From the Guidelines
Cor pulmonale is a condition characterized by enlargement and failure of the right side of the heart due to lung disease, as described in the American Heart Association's scientific statement on the evaluation and management of right-sided heart failure 1.
Definition and Causes
Cor pulmonale occurs when the right ventricle must work harder to pump blood through the lungs because of high blood pressure in the pulmonary arteries (pulmonary hypertension). According to the study published in Circulation in 2018 1, common causes include conditions that abruptly increase RV afterload, such as pulmonary embolism, or decrease RV contractility, such as RV ischemia or myocarditis.
Pathophysiology
The right ventricle is coupled to the high-compliance, low-resistance pulmonary circulation and is suited to adapt to changes in volume rather than pressure 1. An acute increase in RV afterload, such as a large pulmonary embolism, may abruptly decrease RV stroke volume, with minimal increase in RV systolic pressure. Reduced RV stroke volume results in RV dilation, which promotes tricuspid regurgitation, exacerbates RV dilation, and drives a ventricular-interdependent effect on left ventricular filling.
Symptoms and Treatment
Symptoms of cor pulmonale typically include shortness of breath, fatigue, chest pain, swelling in the legs and abdomen, and bluish discoloration of the skin. Treatment should focus on managing the underlying lung condition, and may include oxygen therapy, diuretics, vasodilators, and anticoagulants if pulmonary embolism is involved 1. Lifestyle modifications, such as smoking cessation, maintaining a low-salt diet, and moderate exercise as tolerated, are also important.
Prognosis
The prognosis depends largely on how well the underlying lung disease can be controlled, as the heart changes may be reversible if pulmonary hypertension is adequately treated. It is essential to prioritize the management of the underlying lung condition to improve outcomes in patients with cor pulmonale.
From the Research
Definition of Cor Pulmonale
- Cor pulmonale is defined as right ventricular enlargement and/or failure caused by pulmonary hypertension (PH) resulting from diseases affecting the structure and/or function of the lungs 2.
- It is characterized by the presence of PH, which leads to right ventricular hypertrophy and/or dilation 3.
- The condition can be acute or chronic, depending on the speed of onset of the pathological condition and its effects on the right ventricle 4.
Causes of Cor Pulmonale
- Chronic obstructive pulmonary disease (COPD) is the leading cause of cor pulmonale, accounting for the majority of cases 2, 5, 3.
- Other causes include idiopathic pulmonary fibrosis, obesity-hypoventilation syndrome, interstitial lung disease, sleep apnea, alveolar hypoventilation disorders, and primary pulmonary hypertension 2, 6.
- The loss of vascular bed and chronic hypoxic pulmonary vasoconstriction (HPV) due to alveolar wall destruction are key factors in the development of cor pulmonale in COPD patients 3.
Pathophysiology of Cor Pulmonale
- Pulmonary hypertension (PH) is a pre-capillary condition, resulting from an increase in pulmonary vascular resistance (PVR) due to chronic hypoxic pulmonary vasoconstriction and remodeling of the pulmonary vasculature 2.
- The main characteristic of PH in chronic respiratory disease (CRD) is its mild to moderate degree, with resting pulmonary artery mean pressure (PAP) usually ranging between 20 and 35 mmHg 2.
- However, PH may worsen during exercise, sleep, and exacerbations of the disease, leading to the development of right heart failure (RHF) 2.
Diagnosis and Treatment of Cor Pulmonale
- Echocardiography plays a central role in the diagnostic and therapeutic work-up of cor pulmonale, providing non-invasive and widely accessible assessment of right ventricular function and morphology 4.
- Long-term oxygen therapy (LTOT) is the logical treatment of PH, as it stabilizes or attenuates the progression of PH by reducing alveolar hypoxia 2, 5.
- Vasodilators, such as prostacyclin, endothelin receptor antagonists, sildenafil, and nitric oxide, may be considered in patients with severe PH, but controlled studies are lacking 2, 5.