AAI to DDD pacing mode inappropriate switches in a dual chamber pacemaker due to ventricular blanking period.

A 90-year-old woman received a dual chamber pacemaker (PM) for a sick sinus syndrome. The PM was programmed with SafeR AAI-DD pacing mode at 60 bpm. During a standard follow up, some memorized electrograms (EGMs) were found in SafeR diagnostics, with atrial pacing (Ap) not followed by any ventricular sensing/pacing event, due to simultaneous junctional activity falling into ventricular blanking period during Ap and, for this reason, unsensed by the PM. Blanking periods can affect PM functioning if not revealed and adjusted.

Effectiveness of Implantable DEfibrillators Alert Systems: comparison between audible and vibratory alert: IDEAS study.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) alarm systems are an important means of monitoring device functioning. The aim of this study was to compare the ability of patients with sense two types of device alert systems: an audible alert and a vibratory alarm. METHODS: The ability to recognize the alarms was assessed in three alarm tests performed in a series of consecutive ICD patients enrolled during routine outpatient device follow-up. To avoid overestimating the rate of patients able to sense the alarm, the first test was performed without forewarning. Subsequently, the second test was performed after the patients had been forewarned. Finally, to assess the learning effect of a demonstration test, a third test was performed, again without forewarning. RESULTS: A total of 528 patients (65.4 ±â€Š14.4 years, 74.6% male) were enrolled: 347 (65.7%) with an audible alert-endowed device and 181 (34.3%) with a vibratory alarm-endowed device. When emitted without warning, the alarms were sensed by 72.4% of patients. When patients were forewarned, the probability of sensing the alarms rose to 92.5% (P < 0.001). In both cases, the vibratory alarm was more likely to be sensed than the audible alert (77.3 vs. 67.7% in the first case; 96.1 vs. 87.9% in the second case; all P < 0.05). CONCLUSION: ICD alarms emitted in an outpatient setting are sensed by a large proportion of patients, but not by all. Training patients by means of demonstration tests significantly increases the rate of patients who recognize the alarm. Vibratory alarm seems to be more effective than audible alert.

Reduced long-term overall mortality in heart failure patients with prolonged QRS treated with CRT combined with ICD vs. heart failure patients with narrow QRS treated with ICD only.

AIMS: It is not known whether heart failure (HF) patients with prolonged QRS who undergo cardiac resynchronization therapy combined with a defibrillator (CRT-D) have a prognostic advantage over HF patients with narrow QRS (therefore without indication for CRT) treated with an implantable cardioverter defibrillator (ICD) only. The aim of this study was to compare the long-term mortality of a group of HF patients with prolonged QRS receiving CRT-D with that of a similar group of patients with narrow QRS receiving ICD only. METHODS AND RESULTS: A total of 312 patients (mean age 66 ± 13 years; 84% male, mean left ventricular ejection fraction 25 ± 4%, mean New York Heart Association class 2.6 ± 0.5) were included in the analysis. Of these, 138 with a QRS complex duration ≥120 ms received a CRT-D. During follow-up, the time and cause of death were assessed. During a median follow-up of 46 months, CRT-D patients showed significantly lower overall mortality (P = 0.038). Compared with patients receiving ICD only, CRT-D patients showed lower HF mortality (P = 0.003). Coronary mortality, non-cardiac mortality, and sudden mortality were similar in both groups (all P > 0.05). A positive response to CRT was an independent predictor of reduced mortality on multivariate analysis (hazard ratio: 0.27; P = 0.047). CONCLUSION: In HF patients treated with ICD, the subgroup of patients with prolonged QRS who receive CRT-D displays better long-term survival than narrow QRS ICD recipients, owing to their reduced HF mortality.