has been examined less. Therefore, the aim of this study was to evaluate regional RV transverse wall motion in PH, and its relation to global RV pump function, quantified as RV ejection fraction (RVEF).MethodsIn 101 PH patients and 29 control subjects cardiovascular magnetic resonance was performed. From four-chamber cine imaging, RV transverse motion was quantified as the change of the septum-free-wall (SF) distance between end-diastole and end-systole at seven levels along an apex-to-base axis. For each level, regional absolute and fractional transverse distance change (SFD and fractional-SFD) were computed and related to RVEF. Longitudinal measures, including TAPSE and fractional tricuspid-annulus-apex distance change (fractional-TAAD) were evaluated for comparison.ResultsTransverse wall motion was significantly reduced at all levels compared to control subjects (p < 0.001). For all levels, fractional-SFD and SFD were related to RVEF, with the strongest relation at mid RV (R2 = 0.70, p < 0.001 and R2 = 0.62, p < 0.001). For TAPSE and fractional-TAAD, weaker relations with RVEF were found (R2 = 0.21, p < 0.001 and R2 = 0.27, p < 0.001).ConclusionsRegional transverse wall movements provide important information of RV function in PH. Compared to longitudinal motion, transverse motion at mid RV reveals a significantly stronger relationship with RVEF and thereby might be a better predictor for RV function.

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Section: Discussionmentioning

confidence: 99%

Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension

Kind

Mauritz

Marcus

et al. 2010

Journal of Cardiovascular Magnetic Resonance

188

148

View full text Add to dashboard Cite

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“…Myocardial streamline was confirmed by the CT investigation in a healthy goat heart which was extracted and unfolded based on the Torrent-Guasp's myocardial band concept [8]. The orientation of the device contraction might promote native systolic function while avoiding both the external and internal critical structures of the heart.…”

Section: B Structural and Functional Design Of The Device Based On Tmentioning

confidence: 93%

Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats

Shiraishi

Yambe

Saijo

et al. 2009

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Thromboembolic and haemorrhagic complications are the primary causes of mortality and morbidity in patients with artificial hearts, which are known to be induced by the interactions between blood flow and artificial material surfaces. The authors have been developing a new mechanical artificial myocardial assist device by using a sophisticated shape memory alloy fibre in order to achieve the mechanical cardiac support from outside of the heart without a direct blood contacting surface. The original material employed as the actuator of artificial myocardial assist devices was 100um fibred-shaped, which was composed of covalent and metallic bonding structure and designed to generate 4-7 % shortening by Joule heating induced by the electric current input. In this study, we focused on the synchronization of the actuator with native cardiac function, and the phase delay parameter was examined in animal experiments using Saanen goats. Total weight of the device including the actuator was around 150g, and the electric power was supplied transcutaneously. The device could be successfully installed into thoracic cavity, which was able to be girdling the left ventricle. The contraction of the device could be controlled by the originally designed microcomputer. The mechanical contraction signal input had been transmitted with the phase delay of 50-200 msec after the R-wave of ECG, and hemodynamic changes were investigated. Cardiac output and systolic left ventricular pressure were elevated with 20% delay of cardiac cycle by 27% and 7%, respectively, although there was smaller difference under the condition of the delay of over 30%. Therefore, it was suggested that the synchronization measures should be examined in order to achieve sophisticated ventricular passive/active support on physiological demand.

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“…Information from two-dimensional (2D) ultrasound or angiography alone may not provide a complete picture of the heart, as reported earlier [100] and may led to some misconceptions. 2D ultrasound only provides “flat” views of the heart and is fixed in terms of the piezoelectric element vertical dimension.…”

Section: Ultrasound Imagingmentioning

confidence: 99%

“…Imaging and quantifying fiber orientations in the heart is challenging [100]. At the light-microscopic level, the heart was described as a “sandwich” for which cardiac fibers in the middle layer run mainly circumferentially [8].…”

Section: Overview Of Imaging Technologies For Detecting Heart Failurementioning

confidence: 99%

Imaging technologies for cardiac fiber and heart failure: a review

2018

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There has been an increasing interest in studying cardiac fibers in order to improve the current knowledge regarding the mechanical and physiological properties of the heart during heart failure (HF), particularly early HF. Having a thorough understanding of the changes in cardiac fiber orientation may provide new insight into the mechanisms behind the progression of left ventricular (LV) remodeling and HF. We conducted a systematic review on various technologies for imaging cardiac fibers and its link to HF. This review covers literature reports from 1900 to 2017. PubMed and Google Scholar databases were searched using the keywords “cardiac fiber” and “heart failure” or “myofiber” and “heart failure.” This review highlights imaging methodologies, including magnetic resonance diffusion tensor imaging (MR-DTI), ultrasound, and other imaging technologies as well as their potential applications in basic and translational research on the development and progression of HF. MR-DTI and ultrasound have been most useful and significant in evaluating cardiac fibers and HF. New imaging technologies that have the ability to measure cardiac fiber orientations and identify structural and functional information of the heart will advance basic research and clinical diagnoses of HF.

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Structure and function relationships of the helical ventricular myocardial band

Abstract: Further testing of these spatial anatomic concepts is needed to create a more accurate understanding of the architectural mechanisms that underlie cardiac dynamics to address future problems in unhealthy hearts.

Cited by 77 publications

References 55 publications

Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension

Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension

Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats

Imaging technologies for cardiac fiber and heart failure: a review

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