<prompt> True about stroke volume is?Decreases by increase in hea rateDetermined by pre-diastolic volumeDetermined by afterloadIs equal to cardiac output  <response>: Decreases by increase in hea rate REF: Ganongs 22 e p. 570-571 Stroke volume cardiac outputhea rate amount of blood pumped by hea per beat, hence stroke volume is indirectly propoional to hea rate, hence increases. Hea rate decreases stroke volume. After load is determined by peripheral resistance, hence nothing to do with stroke volume determination. Stroke volume depends upon end diastolic volume. 