Interventional creation of an atrial septal defect and its impact on right ventricular function: An animal study with the pressure-volume conductance system

Background: The aim of our study was to assess the suitability of different interventional techniques to create an atrial septal defect (ASD) and to evaluate the short-term effects of right ventricular (RV) volume overload on RV contractility in the growing swine. Methods: Thirteen ASD and six control animals were studied. An ASD was created by balloon dilatation (BD) of the fossa ovalis (n = 4) or by implantation of a multi-perforated Amplatzer Septal Occluder (n = 4) or a patch-less nitinol device (n = 5). After 4.8 (3.9&#8211;6.0) weeks, the amounts of left-to-right shunting (Qp/Qs) and RV contractility (end systolic elastance &#8212; Ees) were assessed. Results: In the ASD group, a significant left-to-right shunt could be documented (Qp/Qs 1.5 &#177; &#177; 0.4). However, a shunt was absent in the BD subgroup (Qp/Qs 1.1 &#177; 0.1). In animals with devices implanted, a significant relationship between the post-mortem ASD area and Qp/Qs was found (r = 0.68, p < 0.05). Compared to controls, RV contractility was not significantly impaired at rest and during dobutamine in ASD animals (Ees: 0.40 &#177; 0.20 vs 0.54 &#177; 0.12 and 0.75 &#177; 0.29 vs 1.04 &#177; 0.24 mm Hg/mL, p = NS for both). Conclusions: Device implantation is necessary to create a patent ASD resulting in significant left-to-right shunting. In an experimental ASD model, a five week period of chronic RV volume overload does not alter RV contractility significantly. (Cardiol J 2011; 18, 3: 289&#8211;296

Identification of binding proteins for cholesterol absorption inhibitors as components of the intestinal cholesterol transporter

AbstractTo identify protein components of the intestinal cholesterol transporter, rabbit small intestinal brush border membrane vesicles were submitted to photoaffinity labeling using photoreactive derivatives of 2-azetidinone cholesterol absorption inhibitors. An integral membrane protein of Mr 145.3±7.5 kDa was specifically labeled in brush border membrane vesicles from rabbit jejunum and ileum. Its labeling was concentration-dependently inhibited by the presence of cholesterol absorption inhibitors whereas bile acids, D-glucose, fatty acids or cephalexin had no effect. The inhibitory potency of 2-azetidinones to inhibit photolabeling of the 145 kDa protein correlated with their in vivo activity to inhibit intestinal cholesterol absorption. These results suggest that an integral membrane protein of Mr 145 kDa is (a component of) the cholesterol absorption system in the brush border membrane of small intestinal enterocytes

Is the Lecompte technique the last word on transposition of the great arteries repair for all patients? A magnetic resonance imaging study including a spiral technique two decades postoperatively.

ObjectivesTo compare the Lecompte technique and the spiral anastomosis (complete anatomic correction) two decades after arterial switch operation (ASO).MethodsNine patients after primary ASO with Lecompte and 6 selected patients after spiral anastomosis were evaluated 20.8 ± 2.1 years after ASO versus matched controls. Blood flow dynamics and flow profiles (e.g. vorticity, helicity) in the great arteries were quantified from time-resolved 3D magnetic resonance imaging (MRI) phase contrast flow measurements (4D flow MR) in addition to a comprehensive anatomical and functional cardiovascular MRI analysis.ResultsCompared with spiral reconstruction, patients with Lecompte showed more vortex formation, supranatural helical blood flow (relative helicity in aorta: 0.036 vs 0.089; P &lt; 0.01), a reduced indexed cross-sectional area of the left pulmonary artery (155 vs 85 mm²/m²; P &lt; 0.001) and more semilunar valve dysfunctions (n = 5 vs 1). There was no difference in elastic aortic wall properties, ventricular function, myocardial perfusion and myocardial fibrosis between the two groups. Cross-sectional area of the aortic sinus was larger in patients than in controls (669 vs 411 mm²/m²; P &lt; 0.01). In the spiral group, the pulmonary root was rotated after ASO more towards the normal left position (P &lt; 0.01).ConclusionsIn this study, selected patients with spiral anastomoses showed, two decades after ASO, better physiologically adapted blood flow dynamics, and attained a closer to normal anatomical position of their great arteries, as well as less valve dysfunction. Considering the limitations related to the small number of patients and the novel MRI imaging techniques, these data may provoke reconsidering the optimal surgical approaches to transposition of the great arteries repair