Background: Arrhythmia-mediated cardiomyopathy (AMC) is an essential clinical situation that is commonly underdiagnosed. Successful arrhythmia control leads to improvement in health-related quality of life (HRQoL) and heart failure (HF) symptoms in patients with structural heart disease (SHD)., Aims: The study aimed to evaluate the impact of catheter ablation (CA) of persistent arrhythmia on HRQoL, biochemical and clinical parameters HF in patients with SHD and AMC., Methods: Patients with SHD, on optimal medical treatment, with persistent arrhythmia and strong suspicion of AMC, scheduled for CA were prospectively enrolled. Study procedures included: HRQoL measurement (the Minnesota Living with Heart Failure Questionnaire [MLHFQ] and the EuroQol Research Foundation [EQ-5D-3L] questionnaire), biomarkers (N-terminal pro-B-type natriuretic peptide [NT-proBNP], troponin T [TnT], matrix metalloproteinase-9 [MMP-9], soluble suppression of tumorigenesis-2 [sST2], tissue inhibitor of matrix metalloproteinase-1 [TIMP-1]), transthoracic echocardiography and clinical assessment., Results: At 6 months, 30/35 (86%) patients were free of persistent arrhythmia. Patients who underwent successful CA had a significant improvement in HRQoL: MLHFQ (median [interquartile range, IQR], -22 [-28; -11]; P <0.001), EQ5D-3L score (mean [standard deviation], 21.8 (16.8); P <0.001); EQ5D-3L index (median [IQR], 0.09 (0.05; 0.18); P <0.001). A significant decrease in injury bio markers was observed: NT-proBNP (median [IQR], -414 [-1397; -318] pg/ml; P <0.001), TnT (median [IQR], -2.27 (-8.52; 0.55) ng/l; P <0.01) but not in fibrosis biomarkers: (median [IQR], sST2: 2.20 [-5.4; 4.3] ng/ml; P = 0.741, MMP-9: 34 [-376; 283] ng/ml; P = 0.881, TIMP-1: 11.1 [-17.1; 31.9] ng/ml; P = 0.215). There was a significant increase of left ventricular ejection fraction (LVEF) (mean [SD], 9.8 [5.9] %; P <0.01)., Conclusions: Successful CA significantly improved clinical status, LVEF, and HRQoL of patients with SHD and AMC.