An unusual case of severe myocardial dysfunction in a patient with giant left atrium and frequent right ventricular pacing

Giant left atrium is a rare condition, with a reported incidence of 0.3%, and mainly associated with rheumatic mitral valve disease with predominant regurgitation. Giant left atrium has significant hemodynamic effects and requires specific management in the most of the cases. We present an unusual case of a 65-year-old woman with massive left atrial enlargement accompanied by frequent right ventricular pacing, who was documented with severe pacing-induced left ventricular dyssynchrony.