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PR interval is prolonged and measures 280 msec. There is additional incomplete right bundle branch block with rSR’ pattern in V1 with a QRS width of 110 msec. This combination of first degree AV block with incomplete right bundle branch block is seen in familial atrial septal defect, which is transmitted in an autosomal dominant pattern. This means that 50% of first degree relatives have a chance to have atrial septal defect. In this individual there is no family history of atrial septal defect though a formal family study has not been done. Though this person had undergone surgical closure of the atrial septal defect three decades back, the abnormal ECG pattern is persisting.