Comparison of Ventricular Septal Measurements in Hypertrophic Cardiomyopathy Patients Undergoing Surgical Myectomy using Multimodality Imaging and Implications for Diagnosis and Management

Abstract Accurate and reproducible quantification of ventricular septal (VS) thickness in hypertrophic cardiomyopathy (HC) is essential for diagnosis, surgical planning, and risk stratification. We sought to compare VS thickness measurements using transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and cardiac magnetic resonance (CMR) in patients with HC. Prospectively reported measurements of VS thickness were compared using ANOVA and Bland-Altman plots in 90 consecutive patients with HC who underwent a TTE, TEE, and CMR within 3 months. A subset was re-measured on 2 separate occasions by 2 readers to assess inter- and intraobserver variability. There was modest correlation between modalities, with CMR and TTE measurements of VS thickness showing the greatest correlation (CMR vs. TTE, r=0.70; CMR vs. TEE, r=0.60; TTE vs. TEE, r= 0.56). Smaller measurements were seen using CMR vs. either echocardiographic modality (13% smaller vs. TEE; 8% smaller vs. TTE, p