Ventricular pacing: to pace or not to pace

Comparison of pacing algorithms to avoid unnecessary ventricular pacing in patients with sick sinus node syndrome: a single-centre, observational, parallel study

AIMS

Reduction of unnecessary ventricular pacing (uVP) is an essential component in the treatment strategy in any pacing population in general. The aim of this study was to evaluate the efficacy of different algorithms to reduce uVP in an adult population with sick sinus syndrome (SSS) treated outside of clinical trials. Evaluation of the relationship between different types of pacing algorithms and clinical outcomes is also provided.

METHODS AND RESULTS

This was a single-centre, observational, parallel study, based on retrospective analysis of the Arrhythmology Cardiology Center of Armenia electronic clinical database. This study evaluated atrial pacing percentage (AP%), ventricular pacing percentage (VP%), and the incidence of atrial high rate episodes in 56 patients with SSS using three different pacing strategies: managed VP, search atrioventricular (AV), and fixed long AV. We did not find statistically significant differences in the amount of VP between the groups. Although the atrial high rate percentage (AHR%) tended to be higher in the fixed long AV group, this difference was not statistically significant. Mean VP% and AP% were similar in all three groups.

CONCLUSIONS

In our study, all three programmed strategies produced the same mean AP% and VP%, and were equally efficient in uVP reduction. There was no relationship between chosen algorithms and the incidence of pacemaker syndrome, hospitalizations, or change in New York Heart Association class. The percentage of AHR was not associated with pacing strategy or co-morbidities but showed borderline correlation with left atrial size.

What could be the cause of late syncope after pacemaker implantation?

A 21-year-old man who had suffered an episode of complete heart block 2 months earlier and thus undergone pacemaker implantation presented with syncope. Echocardiography showed cardiac tamponade and raised the suspicion of lead penetration. The effusion was drained. Multi-sliced CT scan confirmed that the right aspect of the pacemaker wire was extracardiac, causing the cardiac tamponade.