No abstract available.
Pulmonary Circulation*

No abstract available.
Extracorporeal Circulation* ; Pulmonary Atresia* ; Ventricular Septum*

Humans ; Lung Diseases ; Pulmonary Circulation ; Vascular Diseases

China ; Heart ; Heart Diseases ; Humans ; Pulmonary Circulation

Animals ; Humans ; Hydrogen Sulfide ; Hypertension, Pulmonary ; etiology ; pathology ; physiopathology ; Pulmonary Artery ; physiopathology ; Pulmonary Circulation

BACKGROUND: Low frequency oscillation of systemic artery pressure was known as the marker of sympathetic modulation. Recently the low frequency oscillation of pulmonay artery pressure in pulmonary hypertensive patient was reported. But no further study about its quantitative relationshop and phasic coupling between the low frequency oscillation of pulmonary artery pressure and systemic artery pressure. Power spectral analysis with autoregressive algorithm and cross spectral analysis are powerful tool for investigation these relationship. METHOD: Analog signals of simultaneous measured left pulmonary and femoral artery pressure in thirty one patients with ventricular septal defect were digitized and stored. After modeling each time series with autoregressive algorithm, power spectral density function was obtained by calculation the frequency response function of each model, and then low frequency power was computed. Cross spectral density function provided squared coherence and phase spectrum. Phase between the low frquency oscillation of the two signal was measured from the phase spectrum when the squared coherence is above 0.5. RESULTS: The advantage of using autoregressive model was that the power spectral density function was continous and sharp spectral peak was usually found. In patients with Rp/Rs<0.25, the low frquency power of pulmonary artery pressure(12+/-12) was significantly smaller than that of the systemic artery pressure(144+/-242). In patients with Rp/Rs>or=0.25, there was no significant difference between the low frequency power of pulmonary artery pressure(384+/-461) and that of the systemic artery pressure(752+/-1241). In patients with Rp/Rs>or=0.25, it was more probable that low frequency oscillation of pulmonary and systemic artery pressure was timely coherent(sqaured coherence>0.5) than in patient with Rp/Rs<0.25. And their phase difference was 0~1.96 radian. CONCLUSION: Autoregressive algorithm is a more powerful tool for spectral analysis than the method of conventional spectrum estimation. When pulmonary vascular resistance remains low, the low frequency oscillation of pulmonary artery pressure was negligible compared to systemic artery pressure. But as pulmonary vascular resistance elevates, the low frequency power of pulmonary artery pressure is much the same as that of systemic artery pressure, and there is a explicit time realtionship that pulmonary artery pressure leads the systemic artery pressure about 0~3 seconds in the low frequency range.
Arteries ; Femoral Artery ; Heart Septal Defects, Ventricular ; Humans ; Hypertension, Pulmonary ; Pulmonary Artery ; Pulmonary Circulation* ; Vascular Resistance

Proximal interruption of unilateral pulmonary artery is an uncommon developmental anomaly. Patients without associated cardiac defects may remain asymptomatic but many develop recurrent pulmonary infections, hemoptysis, pneumonitis, bronchiectasis or pulmonary hypertension. We herein reported two cases of interruption of right pulmonary artery which were diagnosed beyond infancy. A remnant of patent ductus arteriosus was revealed on an angiogram in both cases. Surgical intervention could not be considered due to severe hypoplastic right pulmonary artery. Early surgical intervention should be considered to rescue a pulmonary circulation and prevent secondary lung hypoplasia.
Bronchiectasis ; Ductus Arteriosus, Patent* ; Hemoptysis ; Humans ; Hypertension, Pulmonary ; Lung ; Pneumonia ; Pulmonary Artery* ; Pulmonary Circulation

Hypoxic pulmonary vasoconstriction is a unique response of the pulmonary circulation to hypoxia. It constitutes part of the self-regulatory mechanism by which pulmonary capillary blood flow is adjusted to alveolar ventilation for maintaining the optimal balance of ventilation and perfusion. In pathological conditions, hypoxic pulmonary vasoconstriction may occur as an acute episode or as a sustained response with pulmonary hypertension and vascular remodeling. We report a case of reversible pulmonary hypertension induced by acute hypoxic pulmonary vasoconstriction in an 18-year-old man with relapsed acute myeloid leukemia, complicated with severe anemia and pneumonia.
Adolescent ; Anemia ; Anoxia ; Capillaries ; Humans ; Hypertension, Pulmonary ; Leukemia, Myeloid, Acute ; Perfusion ; Pneumonia ; Pulmonary Circulation ; Vasoconstriction ; Ventilation

OBJECTIVETo study the effect of Simulated Microgravity and its Associated Mechanism on Pulmonary Circulation in Rats).

METHODSRat tail-suspension model was used to simulate the physiological effects of microgravity and changes in pulmonary blood vessel morphology, pulmonary arterial and venous blood pressure, pulmonary vascular resistance, pulmonary vasomotoricity, as well as the regulation of pulmonary circulation by cytokines produced and released by the lung of rats were measured.

RESULTSThe walls of pulmonary blood vessels of rats were thickened, and the pulmonary artery was reconstructed with increased pulmonary vascular resistance. The pulmonary blood vessels of rats became more prone to dilation as contractions increased. Rat epithelial Adrenomedulin gene transcription and protein expression were upregulated. The level of basic fibroblast growth Factor of rat was also elevated.

CONCLUSIONFindings from the present study on rats revealed that the microgravity can affect pulmonary blood vessel structure, pulmonary arterial pressure, and pulmonary blood vessel self-regulation and cytokine production.

Animals ; Hemodynamics ; Male ; Pulmonary Artery ; physiology ; Pulmonary Circulation ; physiology ; Rats ; Rats, Wistar ; Weightlessness

Echocardiography, Transesophageal ; Humans ; Monitoring, Physiologic ; standards ; Pulmonary Circulation ; physiology ; Pulmonary Wedge Pressure ; Stroke Volume