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The ventriculophasic response. The tracing recorded in a patient with 2:1 second‐degree heart block demonstrates that 2 P waves with no interposed QRS complex (P1‐P2) have a longer P‐P interval (720 milliseconds) than 2 P‐waves with interposed QRS (P2‐P3 = 600 milliseconds). EKG = electrocardiogram.
