Assessment of diastolic dysfunction markers in hypertrophic cardiomyopathy patients with 4D flow magnetic resonance imaging and Doppler echocardiography

    Authors

    Keywords

    4D Flow, magnetic resonance imaging, echocardiography, hypertrophic cardiomiopathy

    DOI

    https://doi.org/10.15836/ccar2023.168

    Full Text

    Introduction : Transthoracic echocardiography (TTE) is the gold standard in the assessment of diastolic dysfunction, however, measurement of diastolic markers such as the pulmonary vein (PV) inflow velocities is often challenging. 4D flow cardiac magnetic resonance imaging (CMR) enables quantification of velocities in any target volume without the constraints faced by TTE. We explored the use of 4D flow CMR in generating Doppler-like velocity spectrograms of mitral and PV inflow and comparing them to actual echo-based pulsed-wave (PW) Doppler velocity curves. Patients and Methods: A total of 6 HCM patients were included (P1-6). TTE was performed with a GE E95 system. Mitral and PV inflow PW Doppler was performed in the apical 4-chamber view by placing the sample volume at the level of the leaflet tips and at the inflow of the PV. The CMR data was acquired through a GE SIGNA Architect 3.0T scanner. The left atrium (LA), ventricle and outflow tract (LVOT) were segmented from a 4D flow phase contrast angiogram. The sample volume of PW Doppler was imitated using spheres of 4 mm radius placed in the same positions as in TTE. Velocities were projected in the direction typically captured by the echo transducer generating Doppler-like images. The duration of the pulmonary Ar and the mitral A wave was measured using both methods. Results: Figure 1 shows volumetric renderings of velocity at mid-systole. Compared to P1 and P2, P3-6 present an accelerated LVOT flow due to obstruction caused by systolic anterior motion, causing posterolateral mitral regurgitation disrupting LA hemodynamics. Figure 2 demonstrates the mitral and pulmonary inflow patterns obtained with TTE and CMR. Peak velocities and the duration of the A/Ar waves were comparable when quantified using both modalities ( Table 1 ). Ar wave duration could be quantified in all CMR studies, showing heterogeneity between the four PVs, whereas AR could be measured in only 3/6 of the echo studies. Volumetric rendering of the 4D flow MRI velocity fields mid-systole, including arrows pointing in the direction of the blood flow. A clear LVOT obstruction can be observed in patients 3-6 caused by systolic anterior motion. The distinctive rotational flow pattern in the LA is a consequence of the mitral regurgitation jet. The synthetic 4D flow derived PW Doppler velocity curves alongside the authentic PW Doppler. The sample volume for the PV acquisitions was located in the right superior PV, while the mitral valve profiles were extracted from the leaflet tips. Conclusion : 4D CMR shows potential for blood flow assessment previously feasible only via TTE. CMR could provide a more reproducible assessment of PV inflow velocities, relevant in assessing diastolic function, and potentially reveal new insights about LA hemodynamics.

    Cardiologia Croatica
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    Assessment of diastolic dysfunction markers in hypertrophic cardiomyopathy patients with 4D flow magnetic resonance imaging and Doppler echocardiography

    Extended Abstract
    Issue5-6
    Published
    Pages168-169
    PDF via DOIhttps://doi.org/10.15836/ccar2023.168
    4D Flow
    magnetic resonance imaging
    echocardiography
    hypertrophic cardiomiopathy

    Authors

    Filip Lončarić*ORCIDUniversity Hospital Centre Zagreb, Zagreb, Croatia
    Xabier Morales FerezORCIDUniversitat Pompeu Fabra, Department of information technologies and communication, Simulation, Barcelona, Spain
    Gaspar DelsoORCIDCardiovascular Institut, Hospital Clínic, Barcelona, Spain
    Ana Garcia-AlvarezORCIDAugust Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
    Jordi Mill TenaORCIDUniversitat Pompeu Fabra, Department of information technologies and communication, Simulation, Barcelona, Spain
    Adelina DoltraORCIDAugust Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
    Marta SitgesORCIDAugust Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
    Oscar CamaraORCIDUniversitat Pompeu Fabra, Department of information technologies and communication, Simulation, Barcelona, Spain
    Bart BijnensORCIDUniversitat Pompeu Fabra, Department of information technologies and communication, Simulation, Barcelona, Spain

    Full Text

    Introduction : Transthoracic echocardiography (TTE) is the gold standard in the assessment of diastolic dysfunction, however, measurement of diastolic markers such as the pulmonary vein (PV) inflow velocities is often challenging. 4D flow cardiac magnetic resonance imaging (CMR) enables quantification of velocities in any target volume without the constraints faced by TTE. We explored the use of 4D flow CMR in generating Doppler-like velocity spectrograms of mitral and PV inflow and comparing them to actual echo-based pulsed-wave (PW) Doppler velocity curves. Patients and Methods: A total of 6 HCM patients were included (P1-6). TTE was performed with a GE E95 system. Mitral and PV inflow PW Doppler was performed in the apical 4-chamber view by placing the sample volume at the level of the leaflet tips and at the inflow of the PV. The CMR data was acquired through a GE SIGNA Architect 3.0T scanner. The left atrium (LA), ventricle and outflow tract (LVOT) were segmented from a 4D flow phase contrast angiogram. The sample volume of PW Doppler was imitated using spheres of 4 mm radius placed in the same positions as in TTE. Velocities were projected in the direction typically captured by the echo transducer generating Doppler-like images. The duration of the pulmonary Ar and the mitral A wave was measured using both methods. Results: Figure 1 shows volumetric renderings of velocity at mid-systole. Compared to P1 and P2, P3-6 present an accelerated LVOT flow due to obstruction caused by systolic anterior motion, causing posterolateral mitral regurgitation disrupting LA hemodynamics. Figure 2 demonstrates the mitral and pulmonary inflow patterns obtained with TTE and CMR. Peak velocities and the duration of the A/Ar waves were comparable when quantified using both modalities ( Table 1 ). Ar wave duration could be quantified in all CMR studies, showing heterogeneity between the four PVs, whereas AR could be measured in only 3/6 of the echo studies. Volumetric rendering of the 4D flow MRI velocity fields mid-systole, including arrows pointing in the direction of the blood flow. A clear LVOT obstruction can be observed in patients 3-6 caused by systolic anterior motion. The distinctive rotational flow pattern in the LA is a consequence of the mitral regurgitation jet. The synthetic 4D flow derived PW Doppler velocity curves alongside the authentic PW Doppler. The sample volume for the PV acquisitions was located in the right superior PV, while the mitral valve profiles were extracted from the leaflet tips. Conclusion : 4D CMR shows potential for blood flow assessment previously feasible only via TTE. CMR could provide a more reproducible assessment of PV inflow velocities, relevant in assessing diastolic function, and potentially reveal new insights about LA hemodynamics.