Pacing and clinical electrophysiology : PACE
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Pacing Clin Electrophysiol · Feb 2003
Postoperative ventricular arrhythmias after cardiac surgery: immediate- and long-term significance.
AF is frequent after cardiac surgery. However, ventricular arrhythmias are less known. The purpose of the study was to evaluate the causes and the prognostic significance of severe ventricular arrhythmias occurring after cardiac surgery. ⋯ The reduction of indexes reflecting sympathetic and parasympathetic tone could facilitate the occurrence of atrial arrhythmias (and then VT) in patients without ventricular arrhythmogenic substrate or the development of VT/VF in patients with a latent previous ventricular arrhythmogenic substrate. In patients without inducible VT, the prognosis is excellent and an ICD is not recommended in these patients. In those with inducible VT, there is a high incidence of responders to antiarrhythmic drugs with a favorable prognosis.
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Predictors of severity of cardiac arrest or efficacy of cardiopulmonary resuscitation are few. Respiratory end tidal CO2 (ETCO) is a marker of pulmonary blood flow and, possibly, cardiac arrest. The purpose of this study was to evaluate ETCO as a quantitative marker of cardiac arrest in a human model of ventricular fibrillation (VF). ⋯ Significant changes in ETCO were measured during VF arrest. ETCO can predict acute cardiac arrest in a quantitative manner.
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Pacing Clin Electrophysiol · Jan 2003
Implantation of pacemakers and implantable cardioverter defibrillators in orally anticoagulated patients.
The safety of pacemaker and defibrillator implantations in orally anticoagulated patients using standard techniques has not been thoroughly evaluated. This article describes a prospectively collected experience in such patients. Patients presenting for device implantation who were treated with warfarin were allowed to continue therapy provided that the INR was < 3.5. ⋯ One patient had a small soft hematoma, which resolved spontaneously. At 6 weeks, all patients had well-healed scars with satisfactory pacing and sensing thresholds. In experienced centers, patients requiring treatment with warfarin may undergo implantation of pacemakers or defibrillators with minimal risk despite continuation of anticoagulation.
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Pacing Clin Electrophysiol · Jan 2003
Advanced pacemaker diagnostic features in the characterization of atrial fibrillation: impact on preventive pacing algorithms.
Pacing algorithms to prevent PAF are mainly based on the suppression of premature atrial complexes (PACs), which play an important role in its initiation. In contrast to 24-hour ambulatory electrocardiograms, advanced pacemaker (PM) diagnostic features are capable of recording AF episodes during long follow-up periods and of characterizing AF in a detailed fashion. For the specific use of these algorithms, a detailed characterization of AF was performed in 91 dual chamber PM recipients with histories of AF. ⋯ Despite frequent PACs (median 10.8/hour) during sinus rhythm, a median of 66.4% of the AF episodes were preceded by < 2 PACs/min before onset. In conclusion, frequent, short-lived AF episodes seem best suited for AF preventive pacing therapies. However, the small number of PACs preceding many AF episodes may limit the efficacy of PAC suppressing algorithms.
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Pacing Clin Electrophysiol · Jan 2003
Catheter ablation of ventricular tachycardia following myocardial infarction using three-dimensional electroanatomical mapping.
One challenge encountered during catheter ablation of postinfarction ventricular tachycardia (VT) is the inducibility of multiple VT morphologies associated with variable hemodynamic instability. The clinical usefulness and safety of a three-dimensional electroanatomical mapping in guiding radiofrequency (RF) catheter ablation of VT, used in parallel with a multichannel recording system, was studied in 28 men (mean age = 63.8 +/- 10.6 years, mean left ventricular ejection fraction = 28% +/- 9%). Three-dimensional voltage maps of the left ventricle were obtained in sinus rhythm with annotation of areas of fractionated or late potentials, zones of slow conduction and/or dense scar with no pacing capture at 10 mA. ⋯ During a mean follow-up period of 10.6 +/- 6.4 months, catheter ablation was repeated in 6 patients for VT recurrences. No significant complications occurred except for a transient cerebral ischemic attack in one patient. In conclusion, electroanatomical mapping assisted the successful and safe catheter ablation of both mappable and nonmappable VTs in a significant proportion of patients after myocardial infarction.