Procedures
RIGHT ATRIAL ENLARGEMENT, ENLARGEMENT
Clinical assessments included demographics, CAT and SOBQ questionnaires, 12-lead electrocardiography, and pre- and post- bronchidilator spirometry [Trained technicians collected 12-lead ECGs in a supine position at enrollment. ECGs were analyzed using electronic calipers. A group of trained physicians analyzed all ECGs, and all physicians analyzed a standard subset of ECGs to assess interobserver agreement on the presence or absence of P-pulmonale. Baseline ECGs of 501 participants were analyzed for P-pulmonale, a marker for right atrial enlargement that is evidenced by P wave enlargement > 2.5 mm in lead II [