Background: It has been recently demonstrated that the hemodynamic consequences of exercise-induced increase in left ventricular (LV) filling pressure can be demonstrated noninvasively with supine bicycle exercise Doppler echocardiography. One of the practical drawbacks of Doppler echocardiography for assessing LV filling during exercise is the technical difficulty obtaining adequate signals for meaningful analysis during the rapid heart rates achieved during exercise. The purpose of this study was to assess LV filling pressures during the recovery period, as well as at rest, in healthy subjects to establish reference values of Doppler LV filling indices during recovery after exercise.
Methods and results: Seventy-three healthy subjects (age 38+/-14 years, 62 males) underwent supine bicycle exercise. Mitral inflow and annular velocities were recorded at baseline and during recovery at 2, 5, and 10 min after cessation of exercise. The ratio of the mitral inflow early diastolic filling velocity (E) to the mitral annular early diastolic velocity (E') was used as an estimation of mean left atrial pressure (E/E'). The mean E/E' ratio at rest was 7.6+/-1.8 and it was <15 in all patients. Mean exercise duration was 837+/-184 s (range, 390-1,260). The E/E' ratio during recovery 2, 5, and 10 min after cessation of exercise was 8.8+/-1.9, 8.2+/-2.0 and 7.8+/-1.8, respectively, and none of the patients had an E/E' >15 during the recovery phase.
Conclusion: In healthy subjects, the E/E' is less than 15 at rest, as well as during the recovery period up to 10 min after cessation of exercise. Because the E/E' is not elevated in healthy subjects, an elevated E/E' during the recovery period may be helpful for detecting exercise-induced diastolic dysfunction in subjects with tachycardia, even with low levels of exercise.