Today's mini been is here! Causes of High Output Cardiac Failure High-output cardiac failure is a heart condition that occurs when cardiac output is higher than the normal due to an increase in peripheral demand. Dr. Mobeen Syed addresses the conditions in which stroke volume increases. For example, in hyperthyroidism, the excessive amount of thyroid hormones act on the heart and increase the heart's metabolic rate. The excessive amount of thyroid hormones act on the tissues as well and increase