Anrep effect
Encyclopedia
The Anrep effect is an autoregulation method in which myocardial contractility
increases with afterload
. It was experimentally determined that increasing afterload caused a proportional linear increase in ventricular
inotropy.
This effect is found in denervated heart
preparations, such as the Starling Preparation, and as such, represents an intrinsic autoregulation mechanism.
The Anrep effect is named after Russian physiologist Gleb von Anrep (1889 - 1955), who described it in 1912.
Functionally, the Anrep effect allows the heart to compensate for an increased end-systolic volume present and the decreased stroke volume that occurs when aortic blood pressure increases. Without the Anrep effect, an increase in aortic blood pressure
would create a decrease in stroke volume that would compromise circulation to peripheral and visceral tissues.
Contractility
Myocardial contractility is the intrinsic ability of the heart to contract independent of preload and afterload. Changes in the ability to produce force during contraction result from different degrees of binding between myosin and actin filaments...
increases with afterload
Afterload
Afterload is the tension or stress developed in the wall of the left ventricle during ejection. Following Laplace's law, the tension upon the muscle fibers in the heart wall is the product of the pressure within the ventricle, multiplied by the volume within the ventricle, divided by the wall...
. It was experimentally determined that increasing afterload caused a proportional linear increase in ventricular
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
inotropy.
This effect is found in denervated heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
preparations, such as the Starling Preparation, and as such, represents an intrinsic autoregulation mechanism.
The Anrep effect is named after Russian physiologist Gleb von Anrep (1889 - 1955), who described it in 1912.
Functionally, the Anrep effect allows the heart to compensate for an increased end-systolic volume present and the decreased stroke volume that occurs when aortic blood pressure increases. Without the Anrep effect, an increase in aortic blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
would create a decrease in stroke volume that would compromise circulation to peripheral and visceral tissues.
Sources
- von Anrep G. On the part played by the suprarenals in the normal vascular reactions of the body. J. Physiol. 1912 Dec 9;45(5):307–317