Electromagnetic mapping has made possible the routine approach to complex arrhythmia mapping. Originally, it was developed to facilitate accessory pathway location, but it only complicated solitary pathway ablation. Especially, with the introduction of atrial fibrillation ablation, the electromagnetic mapping has become an irreplaceable component of this procedure. Latter, this 3-dimentional mapping method facilitated ventricular foci ablation in patients with ventricular tachycardia. During the last decade, the application of this mapping method is continuously extended and applied to a large number of complex arrhythmia cases. The electromagnetic mapping is based on minimal magnetic field generation around the tip of the catheter and several antennas, located in a special hardware, called location pad, detect this field. In the near future the location pad will be replaced by an intracardiac detection system. As multiple antennas record the signal, the location pad precisely localizes the catheter tip. By apposition of a location on the endocardial surface and the catheter tip, a virtual map of the cardiac chamber is obtained. Multiple points are represented in space and finally, a continuous wall is completed. Moreover, the catheter records the electrical activity in its vicinity, and the electrical flow can be superimposed on the location in the space. A color-coding localizes the starting point of the arrhythmia and the current flow from it. As of today, an advanced generation is used and data from other imaging systems are merged with the electromagnetic picture. First, magnetic resonance data was merged with the electroanatomic mapping, but today cardiac computed tomography and echo picture might also be merged. Using these merged pictures the anatomical presentation more accurately represents the anatomical structure.

Background Survival with implantable cardioverter defibrillator (ICD) in patients with valvular heart disease (VHD) is limitedly explored. We evaluated the long-term outcome of patients with VHD and malignant ventricular arrhythmia protected with ICD. Methods Patient followed in our ICD clinic were enrolled in the study. Survival and effective ICD therapy in 31 patients with VHD was compared with that in 370 patients with other heart disease and 38 patients without significant structural heart disease. Results During 15-years follow-up, there was no failure in VF therapy in patients with VHD and 99.0% of antitachycardia pacing therapy was successful. The percent of appropriate ICD use and therapy success in patients with VHD was not inferior when compared to the control patients. Conclusions In conclusion, ICD provides appropriate protection and therapy in patients with valvular heart disease and the outcome is favorable.

Background: Animal studies and a preliminary human study have suggested that shock delivered on the upslope of the ventricular fibrillation electrogram improve defibrillation efficacy. The purpose of this study was to evaluate the influence of shock timing on the upslope/downslope (Fig 1) of a large patch electrogram on the effectiveness of defibrillation in human hearts.

Insertable Loop Recorder has become an important additional tool in evaluation of patients with unexplained syncope and recent onset epilepsy in young patients (1,2). Evaluation of palpitation in patients with undiagnosed and undocumented arrhythmia may be frustrating especially if the electrophysiologic testing is negative. In this study the application of Insertable Loop Recorder in these patients was evaluated. Based on the information obtained with the Loop Recorder appropriate treatment could be offered to these patients. We conclude that Insertable Loop Recorder may also be an important evaluation tool in patients with unexplained palpitation.

Complex RF ablation may be required because of anatomical anomalies, difficult target point approach, difficult diagnosis misleading the ablation procedure, multiple pathways and multiple types of arrhythmias in the same heart. These conditions were met in 17% of 1000 consecutive ablation procedures. The final success was not significantly affected however there was a trend for multiple procedures to achieve the same success level.

Pacing and Clinical ElectrophysiologyVolume 25, Issue 7 p. 1029-1036 Noninstrumental Pacemaker and Defibrillator Lead Removal. The Importance of the Rotation Forces SHIMON ROSENHECK, SHIMON ROSENHECK Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorALEXEY WEISS, ALEXEY WEISS Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorDAVID LEIBOWITZ, DAVID LEIBOWITZ Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorZEHAVA SHARON, ZEHAVA SHARON Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this author SHIMON ROSENHECK, SHIMON ROSENHECK Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorALEXEY WEISS, ALEXEY WEISS Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorDAVID LEIBOWITZ, DAVID LEIBOWITZ Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this authorZEHAVA SHARON, ZEHAVA SHARON Cardiology Unit, Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, IsraelSearch for more papers by this author First published: 22 July 2003 https://doi.org/10.1046/j.1460-9592.2002.01029.xCitations: 6 Address for reprints: Shimon Rosenheck, M.D., Cardiology Unit, Hadassah University Hospital, Mount Scopus, P.O. Box 24035, Jerusalem 91240, Israel. Fax: 972–2–5844523; e-mail: shimonr@md.huji.ac.il AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume25, Issue7July 2002Pages 1029-1036 RelatedInformation

Physiological pacing can be provided to both children and adults with normal sinus node function, using single pass lead VDD pacing system. The safety and efficaccy of this pacing system during 5.5 years has been evaluated in 15 children (age 6+/-5 years, 10 males) and 31 adults (age 63+/-18 ages, 17 males). The mean atrial signal amplitude was 1.76 mV (1.06 to 2.45) in children and 1.86 mV (1.46 to 2.25) in adults. The mean atrial sensing percent was 93.8 % (88.9 to 98.7) in children and 97.0 % (95.5 to 98.5) in adults. There was no difference in the ventricular pacing efficacy between the two groups. In conclusion, VDD pacing is safe and highly effective in both children and adults during a 5.5 year follow-up.

Pacing failure in bipolar systems using polyurethane insulated leads may be frequent depending on the type of polyurethane and can cause oversensing and or failure to capture. The reason for this failure is often breakage in the inner insulation. The aim of this study was to evaluate the signals created by such a short circuit. Thirty-seven patients were included in the study, 13 with failing leads with polyurethane 80A insulation, 14 with old but normally functioning leads and 10 patients with new leads. Artifacts in the form of spikes were recorded, during surgical revision, from 11 patients with failing leads (84.6%). In patients with normally functioning leads and newly implanted leads no artifacts were recorded. A significant decrease in impedance of 373.4 Ohms (99% confidence intervals 286.4-460.4, P<0.05) was noted in the failing leads compared with a decrease of only 113.0 Ohms (99%, confidence intervals 6.5-219.6, P<0.01) in the control leads. The difference between the groups was highly significant. In 10 newly implanted and five normally functioning bipolar ventricular leads similar artifacts could be created by making intermittent contact between the proximal lead connections. Thus, artifacts could be recorded from failing leads and from intact leads with artificial intermittent connection at the proximal end. Our results suggest that the failure is caused by a short circuit in the lead. This finding may have important clinical applications in the follow-up of bipolar pacing and defibrillation leads.

A new endocardial lead removal method was evaluated in 22 patients with implantable defibrillator and 28 patients with permanent pacemaker and with indication of lead extraction. The method was not instrumental and consisted of manual lead manipulation. 28 of 30 defibrillation leads (93%) and 35 of 40 pacing leads (88%) were successfully and completely removed. One additional defibrillation lead and 3 additional pacing leads were removed from their original position but were abandoned in the superior vena cava. In conclusion, this new non-instrumental method for lead removal is highly effective and my be utilised in patients requiring lead extraction.

The purpose of this study was to evaluate the efficacy of atrial sensing in children with a single pass lead VDD pacing system and to compare it with the efficacy of atrial sensing in adult patients with the same pacing system. Although the feasibility of single pass lead VDD pacing system implantation in children was recently demonstrated, the efficacy of atrial sensing remains unclear. In addition, the effect of accelerated growth of children on the systems' efficacy has not been addressed. Atrial sensing followed by ventricular sensing and atrial sensing followed by ventricular pacing was prospectively evaluated in 13 children (age 0.5–15 years) and 24 adult patients (age 19–74 years). All had the same endocardial pacing system using a single pass lead. The children and adults had effective atrial sensing at a success rate of 94.00 ± 9.687% and 96.04 ± 4.64%, respectively, during mean follow‐up of 3.5 years. The atrial electrogram amplitude was similar in both groups, 1.8 ± 1.5 mV in children and 1.8 ± 1.1 mV in adults. The adult patients more frequently exhibited ventricular sensing following atrial sensing. The ventricular pacing threshold and impedance were stable in both groups. When necessary, in children, the atrial sensing was corrected by adjusting the pacemaker's lower rate programming. Highly effective atrial sensing was demonstrated in children and adult patients with a single pass lead VDD pacing system. During a mean follow‐up of 3.5 years, not only was the atrial electrogram amplitude stable, but the clinically relevant atrial sensing was highly effective, justifying endocardial pacing with single pass lead VDD pacing in children and adults with preserved sinus node function.

Four hundred and fifty ventricular defibrillations were evaluated in patients during defibrillator implantation, using unipolar, biphasic shocks. A pair of large patches were placed on the chest (anode) and on the back (cathode). In the case of low amplitude shocks (< 10 Joules) and high amplitude shocks in patients with high defibrillation threshold (18-25 Joules), 74.1% were effective on the upslope, and only 45.0% of the shocks delivered on the downslope (p=0.0054, odds ratio 3.492, 95%CI between 1.461 to 8.344). In the mid range (10-17 Joules) there was no difference in the effectiveness of defibrillation with shocks delivered on the upslope or downslope. In conclusion, in human hearts, delivery of defibrillation shock on the upslope of the fibrillation electrogram improves the effectiveness of defibrillation.

VDD pacing follow-up is similar in pediatric and adult patients. Atrial and ventricular pacing parameters are stable during 2-year follow-up in children, and single-pass lead VDD pacing is recommended when the sinus node function is normal.

The aim of this study was to assess whether the performance of RF catheter ablations continues to improve by further staff training once an initial success rate of > 90% has been achieved. Two hundred and ninety‐five procedures of SVT catheter ablation using RF energy were studied. Atrial tachycardia and atrial flutter substrate ablations were not included. The procedures were performed during a 4‐year period by the same physician and nurse, who had previous training in these procedures. The 4‐year period was subdivided into four consecutive 1‐year periods in which 69, 72, 68, and 86 procedures were performed. The outcome, recurrence rate, and duration of the curative procedure were compared among the four periods. There was no significant difference in the initial success rate among the four periods. The recurrence rate decreased from 21.74% to 13.95% (P < 0.05). The duration of the curative procedure decreased from 93.7 ± 78.4 minutes to 39.1 ± 32.2 minutes (P < 0.001), and the fluoroscopic time decreased from 25.5 ± 22.3 minutes to 11.3 ± 8.2 minutes (P < 0.001). These results were similar when accessory pathway and selective AV nodal pathways ablations were separately evaluated. Following the initial staff training, during which the expected 80%‐90% success rate is achieved, additional training will reduce the recurrence rate and the duration of the procedures at a similar level of success. (PACF 1997; 20[Pt. I]:1312‐1317)

The minimal requirements for safe and effective performance of catheter ablation using radiofrequency current are still unclear. To determine the feasibility and safety of single physician approach to catheter ablation of supraventricular tachycardia substrate using radiofrequency energy, the results of the ablation procedure in 52 consecutive patients were evaluated. The procedures were performed during 1 year by the same physician and nurse. Twenty-one patients had selective atrioventricular (AV) nodal pathway ablation and 31 patients had accessory AV pathway ablation. Forty-eight patients (89%) had the diagnostic and the ablative procedure during the same electrophysiological test. In the 21 patients with AV nodal reentrant tachycardia, all had successful selective ablation of the fast (13) or the slow (8) pathways. Eight patients had recurrence of the clinical tachycardia and had a successful reablation. No patient developed complete AV block or other significant complications. The mean fluoroscopy time during the procedure was 16.0 +/- 8.6 minutes. In the eight patients with Wolff-Parkinson-White syndrome, all concealed accessory pathways were successfully ablated with a mean fluoroscopy time of 30.0 +/- 27.9 minutes. Two patients had recurrence of the conduction through the accessory pathway and had a successful reablation. Eighteen of 19 patients with a single overt accessory pathway had successful ablation, with a fluoroscopy time of 22.7 +/- 20.6 minutes. Three patients had an early recurrence of the conduction through the accessory pathway, reablation was successful in two of them. Ten accessory pathways were ablated in four patients with multiple pathways during nine procedures. Only two patients developed minor peripheral vascular complications.(ABSTRACT TRUNCATED AT 250 WORDS)