Skip to Content

Cor Pulmonale


Nowell M. Fine

, MD, SM, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary

Last full review/revision Nov 2020| Content last modified Nov 2020

Cor pulmonale is enlargement and thickening of the ventricle on the right side of the heart resulting from an underlying lung disorder that causes pulmonary hypertension (high pressures in the lungs). The enlargement and thickening of the right ventricle result in heart failure.

Pulmonary hypertension is a condition in which blood pressure in the arteries of the lungs (the pulmonary arteries) is abnormally high. Lung disorders can cause pulmonary hypertension in several ways.

When oxygen levels are low for a long time, pulmonary arteries constrict and their walls become thickened. This constriction and thickening increase the pressure in the pulmonary arteries. Lung disorders that damage or decrease the amount of lung tissue (for example, emphysema) also decrease the number of blood vessels in the lungs. The decreased number of blood vessels increases pressure in the remaining vessels.

The most common cause of cor pulmonale is

Other less common causes include

  • Pulmonary embolism
  • Connective tissue diseases
  • Pulmonary interstitial fibrosis
  • Obesity with reduced ability to breathe

Once pulmonary hypertension develops, the right side of the heart has to work harder to pump blood through the lungs. The increased effort causes the heart muscle to become enlarged and thickened. If pulmonary hypertension continues long enough, the right side of the heart can no longer compensate by enlarging and thickening, and right-sided heart failure develops.

The failing right ventricle places a person at risk of pulmonary embolism because blood flow is abnormally low, so blood tends to pool in the legs. If clots form in the pooled blood, they may eventually travel to and lodge in the lungs, with dangerous consequences.

Symptoms of Cor Pulmonale

There may be few symptoms of cor pulmonale until the disorder is quite advanced. When symptoms do occur, people describe

  • Shortness of breath during exertion
  • Light-headedness (particularly with exertion)
  • Fatigue
  • Chest pain

Symptoms of heart failure, such as swelling (edema) in the legs and progressively worse shortness of breath, also develop.

Diagnosis of Cor Pulmonale

  • Echocardiography

A number of tests are available to help doctors diagnose cor pulmonale, but the diagnosis is often suspected on the basis of the physical examination. For example, by listening through a stethoscope, doctors can hear certain characteristic heart sounds that occur when the right ventricle becomes strained. The legs also become swollen, and veins in the neck enlarge.

Chest x-rays can show the enlarged right ventricle and pulmonary arteries.

Doctors evaluate the function of the left and right ventricles with echocardiography, radionuclide studies, and cardiac catheterization (to measure pressures in the heart chambers and lung arteries).

Treatment of Cor Pulmonale

  • Treatment of the disorder causing cor pulmonale
  • Sometimes, anticoagulants and drugs that relax the lung arteries

Treatment is usually directed at the underlying lung disorder. Because people with cor pulmonale are at increased risk of pulmonary embolism, doctors may prescribe an anticoagulant to be taken long-term.

Copyright © 2022 Merck & Co., Inc., known as MSD outside of the US, Kenilworth, New Jersey, USA. All rights reserved. Merck Manual Disclaimer