
Originally Posted by
Lemonada8
the vasodilation decreases the afterload by increasing the diamater of the vessel. This is seen as a decrease in stretch via the baroreceptors in the aortic arch and carotid, and a reflex tachycardia ensues. By decreasing the preload, more blood is kept in the venous side of the body, but since its being used with exercise ( to lose weight) this blood flow is returned back to the heart which actually helps increase stroke volume because of the increased return (because of the physical activity) along with the increase in basal HR, this helps the weight loss benefits. However it does put additional strain on the heart because of the increase in myocardial O2 demand.
So it doesnt directly affect HR, but does cause a reflex increase in HR.