Journal of the American Society of Echocardiography
Imaging StrategiesA Practical Approach to Echocardiographic Imaging in Patients With Hypertrophic Cardiomyopathy
Section snippets
Objective
Hypertrophic cardiomyopathy (HCM) is defined by the presence of left ventricular (LV) hypertrophy with a wall thickness in any segment ≥15 mm in the absence of other potentially causative cardiac, systemic, syndromic, or metabolic diseases associated with myocardial wall thickening.1,2 It is a heterogeneous disease with variability in phenotype, clinical expression, hemodynamic profile, and prognosis. Despite a prevalence estimated from 1:500 to as high as 1:200, HCM is frequently unrecognized
Indications for Echocardiography in HCM
A comprehensive transthoracic echocardiogram (TTE),5 utilizing an HCM-specific protocol,1,2,4 is recommended if there is suspicion for HCM such as in the following clinical scenarios:
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Survivor of a suspected HCM-related sudden cardiac arrest.
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Confirmed diagnosis of HCM in a first-degree relative.
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Symptoms suggestive of HCM including dyspnea or chest pain with exertion (often worse postprandially or with dehydration), palpitations, syncope/near-syncope.
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Systolic murmur suggestive of outflow
Goals of the Echocardiographic Examination for HCM
During the process of image acquisition, there are crucial data elements that must be integrated into the echo report given their importance in patient management:1,2,4, 5, 6, 7, 8, 9
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LV wall thickness: accurate quantitation of the degree and location of maximal LV wall thickness is critical for diagnosis (≥15 mm or ≥13 mm with gene variant positivity or if present in a family member of a patient with HCM) and risk stratification. While HCM is often characterized by asymmetric septal
Technical Considerations for Performing TTE in HCM
The echocardiographic evaluation of a patient with known or suspected HCM should be comprehensive yet tailored to address the unique features of the individual patient. Table 1 provides guidance on key features of the echocardiographic protocol tailored for this patient population, and a sonographer worksheet specific for patients with HCM is provided as a Supplementary Table.
Practical Considerations for Stress Echocardiography in HCM
There are important differences in patient preparation for exercise testing in HCM in contrast to studies performed for ischemia evaluation. Exercise echocardiography has recognized limitations when employed for evaluation of epicardial obstructive coronary disease in patients with HCM.2 The primary clinical utility of stress echocardiography in HCM is to identify occult LVOTO and dynamic MR, which may be responsible for effort-related symptoms in such individuals. Therefore, the stress echo
Considerations for Serial Echocardiography for Patients on Myosin Inhibitor Therapy
As noted previously, therapy with the novel cardiac myosin inhibitor, mavacamten, mandates regular echocardiographic imaging to guide dosing based on the LVOT gradient and to monitor for excessive reduction in LVEF. During the initiation phase of mavacamten therapy an echocardiogram is required every 4 weeks until week 12. The maintenance phase then requires an echocardiogram every 12 weeks indefinitely while on treatment. During this early experience with the use of mavacamten, some centers
Considerations for Echo Imaging After SRT
The 2020 American College of Cardiology/American Heart Association guidelines1,4 for the diagnosis and treatment of patients with HCM provide a class 1 recommendation for the performance of an echocardiogram 3 to 6 months after SRT. However, a limited predischarge examination should be performed if there is concern for complications including a ventricular septal defect, new or worsening aortic or MR, or a pericardial effusion. It is important to recognize the difference between an unroofed
Reporting
The following key features should be noted in the final impressions of a resting TTE report in a patient with HCM or concern for HCM:
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Left ventricular ejection fraction and LV size (based on indexed volume)
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Pattern of hypertrophy (basal septal, reverse septal curvature, apical, etc.)
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Site and severity of maximal wall thickness
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The presence, location, and severity of obstruction both at rest and with provocation
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The presence of an apical aneurysm (and presence of apical thrombus)
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Severity and
Conclusion
Hypertrophic cardiomyopathy is a common condition with a diverse phenotypic expression that all too often goes unrecognized or is misdiagnosed. Echocardiography plays a fundamental role in the diagnosis, risk stratification, and ultimately the management of patients with this disorder. Due to variable disease-specific manifestations and dynamic pathophysiology, HCM-specific echocardiographic imaging protocols are essential for comprehensive assessment under resting and exercise conditions. This
REVIEW STATEMENT
Given his role as Associate Editor, Sherif F. Nagueh, MD, FASE, had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Rory B. Weiner, MD, FASE.
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Cited by (4)
Septal Perforator Artery Doppler Flow in Hypertrophic Cardiomyopathy: Searching for Clinical Applicability
2024, Journal of the American Society of EchocardiographyRole of Imaging in the Diagnosis, Evaluation, and Management of Hypertrophic Cardiomyopathy
2024, American Journal of CardiologyObstruction in Hypertrophic Cardiomyopathy: Many Faces
2024, Journal of the American Society of EchocardiographyReal-world experience with mavacamten in obstructive hypertrophic cardiomyopathy: Observations from a tertiary care center
2024, Progress in Cardiovascular Diseases
Conflicts of Interest: C.C.M. has authored textbook chapters for Elsevier and is the recipient of a W. L. Gore & Associates contracted research grant to the University of Wisconsin–Madison. M.J. is a consultant for Caption Health, is a consultant for and has received an honorarium from Bristol Myers Squibb, and is on the advisory board of Echo IQ. J.S. has received research support from Bristol Myers Squibb, Cytokinetics, Imbria Pharmaceuticals, and CorVista Health. T.A. has no financial conflicts but is a site investigator, steering committee member, or publications committee member for trials sponsored by Bristol Myers Squibb, Cytokinetics, and Tenaya Pharmaceuticals. M.D. is a consultant for Bristol Myers Squibb, Cytokinetics, and Medtronic. M.W.M. receives financial support from Bristol Myers Squibb, Cytokinetics, and Major League Soccer. D.P. is a consultant for Caption Health and a speaker for Pfizer and Bristol Myers Squibb. The remaining authors have no conflicts to report.
Rory B. Weiner, MD, FASE, served as guest editor for this report.