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

OBJECTIVES: The 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. DESIGN: A prospective observational study. SETTING: A university hospital. PARTICIPANTS: Adult patients undergoing cardiac surgery. INTERVENTIONS: Transthoracic echocardiography was performed at baseline and under GA with PPV. MEASUREMENTS AND MAIN RESULTS: Changes 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. CONCLUSIONS: Speckle-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.