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The assessment of the QT interval has been an integral part of ECG interpretation since the first descriptions of long QT syndrome by Wolff in 1950 and by Jervell and Lange-Nielsen in 1957. The correct measurement of the QT interval as well as a correct interpretation of the causes and of the clinical consequences of a QT prolongation, however, may be difficult even for trained internists and cardiologists. In this review, we give an overview on physiological determinants of cardiac repolarization, its marker in the surface ECG - the QT interval -, methods to correctly assess QT interval duration, causes for pathologically prolonged QT intervals, and resulting clinical consequences. A correct measurement of the QT interval should be performed by using the "tangent method", excluding possible U waves. A heart rate correction formula should be employed to determine the heart rate corrected QT interval (QTc).Many factors, which may prolong the QT interval, should be checked whenever a QTc prolongation is observed. These include drugs, electrolyte imbalances, hormonal influence, and comorbidities. The correct management of a patient with (genetically determined) LQTS starts with a risk stratification based on genotype, ECG phenotype, clinical history, age, sex, concomitant diseases, drug therapies, and family history for syncope or sudden cardiac death. The therapeutic approaches for LQTS are multimodal. Prevention is the basis of the therapy and includes avoiding known risk factors / and potentially QT-prolonging drugs, and a pharmacological treatment with non-selective beta blockers. According to the risk profile and to the patient's lifestyle the implantation of an ICD or a pacemaker should be considered., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)

S. truttae is described from brown trout and grayling in Middle Germany. This species is obviously not connected with PKX, the causative agent of Proliferative Kidney Disease (PKD) in salmonids. S. truttae, however, is important in this connection from the viewpoint of differential diagnostics.

It is proved histologically that lacking of tegumented papillae in Paramphistomum cervi is based on the alteration of the tegument furnished with papillae in the normal state. The differences in the dorsal extension of the vitellaria, in the histological structure of the genital opening complex and in other features, used by Eduardo (1982) for the division of P. cervi into 3 species, are refuted as not existing. Therefore the forms P. leydeni, P. scotiae and P. hiberniae remain well established synonyms of P. cervi.

The development of parasitology in the GDR is described. In the GDR there are only 2 chairs of Parasitology in the Faculties of Animal Production and Veterinary Medicine at Humboldt University Berlin and Karl Marx University Leipzig. Parasitology as a teaching field in its own was not become realized in medicine. In the training of zoology parasitology had been recognized only temporarily. For the parasitological practice particular parasitological departments or laboratories developed in each district institute, which are leaded and coordinated by reference laboratories--a state that is an important improvement compared with the situation before the war. The publishing efforts of GDR's authors and publishing houses as well as the mobilizing role of the Parasitological Society of the GDR are especially stressed.

For the first time in Europe simultaneous occurrence of PKX and Sphaerospora sp. is recorded in Salmo gairdneri. Myxosporidian (?) forms hitherto not described have been observed in the kidney interstitium and the epithelium of the renal tubules, sporadically also in the swimbladder wall and the intestinal wall, besides the typical PKX organism in the kidney interstitium. Sporogonic stages and spores of a Sphaerospora species have been found in the lumen of the renal tubules. Neither the exact identification of the Sphaerospora species has been possible, nor the final proof, whether the luminal form, the hitherto undescribed extraluminal forms and PKX belong to one another.

We observed 2 different types of the course of incidence of sporogonic phase and blood phase. Type I shows in both phases a maximum in the first summer, a minimum in winter or autumn and a second maximum between late autumn and second summer. In this case the sporulation was especially distinct with the first maximum. Type II starts in the first summer with the blood phase without occurrence of the sporogonic phase (and the swim-bladder phase), which appears only from autumn until the second summer in a form of three peaks. Here the sporulation was successful only in the third peak. Hitherto there has been no other example of that type. The course of incidence, characterized by peaks and valleys, is regarded as an expression of an internal rhythm of different phases of the parasite and not as caused by the declining of infection and by reinfection. Premunition (if a hitherto unknown reservoir phase is surviving) or age resistance and/or less chance of coincidence of infective stages and older carps are supposed to be the cause of the rare occurrence of the 3 known phases in carps more than 14-15 months old. There are some indications of the infection of carps by carps. Carassius au. auratus was ascertained as a new host for S. renicola in a field experiment.

New data are presented on the development of infection by S. renicola in common carp within the first 15 weeks of their life. The infection of parasite-free common carp succeeded by myxospores as well as by feeding carp kidneys with and without spores in laboratory experiments. In field experiments one year-old parasite-free common carp were successfully infected.

Short systematic-ecographical documentation of the trematode species hitherto found in the territory of the German Democratic Republic and the adjacent region of the Baltic Sea as a systematic list (alphabetically arranged after classes, orders, families, genera and species). Information on the synonyms important for the territory treated, on the cycle (limnical, marine, terrestrial; host categories, host groups), on the host species recorded for the territory, on the district of findings, on the literature referring to the findings, and on the wrong determinations so far recognized. There are 269 recorded species (177 with or presumably with a limnical, 59 with a marine, and 25 with a terrestrial cycle within the territory).

Paramonostomum antarcticum Graefe, 1968 from the rectum of blackbacked gull from King George as Island (South Shetlands, Antarctica) is described. As a result of that Larus dominicanus is presented the new host of this trematode. The morphology is compared with the original description of P. signiense Jones & Williams, 1969. The relations between the two possibly identical Antarctic species are discussed. It is proposed to invalidate the subgenus Paramonostomoides Yamaguti, 1971.

The non-induced, endogeneous periodic destrobilation in Spirometra is conceived as an extreme of pseudapolysis. The patent time of S. erinaceieuropaei and S. sp. with single or with simultaneous infestations is arranged in separate patent periods marked off from each other by negative phases. This phenomenon is due to a periodicity of the strobila. In dissections during the negative phase only the scolex and neck alone or provided with a very short strobila could be found in the intestine. There were no striking differences between single and simultaneous infestations. The periodicity altogether, however, showed a great variability. A synchronization of the periodicity of egg shedding and destrobilation is concluded from one simultaneous infestation with demonstrably at least 2 tapeworms. After successive superinvasion, however, the periodicity evidently does not become synchronous, the periodicity of egg shedding is masked.

The plerocercoids of all Spirometra forms investigated up to now in this regard produce a "Sparganum Growth Factor" (SGF), i.e. one (or more) substance(s) with growth hormone-like effect on certain rodents. The SGF produced by the species S. mansonoides (SGF "mansonoides") is stronger effect than the SGF produced by all the other forms (SGF "non-mansonoides"). The physiological in its effects hitherto investigated mainly with SGT "mansonoides" in the USA are shortly mentioned. In order to get further insights the isolation, purification, and characterization of the SGF are necessary. The both kinds of SGF are also of taxonomic importance.

European Spirometra forms corresponding to S. erinaceieuropaei in morphology, host specificity and periodical destrobilation were tested for a Sparganum Growth Factor (SGF "mansonoides") acting upon hypophysectomized male rats. A Polish form as well as Thai and Burmese forms did not show a SGF "mansonoides". The Polish form partially caused increased growth in normal laboratory mice (similar to a form from Thailand) and in Cricetulus griseus (SGF "non-mansonoides", restricted by host resistance). Procyon lotor can act both as paratenic and as definitive host for the Polish form. The Polish, Thai and Burmese forms are attributed to S. erinaceieuropaei. A Bulgarian form showed a typical SGF "mansonoides". 4 hyposectomized 100 g rats, each of which were implanted 5 spargana subcutaneously, showed weight gains up to 400 g within 7 to 8 weeks. Therefore, this Bulgarian form is treated provisionally as Spirometra sp.

Plerocercoids were found under the skin and in the body cavity of Ahaetulla nastua, Boiga multimaculata, Trimeresurus purpureomaculatus, and Varanus dumerilii, imported from Thailand. Starting with these plerocercoids the cestode cycle was experimentally traced in the laboratory (Lueheela = Spirometra sp.). Domestic cat and domestic dog served as definitive hosts, native copepods at first intermediate hosts, native anurans, reptiles, and chicken as second intermediate hosts and paratenic hosts. Fishes and a Rhesus Macque were shown to act as paratenic hosts. The ferret was only suitable as paratenic host but not as definitive host. The adult worm in the definitive host periodically cast off the whole strobila corresponding to a cyclic appearance of eggs in the faeces.