Multimodality Imaging in Sarcomeric Hypertrophic Cardiomyopathy: Get It Right…on Time

Abstract

Hypertrophic cardiomyopathy (HCM) follows highly variable paradigms and disease-specific patterns of progression towards heart failure, arrhythmias and sudden cardiac death. Therefore, a generalized standard approach, shared with other cardiomyopathies, can be misleading in this setting. A multimodality imaging approach facilitates differential diagnosis of phenocopies and improves clinical and therapeutic management of the disease. However, only a profound knowledge of the progression patterns, including clinical features and imaging data, enables an appropriate use of all these resources in clinical practice. Combinations of various imaging tools and novel techniques of artificial intelligence have a potentially relevant role in diagnosis, clinical management and definition of prognosis. Nonetheless, several barriers persist such as unclear appropriate timing of imaging or universal standardization of measures and normal reference limits. This review provides an overview of the current knowledge on multimodality imaging and potentialities of novel tools, including artificial intelligence, in the management of patients with sarcomeric HCM, highlighting the importance of specific “red alerts” to understand the phenotype–genotype linkage.

Advances in Multi-Modality Imaging in Hypertrophic Cardiomyopathy

“…Proposed molecular mechanisms for explaining the hyper-contractile phenomenon include alterations in the actin-activated β-cardiac myosin chemo-mechanical ATPase cycle, an increased number of functionally accessible myosin heads (i.e., decrease in the super-relaxed state of myosin), and alterations in load dependence contractility that changes the power output of cardiac contraction [10,11]. In this article, we will build on previous reviews [12][13][14][15], published prior to the publication of the ESC cardiomyopathy guidelines, and will outline the role of multi-modality imaging (MMI) in the clinical pathway of HCM. We will explore each modality in turn and discuss their strengths and weaknesses and how an MMI approach provides a holistic and comprehensive assessment in HCM.…”

“…It has utility in diagnoses, monitoring, screening, and prognostication. As shown in Figure 1, TTE enables assessing the severity and pattern of LVH, LVOTO, and mitral valve pathology, as well as both systolic and diastolic function [13]. TTE plays an important role in distinguishing between oHCM and nHCM.…”

“…LVOTO occurs in up to two-thirds of patients with HCM either at rest or only on provocation [13]. LVOTO is a dynamic phenomenon and can vary even within the same patient and is dependent on afterload, preload, and LV contractility.…”

“…Evidence of LVOTO is seen on M-mode, colour Doppler, and pulsed (PW) and continuous wave (CW) Doppler (Figure 3). TTE colour Doppler is used to localize turbulent flow or for aliasing, which indicates increased velocity; then, CW and PW Doppler in the apical 5-or 3-chamber views can be used to precisely localize and quantify any obstruction [13]. In all patients undergoing rest TTE, a Valsalva manoeuvre should be performed: however, due to patients' compli-ance, its efficacy can be variable.…”

“…When the regurgitant jet is eccentric, quantitative assessment, e.g., the proximal isovelocity surface area (PISA) method, can lead to an erroneous estimation of MR severity. The presence of a central or anteriorly directed MR jet should prompt careful evaluation, including with TOE, as MR related to intrinsic mitral valve disease (e.g., mitral valve prolapse, chordal elongation, or rupture with flail) can often occur in patients with HCM and must be addressed separately [2,13]. If there is any concern over intrinsic mitral valve disease, TOE or CMR may enable a better evaluation of the mechanism of MR. LA enlargement provides important prognostic information and the most common mechanisms are SAM-related MR and elevated LV filling pressures [2].…”