2.1 Inclusion and exclusion criteria
This study collected the imaging information and data from inpatients who underwent the LBBAP procedure and CAG in the Center of Cardiovascular Medicine, the Second Affiliated Hospital of Nanchang University between January 1, 2019 and October 1, 2020. The exclusion criterion was patients with one or more of the following diseases: a) acute myocardial infarction; b)intracoronary stenting; c) chronic occlusive disease of the coronary arteries. This study was approved by the local ethical board and was performed in accordance with the Declaration of Helsinki.