Clinical Scorecard: Detection of Midapical Obstruction in Hypertrophic Cardiomyopathy via Midsystolic Doppler Signal Absence

At a Glance

Key Highlights

• A midsystolic Doppler signal void was present in 142 of 606 patients (23.4%).

• Doppler gradients may underestimate midapical obstruction when forward flow ceases during systole.

• Signal void reflects dynamic apposition of hypertrophied midapical myocardial walls.

• Signal void was associated with pronounced regional hypertrophy, smaller cavity size, lower absolute global longitudinal strain, elevated cardiac troponin I, and apical aneurysm.

• The marker identified a distinct midapical HCM phenotype, but longitudinal clinical outcomes were not evaluated.

Guideline-Based Recommendations

This observational study did not issue clinical guidelines; the points below reflect its methods, findings, and clinical implications.

Diagnosis

• The study defined HCM as maximal left ventricular wall thickness of at least 15 mm, or at least 13 mm with a family history or pathogenic genetic finding.

• Signal void required continuous-wave Doppler aligned with the midapical left ventricular cavity, showing abrupt attenuation or near-complete absence of the velocity envelope during midsystole after initial systolic acceleration.

Management

• Signal void may prompt targeted downstream imaging and inform management, but its diagnostic and prognostic value requires prospective validation.

Monitoring & Follow-up

• Echocardiographic assessment may include left ventricular morphology, intracavitary flow, global longitudinal strain, and evaluation for apical aneurysm.

• Prospective longitudinal studies are needed to determine whether early detection modifies clinical outcomes.

Risks

• Signal void was associated with adverse structural features, including apical aneurysm and impaired longitudinal deformation.

• The study did not establish that signal void independently predicts sudden cardiac death or arrhythmic events.

Patient & Prescribing Data

The study included 606 consecutive patients with HCM evaluated from November 2021 through December 2024.

Patients with significant valvular heart disease, prior septal reduction therapy, or known infiltrative or storage disorders were excluded. Comprehensive medication-exposure data were not available for all participants.

Clinical Best Practices

• Perform comprehensive transthoracic echocardiography using standardized HCM imaging approaches.

• Align continuous-wave Doppler with the midapical left ventricular cavity and confirm findings across multiple acoustic windows and cardiac cycles.

• Exclude signal loss caused by Doppler misalignment or inappropriate gain settings.

• Consider contrast echocardiography, cardiac CT, or cardiac magnetic resonance when standard transthoracic echocardiography is suboptimal or further anatomic clarification is required.

Related Resources & Content

• Recommendations for Multimodality Cardiovascular Imaging of Patients With Hypertrophic Cardiomyopathy: An Update From the American Society of Echocardiography, in Collaboration With the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography — Authors: Sherif F. Nagueh, Dermot Phelan, Theodore Abraham, Alicia Armour, Milind Y. Desai, Andreea Dragulescu, Yvonne Gilliland, Steven J. Lester, Yasdet Maldonado, Saidi Mohiddin, Koen Nieman, Brett W. Sperry, and Anna Woo; Publication: Journal of the American Society of Echocardiography; Date published: June 2022.

• A Practical Approach to Echocardiographic Imaging in Patients With Hypertrophic Cardiomyopathy — Authors: Carol C. Mitchell, Cody Frye, Madeline Jankowski, John Symanski, Steven J. Lester, Anna Woo, Yvonne Gilliland, Andreea Dragulescu, Theodore Abraham, Milind Desai, Matthew W. Martinez, Sherif F. Nagueh, and Dermot Phelan; Publication: Journal of the American Society of Echocardiography; Date published: September 2023 (online May 7, 2023).

• Doppler Systolic Signal Void in Hypertrophic Cardiomyopathy: Apical Aneurysm and Severe Obstruction Without Elevated Intraventricular Velocities — Authors: Jose Ricardo F. Po, Bette Kim, Farhan Aslam, Milla Arabadjian, Glenda Winson, Deborah Cantales, Josef Kushner, Robert Kornberg, and Mark V. Sherrid; Publication: Journal of the American Society of Echocardiography; Date published: December 2015.

• Obstruction in Hypertrophic Cardiomyopathy: Don’t Forget Midventricular Obstruction — Authors: Kendra M. Gilreath and Jeffrey B. Geske; Publication: Journal of the American Society of Echocardiography; Date published: August 2025.

• 2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines — Authors: Steve R. Ommen, Seema Mital, Michael A. Burke, Sharlene M. Day, Anita Deswal, Perry Elliott, Lauren L. Evanovich, Judy Hung, José A. Joglar, Paul Kantor, Carey Kimmelstiel, Michelle Kittleson, Mark S. Link, Martin S. Maron, Matthew W. Martinez, Christina Y. Miyake, Hartzell V. Schaff, Christopher Semsarian, and Paul Sorajja; Publication: Circulation; Date published: December 22, 2020 (online November 20, 2020).