Acta medica Austriaca. Supplement最新文献

Heart-rate (HR) and arrhythmias (AR) are influenced by the vegetative balance. This cannot be measured during daily life at present. Otherwise HR and AR can be detected with a high accuracy using the Holter-Method (HM). Therefore we investigated the relationship of HR, AR and left-ventricular function (LVF) in patients with coronary heart disease (CHD: 342 HM; normal LVF 33%, moderate reduced 33%, reduced 35%) and dilative cardiomyopathy (DCM: 225 HM, LVF normal 13%, moderate reduced 39%, reduced 48%), with special emphasis on the problem, whether tachycardia during chronic congestion will stimulate AR (AR due to an increased sympathic tone) or will suppress AR (overdrive suppression). Furthermore we evaluated, whether patients with a loss of the circadian pattern (CP) of HR or AR, who demonstrated an uniform high HR (due to the enhanced sympathic tone), were on higher risk of dying than other collectives. HM were analysed using the computer-supported "Multipass-Scanning" system. The decreasing LVF coincides with an increase in HR and a loss of HR-CP (i.e. dHR-day-night greater than or equal to 10 b.p.m.). The amount of the HR-CP depends on the mean HR during day in the manner of a direct relationship. The prevalence of premature ventricular ectopics (PVC) increases with decreasing LVF from 39 to 53% (CHD) and from 47 to 63%. A positive circadian pattern of the PVC exists in 60% of CHD and in 84% of DCM, which also decreases with the LVF to 54 vs. 52%. Independent from a CP in two thirds of the patients VA were stimulated and in one third suppressed with a worsening of the LVF. The phenomenon of an overdrive suppression of VA starts with a HR of 90 b.p.m. and higher. The 40% mortality in patients with an uniform (day and night) high HR (greater than 90 b.p.m.) was significantly higher than in other collectives (10%).

Early localisation of infarction, estimation of infarct size and visualisation of metabolic and structural changes is of great importance for the management of acute myocardial infarction. This paper is based on an experimental model using a combination of in-vivo and in-vitro methods that allow the evaluation of the area at risk of infarction, the border zone and its changes over time. The purpose of the study was to characterize the topography and the time course of the border zone. The border zone forms an approximately 2 mm wide margin at the lateral edges of the infarct, with increasing width of the border zone along the subepicardium. Increasing duration of ischemia is associated with a dynamic sequence of events, not only within the area at risk of infarction but also in the peri-ischemic border zone, leading to an expansion of the subepicardial margin due to improved collateral blood flow over time. The area at risk of infarction is characterized by early distinct metabolic changes that were visualized as soon as 90 to 120 seconds following coronary artery occlusion. After 6 hours of occlusion almost the entire area at risk shows signs of irreversible injury due to severe hypoperfusion. The border zone, in contrast, is characterized by only moderate metabolic changes due to greater collateral perfusion (45 to 80% of the regional blood flow in the non-ischemic vascular bed). Several interventions were chosen and evaluated for their effects on the dynamic course of events within the area at risk of infarction and in the border zone. Interventions that have strong myocardial protective effects such as the combination of alpha- and beta-blockade, the application of specific O2-carriers (Perfluorocarbons) and pressure controlled retrograde perfusion via the coronary sinus ("PICSO"), not only reduce infarct size by 20 to 40% of the myocardium at risk of infarction, but also induce substantial topographic, functional and metabolic changes within the border zone.

M-mode contrast echocardiography with peripheral venous injections was performed in 73 patients with interatrial communications: 48 (group 1) had a hemodynamically significant atrial septal defect (ASD), 19 (group 2) had a patent foramen ovale (PFO) without clinical or oxymetric evidence of a shunt. The remaining 6 (group 3) had an interatrial communication in combination with severe additional congenital malformations predisposing to a right to left (R-L) shunt. Contrast studies were considered positive for a shunt lesion when at least five clearly recognizable contrast echoes appeared in the left heart following one injection. During quiet respiration positive contrast studies were obtained in 85% of all ASD patients (including all 10 with Eisenmenger's reaction and 31/38 [82%] uncomplicated cases); in 37% of the PFO cases (including 3/13 with normal right heart pressures), and in 53/73 (73%) of all patients with interatrial communications. The intensity of contrast shunting was variable in all groups. Opacification of the mitral funnel (which is typical for an atrial level shunt) was observed in 45 patients. In 8 patients with positive studies the few contrast echoes, that appeared in the left heart were first seen after they had left the mitral valve. Contrast injections into the pulmonary artery were performed in a control group of 29 patients. No contrast appeared in the left heart as expected. In 57 patients (39 ASD, 17 PFO, 1 group 3) contrast studies were also performed during the Valsalva maneuver. Valsalva provocation resulted in increased contrast shunting in 19, led to new mitral funnel opacification in 9 and improved the sensitivity of contrast echocardiography by 9 and 26% in ASD and PFO cases respectively. The intensity of contrast shunting was largely independent of the hemodynamic findings and was often variable upon subsequent injections in the same patient. Therefore contrast echocardiography is not helpful in predicting the L-R shunt or the pulmonary artery pressure and does not seem suited for follow-up studies. The differentiation between true contrast echoes in the left heart and artifacts, noise echoes, "overload", or incomplete mitral structures and the differentiation between interatrial and interventricular contrast shunting is usually easy. However the distinction between a hemodynamically significant ASD and pulmonary arteriovenous fistulas, certain venous anomalies or a patent foramen ovale may be difficult or even impossible by contrast echocardiographic criteria alone. Resting two-dimensional contrast echocardiograms were recorded in 57 patients including 34 with ASD, 18 with PFO and 5 from group 3.(ABSTRACT TRUNCATED AT 400 WORDS)

Regional hepatic blood flow has been determined by 4 methods with the aid of the 133Xe washout technique: scintisplenoportography (direct application of 133Xe into the spleen by means of a thin needle); arterial method (133Xe is injected into the A. hepatica by means of a catheter); retrograde-venous method (133Xe administered by an occluding hepatic vein catheter); percutaneous intrahepatic method (133Xe administered directly into the parenchyma by means of a Chiba needle). Ad 1.: Scintisplenoportography (SSP) was executed with 97 patients: 8 patients with a healthy liver presented a hepatic blood flow of 103.37 +/- 11.5 ml/100 g/min. 4 patients with a chronic hepatitis showed a hepatic blood flow of 105.67 +/- 10.2 ml/100 g/min. In 38 patients with compensated cirrhosis, hepatic blood flow was determined with 58.15 +/- 11.5 ml/100 g/min and 19 patients with decompensated cirrhosis showed a blood flow of 34.54 +/- 7.2 ml/100 g/min. Of the 19 patients, who did not present any liver image, 2 patients suffered from a prehepatic block, 1 patient (female) from a posthepatic block, the rest were decompensated cirrhoses. In 5 patients suffering from steatosis only collateral circulation was determined and in 4 patients the spleen could not be punctured. In the patients with compensated and decompensated cirrhosis of the liver, hepatic blood flow differentiated significantly (p less than 0.001) from patients with healthy livers and chronic hepatitis. In the patients with bioptically assured steatosis only the washout constant was determined. Reproducibility of this method was tested in 4 patients and no statistical difference of hepatic blood flow values could be found and the correlation coefficient amounted to 0.9856. The advantage of SSP lies in the possibility of recording the portal vein circulation: cranial collaterals were found in 33 patients, 2 patients had caudal collaterals exclusively and 29 patients cranial and caudal collaterals. 33 cirrhosis patients presented evidence of hepatic shunts. In nearly all patients hepatic blood flow was higher in the right lobe than in the left. Ad 2.: Arterial method was executed in 26 patients: 2 patients with healthy livers had a hepatic blood flow of 89.85 +/- 2.9 ml/100 g/min, 19 compensated cirrhoses with 49.28 +/- 11 ml/100 g/min and 3 decompensated cirrhoses with 36.43 +/- 3.4 ml/100 g/min. Patients suffering from cirrhosis demonstrated significantly lower hepatic blood flow than patients with healthy livers (p less than 0.001). In arterial application also, with the exception of a single patient, the values for hepatic blood flow were higher for the right than the left lobe of the liver.(ABSTRACT TRUNCATED AT 400 WORDS)

Hemodialysis therapy is the most commonly used renal replacement therapy despite the development of alternative detoxification procedures. As in any therapy hemodialysis treatment shows side effects. These regularly appearing intradialytic complications are essentially responsible for the morbidity of the dialysis patient. Studies were undertaken to clarify the pathomechanisms of the dialysis hypoxemia and dialysis hypotonia. Intradialytic variations of carbohydrate and protein metabolism and of the cellular blood components were analyzed. The exact knowledge of the pathomechanisms of these side-effects should lead to technical improvement in dialysate composition. With this knowledge a more effective treatment and a better prophylaxis of these intradialytic side effects should be possible.