Thickening of muscle fibers ("hypertrophy") to strengthen the heart muscle, which allows the heart to contract more forcefully and pump more blood;
(the heart; to pump; more blood) (the heart muscle; allows; the heart to contract more forcefully and pump more blood) Context(the heart muscle allows,List([58, 88))):(the heart; to contract more forcefully; )
the heart muscle allows,List([58, 88))
the heart the heart muscle the heart
to pump allows to contract more forcefully
more blood
the heart to contract more forcefully and pump more blood