Primary
Pulmonary Hypertension (PPH)
Primary
pulmonary hypertension (PPH) is a form of pulmonary arterial
hypertension (PAH) for which no cause can be identified. PPH
is a rapidly progressive disease with an incidence of one
to two cases per million per year while the other causes of
PAH may account for a further one to two cases per million
per year.
Most
cases of PPH seem to be sporadic, but six to 12 percent are
familial. The cases are inherited in an autosomal-dominant
manner with reduced penetrance and shows anticipation with
presentation at a younger age in successive generations. Recently
a gene has been identified which encodes the type II morphogenetic
protein receptor (BMPR-II). There is growing evidence that
dysfunction of this receptor is directly associated with abnormal
proliferation of pulmonary vascular cells, although the mechanism
by which BMPR-II mutations contribute to the pathogenesis
of PPH remains incompletely understood. Altered growth response
of pulmonary artery smooth muscle cells from patients with
PPH to transforming growth factor-b1 and bone morphogenetic
proteins. Mutations of the gene are seen in at least 26 percent
of sporadic cases of PPH. Since not all individuals who carry
BMPR-II mutations develop pulmonary hypertension, it is likely
that additional factors are necessary. Another clue to the
genetic basis of PPH is the finding that PAH occurs in women
three times more frequently than men.
PPH
symptom onset is usually insidious with several years passing
before diagnosis. It is important that general physicians
should have a high level of suspicion of the subtle nature
of the clinical presentation of PPH. Patients with suspected
PPH should be referred to specialised centers where early
diagnosis and treatment can be initiated.
The
methods for achieving an accurate diagnosis and treatment
of patients with PAH can also be used for PPH patients, with
only a few exceptions.
Diagnosing PAH
Treating PAH
References
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Gibbs
JSR et al. Recommendations on the management
of pulmonary hypertension in clinical practice. British
Cardiac Society Heart (Sept 2001);86(1):i1-i13
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Rich
S, Dantzker DR, Ayres SM et al. Primary pulmonary
hypertension. Ann Intern Med (1987) 107:216-23
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Circulation
(2001) 104:790-795
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Abenhaim
L, Moride Y, Brenot F et al. N Engl J Med (1996)
335:609-16
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Archer
S, Rich S. Primary pulmonary hypertension: a vascular
biology and translational research. 'Work in progress'
Circulation (2000); 102 (22)
: 2781 - 91
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Mikhail
GW, Gibbs JSR, Yacoub MH.Management OF PRIMARY pulmonary
hypertension. < em > Brit J Card < / em >
(2002) < strong > 9 < / strong > (6) : 330
- 335.
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