STEINBACH, K. ET AL; Frequency and variability of ventricular premature contractions-the influence of heart rate and circadian rhythms. Present knowledge about arrhythmias is still too Jimited to prevent sudden cardiac death Long-term ambuJatory ECG monitoring should be the method of choice in further investigating and evaluating the possible relationships between the frequency of arrhythmias and heart rate [MR], circadian patterns, and effects of drugs Using a computer-supported, semiautomatic anaiysis system, 77 patients with a mean premature ventricuiar contraction fPVCJ-rate of over 1% were monitored for 24 hours (group A). Ten other patients with PVC's of over 1% were monitored for up to 96 hrs each, continuousiy, to demonstrate the reproducibility of possible circadian PVC's and HR patterns [group B] Another group of 44 patients (group C] underwent long-term ECG monitoring of 24 hrs before and during drug therapy with disopyramide (n = 15 pts, 200 mg t i d ], mexiJetine (n = 13 pts, 200 mg t.i d J, acebutoioJ (n = 9 pts, 200 mg b i d J and propafenon [n = 7 pts, 300 mg t i.d J to judge the drug effects in relation to their specific chronotropic properties. In group A patients there was a significant correlation (r = -0 602} between mean PVC frequency and respective PVC variabilities The latter increase with a reduction of the PVC rate and vice versa A circadian pattern of HR and PVC's can be demonstrated in the majority of group A and B patients. By using Scheffe's test to determine the required PVC reduction, the statistical PVC reduction curve lp<0 05} does not conform to the PVC-aboiition curve (PVCbeiowI%J in group B patients If patients without circadian PVC/HR patterns are under antiarrhythmic therapy, they need a much higher mean PVC-reduotion rate to reach the statistical significance level than patients without such a PVC and HR behavior. Drugs administered in Group C patients had different chronotropic effects Heart rate spectra were demonstrated for each antiarrhythmic drug used The distribution of arrhythmias, their variability, HR. circadian rhythm and the activity of antiarrhythmic drugs should be taken into account to narrow the gap between current antiarrhythmic treatment and the prevention of sudden cardiac death (PACE, Vol 5, January-February. 1982] antiarrhythmic therapy, circadian rhythm, premature ventricular contractions, longterm ambulatory ECG monitoring Since the establishment of Coronary Care recognize, qualify and treat arrhythmias before Units, the connection between sudden cardiac dangerous cardiac disturbances occur. The use death and life-threatening arrhythmias has been of new antiarrhythmic agents^-' and the applicawell known.'Today the physician's strategy is to • ,

Abstract. Modern distributed software systems must integrate in neartime parallel processes and heterogeneous information sources provided by active, autonomous software systems. Such lively information sources are e.g. sensory data, weather data, traffic data, or booking data, operated by independent distributed sites. The complex integration requires the coordination of these data flows to guarantee consistent global semantics. Design, implementation, analysis and control of distributed concurrent systems are notoriously complex tasks. Petri Nets are widely used to model concurrent activities. However, a higher-level programming abstraction is needed. We propose a new programming model for modeling concurrent coordination patterns, which is based on the idea of "peer workers" that represent re-usable coordination and application components. These components encapsulate behavior, structure distributed data and control flow, and allow integration of pre-existing service functions. A domain-specific language is presented. The usability of the peerbased programming model is evaluated with the Split/Join pattern.

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72 patients with CAD, 10 patients with congestive cardiomyopathies and 10 normal subjects were evaluated by radionuclide angiography. Comparison with contrast angiography showed good results for LVEF (r = 0.83). Regional asynergies observed in the radionuclide angiography correlated well with defects in thallium scintigrams. Extent of abnormal wall motion was measured and compared with normals, appreciating the deviation from the normal mean radial shortening. Good correlation could be demonstrated with radionuclide ventriculography. In 80% of congestive cardiomyopathies the right ventricle wall became visible in the thallium scintigram.

We present the advantages of a new coordination model termed "Peer Model" for the design of coordination strategies and introduce new extensions for the modeling of time and reference. The motivating example is the wireless, reliable, and timely upstream propagation of events about approaching trains, detected by sensors, to a rail crossing. Embedded wireless nodes along the tracks propagate the events upstream. The Peer Model provides flexibility, as new requirements do not demand a complete re-design and reimplementation of notification strategies, which is achieved by means of high-level abstractions, modularization, and patterns with exchangeable policies.