QRS Fragmentation is Associated with Functional Mitral Regurgitation and Papillary Muscle Dyssynchrony in Patients with Non-ischemic Dilated Cardiomyopathy and Sinus Rhythm

Aim: We investigated the impact of fragmented QRS (fQRS) complexes on ECG in predicting papillary muscle dyssynchrony and functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy with narrow QRS and sinus rhythm. Methods: Thirty-one non-ischemic dilated cardiomyopathy patients with fQRS and 16 patients without fQRS were evaluated for intraventricular and papillary muscle dyssynchrony. All patients were in sinus rhythm and having narrow QRS intervals. Maximal Ts (duration between the beginning of the QRS complex and myocardial peak systolic velocity), difference between basal septal and lateral myocardial segments (ASE Sep-Lat Sys) and anterolateral and posteromedial papillary muscles (ASE Inter PAP Sys) were calculated to assess synchronicity. Results: The patients with fQRS had significantly higher mitral regurgitant volume (p=0.043), shorter E wave deceleration (p=0.01) and isovolumetric relaxation time (p=0.044), lower basal septal (p=0.033) and lower basal lateral (p=0.007) TDI peak systolic velocities and higher ASE Sep-Lat Sys (p=0.041) and ASE Inter PAP Sys (p=0.033) values than patients without fQRS complexes. Conclusion: fQRS was associated with intraventricular and papillary muscle dysssynchrony and more severe functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy and sinus rhythm. The presence of fQRS complexes may be useful in selecting patients for cardiac resynchronization therapy.