Pacing and clinical electrophysiology : PACE
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Pacing Clin Electrophysiol · Dec 1999
Case ReportsIntrapulmonary artery and intrabronchial migration and extraction of a fragment of J-shaped atrial pacing catheter.
A fragment of a fractured Telectronics Atrial Accufix 330-801 lead asymptomatically perforated the adjacent bronchus and was detected on routine chest X-ray. The metallic fragment was located by chest CT scan and bronchial fluoroscopy to lie between the right lobar bronchus and the pulmonary artery, confirming bronchial perforation. The foreign body was removed without complication by direct visualisation with rigid bronchoscopy.
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Pacing Clin Electrophysiol · Oct 1999
Percutaneous cephalic vein approach for permanent pacemaker implantation.
Implantation of permanent pacemaker leads into the cephalic vein within the deltopectoral groove is enhanced by introduction of a flexible guidewire into the brachial vein at the antecubital fossa, which is then advanced to the subclavian vein. The cephalic vein within the deltopectoral groove is easily found by incision with the guidewire as a marker. A pacing lead or leads can be inserted along the guidewire or by using a sheath advanced over the guidewire. The procedure was performed on 32 patients and the pacing leads of 28 procedures (DDD 15, VDD 9 and WI 4) were inserted using the cephalic vein without complications.
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Pacing Clin Electrophysiol · Oct 1999
Case ReportsSpurious redetection of sinus rhythm by an implantable cardioverter defibrillator during spontaneous ventricular fibrillation.
Implantable cardioverter defibrillator undersensing leading to delayed or aborted therapy delivery has been reported with induced arrhythmias and following failed defibrillator shocks. We describe a case in which spurious redetection of sinus rhythm during a spontaneous episode of ventricular fibrillation resulted in aborted device therapy.
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Pacing Clin Electrophysiol · Oct 1999
External exponential biphasic versus monophasic shock waveform: efficacy in ventricular fibrillation of longer duration.
Ventricular fibrillation (VF) duration may be a factor in determining the defibrillation energy for successful defibrillation. Exponential biphasic waveforms have been shown to defibrillate with less energy than do monophasic waveforms when used for external defibrillation. However, it is unknown whether this advantage persists with longer VF duration. ⋯ The E50 (J) for M, B1, and B2 were 131 +/- 41, 57 +/- 18,* and 60 +/- 26* with 10 seconds of VF duration, respectively, and 114 +/- 62, 77 +/- 45,* and 72 +/- 53* with 1 minute of VF duration, respectively (*P < 0.05 vs M). There was no significant difference in the E50 between 10 seconds and 1 minute of VF durations for each waveform. We conclude that (1) the E50 does not significantly increase with lengthening VF durations up to 1 minute regardless of the shock waveform, and (2) external exponential biphasic shocks are more effective than monophasic waveforms even with longer VF durations.
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Pacing Clin Electrophysiol · Sep 1999
Comparative StudyComparison of formulae for heart rate correction of QT interval in exercise electrocardiograms.
The study investigated the differences in five different formulae for heart rate correction of the QT interval in serial electrocardiograms recorded in healthy subjects subjected to graded exercise. Twenty-one healthy subjects (aged 37+/-10 years, 15 male) were subjected to graded physical exercise on a braked bicycle ergometer until the heart rate reached 120 beats/min. Digital electrocardiograms (ECG) were recorded on baseline and every 30 seconds during the exercise. ⋯ The differences obtained with the Fridericia formula were not statistically significant. The study shows that the practical meaning of QT, interval measurements depends on the correction formula used. In studies investigating repolarization changes (e.g., due to a new drug), the use of an ad-hoc selected heart rate correction formula is highly inappropriate because it may bias the results in either direction.