Background: LV hypertrophy (LVH) is associated with reduction of subendocardial coronary flow reserve. Because the subendocardial layer consists mainly of longitudinal fibers, the exaggerated decrease in coronary flow during exercise may result in decrease of longitudinal contractile reserve. Therefore, we hypothesized that LVH is associated with diminished longitudinal contractile reserve in hypertensive patients. Methods: A total of 182 patients with hypertension who complained of exertional dyspnea were enrolled.(mean age: 56.6짹10.3) Patients were classified as follows: patients with normal geometry (Group 1) vs. concentric remodeling (Group 2) vs. LVH (Group 3). Exercise stress echocardiography was performed using a symptom limited, multistage supine bicycle test. Variable Doppler parameters were obtained at baseline, at each stage of exercise, and during recovery. Results: There was no significant difference in baseline characteristics between the three groups. However E/E���, an index of LV filling pressure, was significantly higher in group 3 at rest and during exercise. Although the baseline value of annular systolic tissue velocity(S���) was not significantly different between the three groups at baseline, S��� was significantly lower in group 3 during exercise. The changes of S��� from baseline, the longitudinal contractile reserve, was significantly lower in the LVH group. Multiple regression analysis also showed independent association of LV mass index with peak longitudinal contractile reserve.