block record
2.Objective To search proper standards to diagnose atrial fibrillation(AF) with the second degree atrial ventricular block(Ⅱ°AVB) Methods To record 24 hours ECG for 67 patients with AF Results (1)Fifty eight patients had long R R intervals,the mean of the longest R R intervals was 2 30s±0 53s,most of them took place at night(84 91%);

