Background: Several studies on left ventricular relaxation have been undertaken in the past; however, left atrial (LA) relaxation has not been fully evaluated.
Hypothesis: The purpose of this study was to assess abnormalities in LA relaxation by evaluating pulmonary venous flow velocity and interatrial septal motion using transesophageal echocardiography.
Methods: The subjects were 56 untreated patients in sinus rhythm, including 25 with previous myocardial infarction, 9 with hypertrophic cardiomyopathy, 11 with dilated cardiomyopathy, as well as 11 with chest pain syndrome as controls. Peak first systolic velocity (PVS1), peak atrial systolic velocity (PVA), and their time-velocity integrals (PVS1-I and PVA-I, respectively) were calculated from the pulmonary venous flow velocity.
Results: The PVS1 and PVS1-I correlated negatively with the maximum LA dimension and mean pulmonary capillary wedge pressure, and correlated positively with the amplitude of the interatrial septal motion during LA relaxation and percent fractional LA relaxation. The PVA and PVA-I did not correlate with the mean pulmonary capillary wedge pressure. There was a weak positive correlation between PVA and PVS1, and a close positive correlation between the ratio of PVA to PVS1 and mean pulmonary capillary wedge pressure. Multiple regression analysis indicated that the PVS1 was most closely related to percent fractional LA relaxation, followed by mean pulmonary capillary wedge pressure.
Conclusion: The PVS1 determined from the pulmonary venous flow velocity is closely related to parameters of LA relaxation which may be determined by transesophageal M-mode echocardiography, and the ratio of PVA to PVS1 is useful for noninvasive evaluation of LA pressure.