Page 826 - Cardiac Nursing

9-8
9-8
02
d
p79
5
ar
a
Apt
8:
8:
009
0
009
02
2
6
9
2
9
0
/
qx
qx
3
Pa
g
e 8
3
LWBK340-c35_p799-822.qxd 29/06/2009 08:59 PM Page 802 Aptara
LWB
LWB K34 0-c 3 5 _ _ p79 9-8 22. qx d 2 9 / 0 6 / / 2 009 0 8: 5 9 P M Pa g e 8 02 Apt ar a
0-c
K34
K34
5
9 P
M
Pa
22.
22.
802 PA R T V / Health Promotion and Disease Prevention
DISPLAY 35-1 Causes of Secondary Hypertension catecholamines, urinary metanephrine, and urinary vanillylman-
delic acid. Nuclear imaging may also identify certain extra-adrenal
tumors and once detected surgical intervention is needed.
Renal
Obstructive Sleep Apnea. An association between sleep ap-
Renal parenchymal disease
Renal vascular disease nea and systemic HTN has been reported since the 1970s. In-
Renin-producing tumors creasingly this condition has gained more widespread attention
Primary sodium retention (Liddle syndrome) due to the growing rate of obesity. Obstructive sleep apnea affects
Increased intravascular volume 2% to 4% of the general population, and more than 50% of those
affected by it have HTN. 35 It is now a significant health problem
Endocrine causing disrupted sleep, memory loss, personality changes, de-
Acromegaly creased attention span, poor judgment, and frequent episodes of
Hypothyroidism hypopnea (reduced chest movement with 4% or more decrease in
Hyperthyroidism oxyhemoglobin) and or apnea (cessation of airflow for 10 seconds
Hyperparathyroidism or more). 39 A good medical history about sleep patterns is war-
Adrenal cortical ranted and referral to a sleep disorder clinic needed to confirm the
Cushing syndrome diagnosis. Treatment involves not only the use of continuous pos-
Primary aldosteronism itive airway pressure, the most common approach to this condi-
Apparent mineralocorticoid excess
Adrenal medulla tion, but also weight loss and treatment of concomitant HTN
39,40
Pheochromocytoma with medicines as needed. Assessment of sleep patterns and
Carcinoid syndrome snoring is also indicated for those individuals with resistant HTN.
Coarctation of the Aorta. Coarctation or narrowing of the
Drugs and Exogenous Hormones
lumen of the aorta is rare in adults but relatively common in chil-
Neurological Causes dren, accounting for 7% of all congenital CVD. 35,41 The most
Increase intracranial pressure common narrowing occurs distal to the left subclavian artery. 42
Quadriplegia Those individuals with coarctation of the aorta normally have
Guillain-Barre syndrome high upper extremity BPs with low pressures in the lower extrem-
Idiopathic, primary, or familial dysautonomia 43
ities including weak femoral pulses. If this condition is left un-
treated, it can cause left ventricular hypertrophy (LVH). Bruits may
Obstructive Sleep Apnea
be present on physical findings, and screening tests, which include
Acute Stress-Related Secondary Hypertension a transthoracic echocardiogram or contrast computed tomogra-
Diseases of the Aorta phy/magnetic resonance imaging help to visualize this condition.
Rigidity of the aorta Treatment includes surgical repair of the lesion or angioplasty. A
Coarctation of the aorta
comparison of the BP and left ventricular mass among patients who
Pregnancy-Induced HTN had surgical repair of a coarctation and controls found that these
patients had significantly higher 24-hour ambulatory SBP and left
Isolated Systolic HTN Due to an Increased Cardiac Output 44
ventricular mass compared with controls. Thus, follow-up re-
mains important in these patients.
From Chiong, J. R., Aronow, W. S., Khan, I. A., et al. (2008). Secondary hypertension:
4
4
Current diagnosis and treatment. International Journal of Cardiology, 124, 6–21. Pregnancy-Induced HTN. HTN occurs in 5.9% of all preg-
nancies and is classified as preeclampsia–eclampsia, preeclampsia
superimposed on chronic HTN, chronic HTN, or gestational
sodium, chloride, and water resulting in an expanded extracellu- HTN. 38 The cause of preeclampsia is not known but it includes
lar fluid volume. This condition is now thought to be the cause proteinuria, renal insufficiency, impaired liver function, and abnor-
of 5% to 13% of all cases of HTN. 37 Primary hyperaldostero- malities including thrombocytopenia, hemolysis, and fetal growth
nism may be difficult to diagnose due to low serum potassium, restriction. 45,46 Early diagnosis is critical and close monitoring of
the most common sign being found in only one third of the BP essential with treatment being directed at medicines with proven
cases. 37 The best screening test is now the plasma aldosterone to safety for each condition.
38
plasma renin activity ratio. Clinicians should look for this con- As shown in Display 35-1 numerous other causes of secondary
dition in those patients younger than 50 years who appear to HTN are noted. A careful history and physical examination,
have resistant HTN or HTN with hypokalemia. Surgical removal which is discussed in more detail under the section on manage-
of an adenoma reduces BP and if no tumor is present, medical ment, will help reveal many of these secondary causes.
treatment with aldosterone antagonists such as spironolactone is
indicated. 38 Clinical Manifestations of HTN
Pheochromocytoma. Pheochromocytomas are largely be- Signs and Symptoms
nign neuroendocrine tumors of the adrenal medulla and present Unfortunately, there are few signs and no symptoms of HTN un-
in up to 6% of those individuals with HTN. Because excessive til it becomes very severe and target organ damage (TOD) has oc-
amounts of catecholamine occurs with these tumors, individuals curred. The major sign, obviously, is the presence of elevated BP
may experience chest discomfort, tachycardia and palpitations, based on the criteria for the definition HTN (see Table 35-1).
panic attack, and headaches. 35 A pheochromocytoma is normally Other signs and symptoms are described in the next section on
diagnosed by undertaking measurement of urinary and plasma complications of HTN.