What is Cor Pulmonale?
Cor pulmonale is a term from Latin that translates to “pulmonary heart.” The exact definition of this term can vary and there is currently no unanimous agreement on what it means. In essence, cor pulmonale signifies changes in the structure (for instance, thickening or widening) and function of the right side of the heart. These changes are brought on by a primary respiratory disorder that leads to high blood pressure in the lungs. It’s important to note that heart failure on the right side resulting from heart failure on the left side, or from a heart defect present from birth, is not considered to be cor pulmonale.
What Causes Cor Pulmonale?
Pulmonary hypertension – which is high blood pressure in the lungs – can be linked to diseases that affect the lungs (like chronic obstructive pulmonary disease or interstitial lung disease), the blood vessels (like idiopathic pulmonary arterial hypertension), the upper airway (like sleep apnea), or the chest wall (like kyphoscoliosis). Certain diseases that harm the lungs – like autoimmune conditions (scleroderma, for example), cystic fibrosis, and obesity-related breathing issues – can also result in pulmonary hypertension.
A massive pulmonary embolism, a blockage in one of the lungs’ arteries, is a common cause of acute cor pulmonale, a type of heart failure.
This pulmonary embolism can present similar symptoms to those of a heart attack, such as high troponins, changes in ST (a part of a heart rhythm tracing), chest pain, and difficulty breathing.
Chronic obstructive pulmonary disease (COPD) – a type of obstructive lung disease characterized by long-term breathing problems and poor airflow – is the most common cause of cor pulmonale. The severity of cor pulmonale seems to be related to the level of low oxygen in the blood (hypoxemia), high carbon dioxide in the blood (hypercapnia), and the degree of airflow obstruction.
In most people with COPD, cor pulmonale tends to occur alongside mild pulmonary hypertension (i.e., average pulmonary artery pressure of 40 mmHg or less).
Risk Factors and Frequency for Cor Pulmonale
Cor pulmonale, a type of heart disease, is tricky to detect accurately because regular tests and physical exams often miss signs of it. This complicates efforts to understand how many people have it. However, estimates suggest that it’s responsible for 6% to 7% of all heart disease cases in adults in the United States.
- Cor pulmonale is hard to detect with regular exams and tests, making it difficult to know how many people have it.
- In the US, it’s estimated to account for 6% to 7% of all adult heart diseases.
- The number of cor pulmonale cases varies widely from country to country.
- This variance depends on factors like levels of air pollution, the prevalence of smoking, and other risk factors for lung diseases.
Signs and Symptoms of Cor Pulmonale
If you have developed pulmonary hypertension, you might experience a range of symptoms when you exert yourself – this could include shortness of breath (the most common symptom), tiredness, sluggishness, fainting, chest pain, swollen abdomen, and swelling in your lower limbs.
Unfortunately, obvious signs of this disease often show up quite late, usually when the disease has progressed quite a lot.
You might notice various physical signs including:
- Prominently visible jugular veins due to a condition called tricuspid regurgitation
- Swelling in the ankles, typically a sign of right-sided heart failure, but could also be due to other causes
- Distinct heart symptoms such as a palpable force to the left of the breastbone, a louder than normal second heart sound, delayed split second heart sound, a specific kind of heart murmur heard at the lower left of the sternum, or a fourth heart sound located to the right
- In the abdomen, you might observe enlarged liver and a condition called ascites, which presents as fluid build-up in the abdomen
Testing for Cor Pulmonale
When a doctor suspects you might have cor pulmonale, which is a condition that causes the right side of your heart to work less effectively, they may order a series of tests to confirm the diagnosis and understand the severity of your condition.
The first might be a chest X-ray, which helps visualize the size of your heart and the main blood vessels leading to your lungs. If your heart or these arteries are enlarged, it may indicate cor pulmonale.
An electrocardiogram (EKG) can show whether the right side of your heart has become overly stressed and enlarged, a common sign of this condition.
A Doppler echocardiography is another important test that doctors rely on. This scan tracks the speed and direction of blood flow in your heart and can help calculate pressure variations within the heart compartments.
To exclude blood clots in the lung blood vessels as a possible cause, a Chest CT angiography may be done. When measuring the diameter of the primary lung artery, results greater than 29 mm suggest that the person likely has high blood pressure in the lungs, a key feature of cor pulmonale. Further, a ventilation/perfusion (V/Q) scan can be incredibly useful, especially if high blood pressure in your lungs is due to chronic blood clotting issues.
An MRI gives an accurate image of the heart size and is particularly effective at visualizing the dimensions of the right side of your heart. However, it is not commonly used for routine assessments.
Tests that measure lung function, and the 6-minute walk test (assesses exercise capacity), are crucial for understanding the severity of any underlying lung disease contributing to your condition.
Finally, the definitive test for the diagnosis is the right heart catheterization. This test checks for increased pressure (above 25 mmHg) in the right side of your heart without a corresponding increase in the left side. This pressure difference is a critical element in diagnosing cor pulmonale.
Treatment Options for Cor Pulmonale
Treatment primarily focuses on improving the oxygen levels and functioning of the right side of the heart (right ventricle). This is done by increasing the strength at which the right ventricle contracts and reducing the tightening of blood vessels in the lungs (pulmonary vasoconstriction).
Oxygen therapy can improve hypoxic pulmonary vasoconstriction, which means it helps to relieve the tightening of blood vessels in the lungs that happens due to low oxygen levels. This in turn improves the amount of blood the heart pumps out, lessens the tightening of blood vessels caused by the nervous system, helps to alleviate low oxygen levels in tissues, and increases the flow of blood to the kidneys.
Diuretics, or water pills, are used to lower the high amount of blood filling the right side of the heart in patients with chronic lung-related heart disease (chronic cor pulmonale).
The benefit of using heart drugs like digitalis in patients with cor pulmonale is a topic of debate. The positive impact of these drugs isn’t as noticeable as when used for left-side heart failure. However, research has shown a slight positive effect of digitalis on a failing right ventricle in patients with chronic cor pulmonale.
What else can Cor Pulmonale be?
- A mass in the heart known as atrial myxoma
- Health conditions that cause blood to be thicker than normal
- Long term blockage of the lung’s arteries due to blood clots, known as chronic thromboembolic pulmonary hypertension
- Failure of both the right and left sides of the heart, often referred to as congestive or biventricular heart failure
- Tightening of the sac that surrounds the heart, or constrictive pericarditis
- A heart condition where the heart is unable to pump enough blood to meet the body’s demands, known as high-output heart failure
- Heart diseases which cause the heart tissue to be invaded by abnormal cells or materials, known as infiltrative cardiomyopathies
- Lung conditions that cause scarring of the lung tissue, called interstitial lung disease (ILD)
- A common sleeping disorder where breathing repeatedly stops and starts, known as obstructive sleep apnea (OSA)
- A condition where the blood vessel that takes blood from the heart to the lungs becomes narrow, known as primary pulmonic stenosis
- A condition involving high blood pressure that affects the arteries in the lungs and the right side of the heart, known as pulmonary hypertension
- Failure of the right side of the heart caused by birth defects or congenital heart diseases
- Failure of the right side of the heart caused by a heart attack in the right ventricle
- A hole in the wall that separates the heart’s lower chambers, referred to as a ventricular septal defect
What to expect with Cor Pulmonale
The future outlook or prognosis of cor pulmonale can change a lot depending on the exact cause. If cor pulmonale comes about because of a primary lung disease, it usually signals a worse outcome.
For some context, cor pulmonale is a condition where the right side of the heart doesn’t function properly due to high blood pressure in the lungs that’s been present for a long time. Any primary lung disease can lead to this high blood pressure and, as a result, cor pulmonale. The most common symptom is shortness of breath during physical activity. As for treatment, it generally focuses on addressing the underlying condition causing the issue.