Transesophageal echocardiographic evaluation of left ventricular function at rest and during dynamic exercise in...

Transthoracic echocardiography is often of limited value for the evaluation of left ventricular (LV) performance during dynamic exercise (E). Therefore, we studied LV function during maximal E by supine ergometry in 10 normal subjects (N) and 15 patients of aortic regurgitation (AR) with (8) and without (7) symptoms with transesophageal M-mode echocardiography. With this transesophageal approach, where an esophageal transducer is incorporated at the tip of a commercially available gastroscope, good continuous recordings of LV diameter were obtained without being disturbed by respiration or thoracic movement during E. Systolic blood pressure was measured by cuff method and echocardiographic indices such as heart rate, enddiastolic dimension (ED), and fractional shortening (FS) were determined at rest (R) and during maximal E. In N the following significant changes were observed during maximal E; pressure rate product (13 +/- 2 mmHg . min-1 . 10(3) leads to 20 +/0 3 mmHg . min-1 . 10(3), p less than 0.001), ED (51 +/0 5 mm leads to 48 +/- 6 mm, p less than 0.05), and FS (37 +/- 4% leads to 43 +/- 5%, p less than 0.001). In AR no significant change was observed between pressure-rate products in symptomatic and asymptomatic groups at R and during E, respectively. Significant changes in ED during E was observed only in asymptomatic AR (55 +/- 4 mm leads to 51 +/- 6, p less than 0.05). FS was within a normal range in both groups of AR at R. During maximal E, however, symptomatic group exhibited a decrease of FS (33 +/- 7% leads to 28 +/- 5, p less than 0.05), whereas the asymptomatic group showed a significant increase (34 +/- 5% leads to 37 +/- 6%, p less than 0.01). Thus the present study revealed the different response of LV in symptomatic and asymptomatic AR to E in terms of ED and FS.