What is the clinical standard of chronic arterial hypertension?
Greater than or equal to 140/90 over several weeks or months
What is hypertension a leading risk factor for?
What is hypertension a major contributor to?
morbidity and mortality associated with heart failure, coronary artery disease, atherosclerosis, and renal insufficiency
What occurs if hypertension is left untreated?
It gets worse over time and must be treated with medication
More attention is now being paid to reduction of high systolic or pulse pressures: why?
Because of the effect of these variables on myocardial afterload and oxygen demand
Several causes of secondary hypertension are? (6)
Renal artery stenosis, renal parenchymal disease, primary aldosteronism, pheochromocytoma, aortic coarctation, and thyrotoxicosis
Renal artery stenosis:
1. What occurs to the renal arteries?
2. Causes what down stream from the stenosis?
3. How does the body counteract?
1. atherosclerotic plaques in one or both
2. reduced arterial pressure --> reduced water and sodium excretion
3. Activation of the renin-angiotensin system and elevated plasma A II
Renal parenchymal disease
Impairs kidney's ability to do what?
To excrete sodium and water
Hypersecretion of aldosterone results in?
Abnormal retention of salt and water
What does the tumor secrete? What is the result?
Epinepherine and norepinepherine result in elevated peripheral resistance
1. What is CO like?
2. Where is there going to be elevated arterial pressure?
3. Where is the blood pressure normal?
2. Because CO is normal, there will be increased pressure upstream from the coarctation - will read a higher BP in the brachial arteries
3. Normal after the coarctation - will read normal BP in the lower extremities
1. What is this?
3. ONLY form of chronic arterial hypertension caused by elevated ____ with essentially normal ____ ____.
1. Excessive production of thyroid hormone with resultant increase in metabolic activity of all tissues including the heart
2. Increased CO and HR
3. CO; vascular resistance
130/85 - 139/89
Stage one hypertension range?
140/90 - 159/99
Stage two hypertension range?
160/100 - 179/109
Stage three hypertension range?
180/110 - 209/119
Stage four hypertension range?
GREATER than or equal to 210/120
Stages 1-4 required pharmacological intervention. What level is considered a serious threat to the patients immediate well being?
Greater than or equal to 160/100 (Beginning of stage 2)
What are some initiating factors?
Genetics, renal, CNS, sodium
Salt dependent hypertension has been associated with an especially high incidence of ____.
How can this be attenuated?
Increase in dietary K+ consumption
What occurs to the baroreceptors in hypertensive individuals?
They are both re-set to a higher mean arterial pressure reference point AND de-sensitized to any increases in mean arterial pressure
Normal plasma renin levels when arterial pressure goes up in normotensive individuals?
What happenes with hypertensive individuals?
The renin levels should reflexively decrease
Plasma renin levels are not decreased in patients so their "normal" value for plasma renin activity is actually unacceptably high and suggest there must be a defect in the regulatory mechanism involving the renin-angiotensin system
Mean arterial pressure = ______ x _____
Cardiac output X vascular resistance
What are the three ways to sustain an elevation of mean arterial pressure?
However - it has been known that ___ is normal in patients with essential hypertension (except in ____)
1. Increased CO
2. Increased vascular resistance
3. Increase CO and increased vascular resistance
Because there is normal CO (except for thyrotoxicosis) there must be an ____ ____ ___ ___. And thus hypertension is classified as a ____ disease.
Elevated peripheral vascular resistance; vascular
Two major types of vascular change that contribute to increased resistance?
1. Changes in the structure of the arterial wall
2. Functional changes in the responsiveness of arteries to vasoactive agents
What can occur to the structure of the arterial wall?
Thicken and thus narrow the lumens
How do vascular walls thicken?
Smooth muscle hypertrophy and hyperplasia as well as increased accumulation of water and connective tissue in the arterial wall
For the same degree of muscle shortening, an artery with a thickened wall will exhibit a greater increase in ___ as compared to a thinner walled artery.
What mitogens can lead to vascular wall thickening in the absence of an elevation in arterial pressure?
Norepinepherine, Angiotensin II and endothelin
Arteries from hypertensive individuals and animals exhibit excess production of ____ ___ ____ such as ____ ____.
Reactive oxygen species; superoxide anion
ROS are _____ and _____. In addition they damage the arterial endothelium and ______ chemically quenches ___.
mitogenic; vasoconstrictive; superoxide; NO