Figure 1. Interventricular Septal Ablation in Patients with HOCM
(A) CMR end-diastolic long-axis image demonstrates a significant hypertrophy in basal septum. (B) Display of the 16 myocardial segments on a circumferential polar plot. the recommended nomenclature for tomographic imaging of the heart: 1. basal anterior, 2. basal anteroseptal, 3. basal inferoseptal, 4. basal inferior, 5. basal inferolateral, 6. basal anterolateral, 7. mid anterior, 8. mid anteroseptal, 9. mid inferoseptal, 10. mid inferior, 11. mid inferolateral, mid anterolateral, 13. apical anterior, 14. apical septal, 15. apical inferior, 16. apical lateral. (C) The circumferential polar plot presents a limited hypertrophy in basal anteroseptal and inferoseptal segments. The number indicates the average thickness of each segment. (D) Right anterior oblique (RAO) projection of the CARTO shell. Left ventricular (green), aorta (purple), SAM area of hypertrophic septum (pink) and left bundle branch (yellow) are presented. Ablation is performed on SAM area (red). (E) Significant tissue edema can be observed on the live ICE screen. (F) Reduction of obstruction at rest is seen on continuous-wave Doppler echocardiography. the LVOT gradient (in mmHg) is significantly decreased after six months follow up. (P=0.001) LA, left atrium; LV, left ventricle; LVOT, left ventricular outflow tract; RV, right ventricle; IVS, interventricular septum.
Figure 2. Morphologic Abnormalities of Mitral Valve Contributing to Outflow Tract Obstruction
(A, B) The length of the AML was measured in diastole on the apical three-chamber view. (C) Extraordinarily long anterior mitral valve leaflet on CMR (D) On live ICE screen, the AML (white arrow) is reflexed and attached to IVS during systole and pats on the ablation catheter tip during procedure. AML, anterior mitral leaflet.
Figure 3. Morphologic Abnormalities of Papillary Muscle (PM) Contributing to Outflow Tract Obstruction (A: normal; B: abnormal)
(A, B) Hypertrophied and apically displaced papillary muscle (white arrows) with superior head (yellow arrow) in close proximity to the bulged septum, positioning mitral valve plane toward ventricular septum compared with normal positioned PM (B). (C, D) CMR end-systolic image presents a severely narrowed LV cavity (D) in patient with hypertrophied papillary muscle, as compared with a relatively normal papillary muscle object (C).
Figure 4. Different patterns of septum hypertrophy among patients
Patient No.12: B, D, F, H. Patient No.14: A, C, E, G. (A, B) CMR End-Diastolic Images Demonstrating Different Patterns of Interventricular Septum Hypertrophy. The distribution of LV hypertrophy is limited (basal anteroseptal segment) in (A), while diffused (basal, mid anteroseptal, and mid inferoseptal segments) in (B). (C, D) Short-axis view presents a segmental LV hypertrophy of the basal anterior septum in both patients. (E, F) Both mid anteroseptal and inferoseptal segments present hypertrophied phenotype in (E), but neither in (F). (G, H) Apical septal segment is free of hypertrophy in both patients.
Figure 5. The Change of Hemodynamic and Health-related Quality of Life after 6 months follow up
(A) LVOT gradient is shown (in mmHg) before, 1 month after, 3 months after and 6 months after LV septal radiofrequency ablation. Reduction of gradient is significant after 6 months follow up (p<0.001) especially in patient 3, 4, 8, 14, 15, 16. (B) comparison of health-related quality of life before and 6 months after ablation procedure. The score of four dimensions (physical functioning, role-physical, general health and reported health transition) are increased after 6 months follow up.