Regression of left ventricular hypertrophy after a reduction
in blood pressure has been reported with most
antihypertensive medications. However, the effects
of prolonged exercise on ventricular structure and function
are not clear. The rigorous exercise endured by
athletes can provoke cardiac enlargement. The “athlete’s
heart,” as it is commonly called, is exercise-specific.
Purely aerobic exercises induce enlargement of
the left ventricular cavity, with no changes in left-ventricular-wall
thickness. In contrast, combined isotonic
and isometric exercise (e.g., weight training and rowing)
may lead to substantial hypertrophy of the left ventricular
wall. Nevertheless, exercise-induced left ventricular
hypertrophy is considered a normal physiologic
adaptation to the particularly rigorous training of athletes.
It is not associated with diastolic dysfunction,
arrhythmias, or an adverse prognosis, as is hypertension-induced
left ventricular hypertrophy, and it regresses
quickly with detraining.