Bleeding complications after pacemaker or cardioverter-defibrillator implantation in patients receiving dual antiplatelet therapy: Results of a prospective, two-centre registry.

Introduction. The aim of the study was to define the prevalence of bleeding events in patients treated with dual antiplatelet therapy (DAT) in comparison with patients receiving only acetylsalicylic acid (ASA).Methods. Prospective two-centre registry of all first implantations of pacemakers, cardioverter-defibrillators and cardiac resynchronisation therapy units in patients receiving ASA (n=194) or DAT (n=53).Results. Bleeding complications were detected in 27 (16.2%) patients in the ASA group and in 13 (24.5%) in the DAT group. There was no significant difference in the overall number of complications between the patients receiving ASA or DAT, although there was a trend towards a higher incidence of overall complication rates in the DAT group (p=0.0637). The incidence of major complications (requiring blood transfusion or surgical intervention or prolonging hospital stay) was low (3.6%), and similar in both groups (3.6 and 3.8% respectively, ns). The rate of minor complications (subcutaneous haematomas) was greater in the DAT group (p=0.015).Conclusions. Treatment with DAT does not increase the risk of major bleeding complications as a result of device implantation; however, minor complications are significantly more frequent. Our results suggest that DAT could be continued in patients undergoing device implantation with a moderate risk of bleeding complications. (Neth Heart J 2010;18:230-5.).

Near-infrared spectroscopy in evaluation of cerebral oxygenation during vasovagal syncope.

Near-infrared spectroscopy (NIRS) offers a non-invasive, real-time monitoring of cerebral oxygenation. This method is based on the oxygenation and the light wavelength dependent absorption of near-infrared light by tissue chromophores, e.g. oxyhaemoglobin and deoxyhaemoglobin. The objective of the present study was the application of NIRS for evaluation of the brain function during vasovagal syncope (VVS). The VVS is a clinical syndrome affecting ca 3.5% of the population and for which the widely used diagnostic examination in this disease entity is the head-up tilt table test (HUT). In this study 69 patients with a history of VVS were examined using HUT. In 42 patients VVS was provoked. Results of the examination have shown that the changes in cerebral oxygenation measured by the NIRS technique are distinctly visible before the syncope. A gradual decrease of oxyhaemoglobin followed by its sudden drop was observed in all the VVS patients. Changes in the oxyhaemoglobin concentration measured by NIRS were observed on average 3.3 min before the syncope. They preceded the presyncope symptoms about 1.3 min (p < 0.005), the blood pressure and heart rate drop 2.2 min (p < 0.0001) and the arterial blood saturation 2.6 min (p < 0.00001).

The reconstruction, from a set of points, and analysis of the interior surface of the heart chamber.

Adequate description of heart muscle electrical activity is essential for the proper treatment of cardiac arrhythmias. Contemporary mapping and ablating systems allow a physician to introduce an electrode (catheter) into the human heart, to measure the position of the electrode in space and, simultaneously, the electrical activity timing and the bipolar and unipolar signal amplitudes--which correspond to the electrical viability of the heart muscle. If enough data points are collected, an approximate reconstruction of the heart chamber geometry (anatomy) is possible using also surface data such as the viability and local activity isochrones. Myocardial viability in patients after myocardial infarction is crucial for understanding and treating life threatening arrhythmias. Although there are commercial tools for heart chamber reconstruction, they lack the ability to quantitatively analyse the reconstructed data. Here, we show a method of reconstruction of the left ventricle of the heart from a measured set of data points and perform an interpolation of the measured voltages over the reconstructed surface. Next, we detect regions with voltage in a specified range and compute their areas and circumferences. Our methods allowed us to quantitatively describe the 'normal' muscle, the damaged or scar areas and the border zones between healthy muscle and the scars. In particular, we are able to find geometries of the damaged muscle areas that may be dangerous, e.g. when two such areas lie close to each other creating an isthmus--a macroreentry arrhythmia substrate. This work was inspired by a clinical hypothesis that the size of the border zone corresponds to the rate of occurrence of ventricular arrhythmia in patients after myocardial infarction.

Laser Doppler method in evaluation of vasovagal syncope induced by tilt table test.

The laser Doppler flowmetry offers a new noninvasive, real-time technique for monitoring of the blood perfusion in living tissue. In spite of some instrumental problems, e.g. relative calibration and unknown sampling measurement depth, this method has already been used in clinical examination. The purpose of presented study was the application of the laser Doppler method in evaluation of the vasovagal syncope induced in the tilt-table test. Twelve patients with the history of syncopal episodes were examined using the head-up tilt-table test. In the some condition three normal subjects were also examined as the reference. Results of examination have showed that the changes measured by laser Doppler method are clearly visible during the pre-syncope and syncope period. These changes in perfusion precede the subjective clinical symptoms as well as decrease in the blood pressure, blood oxygen saturation and heart rate.

Adaptive filtering in exercise high resolution ECG as applied to the hypertrophic cardiomyopathy.

The application of adaptive filtering to ECG signals has been investigated for many years. This study shows that the exercise high resolution ECG (HRECG) can also be processed successfully in a similar way. Two groups were included consisting of 20 healthy individuals and 24 patients with hypertrophic cardiomyopathy (HCM). The HRECG parameters for both groups were similar (QRSdur: 107 +/- 7 vs 114 +/- 18 ms NS, LAS: 25 +/- 8 vs 22 +/- 6 ms NS). In the first step, the HRECG signal was acquired at rest to obtain the averaged reference pattern. The next step was associated with peak exercise in which one could calculate short duration averaging (approximately 30 beats) or apply adaptive filtering in which the exercise component (EC) was extracted. Exercise was performed in the supine position on a bicycle ergometer. The load of 50 W was incremented by 50-W steps in 3-minute intervals and the test was ended by fatigue. Signals were recorded in X, Y, and Z bipolar leads with a 20-Hz high pass filter. The short time average QRS duration mostly was abbreviated in normal individuals in contrast to HCM patients in which ventricular activity prolonged with sensitivity, specificity, and negative and positive predictive values: 79%, 65%, 73%, and 72%, respectively. The adaptive recurrent filtration (ARF) after cutoff of the EC at the level of 70 ms (this level is the EC mean value of both groups) showed the following statistics: 63%, 90%, 88%, and 90%. The Student's t-test as applied to the duration of EC allowed a statistically significant difference between normals and HCM patients (66 +/- 4 vs 71 +/- 6 ms, P < 0.0052) and between HCM patients with and without ventricular tachyarrhythmia and DS (74 +/- 6 vs 69 +/- 6 ms, P < 0.046).

The middle cardiac vein as a key for "posteroseptal" space--a morphological point of view.

About 25% of accessory pathways (AP) run via "posteroseptal" space (PSS). There are three approaches for ablation of these pathways: from the right atrium, from the left atrium or from the ventricle and coronary sinus (CS). However in some cases AP is too far from all of them. Catheterisation of the middle cardiac vein (MCV) seems to be the only chance for successful ablation. Our aim was to evaluate the topography of the MCV in PSS. Classical anatomical investigation was carried out on the autopsy material of 98 consecutive human hearts (42 F, 56 M; age 57 +/- 21 yrs). It was supported by transverse section performed under coronary sinus. Regions just behind the atrioventricular septum and behind the cavities were respectively classified as "septal", right (RP) and left posterior (LP). Between them right (RPS) and left posteroseptal areas (LPS) were present. At the posterior view of the heart the angle between CS and MCV ranged from 75 to 90 degrees in 62% of hearts, 60-75 degrees in 18%, 30-60 degrees in 10% and 90-130 degrees in 10%. In 16% MCV ran via the "septal" region, 59%--LPS, 10%--RPS, 10%--RP and 5%--LP. At the ostium of 58% MCV a valve was observed, however there was no trouble with insertion of the 6F catheter into it. We concluded that it is possible to insert the 6F catheter into MCV, which makes it possible to perform ablation of epicardial postero-inferior accessory pathways. The origin of MCV is usually located in the left "posteroseptal" region and runs towards the left side of the posterior wall.

Histologic evaluation of the atrioventricular nodal artery in healthy humans and in patients with conduction disturbances.

The anatomy of the conduction system of the heart so relevant in the contemporary invasive cardiology is not fully understood. It has turned out that ablation procedures bring new information as to its structure and function, but in some cases can result in complete a-v block. Atrioventricular nodal artery located within the nodal-perinodal tissue can probably be damaged during the ablation procedures. Therefore, we decided to explore in detail the morphology and the topography of the atrioventricular nodal artery in healthy humans and in patients with clinical traits of a-v conduction disturbances requiring permanent pacing. The microscopic study was carried out on 30 normal human hearts specimens (17 F, 3 M) from 17 to 86 years of age, and on 20 hearts with conduction disturbances (11 F, 9 M) from 39 to 85 years of age. We found that the number of the atrioventricular node arteries is different and independent of the extent that induces block causing conduction disturbances. The topography of the artery in perinodal zone was consistent in normal hearts, yet in hearts with conduction disturbances we observed about 2% of deviations in its location. It might be the reason for generation of iatrogenic complications after invasive cardiological procedures. The morphology revealed changes in 50% of the examined hearts and their vessel walls, which was declared to be connected with ageing. This correlated with certain stages of atherosclerosis as well as hypertension characteristic of elderly patients. We observed that in 33% of hearts from control group small parietal thrombi were detected and in 60% of paced group respectively. Hence, it seems that the procedures in perinodal zone should be performed in its proximal part because of a minor probability of direct and indirect (through nodal artery) damage of the atrioventricular structure of the junction.

The morphological conditions of the permanent pacemaker lead extraction.

Pacemaker lead extraction is the treatment of choice in infectious complications regarding implantation procedure. The purpose of this study was to estimate the safety of the extraction in relation to the morphological changes of the pacing electrode. Research was carried out on materials consisting of 60 human hearts from 45 to 95 years of age (average 63 +/- 15 yrs), with VVI or DDD pacing (pacing duration 84 +/- 26 months) fixed in a formalin solution. Classical macroscopic anatomical methods were applied. In 44 hearts (73.3%) from the investigated group the posterior tricuspid leaflet was thickened only, and in 24 of these hearts the process regarded not only posterior leaflet but also the septal one and especially commissure between them. In 52 hearts (86.6%) inflammatory reaction spread also to the neighbouring part of the electrode. The length of the neointima-inflammatory tissue ranged from 4 to 8 mm (average 5 +/- 2 mm). On the tip of the electrode in the right ventricle cavity in 56 hearts (93.3%) we observed that endocardial leads were surrounded by fibrous thickening, and partially covered by endocardial tissue. We concluded that from the anatomical point of view the extraction of the pacing electrode seems to be questionable, especially in long-term permanent pacing. The experimental traction shows that only recently implanted electrodes were removed without any complications and in others with fraction of the tip, myocardial tissue avulsion or such removal was not successful at all.

Histological examination of the topography of the atrioventricular nodal artery within the triangle of Koch.

UNLABELLED: The treatment of choice in patients with drug-resistant atrioventricular nodal reentry tachycardia is radiofrequency fast or slow pathway ablation. Ablation of the reentrant circuit in the region of the His bundle, when approached from the anterior-superior region (fast pathway); can result in complete AV block. This is less likely if the posterior-inferior (in the region of coronary sinus ostium) approach is used (slow pathway ablation). The possibility that radiofrequency energy may damage the vascular supply to the AV node must be considered. In order to confirm this hypothesis observation was conducted on the autopsy material of 50 human hearts (20 F, 30 M) from 18 to 81 years of age. Specimens were taken containing the triangle of Koch (the apex- right fibrous trigone, the base- coronary sinus ostium). These histological blocks were sectioned in the frontal plane and stained using Masson's method. Koch's triangle was divided in the sagittal plane into 3 parts: inferior (between the base and the attachment of the tricuspid valve), central (between the base and the apex of the right fibrous trigone) and superior (between this trigone and the tendon of Todaro). It was observed that the AVN artery at the coronary sinus ostium level (the base of the triangle of Koch) was positioned in 68% in the central and in 32% in the inferior part of Koch's triangle. The AVN artery in the central part was removed from the endocardium 1 mm (18%), 2 mm (42%), 3 mm (22%), 4 mm (18%). In the inferior part 1 mm (26%), 2 mm (37%), 3 mm (37%). No statistically significant relationship was observed between those groups. CONCLUSIONS: 1) in 20% of examined hearts the AVN artery lay just beneath the endocardium near the coronary sinus ostium 2) there is a risk of the AVN artery coagulation during radiofrequency ablation in the slow pathway region.

[Nonpharmacologic treatment for heart arrhythmia]. / Niefarmakologiczne leczenie zaburzen rytmu serca.

Between 1990-1993 6 patients (4 females and 2 males) underwent the excision of the left atrial myxoma at The II Dept. of Cardiothoracic Surgery in Katowice. With the age range varying from 23 to 59 years. 3 patients presented symptoms of congestive heart failure with exertional dyspnoea, atrial fibrillation and syncope. 3 patients showed cerebral embolism. Every time the diagnosis was confirmed by the 2 D echocardiography. 4 patients were submitted the operation on the urgent basis because of occurring life threatening symptoms. All the patients were operated under cardiopulmonary bypass by the left atrial access, or in one case by the left and right atrial access simultaneously. The myxomas were removed and additionally the underlying endocardium or the full thickness of the interatrial septum, were excised. The surgical excision of the myxoma is the only acceptable therapy to cure. Without surgical treatment long term prognosis is fatal.

Primary ventricular fibrillation is associated with increased paced right ventricular electrogram fractionation.

BACKGROUND: The mechanisms of spontaneous ventricular fibrillation (primary VF) in patients without structural heart disease are obscure. A new technique has shown that in patients with hypertrophic cardiomyopathy conduction of fractionated ventricular paced beats, recorded at several right ventricular sites, is prolonged in individuals who have suffered a VF arrest, and this may reveal one component of a reentrant substrate. Patients with primary VF were studied with the same methods to determine whether similar abnormalities are present in this group. METHODS AND RESULTS: Nine patients with primary VF were studied by pacing one right ventricular (RV) site by use of a constant drive train with an extrastimulus inserted every third beat and reducing the extrastimulus coupling interval (S1S2 interval) by 1 ms on each occasion while recording at three other sites. The delay of each fractionated potential in the high-pass-filtered electrograms in response to the extrastimulus was determined and used to form conduction curves of delay versus the S1S2 interval. These curves were repeated by pacing each RV site in turn and recording from the other three sites. The curves were characterized by determining the S1S2 interval at which electrogram components increased in delay by 0.75 ms/20 ms reduction in S1S2 interval and the increase in electrogram duration between a coupling interval of 350 ms and 1 ms above refractoriness. Seven control patients were studied using the same method. The mean increase in electrogram duration in VF patients was 13 ms (range, 3 to 23 ms) compared with 4 ms (range, -2 to 14 ms) in unaffected control patients. The extrastimulus coupling interval at which delay increased was 318 ms (range, 293 to 334 ms) in VF patients and 274 ms (range, 265 to 284 ms) in control patients (P < .01). There was no difference between the number of fractionated potentials in VF patients and control patients. CONCLUSIONS: In primary VF patients, the individual potentials within fractionated electrograms have increased delays when compared with control patients. This may identify one component of a reentrant arrhythmic substrate.

Dilated cardiomyopathy in children: clinical course and prognosis.

The clinical profile of 19 patients with dilated cardiomyopathy ages 2-18 years (mean 13.4 +/- 4 years) was reviewed to detect any factors that might be predictive for their survival. Follow-up range from 5 to 105 months (mean 39 +/- 33 months). Routine treatment consisted of digitalis and diuretics: 14 patients received antiarrhythmics, 6 received vasodilators, and 12 were managed with immunosuppression. There were 12 survivors and 7 nonsurvivors: The 1-year mortality was 21.2% and the 2-year mortality 35.8%. All deaths were within first 2 years. Of the 12 patients who survived 2 years, a significant improvement was noticed in 9. In 3 patients tachycardia-induced cardiomyopathy was diagnosed, and abolition of supraventricular tachycardia was followed by improvement and regression of cardiomegaly. Endomyocardial biopsy was performed in 16 patients. Four with a histologic diagnosis of active myocarditis survived, and in 3 of them a considerable improvement was noticed. Of the 12 patients with nonspecific histologic findings, 6 died (p < 0.05). There were no significant differences between survivors and nonsurvivors for any of the following parameters: incidence of severe heart failure (NYHA class III-IV) and severe ventricular arrhythmias (Lown class III-V), relative heart volume, echocardiographic left ventricular diastolic diameter and shortening fraction, and the hemodynamic parameters of cardiac index, left ventricular ejection fraction, left ventricular end-diastolic pressure, and left ventricular end-diastolic volume index.

[Difficulties with pharmacologic treatment of a patient with atrioventricular nodal reentrant tachycardia]. / Trudnosci w leczeniu farmakologicznym u chorej z nawrotnym czestoskurczem wezlowym.

A case history of a 38 year old teacher with AVNRT is described. She had been treated for 11 years with 11 antiarrhythmic drugs in various combinations. No treatment prevented recurrence of arrhythmia. During long term treatment with class IA, IC, II, III and IV antiarrhythmic drugs, various side effects occurred. There was also suspicion of proarrhythmic effect, especially of prajmaline. Some of the drugs terminated tachycardia while administered intravenously. But often deep hypotonia, heart automatism disturbances and even asystole occurred, MAS syndrome occurred 5 times. The patient was referred to our laboratory to perform percutaneous radiofrequency ablation of the slow pathway. The procedure was performed without any complications. Efficacy of the ablation was proved by electrophysiologic study before and after intravenous atropine administration. During the 11 months follow-up the patient had no tachycardia. She is on no antiarrhythmic medication and continues her normal activity.

[Selective catheter ablation of the slow pathway in a patient with recurrent atrioventricular nodal reentrant tachycardia]. / Wybiórcza ablacja drogi wolnego przewodzenia usunela napady nawrotnego czestoskurczu wezlowego.

The case of a 35 year-old patient with recurrent, sustained atrioventricular nodal reentry tachycardia (AVNRT)--type slow/fast--refractory to group IA, IC, II, IV antiarrhythmic agents is presented. The maximum rate of the tachycardia was 280/min. During the antiarrhythmic treatment with group IA, IC and IV agents the tachycardia rate was 230/min. The effective refractory period (ERP) of the slow pathway was 200 ms in antegrade direction. ERP of the fast pathway was 260 ms in antegrade and 210 ms in retrograde direction. Ablation of the slow pathway was performed with radiofrequency energy (device HAT 200 S manufactured by Osypka GMBH, catheter Cereblate No 6). The total ablation time was 96 s, maximal temperature of the effective ablation time was 51 centrigrades. Total energy delivered was 2316 J. The ablation caused neither atrioventricular conduction block nor any damage to the heart structure other than the slow conduction pathway. After the ablation there are no evidence of conduction through the slow pathway. Conduction in anterograde and retrograde direction occurs through the fast pathway. No AVNRT were observed. After ablation the patient has no antiarrhythmic treatment.

[Recurrent attacks of antidromic tachycardia in a patient with WPW syndrome and latent accessory pathway A-V conduction]. / Uporczywe napady czestoskurczu antydromowego u chorego z jawnym zespolem WPW i utajonym dodatkowym szlakiem przewodzenia A-V.

A case of a 38 year old male with WPW syndrome and frequently recurrent antidromic atrio-ventricular sustained tachycardias is presented. In his ecg recordings delta wave depolarizations indicated right free wall accessory pathway. This was proved during electrophysiologic study. The effective refractory period of this pathway was short in both directions-below 200 ms. There was a wide zone of sustained antidromic tachycardia 236-247/min induction. Intravenous injection of flecainide terminated antidromic tachycardia but a wide zone of sustained orthodromic tachycardia 150/min induction appeared. Dissection of the right free wall accessory pathway was performed using Sealy technique (Cox modification). During the intraoperation electrophysiologic study an orthodromic tachycardia with retrograde conduction through an antero-septal accessory pathway was induced. After dissection of that second pathway abnormal atrioventricular conduction was abolished. The patients has been free from episodes of tachycardia during one year follow-up period.

[Electrical ablation with high frequency (radiofrequency) in patients with recurrent atrioventricular nodal reentrant tachycardia--introductory information]. / Ablacja pradem wysokiej czestotliwosci (radiofrequency) u chorych z nawrotnym czestoskurczem wezlowym--doniesienie wstepne.

In 10 patients (pts) with atrioventricular nodal reentrant tachycardia type slow/fast (AVNRT) refractory to the antiarrhythmic treatment, radiofrequency current catheter ablation was performed. Adult pts (mean age 31 years) suffered from paroxysms of AVNRT for 2 to 18 years (mean 8 years). Episodes of arrhythmia recurred from 2-3 times a week to 1 for several months during antiarrhythmic therapy. The mean rate of the tachycardia was 243/min. 3 pts had syncope and 5 fainted during the tachycardia. In 2 females mitral valve prolapse was diagnosed. Programmed stimulation of the right atrium on the basic rate 130/min revealed ERP of the slow pathway mean 238 ms and ERP of the fast one mean 346 ms. The tachycardia has been induced with right atrium stimulation--most often programmed or burst stimulation--200 and 220/min, sometimes with incremental pacing. Successful radiofrequency energy ablation was performed in all 10 pts. Average number of the impulses for one pt was 7.7 (from 1 to 18 impulses). The total average time of the ablation was 216 s. The temperature of effective ablation was average 65 centigrade. The effect of the ablation was evaluated during repeated electrophysiological study before and after intravenous injection of atropine. Ablation was considered successful when no tachycardia was induced. P-R interval did not change and no episodes of AVNRT was observed in the 1-3 months follow-up. No complications were observed during the ablation and after the procedure, especially no thromboembolism was noticed. The echocardiographic evaluation revealed no damage to the heart structure. The pts receive no antiarrhythmic treatment and they are systematically controlled.