To the Editor:

I read with interest the report by Otani et al. , “Impact of Diastolic Dysfunction Grade on Left Atrial Mechanics Assessed by Two-Dimensional Speckle Tracking Echocardiography,” recently published in the JASE . The authors suggest in their conclusions that “[left atrial] volumes increase and [left atrial] reservoir and conduit function decrease as the severity of [left ventricular] diastolic dysfunction progresses.” This is against the findings of a previous study my group published several years ago titled “Increasing Degrees of Filling Impairment Modulate Left Atrial Function in Humans.” In that study, we came to the conclusion that “increased early response to early stage [left ventricular] filling impairment is characterized by augmented reservoir and pump function…which becomes hardly effective at late stage…when conduit in the atrium takes precedence.” The discrepancy between our and Otani et al. ’s findings likely derives from the way pump, reservoir, and conduit function is estimated. We are convinced that computing these proportions using a method that does not take into account the diastolic flow coming from the pulmonary veins when the mitral valve is open (in addition to the blood that has been accumulating in the atrium during the immediately preceding systole) forces, by definition, the investigators to underestimate the conduit function in the atrium. This leads the authors to a conclusion that is not completely compatible with basic physiology.