What is the most common morphology of HCM?
Asymmetrical thickening of the interventricular septum.
What is the LV wall thickness required in order to establish a diagnosis of HCM?
As per the 2020 AHA/ACC guidelines for diagnosis and management of hypertrophic cardiomyopathy, the clinical diagnosis is established by imaging with a "maximal end-diastolic wall thickness of ≥15 mm anywhere in the left ventricle, in the absence of another cause of hypertrophy in adults". Examples of such alternative causes include systemic arterial hypertension, athlete's heart, infiltrative cardiomyopathy, and aortic stenosis.
What percentage of LGE (of LV mass) is associated with an increase in adverse events, such as sudden cardiac death, in patients with HCM?
Greater than or equal to 15%.
Cine sequences demonstrate the characteristic "dumbbell" configuration of midventricular hypertrophic cardiomyopathy (HCM) with nearly circumferential mural thickening of the mid-cavity segments of the heart with relative sparing of the basal and apical segments. In particular, the mid-cavity inferoseptal, anterolateral, and inferolateral segments measured 15 mm, 20 mm, and 24 mm, respectively.
- EDVI = 51 ml/m2
- ESVI = 18 ml/m2
- SVI = 33 ml/m2
- LVEF = 65%
- LVMI = 45 g/m2
There are few scattered patchy areas of mid-wall enhancement, including along the basal anterior and anteroseptal segments as well as in the mid-cavity inferolateral segment, with the LGE representing ~4% of LV mass.
There is associated bi-atrial enlargement. Moderate pericardial and bilateral pleural effusions are also present.
Wall-motion is within normal limits. No apical aneurysmal dilatation. No SAM or LVOT obstruction.