الفهرس 
Pulmonary hypertensionOnly 14 pages are availabe for public view
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Abstract
This study was conducted on 45 patients with different causes of pulmonary hypertension attending
the pediatric Cardiology Clinic at the Children’s Hospital-Ain Shams University. Their ages ranged
from 0.3 to 16 years. The study included also 9 apparently healthy, age and sex matched subjects as
control group .
The aim of this study was to investigate changes 1n the level of circulating vWF and platelet
aggregation response to ristocetin in patients with pulmonary hypertension.
The studied subjects were grouped into 3 groups:
group 1: patients with pulmonary hypertension secondary to venous causes (rheumatic heart disease)
, 33 patients.
group II: patients with pulmonary hypertension secondary to arterial causes (Congenital anomalies
with left to right shunt), 11 patients .
group Ill: norma l subjects serving as a control group, 9 patients.
The study also included a single case of primary pulmonary hypertension.
All studied groups were subjected to medical history taking, thorough clinical examination, chest
x ray, electrocardiogram, echocardiography and laboratory tests, which included vWF: Ag level
assay by ELISA technique and ristocetin platelet aggregation test.
The mean value of plasma vWF: Ag level showed significant increase in group I (87.5+ 35.6%; p<0.05)
and group II (84 + 34.7%; p<0.05) as compared to group III (54.1+ 22.1%).
The etiology of pulmonary hypertension (whether due to arterial or venous causes) had no effect on
the degree of rise in circulating vWF:Ag. This was evident by the absence of significant difference
in circulating vWF:Ag levels between group I and II (p
>0.05) .
The mean value of ristocetin platelet aggregation showed significant decrease in group I (27.9 +
19.2%; p<0.001) and group II (43.5 + 17.8%;
p<0.01) as compared to group III (66.5+ 4.4%) indicating defective vWF structure in patients with
pulmonary hypertension.
The degree of severity of pulmonary hypertension is an important determinant of vWF:Ag nse . There was a significant positive correlation
between vWF:Ag levels and the corresponding values of pulmonary artery pressure in all patients
with pulmonary hypertension (p<0.05) .
On the other hand, there was no significant correlation between ristocetin platelet aggregation
and pulmonary artery pressure in all patients with pulmonary hypertension (p>0.05).
There was no significant conelation between the rise of vWF :Ag level or ristocetin platelet
aggregation with the duration of the disease (p> 0.05).
from this study we concluded that:
- vWF proved to be a sensitive indicator of endothelial cell injury and the degree of hemodynamic
abnormalities in patients with pulmonar y hypertension .
- Inspite of high levels of vWF in patients with pulmonary hypertension, it has a
defective structure as proved by decreased ristocetin platelet aggregation in these patients
. However , insitu thrombosis occurs due to high shear stress, which leads to coagulation
abnormalities and thrombin release, leading to the formation of abnormal circulating
aggregates with more vascular injury and perpetuation of pulmonary hypertension