Mayer waves are cyclic changes or ''waves'' in

arterial An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...

blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...

brought about by oscillations in

baroreceptor Baroreceptors (or archaically, pressoreceptors) are sensors located in the carotid sinus (at the bifurcation of external and internal carotids) and in the aortic arch. They sense the blood pressure and relay the information to the brain, so that ...

and

chemoreceptor A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemorecep ...

reflex control systems. The waves are seen both in the

ECG Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the hear ...

and in continuous

curves and have a frequency about 0.1 Hz (10-second waves). These waves were originally described by Siegmund Mayer, Ewald Hering and Ludwig Traube hence originally called "Traube–Hering–Mayer waves". Mayer waves can be defined as arterial blood pressure (AP) oscillations at frequencies ''slower'' than respiratory frequency and which show the strongest, significant coherence (strength of linear coupling between fluctuations of two variables in the frequency domain) with efferent sympathetic nervous activity (SNA). In humans, AP oscillations which meet these properties have a characteristic frequency of approx. 0.1 Hz; 0.3 Hz in rabbits and 0.4 Hz in rats. The hemodynamic basis of Mayer waves are oscillations of the sympathetic vasomotor tone of arterial blood vessels, because Mayer waves are abolished or at least strongly attenuated by pharmacological blockade of alpha-adrenoreceptors. Within a given biological species, their frequency is fairly stable; in humans it has been shown that this frequency does ''not'' depend on gender, age or posture. It has been suggested that Mayer waves trigger the liberation of endothelium-derived nitric oxide (NO) by cyclic changes of vascular shear stress which could be beneficial to end organ functioning. Mayer waves are correlated with

heart rate variability Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include: "cycle length variability", "R–R variabi ...

. Takalo et al. (1999) state that "the frequency shift of Mayer waves to lower frequencies is associated with an increased risk of developing established hypertension."

References

{{reflist Medical terminology

See also

References