Pulmonary Artery

OBJECTIVES To evaluate the safety and efficacy of percutaneous thrombus fragmentation (PTF) for massive pulmonary embolism (PE) in patients with contraindications to the administration of thrombolytics. METHODS Between July 1999 and August 2005, 10 patients (7 males, 3 females, age 57+/-18 years) with massive PE and contraindications to the administration of thrombolytics underwent PTF. A transthoracic doppler echocardiogram was used to evaluate arterial oxygen saturation (Sat O2), the Walsh index (WI), mean pulmonary artery pressure (PAP), mean systemic blood pressure (SBP) and right ventricular function (RVF) before and after the procedure. Statistical analysis was conducted using the paired Wilcoxon test, of which p was significant when < 0.05. RESULTS After the PTF treatment there was an improvement in Sat. O2 [87.4 +/- 1.3% vs 92.3 +/- 3.1% (p < 0.001)], WI [6.4 +/- 1.07 vs 4.4 +/- 1.42 (p = 0.003)], PAP [31.8 +/- 4.6 mmHg vs 25.5 +/- 3.4 mmHg (p < 0.001)] and SBP [73....

In this paper we assume that the blood is to be a Non-Newtonian and incompressible and Homogeneous fluid. An investigation has been done for the resistance to flow across mild stenosis situated symmetrically on steady blood flow through arteries with uniform or non-uniform cross section. An analytical solution for Power law fluid has been obtained. For the physiological insight of the problem various parameters systemic and pulmonary artery are taken and the study reveals that as the height of the stenosis increases in uniform or non-uniform portion of the artery, the resistance parameter and shear stress also steadily increases, whereas, flow rate decreases steadily and we analyze some cases between flux, pressure gradient and radius and give some significant results.

Pulmonary hypertension resulting from chronic hypoxia is at least partly caused by the increased production of reactive oxygen species (ROS). The goal of the presented study was to investigate the dynamics and the site of production of ROS during chronic hypoxia. In our study Wistar rats were kept for 1, 4 and 21 days in an isobaric hypoxic chamber (F(iO2)=0.1), while controls stayed in normoxia. We compared NO production in expired air, plasma and perfusate drained from isolated rat lungs and measured superoxide concentration in the perfusate. We also detected the presence of superoxide products (hydrogen peroxide and peroxynitrite) and the level of ROS-induced damage expressed as the concentration of lipid peroxydation end products. We found that the production and release of ROS and NO during early phase of chronic hypoxia has specific timing and differs in various compartments, suggesting the crucial role of ROS interaction for development of hypoxic pulmonary hypertension.

Introduction In a normal condition, the heart of the fetus, an artery called ductus arteriosus connects the left pulmonary artery to the aorta. Normally in a developed heart, the left and right pulmonary artery carries deoxygenated blood to the lungs (pulmonary circulation), from the lungs then it carried through the pulmonary vein to the left atrium of the heart. The blood then passes through the ventricle to the aortic arch which distributes the oxygenated blood to the rest of the body (systemic circulation) [3]. In the fetal heart, there is only the systemic circulation and normally the pulmonary circulation will developed after the birth. The ductus arteriosus (DA) forms from the sixth aortic arch, and it is attached to the aorta with the first part of the pulmonary artery. In a fetus, the ductus arteries carry blood from the pulmonary artery (left) to the aorta, followed to the body. Soon after birth, the functional closure of ductus arteriosus happens due to the reflexive and hormonal contraction of the smooth muscle and forms the ligamentum arteriosum. Anatomically, the DA would close within one to three months after the birth, by the active proliferation of tunica intima [9]. When it fails to close beyond the normal duration, it is referred to as patent ductus arteriosus (PDA). PDA has caused a lot of mobility rate, and it can be an isolated abnormality or it can occur with other heart defects like coarctation of the aorta and transposition of the great vessels. PDA is asymptomatic in babies when the opening is small but can be diagnosed by examination. A continuous machine-like murmur can be heard at the left infraclavicular part. The murmur radiates along the pulmonary arteries and is well heard over the left back side. Patent Ductus Arteriosus was classified on basis of angiogram appearance. Recently, the PDA is classified based on the size of angiogram by Krichenko in 1989 and hemodynamic sound. Based on the clinical classification, the blood from the descending arch of aorta would flow into the left pulmonary artery due to pressure.

Background Right Ventricular Outflow Tract {RVOT} reconstruction using a conduit may be used in Tetralogy of Fallot patients who would otherwise require a trans-annular patch with the advantages of avoidance of free pulmonary regurgitation with its deleterious short and long term effects. Whereas an ideal conduit remains undefined, Contegra® bovine jugular vein bioprosthesis has been increasingly favored for this purpose worldwide. Present study summarizes the early and midterm outcome of Contegra bioprosthesis in RVOT reconstruction in patients of Tetralogy of Fallot (TOF). Methods Between Jan 2000 to April 2009, 34 patients of TOF required conduit reconstruction of RVOT using Contegra at our centre. Hospital records of these patients were retrospectively reviewed. Results Patients were in the age range of 2 to 20 years [mean age 3.2 years] and weighing between 12 to 57 kg [mean weight 15 kg].There were two early and no late deaths at a mean follow up of 23 months [range 6–110 months]. There were no reintervention or reoperations. All patients had trans-thoracic echo before leaving hospital with a mean pulmonary valve pressure gradient of 11.7 ± 6.1 mmHg. During the whole follow-up, there was no pressure gradient detectable across the conduit valve in 15 patients (44%). The maximal transvalvular peak gradients of 22–28 mmHg were measured in 3 patients (8%). Also, there was no valvular incompetence at all detectable in 20 patients (58%). Grade 1 regurgitation was seen in 10 patients (29%). Conclusions The Contegra bovine xenograft offers many advantages. It is suitable for patients of all age groups and is technically simple and safe to implant and provides excellent midterm hemodynamic results.