Utility of Transesophageal Echocardiography and Isoproterenol Provocation in Detecting Latent Obstruction in Hypertrophic Cardiomyopathy

Transthoracic echocardiography imaging has traditionally been used to screen for left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy. However, there may be limitations in the ability to diagnose LVOT obstruction using transthoracic echocardiography (TTE). We present 6 symptomatic hypertrophic cardiomyopathy patients without significant LVOT obstruction on TTE imaging who underwent transesophageal echocardiography (TEE) with isoproterenol provocation. Four of the 6 patients developed significant obstruction. Three patients underwent septal myectomy and 1 chose cardiac myosin inhibitor therapy, with significant improvement in their symptoms. Our findings suggest that provocation with isoproterenol during TEE can provide a sensitive assessment for latent systolic anterior motion.