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Since 1969 His bundle electrography has been used for diagnosis and for the study of cardiac electrophysiology. This method has employed the catheterization technique and has allowed the continuous recording of electrical activity of the specialized cardiac conduction system in every beat. Such investigation, because of its invasive nature, cannot be considered a routine test; it requires expensive instrumentation, it has physiological and technical limitations that include discomfort, a slight morbidity risk and a rather limited recorded area within the heart. In 1973 a method was developed for a noninvasive recording of the electrical activity within the P-R segment of the electrocardiogram measured from the body surface. This method which employs the signal averaging technique delivers even less medical information than intracardiac measurement. The shortcomings of this averaging method include inability to detect beat-to-beat changes in the true signal. Such a method is not useful in transient arrhythmia detection and a "short acting" drug influence examination. The technical approach to the beat-to-beat noninvasive recording of the HPS activation signal as measured from the body surface has been proposed. Using a specially positioned electrode system, a low noise multiple parallel input amplifier and a computer for sampling, processing and plotting of the measured signal, we have obtained an output curve corresponding to the continuous beat-to-beat HPS activity.  相似文献   
2.
Ablation of Tachyarrhythmia During Pregnancy. Aims: The goal of this study was to describe mapping and ablation of severe arrhythmias during pregnancy, with minimum or no X‐ray exposure. Treatment of tachyarrhythmia in pregnancy is a clinical problem. Pharmacotherapy entails a risk of adverse effects and is unsuccessful in some patients. Radiofrequency ablation has been performed rarely, because of fetal X‐ray exposure and potential maternal and fetus complications. Group and Method: Mapping and ablation was performed in 9 women (age 24–34 years) at 12–38th week of pregnancy. Three had permanent junctional reciprocating tachycardia, and 2 had incessant atrial tachycardia. Four of them had left ventricular ejection fraction ≤45%. One patient had atrioventricular nodal reciprocating tachycardia requiring cardioversion. Three patients had Wolff‐Parkinson‐White syndrome. Two of them had atrial fibrillation with ventricular rate 300 bpm and 1 had atrioventricular tachycardia 300 bpm. Fetal echocardiography was performed before and after the procedure. Results: Three women had an electroanatomic map and ablation done without X‐ray exposure. The mean fluoroscopy time in the whole group was 42 ± 37 seconds. The mean procedure time was 56 ± 18 minutes. After the procedure, all women and fetuses were in good condition. After a mean period of 43 ± 23 months follow up (FU), all patients were free of arrhythmia without complications related to ablation either in the mothers or children. Conclusion: Ablation can be performed safely with no or minimal radiation exposure during pregnancy. In the setting of malignant, drug‐resistant arrhythmia, ablation may be considered a therapeutic option in selected cases. (J Cardiovasc Electrophysiol, Vol. 21, pp. 877‐882, August 2010)  相似文献   
3.
There are two surgical methods for atrial fibrillation (AF) treatment: Maze and corridoring procedures. The first one prevents AF occurrence by performing multiple atriotomies. During the second procedure a corridor between a sino-atrial and the AV node is created together with an electrical isolation of the atria. During 1992 and 1993 seven patients, aged 27–55, mean 43-years-old, with recurrent, resistant to standard therapy AF were referred for surgical treatment to our department. Additional diagnoses include: concealed WPW syndrome in 1 patient, atrial septal defect (ASD) in 3 patients, coronary artery disease in 1 patient. Maze procedure was performed solely in 1 patient, in another together with 2 accessory pathways ablation, in 3 patients with ASD closure and in 1 patient with 2 bypass grafts. In one patient corridoring procedure was performed. Normal sinus rhythm was restored in every patient from 7 to 26 days after the procedure, No surgical complications were noted during the postoperative period. Mechanical function of the atria was documented with echo Doppler 2–6 weeks after the operation. No evidence for AF recurrence was noted within 3–14 months (mean 5 months) of follow-up. The preliminary results of Maze and corridoring procedures are encouraging.  相似文献   
4.
Background: There is some disagreement concerning the minimal value of the interval between components of double potentials (DPs interval) that allows distinguishing complete and incomplete block in the cavotricuspid isthmus (CTI). Objectives: To assess clinical utility of the relationship between atrial flutter cycle length (AFL CL) and the DPs interval. Methods: Ablation of the CTI was performed in 87 patients during AFL (245 ± 40 ms). Subsequently, DPs were recorded during proximal coronary sinus pacing at sites close to a gap in the ablation line and after achievement of complete isthmus block. Results: We noted strong correlation between AFL CL and the DPs interval after achievement of isthmus block (r = 0.73). The mean DPs interval was 95.3 ± 18.3 ms (range 60–136 ms) and 123.3 ± 24.3 ms (range 87–211 ms) during incomplete and complete isthmus block, respectively (P < 0.001). When expressed as a percentage of AFL CL, this interval was 35.7 ± 3.5% AFL CL (range 28–40.2%) and 50.4 ± 6.9% AFL CL (range 39–72%) during incomplete and complete isthmus block, respectively (P < 0.001). A cutoff value of 40% of AFL CL identified CTI block with 96.7% sensitivity and 100% specificity. Conclusions: The interval between DPs after achievement of block in the CTI correlates with AFL CL. The DPs interval expressed as a percentage of AFL CL allows better distinguishing between complete and incomplete isthmus block compared to standard method based on milliseconds. The DPs interval below 40% of AFL CL indicates sites close to a gap in the ablation line. (PACE 2010; 33:1518–1527)  相似文献   
5.
Introduction: Measuring the postpacing interval (PPI) and correcting for the tachycardia cycle length (TCL) is an important entrainment response (ER). However, it may be impossible to measure PPI due to electrical noise on the mapping catheter. To overcome this problem, 2 alternative methods for the assessment of ER have been proposed: N+1 difference (N+1 DIFF) and PPIR method. PPI-TCL difference (PPI − TCL) correlates very well with ER assessed by new methods, but the agreement with PPI − TCL was established only in relation to PPIR method. Moreover, it is not known which of these methods is superior in the assessment of ER.
Methods: We analyzed 155 episodes of ER in 21 patients with heterogeneous reentrant arrhythmias. ER was estimated by PPI − TCL and by both alternative methods. Agreement between methods was assessed by means of the Bland-Altman test, kappa coefficient (κ), and correlation coefficient (r). Finally, a mathematical comparison of the alternative methods was performed.
Results: The agreement between PPI − TCL and alternative methods was very good. For N+1 DIFF the mean difference was −1.86 ± 7.31 ms; kappa = 0.9; r = 0.98; for PPIR method the mean difference was −1.46 ± 7.65 ms; kapa = 0.92; r = 0.99. Agreement between both alternative methods was also very high: the mean difference of 0.5 ± 6.6 ms; kappa = 0.89; r = 0.99. The analysis of the equations used for calculation of ER by these methods revealed that essentially they were mathematically equivalent.
Conclusion: Each of the alternative methods may be used for evaluation of ER when PPI − TCL cannot be assessed directly. Results obtained by both alternative methods are comparable.  相似文献   
6.
We present a case of recurrent outflow tract arrhythmia despite repeated ablations. Premature ventricular contractions (PVCs) morphology suggested a right‐sided focus. However, electrograms preceding PVCs were recorded from the right and left outflow tracts, distal coronary sinus, and right sinus of Valsalva. Arrhythmia was eliminated after radiofrequency (RF) applications delivered from different sites. We conclude that, in patients with recurrent outflow tract PVCs, mapping all the sites mentioned above may be necessary to find the earliest activation site and carry out successful ablation. In some patients, RF applications from multiple sites may be necessary to completely eliminate arrhythmia. (PACE 2012; 35:e6–e9)  相似文献   
7.
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 sjdpply to the AV node must be considered. In order to confirm this hypothesis observation was conducted on the autopsy material of 50 human hearts (20F, 30M) 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 1mm (18%), 2mm (42%), 3mm (22%), 4mm (18%). In the inferior part imm (26%), 2mm (37%), 3mm (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 m the slow pathway region.  相似文献   
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