Cardiology

Cardiology is the medical area of dealing with disorders of the heart. The field includes the medical diagnosis and treatment of various heart defects, coronary artery disease, heart failure, valvular heart decease and electrophysiology.

 

Blood pressure is one of the most important cardiovascular parameters.

 

Blood pressure (BP) fluctuates substantially with behaviour, but the 24-h average BP is tightly regulated. Hypertension is, by definition, a chronic elevation of the 24-h average BP, and the disease is known as neurogenic if the probable cause is an abnormality of the autonomic nervous system rather than a primary vascular or renal defect. This abnormality can originate in the afferent arm of the system (for example, baroreceptors, chemoreceptors and renal afferents) or in the central circuitry.

The neural control of the circulation operates via parasympathetic neurons that innervate the heart and via three main classes of sympathetic efferent — barosensitive, thermosensitive and glucosensitive cardiovascular — that innervate blood vessels, the heart, the kidneys and the adrenal medulla. The barosensitive sympathetic efferents are under the control of arterial baroreceptors. This large group of efferents has a dominant role in both short-term and long-term BP regulation. Their level of activity at rest is presumed to be the most crucial parameter for long-term BP control. This background activity is set by a core network of neurons that reside in the rostral ventrolateral medulla (RVLM), the spinal cord, the hypothalamus and the nucleus of the solitary tract (NTS).