This disease, Liu explains, occurs when the heart muscle is too weak to pump enough blood throughout the body.
(Liu; explains; occurs when the heart muscle is too weak to pump enough blood throughout the body) (This disease; occurs; T:when the heart muscle is too weak to pump enough blood throughout the body) (the heart muscle; is; too weak to pump enough blood throughout the body) (the heart muscle; to pump; enough blood; L:throughout the body)
Liu This disease the heart muscle the heart muscle
explains occurs is to pump
occurs when the heart muscle is too weak to pump enough blood throughout the body
T:when the heart muscle is too weak to pump enough blood throughout the body
too weak to pump enough blood throughout the body
enough blood L:throughout the body