Increased pressures in the pulmonary system can be caused by underlying lung disease (COPD, interstitial lung disease, etc), increased pressures in the
pulmonary vasculature (primary/secondary
pulmonary hypertension,
pulmonary embolism), or problems with the left side of the heart (left heart failure). Problems with the heart can include myocardial infarction, myocarditis, ARVD, or an infiltrative process (amyloidosis, hemachromatosis, etc).