Difference of Late Gadolinium Enhancement on Cardiac Magnetic Resonance Imaging between Arrhythmogenic and Non-Arrhythmogenic Papillary Muscle: A Case Report

Background: Ventricular arrhythmias (VAs) arising from papillary muscles (PMs) have been reported. Some cases with VAs from PMs have been reported to show late gadolinium enhancement (LGE) in arrhythmogenic PMs on cardiac magnetic resonance imaging (CMRI). Case Report: We report on a 54-year-old female presenting with severe left ventricular dysfunction and frequent premature ventricular contractions (PVCs) including non-sustained ventricular tachycardia (NSVT). PVCs (right bundle branch block and inferior axis) comprised 34.7% of total number of QRS complexes during 24 h Holter monitoring. Three dimensional mapping revealed the origin of PVC at the base of the anterior PM, which was also confirmed by transthoracic echocardiography. A total of 17 radio-frequency (RF) energy applications by irrigated-tip catheter were required to eliminate the PVCs. No Purkinje potential was recorded and acceleration of the PVCs was observed during RF delivery. CMRI revealed LGE in both anterior and posterior PMs. The posterior PM was surrounded by widespread LGE in endocardium while the anterior PM was not. Conclusion: Focal delayed enhancement in the anterior PM may indicate the origin of VAs that can exist deep beneath the endocardium. The posterior PM, which also had LGE in itself was not arrhythmogenic this time possibly because of the widespread LGE covering the area.