Coexisting cardiac diseases and pressure recovery phenomenon contribute to discrepancy between the echocardiographic severity of aortic stenosis and left ventricular hypertrophy

Background: Assessing left ventricular (LV) hypertrophy (LVH) is an important step in the echocardiographic diagnosis of aortic stenosis (AS). We aimed to investigate the causes of discrepancies between the degrees of AS and LVH. Methods: The study subjects consisted of 149 consecutive patients with AS having aortic valve area <2.0 cm² (mean age 72.5 ± 11.9 years, 67 men and 82 women). Coexisting cardiac diseases were determined based on echocardiographic findings and comprehensive clinical judgment. Echocardiographic measurements included LV mass index (LVMI), aortic valve area index (AVAI), transaortic mean pressure gradient (MPG), valvulo-arterial impedance (Zva), energy loss coefficient (ELCo), and energy loss index (ELI). Results: LVMI was not significantly correlated with AVAI and Zva, and had a weak correlation with MPG (r = 0.305, p = 0.0001). There were 55 patients in group A (non-severe AS without significant LVH), 58 in group B (non-severe AS with significant LVH), 7 in group C (severe AS without significant LVH), and 29 in group D (severe AS with significant LVH). Coexisting cardiac diseases were more frequently observed (p = 0.0003) in group B (50 %) than in group A (18 %). In group C, ELCo and (ELI - AVAI)/ELI were significantly greater than in group D (p = 0.043 and 0.007, respectively). Conclusion: Significant LVH seen in less than moderate AS is often due to coexisting cardiac diseases, and there may be an overestimation of AS severity due to pressure recovery among patients with apparently severe AS who do not have significant LVH.