LAUSR

In this edition of the journal, Boles et al. report on the inappropriate and appropriate therapy rates among 250 patients (200 for secondary prevention, 50 for primary prevention) who received a dual chamber ICD or a CRTD [1]. The devices were programmed as follows: VT1 zone1⁄4 170e200 bpm (for primary prevention), or VTCL e 20ms (secondary prevention), VT 2 zone1⁄4 200e250 bpm, VF zone1⁄4> 250 bpm. This is comparable to the recommendations in the 2015 HRS/EHRA/APHRS/SOLAECE Expert Consensus Statement on Optimal Implantable Cardioverter-Defibrillator Programming and Testing which advocate the slowest tachycardia rate to be 188 bpm for primary prevention, and VTCL-10 bpm for secondary prevention [2]. The NID of 28e30 beats is also very similar to the 2015 recommendation of 30 beats, and is comparable to the NID used in the PREPARE, RELEVANT, ADVANCE III and PROVIDE studies [3e6]. The time to detect (in devices from Boston Scientific) used in this study was shorter than the 30 second time delay advocated by the 2015 Consensus; the number of Boston Scientific devices in this study, though, were limited. Among the SVTVT discriminators, the authors have suggested that the onset and stability criteria be turned off. It would make sense to retain these criteria as “ON” in patients with AV block, or poor AV nodal conduction. The authors have used up to 6 bursts of ATP in the VT1 zone, and 3 in the VT2 zone. Martins et al. have previously reported that up to 5 ATPs are safe and effective even in the FVT (200e240 bpm) zone [7]. Other studies, as well as the 2015 Consensus recommend at least one ATP, preferably a burst ATP of at least 8 beats. The authors report that using these settings, inappropriate therapies were low. Inappropriate therapies occurred in 11 out of 250 patients (4.4%) over a relatively long follow up duration of 41.9 months. It is to be noted that almost none of these settings are the default settings of the devices used. Thus, this study reemphasises the importance of changing the default settings of currently available ICDs. The overall rate of therapies, and the rate of appropriate therapies in this study was much lower than in previously reported studies. In this study, at a follow up of 41.9 months, 9 out of 250 patients (3.6%) had VT/VF that was appropriately treated by the ICD. None of the 50 patients who received the ICD for a primary prevention indication experienced a therapy for VT/VF. In comparison, in the MADIT-RIT study, at a 1.4 year follow up of 1500 patients receiving a CRTD or dual chamber ICD for primary prevention, 139 out of 514 (27%), 64 out of 500 (12.8%), and 39 out of 486 (8%) patients received appropriate therapies for VT/VF in the conventional (therapy for VT> 190 bpm), high rate (therapy for VT> 220 bpm) and delayed therapy (therapy for VT> 190 bpm lasting> 60 seconds) arms respectively [8]. Comparable data for