Postoperative symptomatic improvement following surgery for aortic stenosis may be predicted using left atrial size.1 An echocardiographic study2 found a significant correlation between left atrial size and atrial natriuretic peptide levels after acute myocardial infarction both at 10 to 12 days post infarction as well as at six months. This evidence concerns the gene NPPA and acute myocardial infarction.