Etiology

Coronary artery disease: post-MI or hibernating myocardium for active ischemia
Hypertension related: chronic sub-optimally treated or hypertensive emergency
Valvular heart disease: aortic stenosis, aortic insufficiency, mitral regurg, mitral stenosis
Infection: viral myocarditis, endocarditis, HIV, acute systemic bacterial infections, chaga's disease, lyme
Autoimmune: lupus-related, giant cell myocarditis
Endocrine/metabolic: hypo or hyperthyroidism, thyroid storm, pheochromocytoma, growth hormone excess
Stress: Takotsubos, post-partum cardiomyopathy
Meds or toxins: anthracylcine or cyclophsophamide based chemotherapy; cocaine, crystal meth, alcohol
Hypertrophic cardiomyopathy, including sub-aortic stenosis
Restrictive or infiltrative cardiomyopathy: sarcoid, amyloidosis, hemochromatosis
Rhythm related: chronic tachycardia (e.g. poor rate control w/a fib); bradycardia
Idiopathic dilated cardiomyopathy