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Transpulmonary Gradient (transpulmonary + gradient)

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Medical Sciences100%

Selected Abstracts

The noradrenaline plasma concentration and its gradient across the lung

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 8 2000
Marenzi
Background We investigated the lung contribution to circulating noradrenaline (NA) homeostasis. Evaluation of the transpulmonary NA gradient, related to the NA amount entering the lungs, is potentially important, mainly regarding clinical conditions, such as congestive heart failure (CHF), that are associated with excessive circulating NA. Materials and methods 15 moderate (group 1) and 15 severe (group 2) CHF patients, and 10 normal individuals had determination of NA transpulmonary gradient in the baseline and during rise (exercise, in normals and group 1) or fall (withdrawal from plasma by ultrafiltration, in group 2) of plasma NA. Results NA gradient (pg mL,1) at rest was 30 ± 3 in normals, 21 ± 6 in group 1 and 5 ± 8 in group 2. Increase of NA concentration in the mixed venous blood with exercise was paralleled by depression of the transpulmonary gradient. Pulmonary arteriovenous difference disappeared when NA entering the lungs averaged 1300 pg mL,1. In group 2, ultrafiltration lowered NA in the mixed venous blood from 1225 ± 213 to 718 ± 182, which caused transpulmonary gradient to increase from 5 ± 8 to 22 ± 9. Conclusions Transpulmonary gradient of NA diminishes when NA entering the lungs increases, and 1300 pg mL,1 in the pulmonary artery is, both in patients and normal subjects, the level at which gradient disappears; which likely reflects cessation of NA uptake or achievement of a balance between lung uptake and production. This may have physiological and pathological implications. [source]

Correlation of Tricuspid Annular Velocities With Invasive Hemodynamics in Pulmonary Hypertension

CONGESTIVE HEART FAILURE, Issue 4 2007
Navin Rajagopalan
The authors performed tissue Doppler imaging of the tricuspid annulus in patients with pulmonary hypertension to assess its correlation with invasive indices of right ventricular function. The study population consisted of 32 patients with suspected pulmonary hypertension who underwent pulsed tissue Doppler imaging of the tricuspid annulus and right heart catheterization. Peak systolic (Sa), early diastolic (Ea), and late diastolic (Aa) velocities of the lateral tricuspid annulus were measured and correlated with hemodynamic variables. Peak Sa demonstrated excellent correlation with hemodynamic variables, including cardiac index (r=0.78; P<.001), pulmonary vascular resistance (r=,0.79; P<.001), and transpulmonary gradient (r=,0.72; P<.001). Peak Sa <10 cm/s predicted cardiac index <2.0 L/min/m2 with 89% sensitivity and 87% specificity. In conclusion, tissue Doppler imaging of the tricuspid annulus is a complementary method to assess right ventricular function in pulmonary hypertensive patients. [source]

The noradrenaline plasma concentration and its gradient across the lung

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 8 2000
Marenzi
Background We investigated the lung contribution to circulating noradrenaline (NA) homeostasis. Evaluation of the transpulmonary NA gradient, related to the NA amount entering the lungs, is potentially important, mainly regarding clinical conditions, such as congestive heart failure (CHF), that are associated with excessive circulating NA. Materials and methods 15 moderate (group 1) and 15 severe (group 2) CHF patients, and 10 normal individuals had determination of NA transpulmonary gradient in the baseline and during rise (exercise, in normals and group 1) or fall (withdrawal from plasma by ultrafiltration, in group 2) of plasma NA. Results NA gradient (pg mL,1) at rest was 30 ± 3 in normals, 21 ± 6 in group 1 and 5 ± 8 in group 2. Increase of NA concentration in the mixed venous blood with exercise was paralleled by depression of the transpulmonary gradient. Pulmonary arteriovenous difference disappeared when NA entering the lungs averaged 1300 pg mL,1. In group 2, ultrafiltration lowered NA in the mixed venous blood from 1225 ± 213 to 718 ± 182, which caused transpulmonary gradient to increase from 5 ± 8 to 22 ± 9. Conclusions Transpulmonary gradient of NA diminishes when NA entering the lungs increases, and 1300 pg mL,1 in the pulmonary artery is, both in patients and normal subjects, the level at which gradient disappears; which likely reflects cessation of NA uptake or achievement of a balance between lung uptake and production. This may have physiological and pathological implications. [source]