In order to assess atrial phasic function, 3D echocardiography can be used to acquire simultaneously LV and LA volume curves during an entire beat. From these curves conduit volume can be computed (provided mitral and/or aortic insufficiency is trivial) as the integral of the net, diastolic instantaneous difference between synchronized LA and LV volume curves, beginning at minimum LV cavity volume (yellow vertical line) and ending just before atrial contraction (red vertical line), at the time of the peak of the P wave on the ECG. The same time intervals can be used to calculate reservoir and pump volume. Modified, with permission, from Ref.⁸⁰ ECG, electrocardiogram; LA, left atrium; LV, left ventricle.