Left ventricular diastolic functional reserve during exercise in patients with impaired myocardial relaxation at rest

Background: Patients with similar grade diastolic dysfunction at rest may have a spectrum of alterations in diastolic function during exercise. Objective: To evaluate (a) whether exercise could unmask further diastolic abnormalities not evident during rest; (b) whether diastolic functional reserve during exercise is associated with exercise capacity. Methods: 141 subjects (77 male, mean (SD) age 62 (9)) with abnormal left ventricular (LV) relaxation (mitral E/A 240 ms, underwent graded supine bicycle exercise with simultaneous respiratory gas analysis and two-dimensional and Doppler echocardiographic study. Mitral inflow and annular velocities were measured at rest and during exercise. The LV diastolic function reserve index (DFRI) was calculated. Results: Patients were classified into two groups: group 1 (n = 64), DFRI