Hypertension Flashcards
There are three primary stimuli for renin secretion:
(1) decreased NaCl transport in the distal portion of the thick ascending limb of the loop of Henle that abuts the corresponding afferent arteriole (macula densa)
(2) decreased pressure or stretchwithin the renal afferent arteriole (baroreceptor mechanism)
(3)sympathetic nervous system stimulation of renin-secreting cells via β1adrenoreceptors.
renin secretion is inhibited by:
increasedNaCl transport in the thick ascending limb of the loop of Henle,
by Increased stretch within the renal afferent arteriole
by β1 receptorblockade.
is a potent pressor substance, the primary tropic factor for the secretion of aldosterone by the adrenal zona glomerulosa.
angiotensin II
the secretion of aldosterone by the
adrenal zona glomerulosa
May play a role in the pathogenesis of atherosclerosis through a direct cellular action on the vessel wall
angiotensin II
The____ induces vasodilation, sodium excretion, and inhibition of cell growth and matrix formation.
Experimental evidence suggests that these receptor improves vascular remodeling by stimulating smooth muscle cell apoptosis and contributes to the regulation of glomerular filtration rate
AT2 receptor
True or false:
AT 1 receptor blockade induces an increase in AT2 receptor activity
True
Renin-producing carcinomas also have been described in
lung, liver, pancreas, colon, and adrenals.
In addition to regulating local blood flow, tissue ___ is a mitogen that stimulates growth and contributes to modeling and repair.
Excess tissue ______ may contribute to atherosclerosis, cardiac hypertrophy, and renal failure, and consequently may be a target for pharmacologic therapy to prevent target organ damage.
angiotensin II
is the primary tropic factor regulating the synthesis and secretion of aldosterone by the zona glomerulosa of the adrenal cortex.
Angiotensin II
True or false:
ACTH is not an important tropic factor for the chronic regulation of aldosterone
True
True or false:
Aldosterone synthesis is also dependent on potassium, and Aldosterone secretion may be decreased in potassium-depleted individuals.
True
True or false
ACTH is an important tropic factor for the chronic regulation of aldosterone.
False
ACTH is not an important tropic factor for the chronic regulation of aldosterone.
Which of the following is true:
- Increased activity of the renin-angiotensin-aldosterone axis is associated with hypertension
- In patients with CHF, low-dose spironolactone reduces therisk of progressive heart failure and sudden death from cardiac causesby 50%.
- Secondary aldosteronism (i.e., increased aldosteronesecondary to increased renin-angiotensin), but not hypertension, also isobserved in edematous states such as CHF and liver disease.
Number 3.
- Increased activity of the renin-angiotensin-aldosterone axis is not invariably associated with hypertension
- In patients with CHF, low-dose spironolactone reduces therisk of progressive heart failure and sudden death from cardiac causesby 30%.
Noninvasive determination of pulse wave velocity between the ___ & ____ arteries is often interpreted as an index of arterial stiffness.
carotid and femoral
a surrogate index of arterial stiffening, is calculated as the ratio of central arterial pressure-to-pulse pressure.
aortic augmentation index,
True or false:
Central blood pressure also appears to be more stronglyassociated with pre-clinical organ damage than brachial blood pressure
True
Ion transport by vascular smooth muscle cells may contribute tohypertension-associated abnormalities of vascular tone and vascular growth, both of which are modulated by
intracellular pH (pHi).
Three ion transport mechanisms participate in the regulation of pHi:
(1) Na+-H+ exchange, (2) Na+-dependent HCO3–-Cl– exchange, and(3) cation-independent HCO3–-Cl– exchange
Na+-H+ exchanger is increased in hypertension, hence increased sodium entry may lead to increased vascular tone by activating Na+-Ca2+ exchange and thereby increasing
intracellular calcium
True or false
Endothelium-dependent vasodilation is impaired in hypertensive patients.
True
is a vasoconstrictor peptideproduced by the endothelium, and orally active endothelin antagonistsmay lower blood pressure in patients with resistant hypertension
Endothelin
True or false
Inflammation and alterations of the immune response have beenimplicated in the pathogenesis of vascular injury and hypertensionfor at least four decades
True
Inflammation,vascular stretch, angiotensin II, and salt have all been shown to result-in the generation of______, which modify T cellfunction and further enhance inflammation.
reactive oxygen species (ROS)
is a key determinant of the set point of the renal pressurenatriuresis curve
ROS within the-renal medulla
True or false
CHF may be related to systolic dysfunction, diastolic dysfunction, or-a combination of the two.
TRUE
True or false
Approximately one-third of patients with CHF have normal systolic function but abnormal diastolic function
True
provides the most accurate assessment of diastolic function
Cardiac catheterization
is the strongest risk factor for stroke.
Elevated blood pressure
True or false
Treatment of hypertension decreases the incidence of BOTH ischemic and hemorrhagic strokes
True
Hypertension is associated with _______, a major pathologic factor in dementia
beta amyloid deposition
Cerebral blood flow remains unchanged over a wide range of arterial pressures (mean arterial pressure of 50–150 mmHg) through a process termed
autoregulation of blood flow.
may include severe headache, nausea vomiting (often of a projectile nature), focal neurologic signs, and alterations in mental status. Untreated, may progress to stupor, coma, seizures, and death within hours.
hypertensive encephalopathy
is the most common etiology of secondary hypertension.
Primary renal disease
True or false:
Renal risk appears to be more closely related to SYSTOLIC than to diastolic blood pressure
True
Atherosclerotic, hypertension-related vascular lesions in the kidney primarily affect_______ arterioles, resulting in ischemic changes in the glomeruli and postglomerular structures
preglomerular arterioles
Clinically these two are early markers of renal injury
macroalbuminuria (a random urine albumin/creatinine Ratio >300 mg/g) or
microalbuminuria (a random urine albumin/creatinine ratio 30–300 mg/g)
is the classic symptom of PAD.
intermittent claudication
is a useful approach for evaluating PAD and-is defined as the ratio of non invasively assessed ankle to brachial (arm)SYSTOLIC blood pressure.
The ankle-brachial index
ABI
An ABI of ____ is considered diagnostic of PAD and is associated with >50% stenosis in at least one major lower limb vessel
ankle-brachial index <0.90
An ankle-brachial index of ______ is associated with elevated blood pressure, particularly systolic blood pressure.
<0.80
True or false
From an epidemiologic perspective, there is no obvious level of blood pressure that defines hypertension.
True
Similarly, results of a meta-analysis involving almost 1 million participants indicate that ischemic heart disease mortality, stroke mortality, and mortality from other vascular causes are directly related to the height of the blood pressure, beginning at ____ mmHg, without evidence of a threshold.
115/75 mmHg
Cardiovascular disease risk doubles for every_____ increase in systolic and ____ increase in diastolic pressure
20-mmHg
10-mmHg
True or false
Among older Individuals, systolic blood pressure and pulse pressure are more powerful predictors of cardiovascular disease than is diastolic blood pressure.
True
Clinical criteria for defining hypertension generally have been based on the average of ________ readings during each of two or more outpatient visits.
two or more seated blood pressure
In children and adolescents, hypertension generallyis defined as systolic and/or diastolic blood pressure consistently ____ percentile for age, sex, and height.
> 95th
90th and 95th percentiles are considered prehypertensive and are anindication for lifestyle interventions
True or false
Blood pressure tends to-be higher in the early morning hours, soon after waking, than at other times of day.
True
Myocardial infarction and stroke are more common in the early morning hours
Nighttime blood pressures are generally lower than daytime blood pressures ___%, and an attenuated nighttime bloodpressure “dip” may be associated with increased cardiovascular disease risk.
10–20%
Recommended criteria for a diagnosis of hypertension, based on 24-h blood pressure monitoring, are average awake blood pressure ____ and asleep blood pressure _______.
These levels-approximate a clinic blood pressure of _____
≥135/85 mmHg average awake blood pressure
asleep blood pressure ≥120/75 mmHg
140/90 mmHg
Approximately 15–20% of patients with stage 1 hypertension based on office blood pressures have average ambulatory reading blood pressure of ____,
termed “white coat hypertension.”
<135/85 mmHg
True or false:
In the majority of patients with established hypertension, peripheral resistance is increased and cardiac output is normal or decreased;
however, in younger patients with mild or labile hypertension, cardiac output may be increased and peripheral resistance may be NORMAL
True
obesity body mass index=
> 30 kg/m2
Most common cause of secondary hypertension
Renal
True or false
hypertension is more severe in glomerular diseases than in interstitial diseases such as chronic pyelonephritis
True
it may be difficult to determine whether hypertension or renal disease was the initial disorder.
What two factors are indicative of primary renal disease.
- Proteinuria >1000 mg/d
2. active urine sediment
Confirmatory test for renal artery stenosis
Contrast afteriography
Screening test for renal artery stenosis
radionuclide [131I]-orthoiodohippurate (OIH) scan,
or glomerular filtration rate may be evaluated with a [99mTc]-diethylenetriaminepentaacetic acid (DTPA) scan before and after a single dose of captopril(or another ACE inhibitor)
Confirmatory test for primary aldosteronism
failure to suppress plasma aldosterone to <277 pmol/L (<10 ng/dL) after IV infusion of 2L of isotonic saline over 4 hours
Screening test for primary aldosteronism
A ratio >30:1 in conjunction with a plasma aldosterone concentration >555 pmol/L (>20 ng/dL)
Screening test for Cushing syndrome
- 24-h excretion rates of urine-free cortisol
- overnight dexamethasone-suppression test
- Late night salivary cortisol
Definitive treatment of pheochromocytoma that results in 90% cure in patients
Surgical excision
Pheochromocytoma is associated with:
- multiple endocrine neoplasia (MEN) type 2A and type 2B
- von Hippel-Lindau disease
- neurofibromatosis
True or false: In diagnosis of pheochromocytoma, measuring catecholamines by urine measurement is LESS SENSITIVE than Plasma
True
Medullary thyroid carcinoma, mucosal neuromas, thickened cornealnerves, alimentary ganglioneuromatoses, marfanoid habitus
Multiple endocrine neoplasia, type 2B
Medullary thyroid carcinoma, hyperparathyroidism
Multiple endocrine neoplasia, type 2A
Multiple neurofibromas, café-au-lait spots, pheochromocytoma
Neurofibromatosis type 1
is the most common congenital cardiovascular-cause of hypertension
Coarctation of the aorta
An ipsilateral/contralateral aldosterone ratio>4, with symmetric ACTH-stimulated cortisol levels, is indicative of
unilateral aldosterone production (primary aldosteronism)
True or false
Hypertension generally is responsive to surgery in patients with adenoma but not in patients with bilateral adrenal hyperplasia.
True
often done via a laparoscopic approach, is curative in 40–70% of patients with primary aldosteronism sec to an adenoma.
Unilateral adrenalectomy
ACTH stimulates cortisol production in the
zona fasciculata.
is related to excess cortisol production due either to excess ACTH secretion (from a pituitarytumor or an ectopic tumor) or to ACTH-independent adrenal production of cortisol.
Cushing’s syndrome
Catecholamine-secreting tumors are located in the
adrenal medulla (pheochromocytoma)
or in extra-adrenal paraganglion tissue (paraganglioma)
True or false:
hypertension occurs in >10% of individuals withobstructive sleep apnea.
False >50%
diagnosis of OSA can be confirmed by
polysomnography
True or false:
With CPAP or BiPAP, patients with apparently drug-resistant hypertension may be more responsive to antihypertensive agents
TRUE
Physical findings include diminished and delayed femoral pulses and a systolic pressure gradient between the right arm and the legs and, depending on the location of the coarctation, betweenthe right and left arms.
coarctation of the aorta
The diagnosis of coarctation of the aorta may be confirmed-by
chest x-ray and transesophageal echocardiography.
Average blood pressure reductions of ___ mmHg have been observed with a reduction-in mean body weight of
- 3/3.1 mmhg
9. 2 kg
True or false
potassium supplementation may be associated with reduced stroke mortality
True
Lowering
systolic blood pressure by 10–12 mmHg and diastolicblood pressure by 5–6 mmHg confers relative risk reductions of
35–40% for stroke
12–16% for CHD within 5 years of the initiation of treatment.
The risk of heart failure is reduced by >50%;
is the single most effective intervention for slowing the rate of progression ofhypertension-related kidney disease.
hypertension control
inhibit-the Na+/Cl– pump in the distal convoluted tubule and hence increase sodium excretion and In the long term, they also may act as vasodilators
Thiazides
The main pharmacologictarget for loop diuretics is the______ in the thick ascending limb of the loop of Henle.
Na+-K+-2Cl– cotransporter
decrease the Production of angiotensin II, increase bradykinin levels, and reduce sympathetic nervous system activity
Ace inhibitors
Side effects of ACEIs and ARBs include functional renal insufficiency due to____ renal arteriolar dilation in a kidney with astenotic lesion of the renal artery.
efferent
Ace and ARBS Additional predisposing conditions to renal insufficiency induced by these agents include 3
dehydration
CHF,
use of nonsteroidal anti-inflammatory drugs
True or false
Dry coughoccurs in ~15% of patients, and angioedema occurs in <1% of patients taking ACEIs.
True
is the first of a class of oral, nonpeptide competitive inhibitors of the enzymatic activity of renin.
Aliskiren
is a nonselective aldosterone antagonist that may be used alone or in combination witha thiazide diuretic.
It may be a particularly effective agent inpatients with low-renin primary hypertension, resistant hypertension, and primary aldosteronism
Spironolactone
Because spironolactone binds to progesterone and androgen receptors, side effects may include 3
These side effects are circumvented by a newer agent, eplerenone, which is a selective aldosterone antagonist.
gynecomastia, impotence, and menstrual abnormalities.
Postsynaptic, selective α-adrenoreceptorantagonists lower blood pressure by decreasing peripheral vascularresistance
Beta blocker
True or false:
In clinical trials of hypertensive patients, alpha blockade has not been shown to reduce cardiovascular morbidity and mortality or to provide as much protection against CHF as other classes of antihypertensive agents.
True
These agents are also effective in treating lower urinary tract symptoms in men with prostatic hypertrophy.
Alpha adrenergic blockers
bind to postsynaptic and presynaptic receptors and are used primarily for the managementof patients with pheochromocytoma.
Nonselective α-adrenoreceptor antagonists
decrease peripheral resistance and concomitantly activate mechanisms that defend arterial pressure, notably the sympathetic nervous system, the renin angiotensin-aldosterone system, and sodium retention
Direct vasodilators
can be used to treat malignant hypertension and life-threatening left ventricular heart failure associated with elevated arterial pressure.
Intravenous nitroprusside
May induce a lupus-like syndrome
is a potent direct vasodilator that has antioxidant And nitric oxide–enhancing actions
Hydralazine
is a particularlypotent agent and is used most frequently in patients with renalinsufficiency who are refractory to all other drugs.
minoxidil
Side effect includes in
hypertrichosis and pericardial effusion
minoxidil
Side effects of ACEIs and ARBs include functional renal insufficiency due to efferent renal arteriolar _____ in a kidney with stenotic lesion of the renal artery
dilation
What diagnostic test would differentiate Syndrome of Inappropriate Antidiuretic hormone secretion from other causes of euvolemic hyponatremia?
Serum uric acid <4mg/dl
