|Type||Category||Key Features||Mechanism(s)||Cause of Heart Failure Syndrome|
|Type 1||Hypertrophic cardiomyopathy||Thick LV walls, small LV chamber||Genetic mutations||Diastolic dysfunction|
|Type 2||Infiltrative cardiomyopathies||Small chamber, generally have ↑ wall thickness, common to have RV involvement||Amyloid, sarcoid, hemochromatosis, endomyocardial fibrotic disease, etc.||Diastolic dysfunction, restrictive physiology|
|Type 3||Nonhypertrophic cardiomyopathy, without significant CV disease (non-LVH)||Normal wall thickness, small or normal chamber size, no significant physiologic stimuli for hypertrophy||Unknown (possible genetic abnormality)||Diastolic dysfunction (with or without restrictive physiology)|
|Type 4||1 or more underlying cardiovascular conditions||Varying combinations of HTN, MI, CAD, DM, CKD, obesity, etc.||Chronic neurohormonal activation, renal dysfunction, abnormal salt/water metabolism||Hypothesized to be due to volume overload state|
CAD = coronary artery disease; CKD = chronic kidney disease; CV = cardiovascular; DM = diabetes mellitus; HFpEF = heart failure with preserved ejection fraction; HTN = hypertension; LV = left ventricular/ventricle; LVH = left ventricular hypertrophy; MI = myocardial infarction; RV = right ventricular.