Morphology Of Current Of Injury Does Not Predict Long Term Active Fixation ICD Lead Performance

Background: Currents of injury (COI) have been associated with improved lead performance during perioperative measurements in pacemaker and ICD implants. Their relevance on long term lead stability remains unclear.Methods: Unipolar signals were recorded immediately after active fixation ICD lead positioning, blinded to the implanting surgeon. Signals were assigned to prespecified COI types by two independent investigators. Sensing, pacing as well as changes requiring surgical intervention were prospectively investigated for 3 months.Results: 105 consecutive ICD lead implants were studied. All could be assigned to a particular COI with 48 type 1, 43 type 2 and 14 type 3 signals. Pacing impedance at implant was 703.8±151.6 Ohm with a significant COI independent drop within the first week. Sensing was 10.6mV± 3.7mV and pacing threshold at implant was 0.8±0.3mV at 0.5ms at implant. There was no significant difference between COI groups at implant and during a 3 months follow up regarding sensing, pacing nor surgical revisions.Conclusions: Three distinct patterns of unipolar endocardial potentials were observed in active fixation ICD lead implant, but COI morphology did not predict lead performance after 3 months

The impact of cardiac resynchronization therapy on the incidence of ventricular arrhythmias in mild heart failure.

International audienceBACKGROUND: Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular (LV) remodeling in selected populations. However, the effect of CRT on ventricular arrhythmias is controversial. This is particularly important among patients with mild heart failure (HF), in whom sudden death is a leading cause of mortality. OBJECTIVE: This study sought to assess the impact of CRT on ventricular arrhythmias in mild HF. METHODS: The REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) study is a multicenter randomized, double-blind trial of CRT among patients with mild systolic HF. The time to first appropriate, treated ventricular tachycardia/ventricular fibrillation (VT/VF) episode or spontaneous sustained VT in cardiac resynchronization therapy plus defibrillation device (CRT-D) patients was compared between groups, as were predictors of VT/VF. RESULTS: The study randomized 508 patients who received CRT-D devices. There were no significant demographic differences between groups. There were no differences in VT/VF episodes or VT storm between groups. Specifically, in the CRT ON group, the estimated event rate was 18.7% at 2 years, compared with 21.9% in the CRT OFF group (hazard ratio 1.05, P = .84). However, among CRT ON patients, those with reverse remodeling had a reduced incidence of VT/VF compared with those without remodeling (5.6% vs. 16.3%, hazard ratio 0.31, P = .001). CONCLUSION: CRT for up to 2 years does not impact VT/VF in mild HF despite marked clinical and remodeling effects of pacing. This neutral effect may be attributable to competing antiarrhythmic effects of reverse remodeling and proarrhythmic effect of pacing. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov/ct2/show/NCT00271154