Pulmonary Hypertension
Your heart is a pumping system with two ventricles (lower chambers). The right side of your heart (right ventricle) pumps blood through the lungs via small blood vessels known as arterioles. The lungs add oxygen to the blood which returns to the left side of your heart (left ventricle) where the oxygenated blood is pumped around your body. If the small blood vessels are reduced in number or become narrowed, it becomes more difficult to get blood from the right ventricle to the left ventricle. As a result, the pressure increases in the lungs and in the right side of your heart. This syndrome is called pulmonary hypertension (PH).
Types of Pulmonary Hypertension
- Pulmonary Arterial Hypertension (PAH): This type of PH is caused by the changes in the walls of the small arteries of the lungs .
- Pulmonary Venous Hypertension (PVH): This type of PH is caused by problems related to the left side of the heart such as heart valve disease, congestive heart failure and cardiomyopathy.
Regardless of whether the problem is PAH or PVH, the right side of the heart has to work harder to push blood through narrowed arteries in the lungs. This compromises the heart’s ability to push blood out of the heart, through the lungs, and into the rest of the body.
Causes of Pulmonary Hypertension
The cause of PAH or PVH is sometimes unknown. However, certain conditions, traits or habits may raise your risk for the condition. These are known as risk factors and include:
Non-Modifiable Risk Factors: These factors are irreversible and cannot be changed. The more of these risk factors you have, the greater your chance of developing PH.
- Family history/Genetics
Modifiable Risk Factors: These factors can be modified, treated or controlled through medications or lifestyle changes.
- Use of cocaine
- The diet drug fenfluramine/phentermine, also known as "fen-phen".
- Living in high altitudes
Other conditions that contribute to the development of PH:
- Aortic valve disease
- Chronic obstructive pulmonary disease “COPD”
- Congenital heart disease
- Liver Cirrhosis: A disease that occurs when healthy cells in the liver are damaged and replaced by scar tissue, usually as a result of alcohol abuse or chronic hepatitis.
- Autoimmune Disease: A condition in which your immune system mistakenly attacks your body (e.g. lupus, rheumatoid arthritis and scleroderma).
- Mitral valve disease
- Pulmonary fibrosis
- Sickle Cell Disease: A condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body.
- Obstructive Sleep Apnea: A condition in which your breathing abruptly stops and starts while sleeping.
Symptoms of Pulmonary Hypertension
The signs and symptoms of pulmonary hypertension in its early stages might not be noticeable for months or even years. As the disease progresses, symptoms become worse and begin to show. Various symptoms include:
- Abdominal bloating
- Shortness of breath during routine activity
- Fatigue
- Heart palpitations
- Heart arrhythmias
- Chest pain
- Decreased appetite
- Pain in your right side of the abdomen.
- Rapid heart rate (tachycardia) of more than 100 beats per minute.
- Lightheadedness/Fainting
- Swelling in your ankles, legs and abdomen.
- Bluish lips or skin (cyanosis)
Diagnosis of Pulmonary Hypertension
Pulmonary hypertension is hard to diagnose early because it's not often detected in a routine physical exam. Even when the condition is more advanced, its signs and symptoms may be attributed to asthma or other lung or heart conditions.
A normal average pulmonary artery pressure is 10-20 mm Hg at rest. If the pressure in the pulmonary artery is greater than 25 mmHg at rest or 30 mmHg during physical activity, it is abnormally high. This is considered “pulmonary hypertension.”
To diagnose your condition, your doctor may review your medical and family history, discuss your signs and symptoms, and conduct a physical examination. After that, your doctor may recommend diagnostic tests. Some of the diagnostic tests and procedures include:
- Blood tests
- Magnetic resonance imaging (MRI)
- X-Rays
- Computed tomography (CT scan)
- Echocardiogram (ECHO)
- Electrocardiogram (EKG/ECG)
- Stress test
- Genetic testing
- Biopsy
- Pulmonary function tests
- Cardiac catherization
- Sleep study
- Lung scan
Classification of Pulmonary Hypertension
The cause of pulmonary hypertension is classified by the World Health Organization into five groups.
Group 1- Pulmonary Arterial Hypertension: This grouping is caused by:
- Certain drugs
- Conditions that affect veins and small blood vessels of the lungs.
- Congenital heart disease
- Autoimmune disease (e.g. lupus, rheumatoid arthritis and scleroderma) is a condition in which your immune system mistakenly attacks your body.
- Genetic tests
- HIV infection
- Liver disease
- Sickle cell disease
- Unknown cause
Group 2- Pulmonary Hypertension Caused by Left-Sided Heart Disease: This grouping is caused by:
- Aortic valve disease
- Cardiomyopathy
- Congestive heart failure
- Mitral valve disease
Group 3- Pulmonary Hypertension Caused by Lung Disease: This grouping is caused by:
- Chronic obstructive pulmonary disease (COPD)
- Interstitial lung disease
- Long-term exposure to high altitudes.
- Sleep apnea and other sleep disorders.
Group 4- Pulmonary Hypertension Caused by Chronic Blood Clots: This grouping is caused by:
- Chronic blood clots in the lungs or general clotting disorders.
Group 5- Pulmonary hypertension associated with other conditions that have unclear reasons why the pulmonary hypertension occurs: This grouping is caused by:
- Blood disorders such as polycythemia vera and essential thrombocythemia.
- Metabolic disorders such as thyroid and glycogen storage diseases.
- Systemic disorders such as sarcoidosis and vasculitis.
- Tumors pressing against pulmonary arteries.
Patients with pulmonary hypertension are normally classified into 4 symptom-based (functional) classes also described by the World Health Organization.
- Class I: Patients in this category show no limitation of physical activity. Ordinary physical activity does not cause fatigue, palpitation or shortness of breath.
- Class II: Patients in this category show slight limitation of physical activity. No symptoms at rest.
- Class III: Patients in this category show great limitation of physical activity. No symptoms at rest.
- Class IV: Patients in this category are unable to carry on any physical activity without discomfort. There are symptoms at rest.
The WHO group classes and the WHO functional classifications are not independent of each other. Your doctor will use them together to help decide your most appropriate treatment options.
Treatment of Pulmonary Hypertension
Although medical treatment can't cure pulmonary hypertension, it can lessen symptoms. Treatment options include:
Lifestyle Changes
- Avoid sitting in a hot tub or sauna or taking long hot baths or showers.
- Avoid smoking.
- Avoid traveling to or living at high altitudes.
- Exercise under the directions of your doctor.
- Eat a heart-healthy diet.
- If you’re overweight, talk to your doctor about weight-loss options.
- Make and keep appointments to see your doctor for routine check-ups and follow-up tests.
Medications
- Anti-arrhythmic medications will help control your heart’s rhythm.
- Beta blockers will help reduce your blood pressure.
- Diuretics “water pills” will help reduce the amount of fluid retention in your body.
- Endothelin receptor antagonists will help lower pulmonary pressures.
- Phosphodiesterase inhibitors will help the vessels produce natural vasodilators.
- Prostacyclins will serve as another type of vasodilator to help with the widening of the blood vessels.
- Soluble guanylate cyclase stimulators will help the vessels relax.