[Quod medicina aliis, aliis est acre venenum**--venoms as a source of anticancer agents]

Natural product derived from plants and animals were used in folk medicine for centuries. The venoms produced by animals for hunting of self-defence are rich in bioactive compounds with broad spectrum of biological activity. The papers presents the most promising compounds isolated from venoms of snakes, scorpions and toads. For these compounds both: mechanism of anticancer activity as well as possibilities of clinical use are presented.

Percutaneous extraction of endocardial leads--a single centre experience in 120 patients

BACKGROUND

The expanding number of patients treated with pacing, especially resynchronisation therapy and pacing system upgrades as well as leads remaining inactive, and prolonged life expectancy are the causes of an increase of the number of electrodes in pacemaker patients. The growing problem with endocardial lead infections and excess leads has made percutaneous lead removal technology widespread as it is less invasive than cardiosurgery.

AIM

We present our experience in percutaneous lead removal in a single reference centre in Poland.

METHODS

During 2.5 years, 236 leads in 120 patients were removed. The criterion for inclusion in the present analysis was the age of the oldest lead: > 12 months in pacemaker patients and > 6 months in patients with implantable cardioverter-defibrillators (ICD). All patients admitted to the hospital for lead removal underwent a percutaneous procedure. The age of the patients ranged from 18 to 87 (mean 65.7) years. The leads were removed using the Lead Extraction System (Cook) with the rotational cutting force only, notlaser or RF energy.

RESULTS

Indications for lead removal were: local (pocket) infection (47%), endocarditis (27%) and lead excess (26%). Seventy six percent of patients had at least two pacemaker/ICD-related procedures whereas 24% had only one implantation procedure in the past. The median time from the preceding procedure was 12 months. In 38 patients there were 60 inactive electrodes. The majority of patients had two (62%) or three (19%) leads, followed by 12% with one lead and 7% of patients with more than three leads. In 27.5% of patients leads from the coronary sinus were removed. The complication rate was 4%.

CONCLUSIONS

Percutaneous lead removal procedures are performed in Poland for class I and II indications according to NASPE classification. In many cases patients had multiple leads, including in the coronary sinus. The majority of patients had two or more interventions in the past.

Effects of different atrial pacing modes evaluated by intracardiac signal-averaged ECG

BACKGROUND

Analysis of high gain, signal-averaged (SA) ECG is an accepted method evaluating abnormalities of atrial repolarization--the presence of late potentials (ALP)--predictive for atrial arrhythmias. Recently it has been proven that the location of atrial leads has an influence on atrial activation and modifies the risk of atrial arrhythmias. The aim of our study was to estimate the effect of different modes of atrial pacing on signal-averaged P waves recorded from external (conventional) and from intra-atrial leads.

METHODS

Recordings were performed in 24 patients during biatrial (BiA) pacing system implantation. A surface SA-ECG was obtained from orthogonal leads, and intra-atrial signals were recorded and averaged separately from the right and left atrium during sinus rhythm (SR) and atrial pacing from the right atrial appendage, coronary sinus or both (BiA pacing). We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 mV).

RESULTS AND CONCLUSIONS

Right atrial appendage pacing prolongs the duration of atrial potential in external and intracardiac leads and decreases its homogeneity in comparison to SR. RAA pacing increases the occurrence of ALP both in external and internal SA-ECG. Coronary sinus pacing does not deteriorate atrial activation in comparison to SR. Biatrial pacing shortens atrial potential, increases its homogeneity and eliminates atrial late potential criteria in most of patients in comparison to SR. It can be observed both in external and intra-atrial leads and confirms the beneficial effects of BiA pacing on atrial excitation, explaining its antiarrhythmic effect. Evaluation of signal-averaged intra-atrial electrograms supplies more data about local conduction disturbances with micro-voltage oscillations during final part of atrial excitation (low RMS20 and prolonged LAS5) than conventional techniques and seems to be a valuable tool for the evaluation of new resynchronizing atrial pacing modes.

Electrophysiological effects of biatrial pacing evaluated by means of signal-averaged P wave time-domain parameters. The significance of persistent atrial late potentials in right atrium during biatrial pacing

BACKGROUND

Atrial conduction disturbances are a known substrate of re-entrant atrial arrhythmia, and their detection is important for the selection of proper therapy. Time-domain analysis of P-wave in signal-averaged ECG (SA-ECG) recorded from chest leads is an accepted method evaluating inhomogeneity of atrial excitation, predictive for atrial arrhythmias. Biatrial (BiA) pacing created a new therapeutic option for patients with atrial arrhythmias. The aim of our study was to estimate the effect of BiA pacing on SA-ECG recorded from conventional external and from intraatrial leads.

METHODS

Recordings were performed on 24 patients during BiA pacing system implantation. A surface SA-ECG was obtained from orthogonal leads, and intraatrial signals were recorded and averaged separately from the right and left atria at sinus rhythm and BiA pacing. We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 mV).

RESULTS AND CONCLUSIONS

BiA pacing favorably modifies SA-ECG parameters in the right and left atrium. BiA pacing significantly shortens P duration, significantly increases RMS20 and reduces atrial late potentials (ALP) occurrence in most patients in comparison to sinus rhythm both atria. ALP are still present in 46% of patients in spite of effective BiA pacing, which can be observed mainly in the right atrium and is connected with increased risk of atrial fibrillation recurrence. This phenomenon suggests a limited effect of RAA-based BiA pacing on the synchrony of atrial activation, and a search is needed for another right atrial lead location for permanent BiA pacing.

Electrophysiological effects of single site RAA pacing evaluated by means of high-gain SA-ECG recorded from intra-atrial leads

BACKGROUND

Conventional right atrial appendage pacing (RAAp) eliminates the electrophysiological consequences of bradycardia only, leading to suppression of the rhythm-dependent arrhythmias but in some patients RAAp may increase AF recurrences or even promote it in patients without AF history. Relatively rare incidence of AF in patients implanted with single lead VDD pacing system may indicate RAAp influence. Atrial conduction disturbances (ACD) are the known substrate of re-entrant atrial arrhythmias and their detection is important for the selection of proper therapy. Time-domain analysis of P-wave in signal-averaged ECG (SA-ECG) recorded from chest leads is an accepted method evaluating inhomogeneity of atrial excitation, predictive for atrial arrhythmias. The aim of our study was to estimate the effect of RAAp on SA-ECG recorded from conventional external and from intraatrial leads.

METHODS

Recordings were performed in 24 patients during biatrial pacing system implantation. A surface SA-ECG was obtained from orthogonal leads and intraatrial signals were recorded and averaged separately from the right and left atrium at SR and RAAp (LA pacing was temporary switched). We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 microV).

RESULTS AND CONCLUSIONS

RAAp significantly prolongs all parameters reflecting atrial activation (P ECG, TAAT, SA-ECG Pdur, SA-IEGM Adur in RA and LA) by 20 to 30 ms in comparison to SR. RAAp decreases RMS20 and prolongs LAS5 values both in external and intraatrial leads, which reflects increased micro-oscillations in the final portion of atrial potential. The lower RMS20 and higher LAS5 values in RA compared to LA suggest less homogenous depolarization in right atrium. This may suggest that atrial activation extinguishes more homogenously in LA. A different explanation may be that the observed sluggish ending of RA signal may be the result of a far-field sensing from the LA. The strong correlations between RAA paced P wave, TAAT, SA-ECG Pdur, SA-IEGM RA and LA Adur confirm that those parameters reproduce mostly the velocity of conduction within the atria. Our findings indicates significant aggravation of ACD (mainly in RAA) and suggests that the search is needed for another RA lead location for permanent single site and biatrial pacing. (Cardiol J 2007; 14: 372-383).

Coronary sinus pacing: Its influence on external and intraatrial signal-averaged P wave time domain parameters

BACKGROUND

The coronary sinus (CS) was, for 10 years, the standard place for permanent atrial pacing, and the antiarrhythmic properties of CS pacing were described by Moss in the early 70's. These observations were confirmed during EP studies, although currently permanent CS pacing is infrequently applied. Signal averaged (SA) P wave analysis has established values for the examination of EP properties of atrial myocardium. The aim of our study was to estimate the effect of CS pacing on the signal-averaged P wave recorded from external and intraatrial leads.

METHODS

Recordings were performed in 24 patients during biatrial pacing system implantation. A surface SA-ECG was obtained from orthogonal leads, and intraatrial signals were recorded and processed separately from the right and left atrium at SR and CS pacing. We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 mV).

RESULTS AND CONCLUSIONS

Coronary sinus pacing favourably modifies SA P wave parameters of the left atrium; it significantly shortens Pdur, distinctly increases RMS20, decreases LAS5 and eliminates ALP in most patients in comparison to SR. It indicates beneficial effects of CS pacing on left atrial excitation and may explain its antiarrhythmic effect. Coronary sinus pacing does not deteriorate right atrium activation; it even slightly increases RMS20 and shortens the duration of LAS5 in RA in comparison to SR. Our findings suggest that CS is still an attractive site for permanent atrial pacing in patients with atrial arrhythmias and atrial conduction disturbances. (Cardiol J 2007; 14: 470-481).

Analysis of high gain signal-averaged P/A wave time domain parameters recorded from external leads (SA-ECG) and internal electrograms (SA-IEGM) recorded from three right- and left-intraatrial leads

BACKGROUND

Time-domain analysis of the P-wave in signal-averaged ECG (SA-ECG) recorded from chest leads is an accepted method for evaluating the inhomogeneity of atrial excitation, predictive for atrial arrhythmias. The aim of the study was to determine the value of the SA-ECG technique for intraatrial signal processing. Additional aims were to evaluate the correlation between SA-ECG parameters (external and intraatrial) and the frequency of atrial fibrillation recurrences, ongoing antiarrhythmic therapy and LA diameter.

METHODS

Recordings were performed in 24 pts during biatrial pacing system implantation. A surface SA-ECG was obtained from orthogonal leads, and intraatrial signals were recorded and averaged separately from the right and left atrium. We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 mV).

RESULTS AND CONCLUSIONS

Intraatrial SA-ECG provides accurate data for ALP analysis, mostly due to its improved signal quality and QRS discrimination. P-duration and RMS20 seem to be parameters with good correlation between external and internal SAECG. Intraatrial SAECG offers a valuable tool to evaluate abnormalities of the final part of atrial excitation. There are no straight associations between SA-ECG parameters and arrhythmic burden, ongoing antiarrhythmic therapy and LA diameter. (Cardiol J 2007; 14: 287-300).

Biventricular versus right ventricular pacing decreases immune activation and augments nitric oxide production in patients with chronic heart failure

INTRODUCTION

Immune system activation and oxidative stress are involved in the pathogenesis of heart failure (HF). We aimed to test the hypothesis that upgrading from right ventricular pacing (RVp) to biventricular pacing (BiVp) can counteract these phenomena.

METHODS

28 HF patients, with BiVp were switched to RVp for one week, and then returned to BiVp. Immediately prior to, and 48 h after the return to BiVp, left ventricular (LV) systolic function was evaluated by echocardiography, and serum N-terminal pro-brain natriuretic peptide (NTproBNP), C-reactive protein (CRP), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL6), nitric oxide metabolites (NO(x)) and malondialdehyde (MDA) were assayed.

RESULTS

LV systolic function significantly improved 48 h after switching from RVp to BiVp: Ao-VTI (p<0.001), SV (p<0.001) and CO (p<0.001), and mitral regurgitation significantly decreased (p=0.003). At the same time, indices of peripheral immune activation decreased: TNF-alpha (p=0.02) and IL6 (p<0.001). MDA decreased (p<0.001), whereas NO(x) increased (p=0.04). NTproBNP and CRP did not change. In addition, in "responders" (i.e. CO increase >10% during BiVp vs. RVp) NTproBNP decreased and NO(x) increased. However, during BiVp, the decreases in TNF-alpha, IL6, and MDA occurred both in responders and in non-responders and were accompanied by a reduction in mitral regurgitation.

CONCLUSION

The beneficial effect of BiVp compared to RVp extends beyond improving cardiac haemodynamics and comprises a decrease in immune activation accompanied by an increase in serum NO(x) and decrease in serum MDA.

Kinetics of degradation of cefetamet pivaloyloxymethyl ester and its hydrochloride in solid phase

The influence of temperature and relative humidity on the stability of cefetamet pivoxil (CFP) and its hydrochloride (CFP.HCl) in solid phase was investigated. The process of degradation was studied using HPLC with UV detection. The degradation of CFP and CFP.HCl occurring at air humidity RH>50% is an autocatalytic first-order reaction with respect to substrate concentration, while at 0% relative humidity of the ambient air it is a first-order reaction relative to substrate concentration for CFP.HCl, and a reversible first-order reaction for CFP. The rate constants (k) were determined in dry air at 373 K, 378 K, 383 K, 388 K and 393 K; at air humidity RH = 76.4% at 333 K, .343 K, 353 K, 363 K and 373 K; and at 363 K at air humidity RH>50%. The kinetic and thermodynamic parameters of the degradation were calculated.

Changes in glucose, cholesterol and serum lipid fraction levels in experimental diabetes

The objective of this research was to trace the changes in serum glucose, cholesterol and lipid fractions during progression of diabetes in rabbits. 89 male rabbits, New Zealand breed were used in the experiment. Diabetes mellitus was induced by a single injection of alloxan. On day 7 the glucose level in the whole blood was measured by a glucometer to confirm the presence of diabetes. From this day the time of disease was counted. The rabbits were divided into the following groups: Group 1--controls (n = 18), Group 2-21 days diabetes mellitus (n = 18), Group 3-42 days diabetes mellitus (n = 17), group 4-90 days diabetes mellitus (n = 19), group 5-180 days diabetes mellitus (n = 17). After above-mentioned periods blood samples were taken and the rabbits were killed by decapitation. The final level of glucose in the sera was determined spectrophotometrically by enzymatic method. The method of cholesterol measurement was based on oxidation of free cholesterol to cholesterol releasing hydrogen peroxide. Measurement of lipid fractions was based on indirect methods consisting in precipitation of specific lipoprotein fractions. Control rabbits revealed highly significant (p < 0.01) or significant (p < 0.05) correlation between initial and final cholesterol and glucose levels. It was not observed in diabetic rabbits. Highly significant correlation (p < 0.01) was found between LDL and total cholesterol concentration in 21 and 42 day of diabetes. Similar correlation was observed between HDL and total cholesterol concentration on 90th day of the course of disease. We concluded that significant disorders of lipid metabolism occur in the course of alloxan-induced diabetes in rabbits, manifested by total cholesterol level increase and changes in proportions and levels of serum lipid fractions.