Individual muscle cells grow larger (in thickness) and change to drive the increased contractile force required to move the blood against greater resistance.

According to Voelkel, et al., pressure overload is the initial step for changes in RV, other factors include:[14] Investigations available to determine the cause of cor pulmonale include the following:[1] The diagnosis of pulmonary heart disease is not easy as both lung and heart disease can produce similar symptoms.

Therefore, the differential diagnosis (DDx) should assess:[15] The treatment for cor pulmonale can include the following: antibiotics, expectorants, oxygen therapy, diuretics, digitalis, vasodilators, and anticoagulants.

[1] A variety of medications have been developed to relax the blood vessels in the lung, calcium channel blockers are used[17] but only work in few cases and according to NICE are not recommended for use at all.

Venesection is used in severe secondary polycythemia (because of hypoxia), which improves symptoms though survival rate has not been proven to increase.