Speckle-Tracking Strain Imaging Identifies Alterations in Left Atrial Mechanics With General Anesthesia and Positive-Pressure Ventilation

ObjectivesThe primary aim of this study was to use speckle-tracking strain imaging to evaluate the effect of general anesthesia (GA) and positive-pressure ventilation (PPV) on left atrial (LA) mechanics. The authors hypothesized that GA and PPV would be associated with a decrease in LA strain. The secondary aims were to investigate the effects of GA and PPV on traditional Doppler-derived measures of LA function and Doppler echocardiographic grade of diastolic function.DesignA prospective observational study.SettingA university hospital.ParticipantsAdult patients undergoing cardiac surgery.InterventionsTransthoracic echocardiography was performed at baseline and under GA with PPV.Measurements and Main ResultsChanges in LA function associated with GA and PPV were assessed using LA speckle-tracking strain imaging. A reduction was observed in LA peak longitudinal strain (24% v 18%, p<0.001) and preatrial contraction strain (13% v 8%, p<0.001). No difference was seen in LA contraction strain or atrial ejection fraction. Indexed LA volume and Doppler diastolic indices also were reduced significantly, and 39% of patients had a change in measured diastolic grade under GA with PPV.ConclusionsSpeckle-tracking strain imaging of the left atrium demonstrated that GA and PPV had a significant impact on LA mechanics by decreasing strain measures of LA preload, with a lesser effect on LA contractility.