English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background Although entrainment mapping is an established approach to atypical atrial flutter ablation, postpacing intervals shorter than tachycardia cycle length (difference between postpacing interval and tachycardia cycle length [dPPI]  30 ms. Methods We studied 24 noncavotricuspid isthmus–dependent macroreentrant atypical atrial flutter in 19 consecutive patients. Ultra high-density electroanatomic activation maps were acquired with a 64-electrode basket catheter. Entrainment mapping was performed at multiple candidate sites. Ablation was performed at the narrowest accessible slow-conducting critical isthmuses. Results Of 102 entrainment mapping sites, dPPI &lt;30 was observed at 72 sites on complete maps of 24 atypical atrial flutter. Compared with dPPI=0–30 sites (N=45), dPPI&lt;0 sites (N=27) were more commonly located within isthmuses &lt;15 mm wide (67% versus 6.7%,P &lt;0.00001; odds ratio, 28.0; 95% CI, 6.8–115.7), more frequently located within 5 mm of the leading wavefront (93% versus 64%,P =0.008), exhibited slower local conduction velocity (0.49±0.43 versus 0.93±0.57 m/s,P =0.0005), lower voltages (0.48±0.79 versus 0.92±0.97 mV,P =0.04), and more frequently fractionated electrograms (67% versus 24%,P =0.0004). High rates of arrhythmia termination or cycle length increase &gt;15 ms by ablation were observed in both dPPI groups (94% versus 86%,P =0.53). Compared with all dPPI  30 sites (N=30) were less commonly observed within isthmuses (3.3%,P &lt;0.001) or within 5 mm of the leading wavefront (30%,P &lt;0.0001); conduction velocity (1.0±0.7 m/s,P =0.002) and voltage (1.1±1.4 mV,P =0.049) were higher compared with dPPI&lt;0 but similar to dPPI=0–30 sites.Conclusions In atypical atrial flutter, sites with dPPI &lt;0 are markers of limited width critical isthmuses with slower conduction velocity, whereas sites with dPPI=0–30 ms are often not in close proximity to the reentry circuit. Virtual electrode simultaneous down and upstream (antidromic) capture of a confined isthmus of slow conduction can explain a dPPI &lt;0. Identifying these sites may improve selective and efficient ablation strategies compared with the standard 30-ms threshold.

Electrophysiological and Anatomical Correlates of Sites With Postpacing Intervals Shorter Than Tachycardia Cycle Length in Atypical Atrial Flutter