title: Successful treatment of a cardiac resynchronization therapy nonresponder by identifying lead malpositioning.
abstract: This case describes some of the commonly overlooked device-related issues in patients who have reportedly failed to respond to cardiac resynchronization therapy (CRT). The case demonstrates voltage-dependent right ventricular capture instead of right atrial capture by a subtly malpositioned right atrial lead. CRT therapy failed to improve symptoms of heart failure and the diagnosis of "CRT nonresponder" was made. With a detailed fact-finding approach, the mechanism behind this nonresponse was identified, and the outcome of CRT was significantly improved with rectification of the problems.
authors.affiliation: Electrophysiology Services and the Center for Comprehensive Cardiovascular Care (C4), St. Louis University Hospital and School of Medicine, St. Louis, Missouri.
authors.forename: Karthik Venkatesh
authors.initials: KV
authors.lastname: Prasad
authors.affiliation: Electrophysiology Services and the Center for Comprehensive Cardiovascular Care (C4), St. Louis University Hospital and School of Medicine, St. Louis, Missouri.
authors.forename: Krittapoom
authors.initials: K
authors.lastname: Akrawinthawong
authors.affiliation: Electrophysiology Services and the Center for Comprehensive Cardiovascular Care (C4), St. Louis University Hospital and School of Medicine, St. Louis, Missouri.
authors.forename: Scott Wayne
authors.initials: SW
authors.lastname: Ferreira
authors.affiliation: Electrophysiology Services and the Center for Comprehensive Cardiovascular Care (C4), St. Louis University Hospital and School of Medicine, St. Louis, Missouri.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Mehdirad