Pulmonary heart disease, referred to as pulmonary heart disease, is a disease that results in increased pulmonary vascular resistance due to bronchial, pulmonary, thoracic or pulmonary vascular pathology, causing pulmonary hypertension and ultimately structural and/or functional changes to the right ventricle. Acute pulmonary heart disease is seen in acute massive pulmonary embolism leading to pulmonary hypertension and subsequent acute right ventricular dilatation, which is relatively uncommon in clinical practice. The term pulmonary heart disease is usually used to refer to chronic pulmonary heart disease, a common condition secondary to lung disease such as chronic obstructive pulmonary disease (referred to as slow-onset lung disease). Pulmonary heart disease has a high rate of disability and death and can cause a serious burden of disease.