The dysfunctional right ventricle: the importance of multi-modality imaging

Figures

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  Figure 1. Importance of multi-parametric approach in accurate interpretation of RV systolic function by conventional echocardiography. (A) In a patient with pulmonary hypertension, TAPSE, and S′ values are normal, however FAC is reduced. 3D surface-rendered model of the RV demonstrates preserved longitudinal contraction (white arrow), but impaired radial contraction (red arrows) due to reduced RV-free wall motion and flattening of the interventricular septum. FAC considers not only longitudinal but also radial RV contraction and in this case is able to reflect the reduced RV systolic function. (B) In a patient with repaired Tetralogy of Fallot, TAPSE, and S′ are reduced (common post-cardiac surgery), but FAC is normal. 3D-derived RV EF is reduced (40%). This is explained by large dyskinetic area in the RVOT (last panel, arrows) which was not included neither in TAPSE nor in S′ or FAC measurements.

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  Figure 2. 3D echocardiographic assessment of the RV. (Upper) Standard 2D echocardiography cannot consider contribution of the RV parts not captured in the scanning plane. 3D echocardiography allows to incorporate all RV components in a single dataset (green surface-rendered model) and enables accurate assessment. (Middle) The 3D full-volume dataset of the RV can be cropped, rotated, and displayed in 3D volume rendering mode or multi-slice display, and provide information targeted to exam question (e.g. assessment of RV morphology, valves, RVOT, or interventricular septum). The multi-slice view is useful during data acquisition to ensure that the whole RV is encompassed in the dataset and can also be used for assessment of RV wall motion abnormalities. (Lower) Post-processing using dedicated software packages provides RV volumes and EF. It also generates the volume curve which details emptying and filling of the RV during cardiac cycle. Different views of surface-rendered 3D model of the RV enable visual assessment of the RV dynamics and contribution of different components of the RV pump function.

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  Figure 3. Right ventricular—arterial interaction. RV function, when measured by tools such as ejection fraction, area change, and strain, is the result of the interaction between the intrinsic muscular force of the RV (contractility) and after-load (often simplified as pulmonary artery pressure)—see panel A. These measures therefore do not enable us to determine whether the RV is matching its work requirements relative to load or whether it is approaching the point of uncoupling (B) at which cardiac output starts to fail relative to demand. RV myocardial work (MW) can be calculated based on non-invasively derived pressure–strain loops for the RV, in this case in a patient with raised pulmonary arterial pressures (C). RVGCW, right ventricular global constructive work; RVGWW, right ventricular global wasted work.

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  Figure 4. Volumetric assessment of RV function by CMR. Traces of the LV endocardium (red) epicardium (green) and the RV endocardium (yellow) are contoured in a short-axis stack with reference to the long-axis plane. Volumes are then imputed using a sum-of-disks method. In this case, an RV ejection fraction of 42% was measured in a young athlete presenting with symptomatic ventricular tachycardia, focal regions of RV akinesia, and widespread T-wave inversion meeting task-force criteria for ARVC.

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  Figure 5. Example of SPECT radionuclide angiography. Regional and global evaluation of kinesis as well as quantitative evaluation of right and left ventricular ejection fraction and volumes are feasible and reproducible.