Structural abnormalities in hypertrophic cardiomyopathy beyond left ventricular hypertrophy by multimodality imaging evaluation

Abstract

Background Echocardiography‐ and cardiovascular magnetic resonance (CMR)‐based studies have revealed a wide range of phenotypic manifestations in hypertrophic cardiomyopathy (HCM) apart from hypertrophy. This study sought to comprehensively describe a number of structural abnormalities in HCM beyond hypertrophy, by multimodality imaging. Methods A total of 100 HCM patients were prospectively enrolled, undergoing standard and contrast echocardiography, and CMR. Morphological characteristics involving mitral valve leaflets (MVL), subvalvular apparatus, and left ventricular cavity and wall were investigated. Seventy healthy volunteers served as control population. Results As assessed by echo, MVLs were longer in HCM patients than in controls (anterior method 1: 24[22,28] vs 19[18,20] mm, P < 0.01; anterior method 2: 27[24, 29] vs 21[19, 23] mm, P < 0.01; posterior: 15[12,19] vs 14[13,15] mm, P < 0.01). Abnormal chordal attachment to anterior MVL, anterior papillary muscle displacement, and accessory apical‐basal muscle bundle were present in 42 (42%), 61 (61%), and 35 (35%) patients, respectively (P values vs controls <0.01); direct papillary muscle insertion into MVL and hypertrabeculation were found in two and five patients, respectively. Contrast echocardiography (n = 94) detected myocardial crypts in 15 patients (16%). Overall, 83% of HCM subjects had at least one of these phenotypic manifestations. Echocardiography and CMR agreement for MVL length was poor, while for structural characteristics was moderate to substantial (Cohen's Kappa: 0.53‐1.00). Except for posterior MVL length and hypertrabeculation, the phenotypic characteristics studied had acceptable reproducibility by echocardiography and CMR. Conclusions Structural abnormalities in HCM beyond hypertrophy are significantly common. Multimodality imaging approach to these HCM facets by echocardiography and CMR is feasible and desirable.

Transaortic Shallow Septal Myectomy and Cutting of Secondary Fibrotic Mitral Valve Chordae—A 5-Year Single-Center Experience in the Treatment of Hypertrophic Obstructive Cardiomyopathy

“…MV malformations in obstructive HCM represent a primary phenotypic expression of the disease [ 42 , 43 , 44 , 45 ], thus a surgical procedure is strongly advised for those patients with structural abnormalities of the mitral apparatus [ 27 ]. It is therefore rational that the mitral apparatus should be thoroughly examined before surgery, using multimodality imaging (TTE, TEE, and CMR) and MV repair should be, in our view, part of the standard surgical protocol.…”

Multimodality Cardiac Imaging in Cardiomyopathies: From Diagnosis to Prognosis

“…TTE allows for localization of the hypertrophy and hence identification of different phenotypes: septal, septal reverse, apical, or diffuse HCM, among others (Figure 2). In addition, patients with HCM present ancillary signs that, although non-specific, can help in the diagnosis: papillary muscle abnormalities (hypertrophic, bifid or trifid, and with an apical insertion), false tendons, myocardial clefts or crypts, aneurysms, or mitral valve and subvalvular structure abnormalities (elongated mitral leaflets with/without systolic anterior motion -SAM-) (Figure 3) [5]. Moreover, the presence of LV outflow tract obstruction (LVOTO) can be easily evaluated and is defined as a peak gradient higher than 30 mm Hg at rest or after provocative maneuvers (typically observed as a dagger-shaped curve on continuous wave Doppler, Figure 3D).…”

Comprehensive left ventricular outflow tract management beyond septal reduction to relieve obstruction

“…8 The anatomic elements that contribute to the LVOTO, deriving from an abnormal embryology, consist of the sub-valvular mitral valve (MV) apparatus including anterior papillary muscle (PM) displacement with abnormal insertion, aberrant chordal attachments to the anterior leaflet of the MV (AMVL), and abnormally elongated anterior and posterior leaflet of the MV. 9,10 These structures can interact with the septum, causing systolic anterior motion (SAM) of the MV leading to LVOTO and mitral regurgitation (MR), the hallmarks of the condition. This LVOTO in HOCM patients can vary from one patient to another depending on which elements are involved.…”

“… 8 The anatomic elements that contribute to the LVOTO, deriving from an abnormal embryology, consist of the sub-valvular mitral valve (MV) apparatus including anterior papillary muscle (PM) displacement with abnormal insertion, aberrant chordal attachments to the anterior leaflet of the MV (AMVL), and abnormally elongated anterior and posterior leaflet of the MV. 9 , 10 …”