A lecture on the echocardiographic evaluation of hypertrophic cardiomyopathy. Starts with an overview of the topic then a systematic approach to diagnosis and then a differential diagnosis followed by take-home messages and conclusion.

1. Senior Clinical Fellow, Adult
Intensive Care
Royal Brompton Hospital,
London, UK
Dr. Hatem Soliman Aboumarie
MBBS, MRCP, MSc, Dip. Cardio. (London), ASCeXAM (USA)
Echo evaluation of
Hypertrophic Cardiomyopathy

2. Background
Approach
Predictors of unfavorable outcome
Tips and Tricks
Take Home messages
Overview
?
What is HCM?
Classification

3. A common genetic cardiovascular disease with the overall prevalence of
0.05-0.2% of the population (1)
Unexplained, marked and asymmetric LV hypertrophy associated with non
dilated ventricular chambers in the absence of another cardiac or systemic
disease(2)
Background
TTE  screening algorithm for family members
(1) 2011 ACC/AHA guidelines (2) 2015 ESC Guidelines.

4. Classification (distribution of hypertrophy)
I (anterior septum)
II (anterior + inferior septum)
III (anterior + inferior septum + lateral wall
IV (apical, etc.)
EACVI Echo Handbook 2015

5. Systematic Approach
Confirming LV hypertrophy
Assessment of LVOT Obstruction
Assessment for Systolic anterior motion of the mitral valve (SAM)
Assessment of LV Systolic function
Assessment of LV Diastolic function and LA size

6. Confirming left ventricular hypertrophy
It preferentially involves the septum in the basal LV segments but often
extends into the lateral wall, posterior septum and LV apex.
The following 2D echocardiographic criteria are used to aid diagnosis:
Unexplained maximal wall thickness >15 mm in any myocardial segment,
Septal/posterior wall thickness ratio >1.3 in normotensive patients,
Septal/posterior wall thickness ratio >1.5 in hypertensive patients
or
or

7. Although HCM is typically characterized by asymmetric septal hypertrophy
(ASH), almost any myocardial segment may be involved.
Top Tips!
Assessment must include the measurement of maximal wall thickness in all
LV segments from base to apex, ensuring that the wall thickness is recorded
at mitral, mid-LV and apical levels.

8. Asymmetric LVH is not pathognomonic of HCM. may be encountered in a
variety of congenital or acquired conditions, including RVH, systemic
hypertension, Aortic stenosis and Amyloidosis.
Top Tips!
In first-degree relatives, lower cut-off values are used,
and a WT ≥ 13 mm in the anterior septum or posterior
wall suggests the diagnosis
Genotype positive adults (including those who die suddenly) may have
normal or near normal wall thickness.

9. Systematic Approach
Confirming LV hypertrophy
Assessment of LVOT Obstruction
Assessment for Systolic anterior motion of the mitral valve SAM
Assessment of LV Systolic function
Assessment of LV Diastolic function and LA size

10. Associated abnormalities of LVOT:
Management strategies are largely dependent on the
presence or absence of symptoms caused by obstruction.
1/3  obstruction under resting conditions (gradients ≥30 mm Hg).
1/3  labile, physiologically provoked gradients (<30 mm Hg at rest and
≥30 mm Hg with physiologic provocation)
1/3  non-obstructive form of HCM (gradients <30 mm Hg at rest and
with provocation).
?
Why
Physiologic provocation = Exercise, Valsalva and standing

11. Dagger shaped

12. LVOT gradients ≥50 mm Hg (at rest or with provocation)  conventional
threshold for surgical or percutaneous intervention if symptoms cannot be
controlled with medications.
Top Tips!

13. ↗ with ↗ myocardial contractility,↘ ventricular volume, or ↘ afterload
Top Tips!
LVOT obstruction is dynamic with loading conditions!

14. Sub-aortic membranes, mitral leaflet abnormalities and mid-cavity
obstruction
Top Tips!
When a gradient is detected in the LV cavity, it is important to
systematically exclude obstruction that is unrelated to SAM especially
when planning interventions

15. Exercise stress echocardiography is recommended in symptomatic patients if
bedside maneuvers fail to induce gradient ≥50mm Hg.
Assessment of latent obstruction
Dobutamine stress test is not recommended (not physiological and can be
poorly tolerated).
Nitrates are not recommended  Reserved for patients who cannot exercise.

16. Other Echo features of obstructive HCM
Mid-systolic closure of the aortic valve
Fibrotic changes at the level of leaflet- septal contact
Coarse systolic fluttering of the aortic valve

17. Apical HCM (Yamagushi)
A rare form of hypertrophic cardiomyopathy (HCM) which usually involves the
apex of the left ventricle
Was thought to be confined to the Japanese population. (13% of all HCMs in
Japanese as compared to 3% in the USA population)
Giant T-waves in ECG is characteristic.

18. Apical HCM (Yamagushi)

19. Systematic Approach
Confirming LV hypertrophy
Assessment of LVOT Obstruction
Assessment for Systolic anterior motion of the mitral valve SAM
Assessment of LV Systolic function
Assessment of LV Diastolic function and LA size

20. Mitral Valve in HCM
Leaflets: anterior leaflet elongation; dysplasia, prolapse
Chordae: elongation, laxity, hypermobility
Papillary muscles: hypertrophy, bifidity, abnormal anterior position,
abnormal insertion in the anterior leaflet

21. Venturi Effect

25. SAM of the mitral valve  failure of normal leaflet coaptation and mitral
regurgitation (typically mid-to-late systolic and posteriorly oriented)
Mitral regurgitation
Central or anteriorly directed jet of mitral regurgitation  an intrinsic
mitral valve abnormality  further assessment with TOE if necessary.
Top Tip

26. Systematic Approach
Confirming LV hypertrophy
Assessment of LVOT Obstruction
Assessment for Systolic anterior motion of the mitral valve SAM
Assessment of LV Systolic function
Assessment of LV Diastolic function and LA size

27. Ejection fraction usually is preserved despite significant impairment of
longitudinal contractile function, evidenced by ↘ MAPSE, S’, Strain and
Strain rate.
Assessment of systolic function Early
Strain imaging  identify regional heterogeneity in contractile function

28. Myocardial fibrosis  progressive impairment of systolic function  end-
stage HCM.
Assessment of systolic function Late
Deterioration of systolic function  ↗ mortality (11% per year) and sudden
cardiac death.

29. Systematic Approach
Confirming LV hypertrophy
Assessment of LVOT Obstruction
Assessment for Systolic anterior motion of the mitral valve SAM
Assessment of LV Systolic function
Assessment of LV Diastolic function and LA size

30. Left atrial (LA) volume is largely determined by the presence of diastolic
dysfunction, mitral regurgitation, and atrial myopathy.
Left atrial enlargement
The EACVI guidelines recommends using Left Atrial volume index (Normal
LAVI= 22 ± 6 ml/m2).
LA enlargement as assessed from linear dimensions was shown to
independently predict long-term prognosis in patients with HCM (not
accurate)

31. LAVI  a long-term independent indicator of functional capacity
Top Tip
LAVI >34 ml/m2 has been shown to be predictive of a greater degree of
LVH, severity of diastolic dysfunction, and adverse cardiovascular
outcomes.

32. Patients with HCM often have diastolic dysfunction regardless of symptoms
or presence of LVOT obstruction.
Assessment of diastolic function
Assessment of LV filling pressures is helpful in the evaluation of symptoms
and disease staging  Patients with a restrictive LV filling pattern may be
at higher risk for adverse outcome, even with a preserved ejection fraction

33. TDI has become standard in most tertiary centers managing patients with
cardiomyopathies.
Tissue Doppler Imaging (TDI)
TDI is very useful in D.D Pathological LVH (HCM, HTN) and athlete’s heart.
Mean systolic annular velocity (S’) <9 cm/s is D.D pathological LVH from
athlete’s heart (diagnostic accuracy of 92%).

34. TDI is an angle-dependent technique, influenced by cardiac translational
motion and tethering.
Tissue Doppler Imaging (TDI) Pitfall

35. 2D strain allows angle-independent, spatial and temporal tracking of
longitudinal, circumferential and radial myocardial deformation.
2D strain or speckle tracking imaging
Significant ↘ strain in the septal segments (particularly the mid-septal
segment), correlate with the septal/posterior wall ratio

36. ↘ longitudinal strain with basal to apical gradient, ↗ circumferential strain,
normal systolic twist or torsion, and ↘ untwisting in diastole.

37. Insights into the mechanics of SAM and deformational geometry of the LVOT
3D Echocardiography
Facilitates the assessment of LVOT area after surgery for septal reduction,
surgical myectomy

38. Should be considered in patients with poor TTE windows
Transesophageal Echocardiography (TOE)
In patients with LVOTO if the mechanism is unclear
When assessing the MV apparatus before a septal reduction procedure
When severe MR caused by intrinsic valve abnormalities is suspected.
?When
Peri-operative TOE: guide surgery and detect complications (VSD, AR)

39. Enhance endocardial definition, Doppler signals, and to evaluate myocardial
perfusion.
Contrast echocardiography
Can help anticipate the location and delineate the extent of septal
infarction (selective injection of contrast into septal perforators) before
alcohol septal ablation.

40. Echocardiographic predictors of unfavorable outcome
Sudden death: Maximal wall thickness >30mm
HCM related death: LVOT gradient at rest >30mmHg, EF <50%
All-cause mortality: Left atrial diameter >48mm
Intraventricular dyssynchrony: delay > 45 ms.
Heart failure: LA volume >27ml/m2 at baseline or during follow up
Alarms!

41. Criteria favoring HCMP vs Physiological LVH (athlete’s heart)
Systolic mitral annual velocity S’ <9m/sec
Diastolic dysfunction
Lack of LVH regression after cessation of exercise
Lack of LV dilatation
Provocable LVOT gradient
Attenuated longitudinal strain
Intraventricular dyssynchrony

42. Echocardiographer Checklist for HCM (EACVI)
Presence of hypertrophy and its distribution; maximum
LV global systolic function (EF) + comments on regional wall motion
V diastolic function and filling pressures
Parameters of regional systolic and diastolic function
Pulmonary artery systolic pressure

43. Echocardiographer Checklist for HCM (EACVI)
Dynamic obstruction at rest and with provocation, site and gradient.
Mitral valve and papillary muscle evaluation
RV hypertrophy and comment on RV dynamic obstruction
Left Atrial Volume Index
Mitral regurgitation: Direction, mechanism and severity

45. TTE is the most readily useful tool in the diagnosis of HCM. It is also the
first noninvasive imaging method for risk stratification, treatment
selection and follow up of the patients.
Take-home messages
2D Strain is a simple, rapid, and reproducible method to early detection
of abnormalities in patients with HCM

46. Thank
You
hatem.soliman@gmail.com
@hatemsoliman
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