PDE3 inhibition and pacing result in an increase in Ca2+- dependent myofilament activation resulting in a leftward movement of the pressure-volume loop and smaller LV volumes. Thus, the ventricle begins to fill at a smaller volume and spends more of its filling on the flatter, nonexponential segment of the diastolic PVR, whereas a prolongation of diastole with heart rate–lowering drugs may do the opposite.
Bibliographical noteFunding Information:
Dr Meyer was supported by grant R01 HL-122744 from the National Institutes of Health.
© 2021 Lippincott Williams and Wilkins. All rights reserved.