Retained pacemaker leads

Increasingly, functionless pacemaker leads are being abandoned in place because they cannot be safely removed. One hundred eighty-nine intact or partially removed pacemaker leads were abandoned in situ in 152 patients between Jan. 1, 1965, and Dec. 31, 1985. The leads, sometimes several leads in a single patient, were deemed uninfected at the time of abandonment in 137 patients and contaminated with Staphylococcus epidermidis in 15 patients. All of the contaminated leads have remained clinically uninfected during follow-up. One clean lead became infected early after implantation and the patient died after an open cardiac operation to remove that lead and an adjacent abandoned lead that was adherent to the subclavian vein. No other patient has had a late complication during follow-up to 256 months (mean 47.6). Properly managed abandonment of an uninfected lead can carry a very low complication rate.     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

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.     

Cost of illness studies: no aid to decision making: Reply to Shiell et al. (Health Policy, 8 (1987) 317-323).

Efficient resource allocation in health care requires adequate techniques of collective decision making. In a recent article Shiell, Gerard and Donaldson (Health Policy 8 (1987) 317-323) claim that cost of illness studies only confuse, mask and mislead, while cost-benefit analysis provides the relevant framework for decisions in health care. We do not agree with their naive approach to decision making in health care. In comparing the two alternative methods, their respective importance for decision making becomes apparent. None of the two techniques may be considered as the one and only means to ultimately solving the problem of efficient resource allocation in health care. Yet, both techniques can provide relevant information on which policy makers can base their decisions in health care.     

MK-801 induced stereotypies in rats are decreased by haloperidol and increased by diazepam

Summary The effects of haloperidol and diazepam were investigated on stereotypies (wall contacts and turn rounds) induced by the non-competitive NMDA antagonist MK-801 in rats. Haloperidol (0.03, 0.10, 0.25 and 0.40mg/kg body weight) caused a dose-dependent antagonism whereas diazepam (3.0 and 5.0 mg/ kg) caused a dose-dependent agonism of the stereotypies induced by 0.30 mg/ kg MK-801 (all drugs given intraperitoneal). Conversely, diazepam (5.0 mg/kg) given alone reduced significantly the number of spontaneous wall contacts and turn rounds. The paradoxial stimulation of MK-801 induced stereotypies by diazepam could be explained by a shift between positive and negative corticostriatothalamic feedback loops envolving GABAergic neurons in favour of the former.     

An algorithm separating saccadic from nonsaccadic eye movements automatically by use of the acceleration signal.

An algorithm is described to discriminate automatically between saccades and slow eye movements. Sampled data of the eye position have been used to calculate the momentary acceleration of the eye. The higher acceleration values of the saccadic eye movements as opposed to the slow compensatory or pursuit eye movements served to differentiate between the two. The method is demonstrated by search-coil data in squirrel monkeys.