Echocardiography has become an indispensable tool in the management of hypertrophic cardiomyopathy (HCM) in the era of cardiac myosin inhibitors (CMI). With the inclusion of CMIs in the 2023 ESC and 2024 AHA/ACC guidelines as a novel therapeutic option, the role of echocardiography has gained even greater importance.

First, echocardiography is essential for identifying latent left ventricular outflow tract (LVOT) obstruction. Beyond resting studies, maneuvers such as Valsalva and exercise echocardiography are critical to uncover obstructive physiology, which is often under-recognized. In Korean patients, treadmill stress echocardiography is particularly valuable for revealing exercise-induced gradients.

Second, during treatment, echocardiography plays a central role in monitoring drug efficacy and safety. In patients receiving mavacamten, regular assessment of left ventricular ejection fraction (LVEF) and LVOT gradients is mandatory. In addition, evaluation of cardiac structural and functional remodeling—including wall thickness, chamber size, left atrial function, and advanced strain parameters (LV-GLS, LARS)—provides critical insights into therapeutic response.

Third, real-world cases demonstrate the dramatic impact of CMIs. Significant reduction in LVOT pressure gradients, regression of hypertrophy, decreases in left atrial volume, and recovery of LV function has been observed. Individualized treatment strategies are required.

In conclusion, echocardiography serves as the cornerstone of HCM management in the CMI era. It not only enables accurate diagnosis and treatment selection but also provides continuous monitoring of therapeutic response and cardiac remodeling. Through precise echocardiographic evaluation, clinicians can optimize outcomes and move toward a better future for patients with HCM.