Automatic left ventricular pacing management: not only a technical step up

Actual delivery of cardiac resynchronization therapy (CRT) and consistent left ventricular capture are critical factors to have a good clinical response in patients with heart failure and cardiac dissynchrony receiving biventricular devices.Left ventricular pacing threshold stability and evolution over time may theoretically differ from right ventricular pacing threshold behaviour because of its epicardial nature. In their interesting study, Burri et al. 1 by using an automatic left ventricular capture management algorithm demonstrated that left ventricular pacing threshold remained stable during 1 year follow-up with more than 90% of patients having a maximum increase in threshold of <1.0 V. Only in patients with left ventricular threshold higher than 2.0 V a greater threshold variability was observed in 21% of cases. Reliability of the algorithm had been demonstrated by Crossley et al. 2 who reported a 99.7% performance of the algorithm. As a matter of fact, Biffi et al. 3 reported a 85% performance. That is probably due to the different time frames of the automatic threshold measurement: shortly after manual testing in the Crossley2 study and in the night before manual testing in the Biffi … *Corresponding author. Tel: +39 06 3306 3934, Fax: +39 06 3306 2489, Email: renatopietroricci{at}tin.it