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Biomedical subjects

I Hulin

Publications and source records attributed to I Hulin.

At least 19 recordsLinked to original sources
PubMed2006

Does vagus nerve constitute a self-organization complexity or a "hidden network"?

The vagus nerve provides wide visceromotor and viscerosensory innervation of internal organs. Findings accumulated in last years suggest that vagus nerve participates on regulation of much wider spectrum of functions than described previously. Many different studies provide plausible evidence that vagus nerve importantly participates not only in transmission of information from inflamed tissues, but also in efferent modulation of inflammatory processes. Moreover, there are some findings supporting the hypothesis that vagus nerve might participates in monitoring and modulation of tumorigenesis. Electrical stimulation of the vagus nerve is used as a treatment of epilepsy. Moreover, data also suggest a beneficial effect of electrical stimulation of the vagus nerve in patients with depression, anxiety, migraine and Alzheimer's disease. We suggest, that the vagus nerve might constitute a highly differentiated complex system which modulates various functions. Moreover, we propose that the vagus nerve as a complex system might participate in constitution of a biological compartment of conscious. In this article we discuss findings and ideas supporting these hypotheses (Ref. 73).

Electric Stimulation Therapy↗
PubMed2005

Body surface integral maps in patients with arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVES: The aim of this study was to evaluate changes in QRST integral maps in patients with ARVC. BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disorder of predominantly right ventricle characterized with arrhythmic events possibly leading to sudden cardiac death. QRST integral maps reflect local disparities of ventricular repolarization and resulting vulnerability to arrhythmias. METHODS: A group of 8 patients with ARVC and a control group of 8 patients with a concealed accessory pathway were studied. Body surface mapping was performed using a 63-lead Savard's system. RESULTS: Mean QRST integral map of patients with ARVC showed abnormal characteristics. The area of negativity was larger than normal and extended to lower border of thorax. Departure map of the mean QRST integral map of patients with ARVC showed areas with departure index < 2 and > 2 in lower part of chest and upper part of back. When statistically analyzed, areas with p < 0.05 covered nearly lower half of chest and upper half of back. CONCLUSIONS: We consider body surface QRST integral mapping to be an adequate method for evaluation of dispersion of ventricular repolarization in ARVC patients (Tab. 1, Fig. 5, Ref. 17).

Adolescent↗
PubMed2005

Arrhythmogenic right ventricular cardiomyopathy/dysplasia.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a progressive disease of predominantly right ventricle, characterized by ventricular arrhythmias possible leading to sudden cardiac death. Genetic predisposition was confirmed more than 15 years ago. Autosomal dominant are forms ARVD1-9, Naxos disease (with subtype Carvajal syndrome) is recessive. In ARVC/D forms associated with desmosomal disorders are ventricular arrhythmias caused by the presence of myocardial damage and in forms associated with ryanodine receptor mutation is electrical instability and subsequent myocardial damage caused by calcium cell overload. Main clinical signs are ventricular arrhythmias originated from areas with slow conduction. Progression of ARVC/D is manifested by RV dilatation and LV echocardiographic abnormalities both considered as main risk factors of fatal ventricular arrhythmias and sudden cardiac death. Therapeutic possibilities include antiarrhythmic drugs, catheter ablation and implantation of cardioverter-defibrillator, in severe right or both ventricle involvement even heart failure treatment (Tab. 1, Ref. 56).

Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2002

Heart remodeling in the hereditary hypertriglyceridemic rat: effect of captopril and nitric oxide deficiency.

AIM: The hereditary hypertriglyceridemic (hHTg) rat is characterized by insulin resistance, hypertension, and hypertriglyceridemia. Thus, we investigated whether (a) remodeling of the heart left ventricle (LV) is present under the given hypertensive situation and (b) whether this potential alteration could be influenced by an inhibition of the angiotensin converting enzyme (ACE) and/or by a blockade of nitric oxide production. METHODS: Five groups of rats were investigated: control Wistar (C) rats, hHTg rats, hHTg rats given captopril (100 mg/kg/day) (hHTg + CAP) or NG-nitro-l-arginine methyl ester (L-NAME, 40 mg/kg/day) (hHTg + L-NAME), and hHTg rats given the combination of both drugs (hHTg + CAP + L-NAME) for 28 days. Systolic blood pressure (SBP) was measured by tail-cuff plethysmography each week. After cervical dislocation, the relative weights of the left and right ventricles (LV/BW, RV/BW) were obtained, the LV nucleic acid concentrations were analyzed, and the fibrosis amount was quantified with aid of a semiquantitative histological technique. RESULTS: In the hHTg group, the increased SBP (141.7 +/- 4.4 vs. 117.2 +/- 3.1 mmHg in controls) was linked to hypertrophy of the LV (1.63 +/- 0.05 vs. 1.30 +/- 0.03 g/kg in controls) with only a minimum of fibrosis. DNA concentration in the LV was decreased (0.45 +/- 0.03 vs. 0.69 +/- 0.04 mg/g w.w. in controls) in the hHTg group. Captopril normalized SBP and decreased the LV/BW (1.44 +/- 0.04 g/kg). Chronic administration of L-NAME to the hHTg rats additionally enhanced (189.3 +/- 5.9 mmHg) the already raised SBP, stimulated fibrosis development, and increased DNA concentration (0.54 +/- 0.02 mg/g w.w.) in the LV compared to hHTg group, yet without additional weight increase of the LV. The combined treatment of the hHTg rats with CAP and L-NAME resulted in normal SBP and the development of LV hypertrophy, and fibrosis was substantially reduced. CONCLUSIONS: (a) The heart of hHTg rats carries signs of LV hypertrophy with minimal fibrosis. (b) Nevertheless, LV fibrosis was increased in the hHTg + L-NAME group. (c) Captopril normalized SBP and decreased the extent of LV hypertrophy in both the nontreated hHTg and the hHTg + L-NAME groups and (d) substantially reduced the development of LV fibrosis in the hHTg + L-NAME group. LVH in hHTg rats may be induced by sympathoadrenal system activation, circulating volume enlargement, and impairment of nitric oxide (NO) production rather than by activation of the renin-angiotensin-aldosterone system.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Adenosine and cardioprotection: what can we learn from nature's genetic polymorphism?

Adenosine is an endogenous nucleoside that has been shown to be beneficial for the myocardium in different settings by a large number of experimental studies. In this article, we 1) outline adenosine's metabolic pathways, 2) address cardioprotective properties of adenosine, and 3) discuss possible implications of the two recently published clinical studies disclosing a positive effect of adenosine monophosphate deaminase 1 (AMPD1) gene mutation on cardiovascular survival in heart failure and ischemic heart disease. (Fig. 2, Ref. 84.)

AMP Deaminase↗
PubMed2001

Frequency-domain analysis of the QRS complex after treatment of childhood cancer with anthracycline cytostatics.

Long-term cardiac complications, occurring several years after completion of anticancer treatment, may develop from subclinical myocardial damage induced during cardiotoxic therapy. The aim of this study was to evaluate the usefulness of frequency-domain signal-averaged ECG analysis of the QRS complex for assessing the cardiotoxicity of anthracycline cytostatics. Altogether, 172 signal-averaged electrocardiography (SAECG) registrations were performed in 50 repeatedly evaluated oncologic patients. These registrations were performed 0.2-15 years after completion of anthracycline therapy for childhood cancer. The control group consisted of 120 healthy children and young volunteers; in 20 of these controls, SAECGs were performed repeatedly. Using gliding window fast Fourier transformation within the QRS complex, values area ratio (AR) 60-120 Hz/0-120 Hz were calculated in X, Y, and Z lead. Area ratio of patients after anthracycline therapy was significantly higher than those in control group in X lead. Differences in frequency content in the QRS complex between patients and controls might signal an initial stage of anthracycline-induced myocardial damage.

Adolescent↗
PubMed2001

Our experience with surgical treatment of ischial nerve injuries.

OUTLINE: This report presents the results of 44 surgical interventions performed on 44 patients during a period of 15 years, from 1985 to 1999. The report presents the basic lines of surgical treatment performed on a total number of 50 peripheral nerves of lower extremities--nervus ischiadicus and its rami. PATIENT GROUP AND METHODS: In the whole group of 44 patients, external neurolysis was performed in 23 individuals on 26 nerves. Remaining 21 patients were treated by reconstruction surgery that included 24 injured nerves. In this subgroup, suture of peripheral nerve was performed in 8 treatments on 9 nerves and neural graft was performed in 13 treatments of 15 nerves in cases of complete and persisting neurological deficit, and in the absence of action potentials as revealed by EMG. Complete or severe motoric defects and the absence of spontaneous recovery during the period of several months were the indications for the treatment. The analysis of the efficiency of surgical treatment was performed with respect to the following parameters: period between the injury and operation, patient's age, character of injury, type of injured nerve, and type of surgical intervention. RESULTS: The best results were obtained in external neurolysis which was applied in traumatic lesions of least severity. The effective degree of recovery M3 was observed in 21 patients (91.3%). With respect to reconstruction surgery, more favourable results were obtained in treatments involving suture (in 6 patients, 75%) than in nerve grafts used for the treatment of the most severe injuries associated with a loss of nerve tissue. In the latter cases, improvement was observed after a delay, and the extent of recovery did not always meet the expectations. The effective degree of recovery was observed in 4 patients (30.8%). Good and excellent results were typical for n. tibialis and they were not dependent on the type of surgical intervention, character and location of the injury, period from the injury or patient's age. CONCLUSION: Our results demonstrate that late and inappropriate treatment of injured peripheral nerves has severe and disturbing consequences for the patient. If a complete treatment of the injured nerve is not possible by the first contact physician, it should be performed as soon as possible by a specialist trained for microneurosurgical techniques of the treatment of peripheral nerves. (Tab. 6, Ref. 11.)

Adult↗
PubMed2000

Late effects of anthracycline therapy in childhood on signal-averaged ECG parameters.

The aim of this study was to investigate the long-term effects of anthracycline cytostatics upon the frequency-domain characteristics of the signal-averaged electrocardiogram (SAECG) and to evaluate the differences in the frequency content according to gender. At mean follow-up period of 4 years 188 SAECGs were repeatedly performed in 62 childhood cancer survivors, who were in complete remission 1-14 years following anthracycline therapy (mean dose 256 mg/m2). No patient had an abnormal end-of-therapy echocardiogram. The control group consisted of 100 healthy children and young adults. 23% patients vs 5% controls had abnormal area ratio (AR) values (over the 97th percentil of normal controls). Abnormalities in AR remained persistent in 15% of cancer survivors. Frequency-domain analysis revealed significantly higher AR 40-100/0-40 Hz in patients after anthracycline therapy than in controls. Within the patient group significantly higher AR were observed in females than in males. Permanent altered frequency components in SAECGs from cancer survivors, evident particularly in female patients, might signal an increased electrical instability in these patients.

Adolescent↗
PubMed2000

[Free nerve transplants in the reconstruction of secondary defects of the peripheral nerves of the hand].

BACKGROUND: Peripheral nerve of the hand significantly participate ub the physiological functions of the hand. A defect in the area of the peripheral nerve therefore represents a problem, the solution of which is in the field of microsurgical reconstruction. The study deals with the possibility of microsurgical reconstruction by use of free nerve draft. SUBJECTIVE: Clinical observation of patients after microsurgical reconstruction of the hand peripheral nerve defect. MATERIAL AND METHODS: 34 patients after lesions of the median nerve, ulnar nerve and mutual impairment of both nerves. The evaluation according the known and spread system system of Medical Research Council, Seddon 1954. RESULTS: We have achieved very good results after isolated lesions of the median nerve, while the results in this, as well a in other groups are better in younger patients and in patients, in whom the devastation of tissue was not too great. Standard results were achieved in the group with isolated injury of the ulnar nerve and the worst results in a small group of concommitant impairment of both median and ulnar nerves. CONCLUSIONS: The results indicate that this method is unambiquously appropriate in such a complicated clinical picture. Our results are in accord with the data from other literature sources. MEANING FOR PRACTICE: Inevitability of specialized centres which would deal with this problem thus reducing the necessity of secondary reconstruction operations and naturally the reduction of financial expenditure or social support provision.

Adolescent↗
PubMed2000

[Frequency analysis of the QRS complex: a new method of detecting development of myocardial damage after anthracycline cytostatics].

The aim of the study was to investigate the effect of the new modification of frequency-domain analysis of ECG signal (gliding-window FFT) in long-term monitoring of cardiac status of patients who received a potentially cardiotoxic anthracycline therapy in childhood. Area ratio (60-120/0-120 Hz) peaks within QRS complex were significantly higher in 60 patients compared with 70 healthy children and young adults. Persistent abnormalities in frequency content of ECG signal in oncologic patients might indicate myocardial damage induced by anthracyclines. (Fig. 1, Ref. 17.)

Adolescent↗
PubMed1996

Signal-averaged ECG in patients with antidepressant therapy.

The signal-averaged electrocardiography (SAECG) identifies patients at risk of ventricular arrhythmias and sudden cardiac death. Since the similarity has been known of the pharmacology of class I antiarrhythmics and tricyclic antidepressants, the potential proarrhythmic effects of antidepressants has become a particular problem. The influence of sodium channel blocking antidepressant drugs on the SAECG time-domain parameters was evaluated, using high-pass filters of 25 Hz and 40 Hz. SAECG was performed in 11 depressed patients with normal cardiac status before and for 4 weeks after antidepressant initiation. At the filter setting of 25 Hz, a significant worsening of all studied SAECG parameters (filtered QRS duration, low-amplitude signal duration, root mean square voltage in the first and in the last 40 ms of the filtered QRS) was found in our patient group. Using a 40 Hz high-pass filter, the results were similar. Antidepressant therapy significantly prolonged filtered QRS duration, significantly reduced root mean square voltages in the first and in the last 40 ms of the filtered QRS and non-significantly prolonged low amplitude signal duration. Amitriptyline and maprotiline induced late potentials (LP) in 2 patients at 40 Hz high pass filter setting. No patient had LP at 25-250 Hz. Our pilot study indicates that sodium channel blocking antidepressant drugs may affect SAECG variables similarly to class I antiarrhythmics. SAECG might be useful in categorizing of antidepressant agents and risk stratification of psychiatric patients.

Adult↗
PubMed1996

Voltage sum of filtered ECG signal--a sensitive parameter of ventricular activation.

On the basis of the signal averaged ECG (SA ECG) principle the authors analyse the gradually filtered ECG signal (in ranges of 0-120 Hz with increments of 10 Hz). The voltage sums are determined in eight segments of the QRS complex. The described VSF-ECG method (Voltage Sum of Filtered ECG) was applied in a group of healthy probands and in groups of selected patients. The measurements in healthy probands were used to determine the value of standard in healthy subjects. Repeated measurements confirmed a good reproducibility of the VSF-ECG method. The method enables a precise quantification of heart activation progression. VSF-ECG is a method revealing the changes of heart activation progression being not reflected as late potentials. Parameters of the method are indicators of activation splitting upon the infarction area and also an indicator of the electric milieu of the entire heart.

Action Potentials↗
PubMed1994

Remodeling in myocardial infarction and body surface potential maps.

This study deals with the capabilities of body surface integral and departure maps to evaluate the chronic stage of myocardial infarction based on dividing the left ventricle into 12 segments. The effects of ventricular remodeling on electrocardiographic potential distributions are considered. A 61-year-old male patient was examined five times by body surface potential mapping during a period of 9 months after acute myocardial infarction. Integral maps were calculated for 60 ms after QRS onset and compared with mean data from a control group using departure maps. Integral maps showed a continual reduction of negative potentials in the lower half of the torso with time. The negative area covered the lower torso in the departure maps during the whole study, but its form and value changed. According to the location of the departure area, the surface projection of the scar moved from a position corresponding to inferior segments to a position corresponding to posterior segments. Its size also decreased. Echocardiographic examinations showed progressive enlargement of both ventricles with time. Therefore, the authors postulate that the changing pattern of body surface potential maps was mainly influenced by ventricular remodeling after myocardial infarction.

Electrocardiography↗
PubMed1993

Gliding window fast Fourier transform analysis--a new method for discovering the contribution of higher frequencies in signal-averaged ECG.

OBJECTIVE: An attempt to detect the 'parasitic contribution' of high frequencies in the electrocardiogram signal. DESIGN: A new method--gliding window fast Fourier transform analysis (GWFFTA)--was developed. It was applied in healthy subjects and in patients with acute myocardial infarction. SETTING: Faculty of Medicine and University Hospital. PATIENTS: The GWFFTA was used in 29 healthy volunteers and in a group of 30 patients with myocardial infarction, on day 7 to 14 after admission to a coronary unit. INTERVENTION: Noninvasive examination, performed under standard conditions. MAIN RESULTS: GWFFTA provides better reproducible results compared with 'classic' fast Fourier transform analysis. The parasitic contribution of high frequencies within QRS complex and ST segment in patients with acute myocardial infarction is independent of presence or absence of late potentials. Contribution of high frequencies are three times higher in patients with acute myocardial infarction than in healthy probands. CONCLUSIONS: GWFFTA is a reproducible method of detection of high frequencies during whole heart activation. Contribution of high frequencies in patients with acute myocardial infarction reflects the state of the entire myocardium. It is also confirmed by the lack of correlation with the presence or absence of late potentials. Late potentials are more reflective of focal changes.

Action Potentials↗
PubMed1992

Does the heart electric activation split upon the infarcted area? An attempt at its detection by high-resolution electrocardiography.

Based on the presumption of the activation front splitting, the authors present their own proposal for the estimation of the myocardial electric activation course and for the detection of micropotentials 'hidden' within QRS complexes by the method of high-resolution electrocardiography. After filtration of QRS complex the values of delta RMS and those of cumulative amplitudes are calculated from the initial and from the terminal parts of QRS complexes. The presence of late potentials is reflected in a slowing down of the termination of activation course. As compared with healthy subjects, a slower rise of activation was observed in patients with myocardial infarction of the anterior wall. The curves of cumulative amplitudes rose very slowly during the first 70 ms of heart ventricle activation, explained according to the hypothesis of authors as being due to splitting of the activation front at the infarction focus. The usefulness of the proposed method was checked in patients with arterial hypertension and left ventricular hypertrophy, and in a group of patients with myocardial infarction. By the construction of cumulative amplitude curves from the onset of filtered QRS complexes, myocardial foci not reflected by 'classic' late potentials can be detected. The partial cumulative amplitudes of the QRS complex are suitable for comparative studies.

Adolescent↗
PubMed1988

Computer graphics and computer animation of the electric heart field.

The authors present in their paper the possibilities of the application of computer graphics and computer animation for visualization of the electric heart field (EHF). They describe the construction of three-dimensional potential maps by the methods of interpolation, perspective projection, hidden line elimination and text generation. They also present a method for making of animation films showing the electric activity of the heart by using 80 three-dimensional potential maps recorded at different intervals over the entire cardiac cycle.

Computer Graphics↗