the decrease in chronotropic and inotropic heart reserve , associated with hypothyroidism , is shown to be rooted in slowed-down relaxation of left ventricular posterior wall in the presence of diastolic arterial hypertension , while limited working capacity , associated with thyrotoxicosis , is rooted in resting myocardial hyperfunction due to hyperkinetic circulation .
C0018787
heart
C0027061
myocardial