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Biomedical subjects

I Lörincz

Publications and source records attributed to I Lörincz.

At least 19 recordsLinked to original sources
PubMed1999

[Prevention of atrial fibrillation by atrial-based pacemaker implantation].

A large number of studies have demonstrated the long term disadvantage of single lead ventricular pacing in sick sinus syndrome. Ventricular pacing mode predicts chronic atrial fibrillation in patients with preimplant paroxysmal atrial fibrillation. The goal of the report was to study the effectiveness of single atrial and dual chamber (atrio-ventricular sequential) pacemaker treatment in the prevention of atrial fibrillation for patients with sick sinus syndrome complicated with paroxysmal atrial fibrillation. In our university hospital 16 atrial based 5 and dual chamber 11 pacemaker were implanted for treatment of patients with sick sinus syndrome (with or without AV conduction disturbances) complicated with paroxysmal atrial fibrillation. The mean age were 61 (24-78), nine males and seven females. Before or during pacemaker implantation sinus node and AV node function analysis, and echocardiography were performed. There were no surgical complications, lead and/or generator failure. All patients had routine follow-up performed at 4 weeks, 3 months, 6 months. Mean follow up was 31 +/- 8 months (range 3 to 93 months). The atrial based and dual chamber pacing were effective in 90% of our cases. In one patient the treatment had to be combined with propafenone. According to our result, the atrial based pacing may be used to reduce the incidence of atrial fibrillation with careful programming of the base atrial pacing rate, and it is associated with lower frequencies of thromboembolic complications and pacemaker syndrome.

Arrhythmias, Cardiac↗
PubMed1999

[Effect of hemodialysis on QT dispersion in chronic uremia].

Interlead variability of the QT interval in surface 12-lead ECG (i.e. QT dispersion) reflects regional differences in ventricular recovery time and it has been linked to the occurrence of malignant arrhythmias in different cardiac diseases. The purpose of the study was to assess the effect of hemodialysis on QT dispersion in chronic hemodialyzed patients. The data of 34 patients (Male/Female = 21/13, mean age 54 +/- 15 years) on chronic hemodialysis were studied. Simultaneous 12 lead ECGs were recorded pre- and post-hemodialysis in a standard setting. The QT intervals for each lead were measured manually by one observer. Each QT interval was corrected for patient's heart rate: QTc = QT/square route of RR (sec). The maximal QT interval changed from 449 +/- 43 to 469 +/- 41 ms (p < 0.01). The maximal QTc interval increased from 482 +/- 42 to 519 +/- 33 ms (p < 0.01). The QT dispersion changed rom 56 +/- 15 to 85 +/- 12 ms (p < 0.001), and the QTc interval from 62 +/- 18 to 95 +/- 17 ms (p < 0.001). During hemodialysis the serum potassium and phosphate decreased from 5.5 +/- 0.8 to 3.9 +/- 0.5 (p < 0.001), and from 2.3 +/- 0.5 to 1.6 +/- 0.4, respectively, whereas calcium level increased from 2.2 +/- 0.23 to 2.5 +/- 0.22 (p < 0.001). It can be concluded that the hemodialysis increased the inhomogeneity of regional ventricular repolarization. Measurement of QT and QTc dispersion by a cheap and simple bedside method could predict the increased myocardial inhomogeneity in dialyzed patients.

Aged↗
PubMed1995

[Cilazapril replacing captopril in the therapy of medium-severe essential hypertension].

Authors performed an open, crossover, multicenter study of oral cilazapril versus previous captopril treatment in mild to moderate hypertension. The treatment of the 100 outpatients on daily three or four times captopril was found ineffective, or in some cases side effects or non compliance necessitated a switch to a once daily dose of cilazapril. Reasons of ineffectivity were compliance problems in 76% of the patients during long term captopril therapy. Blood pressure decreased from 163.28 +/- 14.5/97.5 +/- 9.35 mmHg on captopril therapy to 136.67 +/- 12/83.49 +/- 7.77 mmHg at the end of a 12 week cilazapril treatment (p < 0.001). 80 patients received cilazapril monotherapy (with doses of 2.5 mg in 54 cases, 5 mg in 18 patients). 7.5 mg in 4 cases, 1 and 1.25 mg in 2 patients. In 20 patients an adjunctive diuretic was also added, while the cilazapril treatment was ineffective in 3 patients. In respect of the global evaluation and scoring of cilazapril versus captopril therapy, a clear and statistically significant improvement could be demonstrated in efficacy, tolerability and compliance after a 12 week cilazapril treatment. The 24 hour ambulatory blood pressure measurement performed in 13 patients also verified a decrease in blood pressure achieved by cilazapril therapy. Authors conclude that in case of ineffectivity of three or four times daily captopril treatment (caused most likely by non-compliance), a switch to a once daily dose drug like cilazapril is indicated.

Administration, Oral↗
PubMed1995

[Tilt-table test in the diagnosis of syncope of unknown origin].

71 patients with unexplained syncope was examined by 60 grade of head up tilt table test with or without administration of isoproterenol during 25 minutes interval. The mean age of patients was 71.44 +/- 16.40 (12-86) years. 38 (54%) were female and 33 (46%) were male. The underlying heart disease were 27 (38%) coronary artery disease, 12 (17%) arterial hypertension, 6 (8%) diabetes mellitus, 3 (4%) valvular heart disease and 14 (20%) patients had other diseases. Nine (13%) patients had no organic disease. During head up tilt table test positive reaction was found in 13 (18%) patients. Four (6%) patients were vaso-vagal syncope with classic signs, and 9 (13%) patients were vasodepressor type of syncope, without changes in the heart rate. Isoproterenol was given to 16 (23%) patients, and in 4 (6%) (2 vasodepressor and 2 mixed type of syncope) patients occurred the positive test during isoproterenol administration. Orthostatic reaction occurred during head up tilt table test in 14 (20%) patients. Normal was the result of tilt table test in 42 (59%) patients, and two (3%) patients had autonome neuropathy. The vasovagal syncope was treated by metoprolol, atenolol and disopyramid with success. The head up tilt table testing is a good, simple, useful test for evaluation of syncope patients, especially the diagnosis of vasovagal syndrome.

Adolescent↗
PubMed1994

[Management of drug-resistant supraventricular tachycardia using AV-junction radiofrequency ablation].

The closed chest His bundle ablation is a worldwide accepted therapeutic method for the treatment of drug resistant supraventricular tachycardias. In the first years high-energy DC shock was applied for achieving the needed therapeutic effect. Reducing the complications caused by the DC shock, radiofrequency energy was introduced into the clinical practice. Authors describe the first successful human application of radiofrequency ablation of AV junction in Hungary.

Catheter Ablation↗
PubMed1994

[Clinical cardiac electrophysiological studies in carotid sinus syndrome].

The aim of the present study was to evaluate the impact of electrophysiological study in the diagnosis and treatment of carotid sinus syndrome. The indications for the study include (1) attempting to exclude other cardiogenic causes of syncope; block, tachyarrhythmia, (2) diagnosing a vasodepressor response in the presence of cardioinhibitory type of carotid sinus syndrome, (3) determination of the optimal pacing mode in patients who need pacemaker implantation for treatment. 51 patients, 40 male (78%) and 11 female (22%) with an average age of 62 years suffering from carotid sinus hyperaesthesia--3000 ms ventricular asystole on carotid sinus massage--were investigated with electrophysiological study. The A-H interval in 8 patients (16%), the H-V interval in 5 pts (10%) were prolonged in the His bundle electrocardiogram. In 39 patients (76%) sinoatrial block, in 12 patients (24%) A-H block was found during carotid sinus massage. Early A-H Wenckebach block occurred in 8 patients (16%). Retrograde (V-A) conduction was present in 36 patients (70%) at a frequency of 65-85 bpm, and 22 pts (43%) at a frequency of 120-180 bpm. Sinus node disease was found in 10 patients (20%) according to the sinus node recovery time and sinoatrial conduction time. In 8 patients (16%) supraventricular and in 4 patients (8%) ventricular tachyarrhythmia was induced during study. The atrial stimulation could not prevent the occurrence of A-V block during carotid sinus massage in any of the 51 patients. In 2 patients (4%) the vasodepressor reaction with ventricular stimulation was determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Ethanol-induced signal transducing mechanism associated with a transient antiviral state in human amniotic cells.

Short-term effects of ethanol on human amnion cells were investigated by studying the cellular signaling processes and the replication of vesicular stomatitis virus. Treatment of human amniotic cells with ethanol transiently triggers the breakdown of inositol phospholipids, stimulates intracellular [Ca2+]i mobilization and activates the translocation of protein kinase C. Activation of this signal transduction mechanism is associated with the development of an antiviral state, as proven by studying 3H-uridine incorporation into the RNA of vesicular stomatitis virus. Induction of the antiviral state in human amniotic cells correlates with the solubility of the alcohols in the lipid membrane of the cells.

Amnion↗
PubMed1990

Incidence of rhythm disorders in hyperthyrosis with special respect of old age form.

Sinus tachycardia and atrial fibrillation are frequent features in hyperthyrosis while sinus node dysfunction is regarded as a rare complication. Bradycardia may cause diagnostic problems mainly in atypical hyperthyrosis of the old age. The authors analysed distribution and age related association of the rhythm disorders in hyperthyrosis. In case of the appearance of Sick Sinus Syndrome (SSS), parameters representing the function of sinus node were studied by electrophysiological investigations. Above the age of 50 years incidences of atrial fibrillation and SSS were significantly increased. The abnormal sinus node function proved to be reversible in a portion of the cases. In old age, in case of occurrence of the symptoms of SSS, possibility of hyperthyrosis also should be considered, especially when indication of permanent pacemaker is established.

Adult↗
PubMed1989

[Atrioventricular block caused by tick bite--Lyme's carditis].

The authors present the case of a 44-year-old patient who was admitted to the hospital because of AV block of degree III. Six weeks earlier a tick was removed from the left foot of the patient. Two weeks later an erythema of 8 cm in diameter, spreading peripherally as well as painful inguinal lymphadenitis developed at the site of the bite with transient arthralgia and myalgia in the region of the waist and left lower limb. After the temporary use of pacemaker, steroid and atropine therapy applied because of the pronounced bradycardia the block became of degree I on the 4th day however negative T-waves appeared in leads III, aVF, V3. By the 14th day the AV time returned to normal and the pathological signs of repolarization disappeared. Serological examinations revealed increased Borrelia burgdorferi antibody level. Lyme's carditis may be prevented by starting the antibiotic therapy at the time of the chronic erythema migrans. Upon medication the patient may recover from the carditis without remaining symptoms.

Adult↗
PubMed1988

Changes in the polyamine and nucleotide metabolism of P388 leukemia cells treated with DL-alpha-difluoromethylornithine in culture.

Influence of DL-alpha-difluoromethylornithine (DFMO) treatment on the growth kinetics, labelling index, extra- and intracellular polyamine and nucleotide concentrations was monitored in cultured P388 leukemia cells. A substantial decrease of cell proliferation was observed when the cells were continuously treated with 1-5 mM DFMO. Depletion of cellular polyamines, mostly of putrescine and spermidine, was seen with a concomitant but delayed increase of spermidine and spermine levels in the culture medium. Changes of DNA content and of labelling index of untreated and treated cells seem to indicate that DFMO arrested cells in G1/S transition. The results presented here provide additional in vitro evidence on the characteristic changes in the metabolic imbalance of ornithine in tumor cells induced by DFMO via inhibition of ornithine decarboxylase and ornithine carbamoyl transferase activities.

Animals↗