The diagnosis of hypertrophic cardiomyopathy by cardiovascular magnetic resonance

Abstract

Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease.

Figure 1

Left ventricular patterns in HCM, each drawing is accompanied by its corresponding image, (A, a) normal LV, (B, b) sigmoid septum showing SAM of mitral valve (white arrow), (C, c) reversed septal contour, note that there is no signs of LVOT, (D, d) mid ventricular hypertrophy, (E, e) Apical HCM, (F, f) symmetric HCM.

Figure 2

Late gadolinium enhancement patterns involving the anterior and posterior RV insertion points, as shown; the interventricular septum is involved, particularly the anteroseptal basal segment (three arrow heads).

Figure 3

Patchy mid wall, variable sized foci of hyperenhancement in a non-coronary distribution, involving mainly the hypertrophied parts (arrow heads). Right ventricle is also hypertrophied (large arrows).