HPSD ablation: Power Settings
The impact of power output during RF ablation on efficacy and safety has
been studied in human subjects. There is significant variability in the
power settings (ranging from 40 W to 90 W), types of ablation catheters
and irrigation flow used in these studies as summarized in Tables 1 and
2. Table 1 lists studies comparing high power to low power ablation
strategies.29-39 Table 2 lists studies which only
included high power ablation strategies.23, 40-42Conventional irrigated CF-sensing catheters have been safely used to
deliver high power (60-70 W) for 5-7 seconds in the left
atrium.29, 43 Reddy et al23 studied
the concept of very high power short duration (vHPSD) ablation for PV
isolation in a multicenter study. The novel CF catheter (QDot Micro
catheter, Biosense Webster, Inc., Irvine, CA) used to deliver 90 W/ 4 s
lesions allows for real-time temperature monitoring using
microelectrodes and 6 thermocouples. The vHPSD algorithm rapidly
modulates power based on the hottest surface thermocouple (cutoff at 65°
to 70°C) thereby reducing excessive tissue heating leading to steam
pops.