Effect of ECG filter settings on J-waves

BackgroundWhile J-waves were observed in healthy populations, variations in their reported incidence may be partly explicable by the ECG filter setting.MethodsWe obtained resting 12-lead ECG recordings in 665 consecutive patients and enrolled 112 (56 men, 56 women, mean age 59.3 ± 16.1 years) who manifested J-waves on ECGs acquired with a 150-Hz low-pass filter. We then studied the J-waves on individual ECGs to look for morphological changes when 25-, 35-, 75-, 100-, and 150 Hz filters were used.ResultsThe notching observed with the 150-Hz filter changed to slurring (42%) or was eliminated (28%) with the 25-Hz filter. Similarly, the slurring seen with the 150-Hz filter was eliminated on 71% of ECGs recorded with the 25-Hz filter. The amplitude of J-waves was significantly lower with 25- and 35-Hz than 75-, 100-, and 150-Hz filters (p < 0.0001).ConclusionsThe ECG filter setting significantly affects the J-wave morphology.