Experimental atrioventricular block without thoracotomy: a new instrument

Experimental permanent total atrioventricular block was produced by a simplified method, without thoracotomy, by one person, and without the aid of x-ray apparatus. For this purpose, a newly designed cannula for the injection of 40% formalin into the bundle of His was mad

Production of Chronic Atrioventricular Block in Dogs Without Thoracotomy

Total heart block was produced in dogs without thoracotomy by means of a formaldehyde injection into the bundle of His. The method was successful in 22 out of 24 experiments. It is a useful model for haemodynamic studies in the intact anima

Native or naturalized? : validating alpine chamois habitat models with archaeozoological data

Conservation of mammal species often requires the application of predictive habitat models. While empirical models can indicate the potential suitability and distribution of recent habitat, they may fail to depict native habitat and distribution. Therefore, we advocate validating such models with archaeozoological data. To demonstrate the power of archaeozoological data in investigating native distribution patterns, we use the alpine chamois (Rupicapra rupicapra) as a model species. After experiencing a severe historical population bottleneck due to overexploitation, chamois populations recovered markedly during the last century. Fostered by humans and having profited from translocations, this alpine ungulate greatly expanded its range and began to invade forested areas both within and outside the Alps, where damage to vegetation was soon obvious. Consequently, a controversy arose concerning the natural distribution and habitat of chamois. To study the native habitat and distribution of alpine chamois in Switzerland, we focus on the Late Mesolithic and Neolithic period (6000-2200 BC). This period best Suits our purpose because pristine forests then dominated the landscape and human influence was as yet minimal. We describe two opposing habitat models: the alpine model assumes that chamois had survived only in alpine areas, whereas the forest model assumes that they also roamed in steep, entirely forested areas. We validate these models with archaeozoological data. Because the probability of chamois bone occurrence in prehistoric settlements is expected to decrease with increasing distance from chamois habitat, the models differ in their geographical predictions of chamois bone records. Applying logistic regression models, only settlement proximity to chamois forest habitat explains recoveries of fossil chamois bones. The resulting function of catchment distances (i.e., the likelihood of hunting chamois depending on the distance between a settlement and the nearest chamois habitat) matches the spatial behavior of extant hunters within pristine forests. We conclude that Holocene chamois range in Switzerland naturally included steep and entirely forested regions, like the Jura Mountains. The recent invasion of these areas by chamois thus constitutes repatriation of native habitat. Accordingly, we propose a shift in perspective toward landscape integration of chamois

Experimental atrioventricular block without thoracotomy: a new instrument

Experimental permanent total atrioventricular block was produced by a simplified method, without thoracotomy, by one person, and without the aid of x-ray apparatus. For this purpose, a newly designed cannula for the injection of 40% formalin into the bundle of His was mad

Production of chronic atrioventricular block in dogs without thoracotomy

Total heart block was produced in dogs without thoracotomy by means of a formaldehyde injection into the bundle of His. The method was successful in 22 out of 24 experiments. It is a useful model for haemodynamic studies in the intact anima

Die chirurgische Behandlung von Herzrhythmusstorungen. [Surgical treatment of heart rhythm disorders]

Six patients underwent cardiac surgery for refractory tachyarrhythmias. Four had Wolff-Parkinson-White syndrome and 2 ventricular tachycardias after myocardial infarction. The results of preoperative electrophysiologic studies corresponded in 5 cases to intraoperative findings of epicardial and pace-mapping. These patients were free of symptoms for the 4-16 months' follow-up. In one patient with divergent results, tachycardia and preexcitation returned two months postoperatively. In the light of the foregoing the authors suggest surgical treatment for 1. preexcitation with life-threatening arrhythmias, 2. refractory ventricular tachycardias with coronary artery disease and 3. preexcitation in patients undergoing open heart surgery for other reasons

Frequenzverhalten von Lithium-Schrittmachern bei Batterieerschopfung. [Stimulation rate of lithium powered pacemakers in the event of battery depletion]

Between 1976 and 1977, 347 lithium powered pacemakers with capacity below 1.8 Ah have been implanted at Zurich University Hospital. 25 (7%) had to be explanted after an average of 37.3 months because of premature battery depletion, the reason for which was low resistance electrodes (Elema EMT 588 A and C) in CPI-502 UD and Telectronics 150B. Both types showed a drop in stimulation rate as an EOL-characteristic, as predicted by manufacturer. Rate controls at 6 month intervals have proven a reliable means of detecting premature failure. With ARCO Li-3D, prediction of battery depletion was possible only in one case out of 5 because of sudden and unpredictable EOL. In pacemaker dependent patients this type should be explanted by the end of the guarantee period at the latest