ii) Homeometric Autoregulation

A second autoregulatory mechanism not dependent on change in myocardial fibre length. Under conditions of increased aortic pressure (increased afterload) myocardial contractility increases. Initially there is a Frank-Starling response but after a delay of about 30 seconds the contractility increases to maintain stroke volume at the same myocardial fibre length. This is known as the Anrep effect and may have little relevance in the intact heart.