Ralph Augostini

Ineffectiveness and Potential Proarrhythmia of Atrial Pacing for Atrial Fibrillation Prevention After Coronary Artery Bypass Grafting

BACKGROUNDnAtrial pacing is often used empirically to suppress atrial ectopy and prevent atrial fibrillation after coronary artery bypass grafting.nnnMETHODSnTo determine whether atrial overdrive pacing reduces atrial fibrillation and atrial ectopy after coronary artery bypass grafting, 100 patients were randomized to no atrial pacing (Control) versus AAI pacing at 10 beats/min or more above the resting heart rate (Paced), started by postoperative day 1 and continued through day 4. Major end points were new atrial fibrillation and frequency of atrial ectopy during the first 4 days after coronary artery bypass grafting.nnnRESULTSnAtrial fibrillation occurred by day 4 in 13 of 51 (25.5%) Paced and in 14 of 49 (28.6%) Control patients, p = 0.90. Control patients who developed atrial fibrillation had significantly more atrial ectopy than those who did not. Atrial ectopy was paradoxically more frequent in the Paced group (2,106+/-428 versus 866+/-385 per 24 hours, p = 0.0001). Loss of capture, sensing, and consistent atrial pacing occurred frequently during atrial pacing.nnnCONCLUSIONSnContrary to prevailing opinion and practice, postoperative atrial overdrive pacing significantly increases atrial ectopy and does not reduce the likelihood of atrial fibrillation.

Higher energy synchronized external direct current cardioversion for refractory atrial fibrillation.

OBJECTIVESnWe sought to evaluate the safety and efficacy of higher energy synchronized cardioversion in patients with atrial fibrillation refractory to standard energy direct current (DC) cardioversion.nnnBACKGROUNDnStandard external electrical cardioversion fails to restore sinus rhythm in 5% to 30% of patients with atrial fibrillation.nnnMETHODSnPatients with atrial fibrillation who failed to achieve sinus rhythm after at least two attempts at standard external cardioversion with 360 J were included in the study. Two external defibrillators, each connected to its own pair of R-2 patches in the anteroposterior position, were used to deliver a synchronized total of 720 J.nnnRESULTSnFifty-five patients underwent cardioversion with 720 J. Mean weight was 117 +/- 23 kg (body mass index 48.3 +/- 4.1 kg/m2). Structural heart disease was present in 76% of patients. Mean left ventricular ejection fraction was 45 +/- 12%. Atrial fibrillation was present for over three months in 55% of the patients. Sinus rhythm was achieved in 46 (84%) of the 55 patients. No major complications were observed. No patient developed hemodynamic compromise and no documented cerebrovascular accident occurred within one month after cardioversion. Of the 46 successful cardioversions, 18 patients (39%) remained in sinus rhythm over a mean follow-up of 2.1 months.nnnCONCLUSIONSnExternal higher energy cardioversion is effective in restoring sinus rhythm in patients with atrial fibrillation refractory to standard energy DC cardioversion. This method is safe and does not result in clinical evidence of myocardial impairment. It may be a useful alternative to internal cardioversion because it could be done within the same setting of the failed standard cardioversion and obviates the need to withhold protective anticoagulation for internal cardioversion.

Transiliac Permanent Pacemaker Implantation After Extraction of Infected Pectoral Pacemaker Systems

Infected pectoral pacemaker systems were extracted in 5 patients and new pacemakers were reimplanted in a pelvic pocket through the iliac veins. In patients who have infected pectoral pacemaker systems, this easy and safe technique provides an alternate route for reimplantation of permanent pacemakers.

T Wave Oversenising From Postural Changes: A Rare Cause of Inappropriate Shock Form A Subcutaneous Defibrillator

2214-0271/© 2017 Heart Rhythm Society. Published by Elsevier Inc. This is an op under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4 Introduction Inappropriate shock therapy from T-wave oversensing (TWOS) is a well-described complication in patients with subcutaneous implantable cardioverter-defibrillator (S-ICD). We report a case of inappropriate shock from TWOS during postural change.

Implantable Cardioverter Defibrillator Therapy

The implantable cardioverter defibrillator (ICD) was initially designed to automatically detect and treat tachyarrhythmias (1, 2). The modern ICD has evolved into a multifunctional, multiprogrammable electronic device designed to treat episodes of ventricular tachycardia (VT) and ventricular fibrillation (VF), and to support bradycardia. The ICD consists of a pulse generator and a lead system with electrodes for pacing and coils for defibrillation. Current ICDs have the programming potential to deliver multi-level therapies, which may include a combination of anti-tachycardia pacing, cardioversion, or defibrillation. Contemporary ICDs also have extensive bradycardia functionality, which may include single-chamber pacing, dual-chamber pacing, automatic mode-switching, and sensor-driven rate-responsive pacing. ICDs incorporate sophisticated algorithms to detect and differentiate supraventricular tachycardia (SVT) from ventricular arrhythmias. Additionally, some models deliver pacing or defibrillation therapy for atrial arrhythmias. Multiple clinical trials have demonstrated the efficacy of ICDs to accurately detect and treat VT and to reduce the risk of sudden cardiac death.