Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing
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J Interv Card Electrophysiol · Sep 2001
Case ReportsCase report: severe skin burn at the site of the indifferent electrode after radiofrequency catheter ablation of typical atrial flutter.
Although radiofrequency (RF) catheter ablation has been shown to be an effective treatment strategy in patients with supraventricular tachycardia, RF ablation may lead to potentially serious complications. We describe a case of a 65-year old man who was transferred for catheter ablation of typical atrial flutter. 21 RF applications (mean energy: 81+/-9 watts) were applied in the temperature-controlled mode (70 degrees C) between a 8-mm tip electrode and an indifferent electrode using a high-power RF generator (100 watts) until bi-directional atrial isthmus block was achieved. ⋯ The present study demonstrates a severe skin burn induced by mal-attachment of an indifferent electrode during RF ablation. Long RF energy application times, high-power settings, and heavy sedation may have contributed to the observed severity of skin damage.
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J Interv Card Electrophysiol · Jun 2001
Case ReportsEntrapment of a guide wire by the Chiari network in a patient with ablated idiopathic ventricular tachycardia.
Using a guide wire before insertion of a sheath is a common procedure with infrequent complications. We report an unusual case of a guide wire having been entrapped by the Chiari network prior to an intended radiofrequency ablation procedure, and which could be observed using intracardiac echocardiography. Using transthoracic echocardiography prior to ablation, this patient had been shown to have a relatively large Chiari network. We caution against using a long guide wire in patients with a large Chiari network.
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J Interv Card Electrophysiol · Jun 2000
Accuracy of fluoroscopic localization of the Crista terminalis documented by intracardiac echocardiography.
The crista terminalis is an important anatomic target for ablation of atrial arrhythmias. We determined the accuracy of catheter placement guided by fluoroscopy alone when directed to 24 sites along the crista terminalis in 6 patients. The sites selected included the most medial superior, most lateral superior, mid lateral, and most inferolateral sites along the crista terminalis in each patient. ⋯ In conclusion, it appears that using fluoroscopic guidance alone: 1) localization of the crista terminalis is frequently inaccurate and 2) catheter positioning in the superior/inferior vena cava is commonly noted when targeting very superior and inferior sites along the crista terminalis. A learning curve, assisted by review of ICE recordings after each procedure, appears to improve the accuracy of catheter placement by fluoroscopy alone but still does not result in uniform success. ICE appears to facilitate and ensure accurate targeting of specific anatomic sites along the crista terminalis and thus may serve as an important adjunctive imaging technique in electrophysiology.
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J Interv Card Electrophysiol · Apr 2000
Case ReportsUnique interaction between an atrial single-chamber pacemaker and a ventricular defibrillator.
A well described interaction between an antibradycardia pacemaker and a ventricular defibrillator is sensing of pacemaker stimuli by the ventricular defibrillator. This report describes an interaction between an atrial demand pacemaker and a ventricular defibrillator that resulted in ventricular asystole and polymorphic ventricular tachycardia. In this case, the ventricular defibrillator sensed atrial pacing stimuli when complete atrioventricular block with a slow ventricular escape rate developed. ⋯ Ventricular defibrillator sensing of atrial pacemaker stimuli in the setting of complete atrioventricular block and ventricular asystole cannot be simulated during defibrillator implantation when atrioventricular conduction is intact. Therefore, a pacemaker programmed to atrial demand pacing in a patient with a ventricular defibrillator can result in inappropriate inhibition of ventricular pacing in the setting of complete heart block. Furthermore, this interaction can be avoided with a dual-chamber pacing ventricular defibrillator.
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J Interv Card Electrophysiol · Jul 1999
Correlation of acute and chronic defibrillation threshold with upper limit of vulnerability determined in normal sinus rhythm.
The upper limit of vulnerability (ULV) is the stimulus strength above which ventricular fibrillation cannot be induced, even when the stimulus occurs during the vulnerable period of the cardiac cycle. Determination of ULV using T-wave shocks during ventricular pacing has been shown to closely correlate with the defibrillation threshold (DFT) at ICD implantation. However, there are no data correlating ULV determined in sinus rhythm at ICD implantation, with DFT determined at implantation or during long-term follow-up. This is of clinical importance since ULV may be used to estimate DFT during ICD implantation, both during ventricular pacing or sinus rhythm. ⋯ The purpose of this study was to determine if the upper limit of vulnerability (ULV) determined during normal sinus rhythm correlates with the defibrillation threshold (DFT), as has been previously shown when determined during ventricular pacing. The linear correlation coefficient between the ULV and DFT was r = 0.73 (p < 0.001). Mean ULV at implant was 9.2 +/- 5J, not statistically different from mean DFT of 0.4 +/- 4J. During long-term follow-up of 10.1 +/- 1.8 months in 8 patients, DFT was 8.75 +/- 8J, not significantly different than the DFT of 7.5 +/- 4.1J or ULV of 8.0 +/- 5.3 at implant. Shocks energies of ULV + 5J successfully defibrillated 19 of 21 patients at implant and 8 of 8 at follow-up. This study indicates that the ULV determined in normal sinus rhythm closely correlates with the DFT, and that ULV + 5J defibrillated most patients. ULV testing could be used to predict DFT and reduce or eliminate the need for DFT testing and VF induction. Programming ICD first shock energy for VF to ULV + 5J will result in lower energy than that used with standard DFT testing.