Level Of Mean Pulmonary Pressure Research Articles

Altered expressions of alkane monooxygenase and hypoxia inducible factor-1α expression in lung tissue of rat hypoxic pulmonary hypertension

To explore the altered expressions of alkane monooxygenase (AlkB) and hypoxia-inducible factor-1α (HIF-1α) in a rat model of hypoxic pulmonary arterial hypertension. Twenty Wistar rats were divided randomly into normal control and hypoxia groups after 1-week adaptive feeding. Hypoxia group was raised in a homemade organic glass tank with a 24-h continuous supply of air and nitrogen atmospheric mixed gas. And the oxygen concentration of (10.0 ± 0.5)% was controlled by oxygen monitoring control system. The control group was maintained in room air. Both groups stayed in the same room with the same diet. After 8 weeks, the level of mean pulmonary pressure (mPAP) was measured by right-heart catheterization, right ventricular hypertrophy index (RVHI) calculated by the ratio of right ventricle to left ventricle plus septum and hypoxic pulmonary vascular remodeling (HPSR) observed under microscope. And the levels of AlkB and HIF-1α mRNA and protein in lungs were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. At 8 weeks post-hypoxia, compared with the control group [11.0 ± 0.7 mm Hg (1 mm Hg = 0.133 kPa), 0.210 ± 0.035], the levels of mPAP and RVHI in hypoxia group (33.3 ± 1.3 mm Hg, 0.448 ± 0.013) increased significantly (both P < 0.05), the expressions of AlkB mRNA and protein in pulmonary tissue decreased significantly (0.338 ± 0.085 vs 0.688 ± 0.020, P < 0.01) (0.483 ± 0.052 vs 0.204 ± 0.010, P < 0.01), and the expressions of HIF-1α mRNA and protein increased significantly (0.790 ± 0.161 vs 0.422 ± 0.096, P < 0.01) (0.893 ± 0.080 vs 0.346 ± 0.008, P < 0.01). The down-regulation of AlkB in lung tissue may increase the activity of HIF-1 to participate in the occurrence and development of pulmonary hypertension.

Surgical treatment of secundum atrial septal defects in adults over 30 years old

To summarize the experience of surgical treatment of secundum atrial septal defects in adults over 30 years old. There were 469 patients with secundum atrial septal defects in our study (male 144, female 325; ages 30-68, mean 38.6 years old). There were 105 cases with pulmonary hypertension and 458 cases with arrhythmia in the group. Surgical closure of defects were performed in all patients. Surgical closure of 358 cases were done by patches including 305 autologous pericardial patches. The low dose (6 x 10(-6)) nitric oxide inhalation was used in 25 postoperative patients with pulmonary hypertension. Right sided maze procedures were done in 5 cases with atrial fibrillation. Surgical mortality was 0.6% (3 cases), the others were healed. In the group, there were 180 cases with arrhythmia, 27 cases with left ventricular function amyoplasia, 28 cases with low cardiac output syndrome, 12 cases in secondary operation for bleeding and 1 case with air-embolism. The level of mean pulmonary artery pressure of 25 postoperative patients with pulmonary hypertension inhaled nitric oxide was down 28.5%. After right sided maze procedures were done in 5 cases with atrial fibrillation, atrial fibrillation disappeared. 352 cases were followed up from 3 months to 20 years (mean 5.6 years). Twenty-nine cases were in class I-II of cardiac function, and the others were better than class I of cardiac function. Atrial septal defects in adult should be operated as early as possible. When patch is needed, an autologous pericardial patch is the first selection. Inhaled nitric oxide is an effective method to postoperative pulmonary hypertension. The maze operation should be performed for atrial septal defect with atrial fibrillation while the surgical closure of defect was done. During and after operation, much attention should be paid to preventing and curing arrhythmia and protecting and supporting left heart function.