Left atrial enlargement (LAE) on echocardiogram, evidence of left atrial abnormality demonstrated by increased p-wave terminal force in lead V1 (PTFV1) on ECG, and increased serum levels of a form of brain natriuretic peptide (NT-proBNP) and other markers for atrial disease have been used to define atrial cardiomyopathy [30]. This evidence concerns the gene NPPB and Left atrial enlargement.