In physiology, a pressure pulse is the representation of blood pressure in the form of a curve. To be distinguished from this is the cardiac pressure pulse, which corresponds to a bradycardic vigorous pulse with a simultaneous rise in blood pressure and is considered a symptom of rising intracranial pressure. Increases in intracranial pressure may be associated with inflammation, tumors, or cerebral hemorrhage.
What is the pressure pulse?
In physiology, the pressure pulse is the representation of blood pressure in curve form. The pulse is the mechanically rhythmic expansion or contraction of the vessel wall musculature prompted by cardiac action. Sometimes pulse also refers to the electronically measurable and palpable vascular dilation of arteries in specific regions of the body. The heart emits pressure waves that are reflected in the behavior of individual vessels. The recording of the pressure waves or the course of blood pressure during diastole and systole of the heart is called pressure pulse by physiology. This recording is done as a curve plot that can clearly capture the pressure waves. Cardiology also refers to a pressure pulse when there is a certain quality of pulse. Thus, the cardiologist refers to a bradycardic, strong pulse with a simultaneous increase in blood pressure as a pressure pulse. Bradycardia in this context means that the patient’s heart rate slows down despite the increase in blood pressure. As a pulse quality of cardiology, the pressure pulse is pathophysiologically associated and thus symptomatically indicative of pathological body processes.
Function, effect, and goals
The pressure pulse of physiology corresponds to the graphical recording of the course of blood pressure during sys- and diastole of the heart, which is equivalent to a curve plot. Within the aorta lies a slow blood pressure curve with lower values than in the peripheral vessels. The individual vessels in the human body have different anatomical structures. In the periphery of the body, the vessels are somewhat narrower and somewhat less elastic than in the center of the body. These differences in quality lead to differences in the course of blood pressure between the periphery and the center. The differences are noticeable quantitatively as well as qualitatively. In addition, the pressure waves emitted by the heart reflect off vascular branches and sphincter vessels. The reflected pressure waves are pulled back in the direction of the heart, so to speak, which is already emitting the next pressure wave. The reflected pressure waves add up with this newly emitted wave, so that the newly emitted wave is exaggerated. In addition, the newly emitted pressure wave of the heart also reflects again at vascular branches and sphincter vessels, and this reflection gives rise to a weak two-lobe pulse wave, which is also referred to as a dicrotic pulse wave. For this reason, the pressure pulse in the sense of the graphic pulse representation naturally shows a higher blood pressure amplitude in the peripheral vessels than in the center. The term pulse amplitude refers to the relationship that the heart operates in two distinct phases. The first of these is the contraction or ejection phase, also known as systole. The second phase is the relaxation phase or diastole, which is known as the filling or resting phase. For this reason, the heart generates its pressure waves only during the contraction of systole. The difference between peak systolic pressure and minimum diastolic pressure is the pulse amplitude, pulse pressure or blood pressure amplitude. Because of the vascular qualities in the periphery and center, and because of wave reflections, a greater amplitude of blood pressure is present in the pressure pulse measurement even on an examinee in a recumbent position within the legs or feet than within the center. In the vicinity of the heart, the curve of the pressure pulse shows a notch, which is also called an incision. This notch is due to a low backflow of blood against the aortic valves. Closure of the aortic valve usually cancels the incision.
Diseases and conditions
In cardiology, the pressure pulse does not mean the graphic representation with the peculiarities described, but rather a slow and at the same time vigorous pulse associated with blood pressure increase. In this context, the pressure pulse is a possible symptom of pathological body processes. Pathophysiology recognizes the cardiac pressure pulse as a symptom of a rapid increase in intracranial pressure. A rapid increase in intracranial pressure is life-threatening.At some point, the brain no longer has sufficient space when the pressure rises and is ultimately pinched or compressed. Death occurs when autonomic brain areas are compressed. Different disease processes can be responsible for a rapid increase in intracranial pressure and the associated pressure pulse. One of these is a rapidly growing tumor. The tumor tissue expands and thus displaces the nerve tissue of the brain, so that bit by bit the intracranial pressure increases. However, an increase in intracranial pressure does not always have to be associated with tumor disease. Meningitis or other inflammatory processes in the brain tissue can also cause the pressure inside the skull to rise. Microorganisms such as bacteria may be responsible for inflammatory processes in the brain. Autoimmune diseases such as multiple sclerosis can also cause a slight increase in pressure due to inflammatory processes, but this does not usually result in a life-threatening situation and is not typically accompanied by pressure pulses. The situation is different with cerebral edema. Above a certain size, such accumulations of water in the brain can manifest themselves in a rapid increase in intracranial pressure with a pressure pulse. Cerebral hemorrhages in the context of accidental trauma are also life-threatening once the bleeding reaches a certain extent, since the brain tissue can lose space due to the escaping blood, causing the pressure in the brain to rise. In addition to the pressure pulse, rising intracranial pressure is noticeable in symptoms such as clouding of consciousness or unconsciousness, as well as nausea and even vomiting with a severe headache. The compression of brain tissue associated with the increase in pressure can also cause deficits in all bodily processes, such as motor, speech, or cognitive deficits.
