Entrapment of pacemaker lead by a large netlike Eustachian valve within the right atrium

Summary During pacemaker implantation in a patient with permanent atrial fibrillation, it remained impossible to advance a passive fixation lead with fins through the right atrium. However, a lead with a retractable screw easily passed the right atrium and was positioned in the right ventricle. Transesophageal echocardiography revealed an extensive net–like perforated Eustachian valve within the right atrium that had caused entrapment of the anchor fins during lead implantation. Remnants of embryonal structures within the right atrium should be considered a rare possible barrier during pacemaker implantation.     

Statins, fenofibrate, and quinapril increase clot permeability and enhance fibrinolysis in patients with coronary artery disease

BACKGROUND: Aspirin increases fibrin clot porosity and susceptibility to lysis. It is unknown whether other drugs, in combination with aspirin, used in the treatment of coronary artery disease (CAD) might affect clot structure and resistance to lysis. AIM: The aim of the study was to assess the effects of statins, fibrates, or angiotensin-converting enzyme inhibitors (ACEIs) on fibrin clot properties. PATIENTS AND METHODS: In a randomized double-blind study, men with advanced CAD taking low-dose aspirin were assigned to receive one of the four drugs: simvastatin 40 mg day(-1) (n = 13), atorvastatin 40 mg day(-1) (n = 12), fenofibrate 160 mg day(-1) (n = 12), and quinapril 10 mg day(-1) (n = 11) for 28 +/- 2 days. Moreover, CAD patients (n = 13) taking aspirin (75 mg day(-1)) for 8 weeks were studied after additional 4 weeks on an open-label basis. Thirty men served as healthy controls. Plasma clot permeability and tissue plasminogen activator-induced fibrinolysis were evaluated at baseline and after drug administration. RESULTS: Permeability increased following the administration of simvastatin (by 20%; P = 0.01), atorvastatin (by 22%; P = 0.001), fenofibrate (by 16%; P = 0.02), and quinapril (by 13%; P = 0.04) like for aspirin (P < 0.001). Turbidity analysis showed that administration of any of the drugs was associated with higher maximum absorbancy, suggesting thicker fibers, and shorter fibrinolysis time (P < 0.001). Post-treatment reduction in lysis time correlated with an increase in clot porosity in all the groups (r from 0.42 to 0.61; P from 0.01 to 0.001). CONCLUSIONS: Statins, fibrates, and ACEIs may increase plasma clot permeability and susceptibility to fibrinolysis in CAD patients receiving aspirin. This novel antithrombotic mechanism might contribute to clinical benefits of the drugs tested.     

Effects of halothane on spinal dorsal horn WDR(wide dynamic range) neuronal activity in cats

The effects of halothane (0.2%, 0.5%, and 1.0%) on the spinal dorsal horn wide dynamic range (WDR) neuronal activity was studied in either spinal cord intact or spinal transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind foot pads of intact or decerebrate, spinal cord transected (L 1-2) cats. When 10 micrograms of bradykinin was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cat, all of 7 WDR neurons gave excitatory responses which were not depressed by 0.2% and 0.5% halothane but were depressed significantly by 1.0%. On the other hand, when the injection of 10 micrograms of bradykinin into the femoral artery ipsilateral to the recording site was used in the intact cat, 7 of 14 WDR neurons (50%) gave excitatory responses, which were not depressed by 0.2% halothane but were significantly depressed by 0.5% and 1.0% halothane, and 7 of 14 WDR neurons (50%) gave inhibitory responses, which were significantly depressed by 0.2%, 0.5%, and 1.0% halothane. We have found that halothane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by bradykinin injection.     

Adrenoceptors on blood cells from patients with primary Raynaud's phenomenon.

1. alpha 2-Adrenoceptors on platelet membranes and beta 2-adrenoceptors on lymphocytes were studied in 24 patients with primary Raynaud's phenomenon and in 24 age- and sex-matched control subjects. In two subgroups, a standardized mental arithmetic test and a finger-cooling test were performed. 2. Baseline blood pressure, heart rate and forearm blood flow did not differ between the two groups. 3. Baseline skin microcirculation (laser Doppler flux) was decreased in primary Raynaud's phenomenon (19 +/- 15 arbitrary units) compared with control subjects (33 +/- 14 arbitrary units) (P less than 0.01). 4. Baseline plasma noradrenaline concentration (2.00 +/- 1.44 versus 1.16 +/- 0.36 nmol/l) and alpha 2-adrenoceptor density (301 +/- 119 versus 210 +/- 82 fmol/mg) were increased in patients with primary Raynaud's phenomenon in comparison with the control subjects. The alpha 2-adrenoceptor density/beta 2-adrenoceptor density ratio in patients with primary Raynaud's phenomenon was, with a value of 0.37 +/- 0.04, higher than in the control subjects, where a value of 0.25 +/- 0.02 was measured (P less than 0.001). Plasma adrenaline concentration, beta 2-adrenoceptor density and the antagonist affinity to both receptor subtypes did not differ between both groups under baseline conditions. 5. Whereas during the finger-cooling test no differences were seen in the responses of the parameters measured, the mental arithmetic test induced an increase in laser Doppler flux in patients with primary Raynaud's phenomenon and a decrease in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)