(3) Disease. Disease conditions may cause abnormal increase or decrease
of blood pressure.
e. In patients with hypertension or other cardiovascular disease, it is best to
measure blood pressure in both the right and left arms. There should be no more than
5 mmHg difference between the two readings. A greater difference is indicative of
vascular disease.
f. The physician may order blood pressure checks to be done with the patient
lying down, sitting, and standing. The corresponding rise or fall in pressure with the
change of position may give the physician valuable information about the nature of the
cardiovascular disease.
g. Pulse pressure is the difference between the systolic and diastolic pressures.
Normal range for pulse pressure should be 30-50 mmHg, with 40 mmHg the average.
(1) A decreased pulse pressure (less than 30 mmHg) is related to factors
that cause an increase in the diastolic blood pressure, a decrease in systolic blood
pressure, or a combination of both. Causes of decreased pulse pressure included
peripheral vasoconstriction, aortic valve stenosis, mitral valve insufficiency, or
decreased stroke volume due to heart failure or hypovolemia.
(2) An increased pulse pressure (greater than 50 mmHg) is related to
factors that cause a decrease in the diastolic blood pressure, an increase in systolic
blood pressure, or both. Causes of increased pulse pressure include hypertension,
circulatory overload, arrhythmias, increased stroke volume caused by anxiety or
exercise, or decreased distensibility of the arteries as seen in arteriosclerosis and aging.
Section III. CARDIOVASCULAR DISORDERS
1-21. CORONARY ARTERY DISEASE
Coronary artery disease (CAD) is the condition in which the coronary arteries
cannot deliver adequate blood supply to the heart muscle to meet the tissue demand.
This condition is characterized by obstruction or narrowing of the vessel lumen.
Coronary artery disease has been linked with certain "risk factors." In general, the more
risk factors associated with an individual, the greater the chance for development of
CAD. Some risk factors cannot be changed, while other risk factors can be modified or
eliminated. Patient education is an important aspect of the nursing care of patients with
CAD because the educated patient can take steps to improve his condition.
MD0917
1-21