Pleomorphic Ventricular Tachycardia: Demonstration of Conduction Reversal Within the Reentry Circuit

A case is presented of a patient with incessant venfricular tacbycardia of left bundle branch block morphology. Endocardial mapping revealed the site of earliest activation during tachycardia to be the proximal right ventricular septum. Pacing at this site elicited the clinical tachycardia, whereas pacing at the proximal left ventricular septum induced a right bundle branch block morphology identical to that of a previously recorded spontaneous ventricuiar tachycardia. Electrophysiological evidence is given that both types of tachycardia originate from a single reentry circuit located in the proximal ventricular septum in which the reentrant wavefront may travel either orthodromically (during spontaneous tachycardia and right ventricular pacing) or antidromically (during left ventricular pacing).     

Effects on mortality of alcohol consumption, smoking, physical activity, and close personal relationships

The study analyses the risks of mortality associated with alcohol consumption and smoking, as well as possible counteracting effects of physical activity and social support through close personal relationships. Data are based on the Upper Bavarian Study, a longitudinal epidemiological study of a representative community sample (n = 1668) in a rural area. Extensive semistructural psychiatric interviews by research physicians were conducted between 1975 and 1977 (n = 1536). Thirteen years after psychiatric assessment, information was obtained from the community register concerning death in the interval, date of death and cause of death according to ICD 9. Tins information could be ascertained for 93.1% (n= 1430) of those who had been interviewed, thus providing a good basis for generalizing the findings. Results indicate that alcohol intake and cigarette smoking increased mortality while physical activity and the availability of a steady partner had protective effects. There were no interactive effects between the four variables studied, except far a dramatically increased risk for women drinking more than 20 ml of pure alcohol a day and reporting no physical exercise at wave one assessment. The relative risks of alcohol intake and smoking, and the counteracting effects of physical activity and partnership, are exemplified in the cases of a 40-year-old female and a 40-year-old male. Specific analyses of the relationship between alcohol consumption, smoking, physical exercise and personal relationships, on the one hand, and, on the other, different causes of death, are presented.     

The role of auxiliary dihydropyridine receptor subunits in muscle

The skeletal muscle dihydropyridine receptor is a slowly-activating calcium channel that functions as the voltage sensor in excitation-contraction coupling. In addition to the pore-forming α_1S subunit it contains the transmembrane α₂δ-1 and γ₁ subunits and the cytoplasmic β_1a subunit. Although the roles of the auxiliary subunits in calcium channel function have been intensively studied in heterologous expression systems, their functions in excitation-contraction coupling has only recently been elucidated in muscle cells of various null-mutant animal models. In this article we will briefly outline the current state of these investigations. * To whom correspondence should be addressed: Tel.: +43-512-507-3787; Fax: +43-512-507-2836; E-mail: bernhard.e.flucher@uibk.ac.at     

Canine Exocrine Pancreatic Secretory Changes Induced by an Intragastric Ethanol Test Meal

In five dogs with chronic gastric fistulas (Thomas cannula) and a new type of chronic pancreatic fistula which permits collection of pure nonactivated pancreatic juice after ingestion of a test meal, the following series of experiments were performed: In the first series, a test meal (400 gm. canned dog meat) was given with 200 ml. saline simultaneously infused through the gastric cannula. In response to this stimulus, the 20-minute peak pancreatic flow rate and bicarbonate output were respectively 33% and 34%, of the maximal secretion of the pancreatic gland obtained with secretin in six control dogs provided with gastric and the classical Thomas duodenal fistula. The 20-minute peak protein output represented 84% of the maximal secretory capacity attained with dose-response curves to CCK in the same group of control animals.
In the second series either 1.5 or 2.0 gm./kg. ethanol were given instead of saline. Intragastric ethanol induced a dissociation of pancreatic secretion: a significant inhibition of flow rate, of bicarbonate concentration and output and a significant rise of protein concentration; protein output remaining unchanged.
It is postulated that ethanol, acting on the stomach and duodenojejunum, evokes, independently of its gastrin-releasing capacity', an unknown humoral or nervous mechanism that counteracts the ethanol-elicited cholinergic-mediated inhibition of pancreatic protein secretion which has been previously described.     

A study of the antigenicity of Rickettsia helvetica proteins using two‐dimensional gel electrophoresis

Rickettsia helvetica is an obligate intracellular Gram‐negative microorganism found in Ixodes ricinus ticks. When R. helvetica was first discovered in 1979, little was known about its physiology and it fell into oblivion until it recently was suspected of being pathogenic to humans. However, all efforts to isolate R. helvetica from patients have been unsuccessful, although serological responses against R. helvetica can be demonstrated. The aim of our study was to investigate the protein profile of R. helvetica and study the antigenicity of its proteins using two‐dimensional (2D) immunoblot in order to characterize the immunological response against R. helvetica infection. Our results show that in addition to the known PS120 and OmpB antigenic R. helvetica proteins, three other antigens exist: a 60 kDa GroEL protein, a 10 kDa GroES protein and a hitherto unknown 35 kDa hypothetical protein that has similarities with ORF‐RC0799 of Rickettsia conorii. Furthermore, the lipopolysaccharide showed strong antigenicity. In this study, we present the first proteome map and the first 2D immunoblot profile of R. helvetica and finally we present the 35 kDa R. helvetica as an additional antigen to the previously known rickettsial antigens.     

Vecuronium titration for muscle relaxation in myotonic dystrophy

A 14-year-old boy with pronounced myotonic dystrophy and cardiac malformation had a normal ED₉₅ (53 μg·kg^?1) of vecuronium, whereas the recovery index (25-75% twitch recovery) was three times as long as in the absence of neuromuscular disease. We conclude that in young patients with dystrophic muscle disease individual titration of the muscle relaxant with the aid of a nerve stimulator does not preclude a considerable delay in the recovery of neuromuscular transmission.     

Pulmonary Venous Flow Pattern in Severe Aortic Regurgitation with Diastolic-Systolic Mitral Regurgitation Detected by Transesophageal Echocardiography

The pulmonary venous flow patterns of two patients with severe aortic regurgitation (AR) (one with 2+ diastolic, 2 + /3 + systolic mitral regurgitation (MR), the other with minimal diastolic and 1 + /2 + systolic MR) was examined with TEE. A reduced systolic forward flow and an accentuated diastolic reversal flow were found in each case, irrespective of the amount of MR. According to the first impression it could perhaps be possible to judge the amount of AR on the basis of the VTI measurement of the pulmonary venous flow pattern.     

Differential effects of dobutamine, dopamine, and noradrenaline on splanchnic haemodynamics and oxygenation in the pig

Supranormal oxygen (O₂) transport may benefit critically ill patients. Catecholamines are clinically employed for this purpose. However, their effects on splanchnic haemodynamics and oxygenation are not well defined. The effects of dobutamine (DOBU), dopamine (DOPA), and noradrenaline (NA) on splanchnic blood flows (electromagnetic flow probes), O₂ deliveries and uptakes (catheterisation of portal and hepatic veins) were studied in nine anaesthetised (ketamine/flunitrazepam), ventilated, paralysed, and laparotomised pigs. All three catecholamines (DOPA at 15 μg·kg^-1 · min^-1, DOBU at 13 μg · kg^-1 · min^-1, NA at 0.4 μg · kg^-1 · min^-1) significantly ( P <0.05) increased cardiac output and systemic O₂ delivery. Only DOPA increased small intestinal and total hepatic blood flows, and O₂ deliveries, and decreased O₂ extractions. The same parameters did not change during DOBU. During NA, total hepatic blood flow and O₂ delivery decreased, and hepatic O₂ extraction increased. During all three catecholamines, small intestinal and total hepatic O₂ uptakes did not change significantly. Whereas hepatic arterial blood flow decreased during both DOPA and NE, portal venous flow increased during DOPA. These data suggest that in the experimental model used splanchnic O₂ supply and O₂ reserve capacity appear improved by DOPA, unaffected by DOBU, and impaired by NA.