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Quantitative assessment of right ventricular structure and flow dynamics in pulmonary homograft obstruction.

Chapron J, Aguib H, Theodoropoulos S, Kalantzi M, Yacoub M, Torii R - Glob Cardiol Sci Pract (2014)

View Article: PubMed Central - PubMed

Affiliation: Qatar Cardiovascular Research Centre, Doha, Qatar.

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The insertion of cryopreserved homograft conduit into the pulmonary outflow tract is an effective method of relieving severe pulmonary valve dysfunction... He remained asymptomatic, however, routine echocardiography six months after the operation showed a peak gradient of 25mmHg across the right ventricular outflow with evidence of diminution of right ventricular size and a competent pulmonary valve (homograft)... The cardiac output measured 4.55 L/min... Applying the jet shear layer detection method by Garcia et al. to the through-plane velocity map, effective orifice area (EOA) was also estimated to be 1.36 cm... Energy loss is in mmHg and was initially introduced to indicate the portion of the transvalvular pressure that is not recovered, in order to assess the severity of aortic stenosis... Indexed energy loss coefficient is an improved indicator which has been shown better correlated to clinical outcomes, i.e. mortality and reoperation... The diameter of the homograft in proportion to the dilated MPA was 57% and also due to relatively small orifice area equivalent to a moderate stenosis in case of the aorta (Bonow et al. ), the flow through the homograft became a high-speed jet... The jet flowing into the dilated MPA is accompanied by flow separation and recirculation (Figure 3) which are likely cause of disturbance in the flow, resulting in a significant energy loss that was estimated 26.6 mmHg... This means that the RV of this patient is required to provide extra 26.6 mmHg of pressure to overcome energy loss and ensure perfusion of the blood to the lungs... One of the limitations of this study is that we have used the energy loss equation for the pulmonary valve... However, the flow characteristics through the two semilunar valves is similar... Another limitation relates to the fact that we have not studied the effect of turbulence using computational fluid dynamics... This report illustrated the utility of multi-modality imaging analysis to fully characterize both the structural and functional changes at different times during follow-up of operations for complex heart disease... This has the potential to influence decision making regarding re-operation, and possibly optimise surgical techniques in the future.

No MeSH data available.


3D anatomical model reconstructed from gadolinium-enhanced MR images (red: systemic circulation, blue: pulmonary circulation with the homograft shown in dark gray, light gray: myocardium). Measurements in the right panel are in mm.
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fig1: 3D anatomical model reconstructed from gadolinium-enhanced MR images (red: systemic circulation, blue: pulmonary circulation with the homograft shown in dark gray, light gray: myocardium). Measurements in the right panel are in mm.

Mentions: The 3D model showed slightly enlarged right ventricular (RV) cavity with good contractility. Importantly there was no evidence of RV hypertrophy, with the thickness of the free wall of the RV measuring 2 mm. The allograft valve (shown in dark grey in Figure 1) measured 2.4 cm in diameter, which was identical to the original size at insertion. The main and left pulmonary arteries were markedly dilated, measuring 4.19 cm and 4.35 cm respectively (Figure 1).


Quantitative assessment of right ventricular structure and flow dynamics in pulmonary homograft obstruction.

Chapron J, Aguib H, Theodoropoulos S, Kalantzi M, Yacoub M, Torii R - Glob Cardiol Sci Pract (2014)

3D anatomical model reconstructed from gadolinium-enhanced MR images (red: systemic circulation, blue: pulmonary circulation with the homograft shown in dark gray, light gray: myocardium). Measurements in the right panel are in mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4352686&req=5

fig1: 3D anatomical model reconstructed from gadolinium-enhanced MR images (red: systemic circulation, blue: pulmonary circulation with the homograft shown in dark gray, light gray: myocardium). Measurements in the right panel are in mm.
Mentions: The 3D model showed slightly enlarged right ventricular (RV) cavity with good contractility. Importantly there was no evidence of RV hypertrophy, with the thickness of the free wall of the RV measuring 2 mm. The allograft valve (shown in dark grey in Figure 1) measured 2.4 cm in diameter, which was identical to the original size at insertion. The main and left pulmonary arteries were markedly dilated, measuring 4.19 cm and 4.35 cm respectively (Figure 1).

View Article: PubMed Central - PubMed

Affiliation: Qatar Cardiovascular Research Centre, Doha, Qatar.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

The insertion of cryopreserved homograft conduit into the pulmonary outflow tract is an effective method of relieving severe pulmonary valve dysfunction... He remained asymptomatic, however, routine echocardiography six months after the operation showed a peak gradient of 25mmHg across the right ventricular outflow with evidence of diminution of right ventricular size and a competent pulmonary valve (homograft)... The cardiac output measured 4.55 L/min... Applying the jet shear layer detection method by Garcia et al. to the through-plane velocity map, effective orifice area (EOA) was also estimated to be 1.36 cm... Energy loss is in mmHg and was initially introduced to indicate the portion of the transvalvular pressure that is not recovered, in order to assess the severity of aortic stenosis... Indexed energy loss coefficient is an improved indicator which has been shown better correlated to clinical outcomes, i.e. mortality and reoperation... The diameter of the homograft in proportion to the dilated MPA was 57% and also due to relatively small orifice area equivalent to a moderate stenosis in case of the aorta (Bonow et al. ), the flow through the homograft became a high-speed jet... The jet flowing into the dilated MPA is accompanied by flow separation and recirculation (Figure 3) which are likely cause of disturbance in the flow, resulting in a significant energy loss that was estimated 26.6 mmHg... This means that the RV of this patient is required to provide extra 26.6 mmHg of pressure to overcome energy loss and ensure perfusion of the blood to the lungs... One of the limitations of this study is that we have used the energy loss equation for the pulmonary valve... However, the flow characteristics through the two semilunar valves is similar... Another limitation relates to the fact that we have not studied the effect of turbulence using computational fluid dynamics... This report illustrated the utility of multi-modality imaging analysis to fully characterize both the structural and functional changes at different times during follow-up of operations for complex heart disease... This has the potential to influence decision making regarding re-operation, and possibly optimise surgical techniques in the future.

No MeSH data available.