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Unmasking Latent Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy

Year: 2026

Type: article

Abstract: BACKGROUND: Dynamic left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy may be missed on resting echocardiography, and it requires provocation for detection. CASE SUMMARY: A 41-year-old man with previously classified nonobstructive hypertrophic cardiomyopathy presented with recurrent syncope. Serial echocardiography had demonstrated no significant dynamic LVOT obstruction. During reassessment, repeated Doppler interrogation with Valsalva maneuver revealed variable pressure gradients ranging from 25 to 46 mm Hg. Exercise stress echocardiography further unmasked severe LVOT obstruction, with a peak gradient of 108 mm Hg and worsening mitral regurgitation. Multimodality assessment, including postextrasystolic provocation and invasive hemodynamics, demonstrated comparable augmentation of LVOT gradients. Mavacamten therapy eliminated LVOT obstruction, with no recurrence of syncope. DISCUSSION: Exercise-induced gradients paralleled those obtained with mechanistic provocation, indicating that physiologic stress can reliably reflect the magnitude of latent obstruction. TAKE-HOME MESSAGE: Exercise stress echocardiography, supported by complementary provocation, may provide a practical approach to identify clinically significant latent LVOT obstruction.

Source: JACC Case Reports

DOI: 10.1016/j.jaccas.2026.109898

Authors: Hyunseok Cho, Jihoon Kim, Sang-Chol Lee, Ki Hong Choi, Jeong Hoon Yang

Institutions: Samsung Medical Center, Sungkyunkwan University

Language: English

Topic: Cardiomyopathy and Myosin Studies

Subfield: Cardiology and Cardiovascular Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $850