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Biomedical subjects

P Probst

Publications and source records attributed to P Probst.

At least 91 records · Page 5Linked to original sources

[Real-time sonography of cholangiolithiasis. Dependence of the diagnostic accuracy on the competence of the operator].

The reliability of sonography for demonstrating bile duct stones depends on technical factors and on the experience of the operator. The pick up rate of an experienced operator has been compared with that of three other doctors who had performed sonography only briefly and intermittently. This was based on the results of surgery in 142 patients. The sensitivity of the experienced operator was 72.4% and almost twice that of the other doctors, who showed an accuracy of 37.5 and 44%. The competence of the operator depends not only on adequate training, but also on continuous practice.

Adult↗

A new puncture needle (Seldinger technique) for easy antegrade catheterization of the superficial femoral artery.

Mainly for anatomical reasons a guide-wire or a catheter has a tendency to turn into the deep femoral artery during antegrade catheterization of the lower limb. To overcome this problem a curved puncture needle has been designed which allows positioning of the guidewire in an anterior direction. Antegrade catheterization of the superficial femoral artery was achieved in 25 patients without lengthy manipulations or complications. With this technique the rate of complications at antegrade catheterization will probably be reduced.

Catheterization↗

[A new method for the treatment of supraventricular rhythm disorders].

Initial experience of His-bundle ablation is presented in 12 patients with intractable supraventricular arrhythmias which were not amenable to treatment with conventional drugs. In 8 patients His-bundle ablation resulted in total AV-block and in 2 patients significant improvement without total AV-block was achieved. During long-term follow-up (mean 5.3 months) tachycardia recurred in 1 patient with total AV-block resulting in an overall success rate of 75%. A permanent pacemaker was implanted in 10 patients. 1 patient developed deep leg vein thrombosis as a direct result of this procedure and in 2 patients there were complications due to pacemaker implantation. His-bundle ablation appears to be a promising tool in the management of intractable supraventricular tachycardia.

Aged↗

[Radioiodine therapy in hyperthyroidism: reliability of a long-term follow-up scheme for the diagnosis and treatment of hyperthyroidism based on the family physician and on a central registry].

We assessed the reliability of a follow-up scheme for radioiodine-treated patients which involved the general practitioner after the first year, leaving to the center only the operation of a central recall registry and the analysis of mailed blood samples and simple questionnaires. The analysis of 238 patients followed up for 3-6 years showed that the scheme was equal or superior to follow-up rates of published systems in Switzerland which rely on regular recalls of the patients to the center. However, the excellent follow-up rates published with similar systems in Great Britain were not quite achieved and efforts will be needed to diminish the number of patients lost to follow-up. Contrary to the experience of other authors, our laboratory results did not allow us to single out a group of patients with low likelihood of developing hypothyroidism and in whom follow-up examinations could be spaced at longer intervals. Reversing our current practice, we now recommend that hypothyroid patients be left on our registry once they are on replacement therapy with thyroxine. Examination of this patient group has revealed that 27% are undersubstituted, albeit only to a borderline degree in most cases.

Aged↗

[The treatment of Basedow's disease. The agony of selection].

The treatment mode of Graves' disease should be chosen individually for each patient. This requires a thorough knowledge of the advantages and disadvantages of the various methods, and also bias-free interdisciplinary cooperation. Surgery reestablishes euthyroidism in about 80%, with 10% becoming hypothyroid. In centers practising more radical surgery hypothyroidism has developed in up to 49% and there is now evidence of occurrence of late hypothyroidism in the same way as after radioiodine. Radioiodine is cheap and causes minimal inconvenience to the patient. Because prevalence of hypothyroidism rises in a cumulative way over decades, lifelong follow-up is necessary with an examination every 1 to 2 years. The genetic risk and the danger of thyroid carcinoma have been shown to be negligible by gonadal dose calculations and by longterm prospective follow-up. Antithyroid drugs inhibit incorporation of iodide into thyroglobulin and produce rapid clinical improvement. It seems probable that, in longterm treatment, they also specifically suppress the synthesis of thyroid-stimulating immunoglobulins. The significance of "allergic" reactions such as skin rash, leukopenia and agranulocytosis is usually overestimated. The hematologic side effects are rare, dose-related and reversible in most cases. The major drawback of antithyroid drugs is the high recurrence rate (50%) of hyperthyroidism after cessation of therapy. It is still undecided whether a long course of treatment (one year or longer) produces better longterm results than short courses.

Antithyroid Agents↗

[R spike potentials in ergometric stress: patients with dilated cardiomyopathy in comparison to coronary heart disease].

R-wave amplitude changes during exercise were compared in patients with cardiomyopathy (n = 32), patients with coronary artery disease (n = 58) and controls (n = 12). Patients with cardiomyopathy (CMP) had a smaller R-wave amplitude (RWA) at rest than those with coronary artery disease (CAD). At comparable levels of exercise patients with CMP showed no change in RWA, while those with CAD demonstrated an increase in RWA. Controls showed a decline in RWA. In patients with CAD changes in RWA during exercise were more sensitive in the detection of disease than ST-segment changes. Left ventricular function was the major determinant of the direction and magnitude of RWA changes both in patients with CMP and CAD, with lesser changes in RWA in patients with more severely reduced left ventricular function.

Blood Pressure↗

[Radiologic follow-up of the replacement of the ascending aorta with a composite graft. Comparison of angiography and computed tomography].

Only a few long-term results after replacement of the ascending aorta with a composite graft are available. Twelve patients were therefore evaluated clinically, by computer tomography (CT) and angiography 8-102 months postoperatively. 7 patients had a type I dissecting aneurysm, 1 patient a type II and 4 patients a true aneurysm. Clinically there were no signs of valvular dysfunction or symptoms of lower limb ischemia. All patients were in functional class I or II. On CT all patients with a type I aneurysm showed a chronic dissection with a perfused false lumen extending into the descending aorta. Opacification of the coronary ostia was possible in 4 patients. In 1 patient a false aneurysm at the distal suture line was visualized. Angiography confirmed all CT findings. Coronary angiography demonstrated widely patent coronary ostia. No false aneurysm around the implants was found. Thus, functional results after composite graft operation are good despite the persistence of massive chronic dissection in all patients with a type I aneurysm. CT is an ideal method of evaluating the extent of this dissection. Angiography is necessary to visualize the anatomy of the aortic root and of the coronary ostia.

Adult↗

Relation of coronary arterial occlusion pressure during percutaneous transluminal coronary angioplasty to presence of collaterals.

To investigate the relation of the gradient across a coronary artery stenosis and the pressure distal to the stenosis after proximal occlusion during percutaneous transluminal coronary angioplasty to the amount of angiographically estimated collateral circulation, 63 patients (55 men, 8 women) were studied. All patients had 1-vessel disease (54 left anterior descending, 8 right coronary artery and 1 circumflex coronary artery). All patients had documented ischemia, and angioplasty was carried out within 4 weeks after the initial angiogram. The patients were separated into 4 groups: 0 = no collaterals (35 patients), +1 = just visible collaterals (8 patients), +2 = collaterals without reaching the contralateral vessel (10 patients), and +3 = filling of the contralateral vessel (10 patients). There was no difference in age among the 4 groups. There was a significant negative relation of the gradient vs the extent of collateral circulation, although the degree of stenosis increased significantly from group 0 to group +3. There was a significant positive relation of the occlusion pressure (in absolute terms and in percent of the proximal systolic pressure) vs the extent of collateral circulation. There was a significantly smaller change of the occlusion pressure vs the distal pressure before occlusion if good collaterals were present. The occlusion pressure remained constant during 1 occlusion up to 40 seconds and was reproducible in 3 successive occlusions. In conclusion, the pressure distal to a coronary artery stenosis is mainly dependent on the severity of the stenosis and on the collateral flow. If anterograde flow is eliminated by proximal occlusion the distal pressure is only dependent on the extent of collateral circulation.

Adult↗

Renal handling of norepinephrine and epinephrine in the pig.

To investigate the renal handling of catecholamines in the pig, intravenous infusions of 51Cr-EDTA and PAH were performed in 7 animals, and samples for simultaneous measurement of norepinephrine (NE), epinephrine (E), 51Cr-EDTA and PAH were obtained through catheters placed into the aorta, left renal vein and both urethers. For both kidneys together, 51Cr-EDTA clearance [GFR] averaged 48 +/- 14 (+/- SD) ml/min (2.23 +/- 0.66 ml/kg/min). In the left kidney, GFR averaged 22 +/- 9 ml/min, arteriovenous PAH extraction 0.87 +/- 0.09, and calculated total renal plasma flow 91 +/- 30 ml/min. Plasma NE and E were lower in renal venous than arterial blood (P less than 0.005), extraction ratios averaging 0.36 and 0.77, respectively. NE excretion rate in final urine (8.9 +/- 4.3 ng/min) exceeded transrenal NE extraction rate (5.2 +/- 3.9 ng/min) by 3.7 +/- 4.4 ng/min. In contrast, urinary E excretion rate (2.9 +/- 2.0 ng/min) was slightly lower than transrenal E extraction rate (3.6 +/- 3.8 ng/min). These observations suggest that in pig kidneys, plasma PAH extraction rate and GFR related to body weight are quite similar to values in man. Three quarters of circulating E are extracted for the most part by tubular secretion, and the slightly smaller amount appearing in urine is consistent with some intrarenal metabolism. NE, presumably originating from intrarenal neuronal release and/or de novo production, is secreted into the urine.

Animals↗

[Invasive diagnosis of arrhythmias].

This paper deals with the methods, the indications and the clinical relevance of the invasive diagnosis of arrhythmias. The change of the indication of this method from bradyarrhythmias to tachyarrhythmias is particularly discussed. This method has developed from a purely diagnostic tool to a therapeutic instrument. During one investigation the diagnosis, the mechanism and the localisation of an arrhythmia can be detected and in addition the optimal therapy can be found. The complication rate is low provided that it is performed in specialized cardiological centers. This method has itself established as an important tool in diagnosis and treatment of tachyarrhythmias.

Bundle of His↗

[Antiarrhythmic effect and side effects of amiodarone].

UNLABELLED: Amiodarone (AM) is one of the most potent antiarrhythmic drugs, the value of which is limited by reversible and irreversible side-effects (SE). 59 patients, 50 male, 9 female (age 33 to 81 years) entered the study with ventricular tachycardia (VT, 68%), WPW-tachycardia (12%), non-sustained VT (12%) or untreatable paroxysmal atrial fibrillation or supraventricular tachycardia (8%). Prior to AM the patients had received 1 to 8 different antiarrhythmic drugs (m 3.5) and maximal 9 different combinations of antiarrhythmics. The drug regimen started with a loading dose of 1200 mg/d for 1 to 2 weeks and was continued with a maintenance dose of 200 to 600 mg/d. The patients were followed up 1 to 41 months (m 14 m). The drug effect was evaluated using clinical criteria (recurrence of arrhythmias, death), computer-assisted analysis of several 24 hr long-term ECGs and programmed electrophysiological stimulation. Three- to six-monthly the patients were seen in our outpatient department for check up and blood-sample analysis (liver, thyroid gland etc.). Also in the majority of the patients frequent ophthalmological and dermatological investigations, as well as lung functions tests were carried out. RESULTS: under AM therapy the initial arrhythmias were no longer detectable in 41% of the patients. In 37% a significant amelioration of the formerly life-threatening arrhythmias was found. 7 patients (12%), predominantly with reduced left ventricular function, died during follow up. No pulmonary, hepatotoxic or neurological SE were found. All patients developed reversible AM keratopathy. In 27% ETR and T4 were elevated, but only one patient developed hyperthyroidism with an increase in TT3. Another patient showed signs of hypothyroidism with an elevated TSH prior to TRH stimulation. Increased phototoxicity was found in 31%, whereas in two patients typical AM hyperpigmentation occurred, especially on the face. In conclusion, AM is a highly effective antiarrhythmic agent, despite a negatively selected collective, but it should only be used in patients with refractory arrhythmia in view of the SE.

Adult↗

Radionuclide imaging after coronary vasodilation: myocardial scintigraphy with thallium-201 and radionuclide angiography after administration of dipyridamole.

Tl-201 imaging was performed in 194 patients who had undergone coronary angiography which had demonstrated coronary artery disease in 149 and normal coronary vessels in 45.91 patients had had previous myocardial infarction. Sensitivity for dipyridamole stress imaging was 92% for all 149 patients. 79% for the patients without previous infarction. Specificity was 81%. In a subgroup of 40 patients (32 patients with reversible Tl-201 defects and 8 normals), an additional dipyridamole wall motion study was performed in order to evaluate the correlation of Tl-201 perfusion abnormalities and ventricular function after dipyridamole. Only 19% of the patients had a dipyridamole-induced drop of global left ventricular ejection fraction, 31% showed dipyridamole-induced wall motion abnormalities; the predictability of specific vessel involvement by regional wall motion and regional ejection fraction assessment was 26% as compared with 70% for thallium imaging. Tl-201 perfusion defects after dipyridamole administration can also occur independent of ischaemia-induced changes in global and regional ventricular function. Coronary vasodilation with dipyridamole using Tl-201 imaging is a reliable alternative method in patients with coronary artery disease with an accuracy comparable to exercise studies with the advantage of not necessarily needing ischaemia as an endpoint of the test.

Cineangiography↗

Percutaneous transluminal angioplasty of the arteries of the lower limbs: a 5 year follow-up.

A total of 482 percutaneous transluminal angioplasties (PTAs) of the arteries of the lower limbs were performed in 411 patients between 1977 and 1983. The 5 year patency rate, calculated by the life table method, was 83% for iliac and 58% for femoropopliteal PTA. Clinical improvement after the procedure was confirmed by a significant drop of the arm-ankle pressure difference: 48 +/- 5 mm Hg before vs 17 +/- 5 mm Hg 2 years after iliac PTA (p less than .01) and 73 +/- 5 mm Hg before vs 28 +/- 6 mm Hg after femoropopliteal PTA (p less than .01). The majority of reocclusions occurred within the first year after angioplasty. Patients with stenoses or occlusions of less than 3 cm had a favorable long-term patency rate of 74%. Conversely, patients with femoropopliteal occlusions presenting with pain at rest, diabetes, occlusions of greater than 3 cm, or poor distal runoff had an elevated rate of reocclusion. Complications, which occurred in 8% of the patients in whom PTA was attempted, included local hemorrhage, dissection, embolism, and spasm necessitating surgical intervention in 2%. No deaths or amputations were a direct consequence of PTA. PTA of arteries of the lower limbs may thus be regarded as a valid complementary treatment to vascular surgery in patients with occlusive disease of the peripheral arteries.

Aged↗