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Biomedical subjects

I Kruse

Publications and source records attributed to I Kruse.

At least 19 recordsLinked to original sources
PubMed1989

Atrial inhibited pacing in the sick sinus node syndrome: clinical value and the demand for rate responsiveness.

A consecutive series of 66 patients (males = 32; mean age +/- SD = 71 +/- 9 years) given atrial inhibited pacemakers for sick sinus nodes were followed to study the incidence of lead failures, chronic atrial tachyarrhythmias, and atrioventricular conduction disturbances. The need for rate responsive pacing was also assessed. Pre and postoperative investigation could include carotid sinus massage, Holter monitoring, exercise testing, and invasive electrophysiology. The mean follow-up time +/- SD was 32 +/- 29 months (median = 26 months). Three patients (5%) had their pacemakers replaced due to lead failures (loss of sensing = 2; exit block = 1). Two pacemakers (3%) were replaced after 5 and 22 months due to atrial fibrillation. Four patients (6%) received new pacemakers because of development of second-degree or complete atrioventricular block after 1, 6, 12, and 31 months, respectively. During exercise, most patients (76%) responded with an increase in sinus rate at least as marked as that achievable with the currently available rate responsive pacemakers. Assuming careful patient selection, atrial inhibited pacing is well suited for many patients with sinus node dysfunction and preserved atrioventricular conduction. There is a limited need for rate responsive pacemakers in these patients.

Aged↗
PubMed1989

[Kidney function in the course of compensatory hypertrophy following unilateral nephrectomy in the Wistar rat].

Unilateral nephrectomy was performed in 109 male Wistar rats, 35 animals served as controls. Determinations of glomerular filtration rate (GFR) using slope clearance of 99mTc-DTPA and of tubular function using an orally water-loading test were made. The tests were performed 2 and 5 days as well as 2, 4, 5 and 6 weeks after nephrectomy. In all examinations the GFR was more than 50% of the level of two-kidney control animals. Fractional maximum diuresis was increased in the first 2 examinations after nephrectomy from 8.9 +/- 2.1 to 15.4 +/- 4.2% of the GFR and fractional clearance of osmotically free water from 6.8 +/- 1.9 to 10.9 +/- 3.5%. In the fourth and sixth week the proximal tubular reabsorption was increased and the glomerulo-tubular balance had been recovered. However, the minimal urine osmolarity was increased to 107.8 +/- 17.7 mmol/l and the osmotic load of the nephrons remained elevated. Possible clinical implications of the results are discussed.

Animals↗
PubMed1987

Rate-responsive pacing by means of activity sensing versus single rate ventricular pacing: a double-blind cross-over study.

The clinical applicability of rate-responsive pacing (RRP) by means of activity sensing has been tested in 15 patients. The patients (ages 24-85) had sinus node dysfunction (2), atrial fibrillation (7), or sinus rhythm (6) combined with complete atrioventricular block. Exercise capacity was investigated on a bicycle ergometer and on a treadmill in a double-blind cross-over study design following one week each of fixed rate ventricular pacing (70 bpm) and rate-responsive pacing (60/125-150 bpm). The patients answered a questionnaire concerning subjective symptoms. A Holter ECG was recorded during 24 hours of all day activity on rate-responsive pacing. During exercise in the rate-responsive mode, heart rate increased more on the treadmill than on the bicycle. A majority of the patients (13 of 15) preferred rate-responsive pacing mainly due to less dyspnea and tiredness. Exercise capacity improved significantly both on bicycle (+7%; p less than 0.01) and on treadmill (+19%; p less than 0.01) during rate-responsive pacing. There were no complications during the follow-up period. In conclusion, the activity-sensing pacemaker is a valuable supplement to existing types of pacemakers. It should be used in patients in whom an atrial electrogram cannot be used for rate triggering.

Adult↗
PubMed1987

[Kidney function in spontaneously hypertensive rats under minoxidil treatment].

In 25 spontaneously hypertensive rats the blood pressure was lowered from 192 +/- 11.6 to 130 +/- 11.7 mm Hg and in 26 normotensive Wistar rats from 129 +/- 9.1 to 107 +/- 6.7 mm Hg by applying 1 mg/kg body weight minoxidil twice a day orally. 19 spontaneously hypertensive and 21 normotensive rats served as untreated control groups. During the treatment the glomerular filtration rate, determined by the slope clearance of Tc-99m-DTPA, remained unchanged. Under maximal water diuresis the excretion fraction of sodium was diminished compared with the control data. The Na+ and water reabsorption was increased in the proximal tubules (not an aldosterone effect) only in the treated spontaneously hypertensive rats. The potassium clearance was increased in this group, but decreased in the treated normotensive group. The different reactions of the renal tubular function to the treatment with minoxidil in spontaneously hypertensive compared with normotensive rats were discussed in connection with changes of membrane transport in essential hypertension.

Animals↗
PubMed1985

[Bacteriologic, histologic and functional studies of the kidney in 5 days' therapy of experimental E. coli pyelonephritis with gentamycin. Comparison with 9 days' therapy].

Short-term antibiotic treatment is recommended in infections of the lower urinary tract but its effectiveness is questioned in the upper urinary tract infections. We compared a 5 and a 9 day treatment of experimental E. coli 022 pyelonephritis after unilateral nephrectomy in 127 mal Wistar rats. We used 9 mg gentamycin per kg b.w. twice daily. I131 hippurat excretion was not decreased during the 5 day treatment but was only temporarily diminished during the 9 day treatment. Histologically the severe acute pyelonephritis was decreased after the 9 day treatment but not after 5 days of treatment. Bacteriologically almost all the kidneys were sterile after the 9 day treatment but the majority of the kidneys showed the injected strain of E. coli after the 5 day treatment. The results indicated that the shortened treatment was much less effective in our acute experimental pyelonephritis.

Animals↗
PubMed1985

[Kidney function and bacteriological and histological research in the therapy of experimental E. coli pyelonephritis using trimethoprim-sulfamethoxazole (TMP-SMO)].

40 uninephrectomized male Wistar rats with an experimental E.-coli-022-pyelonephritis (PN) were treated twice daily for 9 days with 30 mg trimethoprim and 150 mg sulfamethoxazole (TMP-SMO) i.p. Bacteriologically most of the kidneys became sterile. Histologically a significant reduction of the frequency of severe PN was found in the treated group. The biologic half-life of 131I-hippuran indicated a decrease of excretory function which was reversible. Urine osmolality and osmotic clearance were increased after oral water loading in 10 untreated control animals with PN but not in the treated group. The 9 day treatment had a favourable effect bacteriologically, histologically and also on renal function.

Animals↗
PubMed1983

A new transvenous lead for both atrial and ventricular pacing.

A new transvenous tined unipolar lead (Medtronic SP 342) has been implanted in 56 patients; 35 leads were positioned in the atrium and 34 in the ventricle. The lead comprises a trifilar DBS-conductor within an insulation of polyurethane, four symetrically placed polyurethane tines furnished with scallops and a platinum-iridium ring-tipped electrode. The scallops in the tines ensure flexibility and a small effective diameter of the lead which makes the choice of vein less critical than with most previous tined leads. It allows use of the same normally sized vein for a second lead for dual-chamber sensing pacing. Mean atrial and ventricular electrogram amplitudes (+/-SD) were 4.6 +/- 1.2 mV and 8.8 +/- 4.4 mV; mean atrial and ventricular stimulation thresholds were 0.8 +/- 0.3 V and 0.4 +/- 0.2 V; and mean atrial and ventricular lead impendances were 415 +/- 114 ohms and 456 +/- 105 ohms, respectively. The results of this study show that the SP 342 lead is useful especially in dual chamber systems.

Adolescent↗
PubMed1983

Pacemaker-induced arrhythmias.

The pacemaker ECG with different types of pacemakers used for the treatment of bradyarrhythmias is considered. The arrhythmias induced or interfered with by the pacemakers receive special consideration. The normal function of the most common types of pacing systems is schematically presented.

Arrhythmias, Cardiac↗
PubMed1982

Physiological pacing.

Explore the source record for details and available documents.

Cardiac Pacing, Artificial↗
PubMed1982

A comparison of the acute and long-term hemodynamic effects of ventricular inhibited and atrial synchronous ventricular inhibited pacing.

Sixteen patients treated with a noninvasively programmable pacemaker were examined after a prolonged period of ventricular inhibited (VVI) and atrial synchronous ventricular inhibited (VDD) pacing. Maximal working capacity was determined by bicycle ergometry. Atrial and ventricular rates, brachial artery cuff pressure and breathing rate were determined at rest and during exercise. There was a mean increase in working capacity of 24% with VDD compared with VVI pacing (p less than 0.001). Thirteen of the patients were catheterized. During VDD pacing, cardiac output was significantly higher, particularly during exercise (+/- 32%) due to the capability of heart rate increase and despite a substantial compensatory stroke volume increase during VVI pacing. Arteriovenous oxygen difference was much higher during VVI pacing, reaching 164 +/- 14 ml/l during the highest work load, while the corresponding level during VDD pacing was 140 +/- 14 ml/l (p less than 0.001). During exercise, arterial blood lactate was significantly higher during VVI than during VDD pacing. Heart size was significantly smaller, 568 +/- 98 vs 530 +/- 96 ml/m2 BSA (p less than 0.05), during VDD pacing a questionnaire was completed by the patients to evaluate subjective symptoms and pacemaker preference. This part of the study favored the VDD mode of pacing. The conclusion of this study is that VDD pacing is superior to VVI pacing.

Aged↗
PubMed1981

Comparison of physical work capacity and systolic time intervals with ventricular inhibited and atrial synchronous ventricular inhibited pacing.

Sixteen patients with a non-invasively programmable pacemaker (Medtronic 2409) were examined with the unit in ventricular inhibited (VVI) and atrial synchronous ventricular inhibited (VDT/I) mode, respectively. Maximal exercise capacity was determined by means of bicycle ergometry. Work load was increased in steps of 10 watts each minute. Atrial and ventricular rates, brachial artery pressure, and respiratory rate were studied at rest and during exercise while systolic time intervals were determined at rest. There was an important increase in maximal exercise capacity when changing from VVI to VDT/I pacing. The extent of improvement was the same for patients above and below the age of 65 years. At comparable work loads VDT/I pacing resulted in significantly lower atrial rates than VVI pacing. Systolic time intervals did not differ between VVI and VDT/I pacing apart from an increase in left ventricular ejection time index with VDT/I pacing. Systolic time intervals and maximal exercise capacity with VVI pacing did not correlate with the increase in exercise capacity induced by VDT/I pacing. Physical performance can be significantly improved by VDT/I pacing in both young and old patients. Exercise capacity on VVI pacing cannot predict the possible benefit of change to VDT/I pacing.

Aged↗
PubMed1980

Clinical evaluation of atrial synchronous ventricular inhibited pacemakers.

The technical specifications and the operation of two atrial synchronous ventricular inhibited (ASVIP) pacemaker designs are described along with the results of clinical evaluation of these pacemakers in 30 patients. Clinical advantages of such pacemakers are contrasted with the performance of A-V sequential (DVI) and atrial synchronous (VAT) systems.

Aged↗