Pulmonary arterial extensibility in XXXX with intracardiac left to right shunt.

@entity1 @entity118 @entity120 @entity1757
The extensibility of the pulmonary artery (PA) were examined using a combined hemodynamic and ultrasonic technique in 14 @entity1 with @entity118 ( @entity118 ), three with @entity118 and @entity120 ( @entity120 ), 17 with @entity1757 ( @entity1757 ) and 11 with @entity1757 and @entity120 . Seven @entity1 with neither intracardiac shunt nor @entity120 served as controls. The tension (T) of PA was measured as the product of the pressure and the diameter (D) and was found to be high in the @entity1 with intracardiac shunt. The resting diameter of PA (D0) was calculated as the intersect with the D axis in the regression line of PA tension-diameter relation. The Lagrangian strain of PA [(D--D0)/D0] was obtained using D0 and correlated with T yielding a linear regression equation. The elastic modulus (E) was obtained as the slope of this equation. E in the @entity1 with @entity118 [(1.0 +/- 0.5) x 10(5) dynes/cm] or @entity1757 [(9.8 +/- 4.6) x 10(4) dynes/cm] were slightly higher than that of the control [(6.7 +/- 2.9) x 10(4) dynes/cm], but these differences were not statistically significant. However, E in the @entity1 with @entity118 and @entity120 [(2.5 +/- 1.3) x 10(5) dynes/cm] or in the @entity1 with @entity1757 and @entity120 [(2.6 +/- 0.9) x 10(5) dynes/cm] were significantly higher than the control. E seemed unlikely to be causally related to the resistance of PA capillary beds, and was suggested to be influenced by the histological changes of the pulmonary trunk. It was concluded that the extensibility of PA in the @entity1 with @entity118 or @entity1757 was not altered secondary to the increased blood flow unless @entity120 was associated.
