1. ‘How I do’ CMR in HCM Dr Sanjay Prasad, Royal Brompton Hospital
London, UK. For SCMR August 2006
This presentation is posted for members of scmr as an educational guide – it represents the views and practices of the author, and not necessarily those of SCMR.

2. Hypertrophic Cardiomyopathy

3. Hypertrophic Cardiomyopathy: Clinical Aspects
Characterized by myocyte disarray, hypertrophy, and interstitial fibrosis
90% of pts have familial disease
10% de novo mutations
Increased risk of SCD
Adult prevalence 1:500 (Autosomal Dominant)
1st degree-relatives -1:2 risk gene carrier

4. HCM: Diagnosis Unexplained hypertrophy
Measured wall thickness exceeds 2SD for gender-,age-, and BSA-matched populations
≥ 1.5cm in absence of a recognized cause
There may be associated systolic anterior motion of the mitral valve leaflets and outflow tract obstruction
Multiple causative mutations in at least 10 different sarcomeric proteins
Variable phenotype and clinical outcome
Seidman et al 2002; Chien 2003

5. HCM – Histopathology Myocyte Disarray
Here with some associated fibrosis

6. HCM and Fibrosis
In addition to asymmetric hypertrophy, there is often extensive fibrosis

7. HCM: SAM + LVOTO
ADD DCM Cine

8. CMR Evaluation of HCM
The first important aspect is determining LV and RV volumes, ejection fractions, maximal wall thickness and mass
We recommend the modified Simpson’s method rather than biplanar assessment since it makes no assumptions on cardiac morphology and is both more accurate and reproducible.
After piloting the 4ch and VLA views, retrospectively gated gradient echo cine slices are taken from the base to apex
Typically 7mm slices with a 3mm gap.
Usually myocardial coverage is achieved in 9-10 slices

9. CMR Quantification See the presentation ‘how I do’ LV volumes
Downloadable from

10. HCM: Cine Imaging
The key questions to address are: -
Presence, distribution, and severity of LVH and RVH. LV/RV mass and wall thickness
Extent of septal involvement
Distribution of hypertrophy in the variant forms of hypertrophic cardiomyopathy

11. Functional Assessment
Cine images are then acquired to determine if there is SAM and LVOTO.
SSFP images with retrospective gating recommended

12. HCM: LVOTO Assessment
In-plane followed by through plane breath-hold flow mapping is performed to look at the peak velocity at the outflow tract (red-bar) and at the level of the aortic valve.

13. Assessment of Fibrosis
The presence of replacement fibrosis can be detected using the inversion recovery late enhancement technique following gadolinium-DTPA administration.
After all, fibrosis is the main component of chronic MI which is visible with the late enhancement technique

14. Fibrosis imaging in HCM
Gd infarct imaging
HCM fibrosis imaging?

15. HCM – a wide variety of scar
2 patients. For the lower patient, scar is present and invisible without Gd-DTPA. Many patients have no detectable scar

16. Fibrosis -not like IHD Picro sirius red stains collagen red.
In-vivo vs exvivo match

17. Detection of Fibrosis: Inversion Recovery Sequence
Dosage of Gd-DTPA: mmol/kg
At 0.1mmol/kg, images are usually acquired after about 5 minutes with a TI starting at ~340ms (every other heart beat).
At 0.2 mmol/kg, scans are acquired after about 15 minutes with a TI starting at ~250ms.

18. HCM: Detection of Fibrosis
LGE is predominantly seen in a patchy distribution and correlates with wall thickness.
Unlike in IHD, the subendocardium is not necessarily affected.
Unlike DCM, the distribution is typically more diffuse and not specific to mid-wall circumferential fibres.

19. Detection of Fibrosis: Inversion Recovery Sequence
Tips to confirm fibrosis and not artefact:
Phase swap each slice
If mid-wall enhancement is seen, ensure TI is optimal and if need be, repeat the slice with a different TI
Cross-cut through any areas of suspected mid-wall enhancement
If subendocardial enhancement is seen, reconsider the diagnosis or assess if this reflects ‘bystander’ coronary disease
It is common to see some fibrosis around the LVOT and at the RV/LV septal insertion points

20. Assessment of Fibrosis
late enhancement in the septum reflecting fibrosis

21. RV insertion point enhancement
2 spots of enhancement at RV insertion points
The 3rd point is artefact
– Present AP phase encoding, disappears head-foot.
This is artefact ghosting across the image.

22. Other techniques: perfusion
Rest Perf
Late Gd
Perfusion defects in HCM – uncertain significance;
here matching enhancement

23. Summary
Evaluate function, volumes, maximal wall thickness, distribution of hypertrophy and overall mass index.
Flow mapping to assess LVOTO
Presence of fibrosis important using inversion-recovery Gd-DTPA