Discrete upper septal hypertrophy (DUSH) is a well-recognized but poorly understood echocardiographic finding that may indicate localized remodeling modulated by pressure loading or a forme fruste variant of obstructive hypertrophic cardiomyopathy (HC). It was hypothesized that (1) a comparison of tissue Doppler indexes of myocardial function in normal patients and those with DUSH or aortic stenosis (AS) could provide insight into the clinical significance of DUSH and (2) these indexes could distinguish between DUSH and obstructive HC. A retrospective analysis was performed on patients aged 50 to 80 years who underwent routine echocardiography and who could be classified into normal, DUSH, AS, and HC groups (n = 25, 33, 23, and 34, respectively) on the basis of clinical and echocardiographic criteria. Early diastolic mitral annular velocities (Ea) in the DUSH (7.1 +/- 1.8 cm/s) and AS (7.1 +/- 1.7 cm/s) groups were lower compared with those in the normal group (9.3 +/- 1.9 cm/s) and higher compared with those in the HC group (5.4 +/- 1.3 cm/s), whereas the E/Ea ratio was higher in the DUSH and AS groups (10.0 +/- 3.1 and 11.3 +/- 2.8, respectively) compared with the normal group (7.1 +/- 1.6) and lower compared with the HC group (18.8 +/- 7.5). These differences remained significant after adjusting for age and the use of beta blockers and calcium channel blockers. E/Ea > or =13 distinguished between patients with HC and those with DUSH (sensitivity 78%, specificity 90%, positive predictive value 90%, negative predictive value 81%). In conclusion, abnormal Ea and E/Ea in patients with DUSH, with values similar to those in patients with AS, suggest that DUSH may represent a variant hypertrophic response to chronic pressure loading. Simple echocardiographic indexes may be helpful in distinguishing between patients with DUSH and those with obstructive HC.