Electrogram-Guided Myocardial Advanced Phenotyping

Inclusion Criteria: 1. Age ≥ 18 years 2. New onset NICM as defined by the presence of left ventricular dysfunction (LVEF \< 45% by echocardiography and/or MRI), with symptoms or signs of HF (dyspnea, orthopnea, edema, ascites, rales or pulmonary vascular congestion on chest radiography) of less than 3 months in duration. 3. Persistent recent onset NICM as defined by the LVEF and signs/symptoms in #2 above with persistence of the LVEF \< 45% despite evidence-based treatment for HF with reduced LVEF for 2 to 6 months. 4. Willingness to provide informed consent \- Exclusion Criteria: 1. Prior diagnosis of HF or documented LVEF \< 45% more than 6 months prior to enrollment. 2. Coronary artery disease, either by history or as determined by coronary angiography demonstrating hemodynamically significant lesions deemed sufficient to potentially contribute to left ventricular dysfunction. 3. Ongoing hemodynamically significant arrhythmias deemed to be an independent cause of HF decompensation 4. Constrictive pericarditis or tamponade 5. Complex congenital heart disease 6. History of malignancy with treatment by anthracyclines or other known cardiotoxic chemotherapeutic agents 7. More than mild aortic or mitral stenosis 8. Intrinsic (prolapse, rheumatic) valve disease with severe mitral, aortic or tricuspid regurgitation 9. Primary hypertrophic cardiomyopathy 10. Untreated thyroid disease 11. Severe nutritional deficiency 12. Severe uncontrolled hypertension 13. Sepsis, active infection (excluding cystitis) or other comorbidity driving the HF decompensation 14. History of cardiac transplantation 15. Acute or chronic severe liver disease as evidenced by any of the following: encephalopathy, variceal bleeding, INR \> 1.5 in the absence of anticoagulation treatment 16. Inability to comply with planned study procedures \-