Left atrial volume during the early convalescent phase of acute MI is strongly related to expansion of myocardial extracellular matrix during infarct healing and ventricular remodeling

Background Changes in left ventricular compliance caused by diffuse fibrosis after MI may result in diastolic dysfunction and left atrial enlargement. We sought to test the hypothesis that left atrial volume is associated with ECV (a marker of diffuse myocardial fibrosis) during the sub-acute phase of infarction and can predict the increase of ECV during the ensuing months of infarct healing. We quantified left atrial volumes serially in patients after ST-elevation myocardial infarction and assessed their relationship with indices of post-MI remodeling including left ventricular dimensions, ECV, and infarct size.