[Short QT syndrome]. / Short-QT-Syndrom.

Short QT syndrome was first described in 2000. It is a sporadic or familial ion channel disease that is associated with abbreviation of the QT interval permanently or transiently. The time of first manifestation of symptoms such as atrial fibrillation or syncope or even sudden death is between the 2nd and 4th decade. Sudden death has also been described for newborns and adolescents. Therapy depends on the severity of the symptoms. The therapy of choice for secondary prevention of sudden death is the implantable cardioverter-defibrillator (ICD). Quinidine has been shown to be effective in preventing arrhythmias in a number of patients. It is mostly used as an adjunct to the ICD but has also been used with considerable success in children and individuals who refused ICD implantation.

[Significance of diagnostic methods in the work-up of syncope]. / Stellenwert diagnostischer Methoden in der Synkopenabklärung.

After the initial evaluation including detailed history, physical examination, electrocardiogram, and orthostatic blood pressure measurements, risk stratification should follow, if the cause of syncope is still unclear in order to define the acuteness and extensiveness of the further diagnostic evaluation. The documentation of arrhythmia during syncope is the gold standard for diagnosis of arrhythmic syncope. The implantable loop recorder should be integrated early in the diagnostic work-up. In patients >40 years with otherwise unexplained syncope, carotid sinus massage is recommended. In suspected reflex-mediated syncope, the tilt test is able to confirm the diagnosis and gives information about the underlying pathomechanisms, while electrophysiological studies have still a proven indication in patients with previous myocardial infarction and preserved left ventricular function. The adenosine triphophate test has no clinical relevance in the diagnostics of syncope. Echocardiography plays an important role in the risk stratification by diagnosing structural cardiac disease. In patients experiencing syncope associated with exertion, exercise stress testing is indicated. Finally, a coronary angiogram should be performed, if ischemia triggered syncope is suspected. A routinely performed neurological evaluation is not recommended.

Effect of different concentrations of carbon dioxide and oxygen on the growth of pathogenic Yersinia enterocolitica 4/O:3 in ground pork packaged under modified atmospheres.

The influence on Yersinia enterocolitica counts of a gradual increase of carbon dioxide concentrations (percentage by volume in air) during packaging and storage of ground pork meat artificially contaminated with this pathogen was evaluated. Ground meat was packaged under customary conditions using modified atmospheres with various carbon dioxide percentages (0, 30, 50, 70, and 100% CO2 by volume; for atmospheres of less than 100% CO2, the rest of the gas was O2). The packs were stored at 2 degrees C for 12 days. During the entire storage time, counts of Y. enterocolitica were determined by the spread plate method for direct plate counts (DPCs). Microbiological shelf life of the stored ground pork also was assessed by total mesophilic aerobic bacterial plate counts (APCs). Y. enterocolitica counts were not significantly different (P > or = 0.05) in the ground pork packaged under the various CO2-enriched atmospheres. The growth of Y. enterocolitica was nearly entirely inhibited in all tested modified atmospheres containing the protective CO2. However, in ground pork packaged with 100% oxygen, there was a significant decrease (P < or = 0.05) in the DPC for Y. enterocolitica from 4.30 log CFU/g (day 0) to 3.09 log CFU/g at the end of the storage time (day 12). The decrease was presumably due to the marked increase in APC seen only in those packages stored under 100% O2. Packaging with high CO2 concentrations had significant inhibitory effect (P < or = 0.05) on the growth of mesophilic aerobic bacteria.

Conventional high resolution versus fast T(2)-weighted MR imaging of the heart: assessment of reperfusion induced myocardial injury in an animal model.

Cardiac image quality in terms of spatial resolution and signal contrast was assessed for conventional and newly developed T(2)-weighted fast spin-echo imaging with high k-space segmentation. The capability in revealing regional myocardial edema and cellular damage was examined by a porcine model using histopathologic correlation. Twelve porcine hearts were excised from slaughtered animals and instantly perfused with 1000 mL cold cardioplegic solution. After 4 h of cold ischemia the hearts were reperfused for one hour using a "Langendorff" perfusion model followed by MR imaging at 1.5 Tesla. Three additional pig hearts served as controls and were studied by MR directly after harvesting. Histopathological analysis of regional tissue changes was performed macro- and microscopically. Short axis T(2)-weighted (3000/45 and 90) high quality fast spin-echo (FSE) images were recorded without cardiac action and signal intensity was correlated with histology. These images also served as gold standard for evaluation of newly developed faster sequences allowing measuring times shorter than 20 s. Fast T(2)-weighted imaging comprised single-slice fast spin echo (moderate echo train length of 23 echoes, FSE(m)), and multi-slice single-shot half-Fourier fast spin-echo (71 echoes, FSE(HASTE)) sequences, supplemented by versions with inversion recovery preparation (FSE(m)IR and FSE(HASTE)IR). Systolic function after reperfusion was restored in 10 porcine hearts. Tissue alterations included myocardial edema and contraction band necrosis which was found to be most severe in myocardium with maximum T(2) SI. Especially FSE(m) and FSE(m)IR sequences allowed differentiation of all categories of tissue damage on a high level of significance. In contrast, single-shot FSE(HASTE) and FSE(HASTE)IR sequences did not provide sufficient image quality to discriminate moderate and severe myocardial damage (p > 0.05). Different degrees of myocardial injury after ischemia and reperfusion can be staged by MR imaging, especially using conventional high resolution T(2)-weighted FSE sequences. The animal study indicates that fast T(2)-weighted FSE(m) and FSE(m)IR sequences lead to superior image quality and diagnostic accuracy compared to FSE(HASTE) and FSE(HASTE)IR imaging.