Can lung disease cause heart disease?
Heart disease as a consequence of lung disease is known as cor pulmonale. ‘Cor’ means related to heart and ‘pulmonale’ means related to the lungs. When there is severe lung disease, the blood vessels in the lung get destroyed or contract, increasing the blood pressure in the main blood vessels taking deoxygenated blood to the lung for oxygenation (pulmonary arteries). When the pressure in the pulmonary arteries rise (pulmonary hypertension), the strain on the right ventricle which pumps blood to the lungs increases. The right ventricular muscle gets thickened (right ventricular hypertrophy). When the load is more, the right ventricle becomes enlarged in addition to being thickened. If the lung disease is progressive, a stage may come when the right ventricle is unable to bear the extra load and may fail. When the right ventricle fails, the pressure in the right atrium increases. Walls of the right atrium gets thickened. Back pressure into the great veins which bring blood to the right atrium causes prominent distended neck veins (jugular veins). Increased pressure in the venous system of the abdomen and lower limbs cause excess fluid (edema) to collect in the lower limbs and abdomen (ascites). Increased pressure in the veins of the face give the face a congested appearance.