Pulmonary Hypertension: Explained!
Pulmonary hypertension is a disorder where the pressure in the lung is increased.
When a cause for pulmonary hypertension cannot be found it is termed primary pulmonary hypertension. When the cause is found, it is termed secondary pulmonary hypertension.
Pulmonary hypertension is a serious disorder and once it develops there is no cure for it. Overall, secondary pulmonary hypertension is far more common than primary pulmonary hypertension.
What Is Pulmonary Hypertension?
Pulmonary hypertension is said to occur when the pressure in the lung blood vessels increases. It initially affects the right side of the heart but if not treated, pulmonary hypertension can affect many other organs.
In normal circumstances, blood from the right side of the heart is pumped to the lungs, where it is oxygenated. The pressure in blood vessels in normal lungs is very low at 2-4 mmHg. When the blood vessels in the lungs become narrowed or blocked, the right side of the heart is not able to pump blood to the lungs. Consequently the patient is not able to oxygenate the blood.
With time, the right side of the heart has to work a lot harder to pump the blood into the lung and eventually it fails. Unlike the left side of the heart, the right side of the heart is not meant for stressful and heavy work.
In general, pulmonary hypertension from whatever cause is a serious problem which, in most cases, cannot be cured.
With time, most patients affected by pulmonary hypertension become fatigued and short of breath. The earlier treatment is sought, the better the quality of life going forward.
To be cured, a heart and lung transplant would be required. However, with a shortage of organ donors, the majority of patients succumb to an early death.
What Are The Different Types Of Pulmonary Hypertension?
It is important to know the difference between primary and secondary pulmonary hypertension. Primary pulmonary hypertension is said to be present when no cause is ever found. This disorder is typically seen in women in the 3rd of 4th decade of life and has a very poor prognosis.
Secondary pulmonary hypertension is said to be present when there is cause for it. For example a patient who smokes can develop emphysema, which can later in life cause secondary pulmonary hypertension. In this scenarios, treatment is directed at emphysema and smoking. It has a slightly better prognosis that primary pulmonary hypertension.
Other causes of secondary pulmonary hypertension include AIDS, lupus, and sarcoidosis.
Pulmonary arterial hypertension is an older term used to describe secondary pulmonary hypertension.
What Are Symptoms Of Pulmonary Hypertension?
In the early stage, pulmonary hypertension usually does not present with any symptoms. In some cases, the individual may be free of symptoms for months or even years. However, as the disorder progresses, most patients will become symptomatic.
The typical symptoms of the disorder include the following:
- Bluish tinge to the skin and lips
- Chest discomfort or pain
- Dizziness or fainting spells
- Extreme fatigue
- Shortness of breath which initially only occurs during physical activity but later may even occur at rest.
- The pulse or heart rate may often be racing or one may sense palpitations.
- The ankles and legs may become swollen.
- The abdomen usually appears distended because of accumulation of fluid.
Individuals who develop the above symptoms should make an effort to see the doctor. In most cases, the symptoms of pulmonary hypertension develop slowly but when they develop, it usually means that the disorder has progressed significantly.
How Does Pulmonary Hypertension Develop?
The right side of the heart pumps blood to the lungs, where it can be oxygenated. The right side of the heart is much weaker than the left side and is not used to working under high pressure. Normally, the pressure in the blood vessels of the lung is only 2-5 mmHg, so the right side of the heart only needs minimal pressure to push the blood into these vessels.
If for any reason the lung blood vessels get narrowed, lose their elasticity or become blocked, then the right heart cannot pump blood to the lungs. Thus, the blood cannot be oxygenated. Further, since the right heart has to work harder to pump the blood against resistance, it eventually fails.
When the right heart fails, blood starts to back up in the body. The abdomen starts to swell; the liver starts to enlarge and there is swelling of the feet and ankles. Plus because the body is not able to get oxygenated blood, there is a blush tinge of the skin and lips.
Without oxygen, most people have little exercise endurance and remain fatigued and short of breath.
What Are Causes Of Pulmonary Hypertension?
There is no known cause of primary pulmonary hypertension, but there are several causes of secondary pulmonary hypertension. These include:
- Genetic or familial
- Use of certain drugs – the most well known is fenfluramine, which is no longer on the market.
- Heart defects at birth
- Disorders like scleroderma, liver disease, lupus or HIV infection
- Lung disease like emphysema, interstitial fibrosis
- Sleep apnea
- Living at high altitudes
- Presence of blood clots in the lung
Irrespective of the cause, pulmonary hypertension is a serious disorder that needs treatment.
Who Is At Risk Of Developing Pulmonary Hypertension?
In general, people with a certain lifestyle are at a high risk for developing pulmonary hypertension. This includes individuals who are obese, smoke or use illicit drugs.
Other risk factors include having a family history of the disorder or living at high altitude.
When the cause is lifestyle related, the earlier the lifestyle is changed, the better the prognosis.
What Are Complications Of Pulmonary Hypertension?
The disorder can results in:
- Right heart failure because the right side of the heart can no longer pump blood into the lungs.
- Abnormal heart rate and rhythms that can cause palpitations, fainting or dizzy spells
- Coughing up blood, which can be massive.
- Fatigue and shortness of breath
Once the complications of pulmonary hypertension develop, the quality of life is poor. These people are often fatigued, unable to perform any type of physical activity or even accomplish any daily living activity like dressing, bathing or shopping. The shortness of breath can be so severe that it often occurs at rest.
How Is The Diagnosis Of Pulmonary Hypertension Made?
The diagnosis of pulmonary hypertension is difficult to make because often there are no obvious signs on a physical exam. Even the symptoms are not specific and are often confused with other lung and heart disorders. To confirm the diagnosis the patient will usually undergo a number of tests that include:
- An echocardiogram, which uses sound waves to assess the structure and heart function.
- Chest x-ray to look at the size of your heart and blood vessels of the lung
- ECG to look for abnormal heart rate and rhythm
- Right heart angiogram, which includes injecting a dye into the right heart and lungs. In this test the doctor can also measure pressure in your lungs.
Other tests depend on your symptoms and may include a CT scan, lung function tests, sleep study, MRI and a lung biopsy.
If a familial cause is suspected, a genetic test may be ordered.
How Is Pulmonary Hypertension Treated?
There is no cure for pulmonary hypertension. Once a diagnosis is made the disease is staged based on its severity. The treatment then depends on the stage and symptoms.
All current treatments are aimed at reducing the symptoms and slowing the progress of the disease. There are several drugs that are used to open up blood vessels and some have to be administered via an intravenous drip. The downside of these drugs is that they only work for short period, have side effects and are expensive.
If the drugs fail, a heart and lung transplant is the only other option.
What Are Survival Rates For Pulmonary Hypertension?
The survival rates of people with pulmonary hypertension are poor. Once the diagnosis is made, only 70% of sufferers survive beyond 12 months and this falls to 30% after 5 years.
People with a chronic disorder like lupus or sarcoidosis who develop secondary pulmonary hypertension also have a poor prognosis; only 40% being alive at the end of 2 years.