Pacing and clinical electrophysiology : PACE
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Pacing Clin Electrophysiol · Nov 1998
Case Reports Comparative StudyRight ventricular outflow tract tachycardia as a result of blunt chest trauma.
Two patients presented with monomorphic ventricular tachycardia after blunt chest trauma. In both cases, the arrhythmia had a left bundle branch block, inferior axis morphology comparable to that seen with idiopathic ventricular tachycardia originating from the right ventricular outflow tract (RVOT). In one patient, the arrhythmia persisted and required catheter ablation. A history of cardiac trauma should be considered in patients presenting with RVOT tachycardia.
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Pacing Clin Electrophysiol · Oct 1998
Case Reports Comparative StudyElectromagnetic interference from a muscle stimulation device causing discharge of an implantable cardioverter defibrillator: epicardial bipolar and endocardial bipolar sensing circuits are compared.
This case report is about two patients with two different types of ICDs who underwent electrical muscle stimulation (EMS) therapy. In one patient with an ICD that has epicardial screw-in bipolar sensing leads, electromagnetic interference (EMI) from the EMS device caused the delivery of an inappropriate ICD discharge. In a second patient with an ICD with endocardial true bipolar sensing, there was no evidence of EMI during the EMS therapy despite all of our attempts to reproduce it. The sensing circuits in the two different ICDs are compared.
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Pacing Clin Electrophysiol · Oct 1998
Atrial vulnerability in patients with paroxysmal "lone" atrial fibrillation.
Little is known about the electrophysiological properties of the atrium predisposing to paroxysmal atrial fibrillation (AF), especially in patients without structural heart disease. This study was conducted to analyze intraatrial conduction, atrial refractoriness, and arrhythmia inducibility in patients with lone paroxysmal AF. An electrophysiological study was performed in 24 patients with a documented history of lone paroxysmal AF but in sinus rhythm at the time of the electrophysiological study. ⋯ The presence of a prolonged (> 50 ms) S1A1 and/or the presence of a lack of rate adaptation of the FRP and/or the presence of inducible AF identified patients with spontaneous lone paroxysmal AF with a sensitivity of 96%, a specificity of 67%, a positive predictive value of 85%, and a negative predictive value of 89%. In patients with lone paroxysmal AF, the electrophysiological study using conventional techniques allows not only to detect AF inducibility using a nonaggressive protocol, but also to reveal several electrophysiological abnormalities related to the atrial substrate itself. This atrial vulnerability may explain the high incidence of recurrences in patients with lone paroxysmal AF.
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Pacing Clin Electrophysiol · Aug 1998
Comparative StudyStent dilation of superior vena cava and innominate vein obstructions permits transvenous pacing lead implantation.
The purpose of this study was to assess the feasibility of stent dilation of venous obstructions/occlusions to permit transvenous pacing lead implantation. Innominate vein or superior vena cava (SVG) obstruction may preclude the implantation of transvenous pacing leads. Patients with d-transposition of the great arteries, after a Mustard or Senning procedure, and children with previously placed transvenous pacing leads are at higher risk for this vascular complication. ⋯ Following implantation of 15 Palmaz P308 stents in eight vessels, the mean diameter increased to 14.2 +/- 1.9 mm and the mean pressure gradient across the stented vessels decreased to 1.0 +/- 2.0 mmHg. A transvenous pacing lead was implanted successfully through the stent(s) immediately or 6-8 weeks later. Innominate vein and SVC obstruction can be safely and effectively relieved with intravascular stents and permit immediate or subsequent transvenous pacing lead implantation.
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Pacing Clin Electrophysiol · Jul 1998
Randomized Controlled Trial Clinical TrialPrediction of maintenance of sinus rhythm after cardioversion of atrial fibrillation by analysis of serial signal-averaged P waves.
After cardioversion from atrial fibrillation (AF) many patients develop early recurrence of the arrhythmia. While these patients may be appropriate for immediate prophylaxis against AF recurrence their identification at the time of cardioversion is not possible. Since the signal-averaged P wave (SAPW) is abnormal in individuals with atrial arrhythmia, we assessed its utility for predicting early AF recurrence after cardioversion. ⋯ Patients with relapsing permanent AF who remain in sinus rhythm for at least 1 week after cardioversion show a fall in P wave energy within the first 24 hours. However, in these patients the technique does not predict recurrent AF within 1 week nor sinus rhythm > 4 weeks. These observations suggest persistent disordered atrial activation as a mechanism for early recurrence of AF after cardioversion.