Pulmonary hypertension is high blood pressure in the arteries going to the lung. In healthy individuals, the blood pressure in these arteries is much lower than in the rest of the body. In a healthy individual, the blood pressure of the arteries going to the rest of the body is around 120/80 millimeters of mercury (mm Hg) and pulmonary artery blood pressure is about 25/10 mm Hg. If the pulmonary arterial pressure exceeds about 40/20 mm Hg or the average pressure exceeds 25 mm Hg, then pulmonary hypertension is present. If pulmonary hypertension persists or becomes very high, the right ventricle of the heart, which supplies blood to the pulmonary arteries, unable to pump effectively, and the person experiences symptoms that include shortness of breath, loss of energy, and oedema, which is a sign of right heart failure. Many diseases and conditions increase the pulmonary artery pressure.
Whom does it affect?
Epidemiology, prevalence, economic burden, vulnerable populations. The exact prevalence of all types of pulmonary hypertension in the USA and the world is not known. In Australia Pulmonary Hypertension is a relatively rare disease considered to be present in between 15 – 55 patients per million people of the general population in its rarest form of Pulmonary Arterial Hypertension (PAH). This has substantively increased from historical data suggesting only 1-2 patients per million in the general population. Pulmonary Hypertension is however more of an ‘umbrella’ disease encompassing more common forms of associated Pulmonary Hypertension affecting much larger numbers of patients. Recent Australian data suggests that pulmonary hypertension, in all its forms, may affect up to 5,000 people per million or 500 in every 100,000 people in Australia.
(Above information shared with you by the Pulmonary Hypertension Society Australia & NZ).
Higher Risk areas for Pulmonary Hypertension %
Causes of pulmonary arterial hypertension
Portal HT is pulmonary hypertension associated with liver disease.
CTD is connective tissue disease.
CHD is congenital heart disease.
(Chronic thromboembolic pulmonary hypertension was not part of this registry, CTEPH.) Blood clots in the lung or leg attribute about 3.5% source phaware.global (for more info on children and babies CLICK).
PAH Diagnoses Associated Pulmonary Arterial Hypertension
Familial (hereditary) 51%
Pulmonary Arterial Hypertension 3%
Idiopathic Pulmonary Arterial Hypertension 47% (cause is unknown).
PAH Associated With Other Diseases (APAH)
Portal HT 11% liver disease (such as autoimmune).
Drugs/Toxins 10% (such as diet pills / environmental, soils).
CHD 19% congenital heart disease (such as a hole in the heart).
CTD 50% connective tissue disease (such as scleroderma & lupus).
Most medical references are to left heart failure; pulmonary hypertension causes right heart failure and affects all races, genders and socio economic groups.
CLICK to go to Thoracic.org for a detailed article. Or read on for the PHWA adapted version. Reprinted from the Journal of the American College of Cardiology, Vol. 53. Issue 17, “ACCF/AHA 2009 Expert Consensus Document on Pulmonary Hypertension: A Report of the American College of Cardiology Foundation Task Force on Expert. Consensus Documents and the American Heart Association,” with permission from Elsevier.
The most common cause of pulmonary hypertension in the developing world today is Schistosomiasis, a parasitic infection in which the parasite's eggs can lodge in and obstruct the pulmonary arteries. Another risk factor for pulmonary hypertension is high altitude. More than 140 million persons worldwide live 10,000 feet or more above sea level. In African Americans, sickle cell anaemia is an important cause of pulmonary hypertension. A specific type of PH in which the disease process occurs in the pulmonary arteries themselves is called pulmonary arterial hypertension (PAH). This condition generally affects young and otherwise healthy individuals and strikes women twice as frequently as men. The average age of diagnosis is 36 years, and three-year survival after diagnosis is only about 50%. Each year, between 10 and 15 people per million population are diagnosed with the disease.
With improved treatments and survival, the number of USA patients living with the disease has increased to between 10,000 & 20,000.
Because so many disorders can result in severe pulmonary hypertension and treatments may vary dramatically, it is important for a thorough evaluation to occur when pulmonary hypertension is detected or suspected. For instance, pulmonary hypertension related to blood clots in the pulmonary arteries (pulmonary embolism and thromboembolic pulmonary hypertension) requires anti coagulation and, in some cases, surgical removal of the clots. Because about 250,000 cases of pulmonary embolism occur each year in the USA, thousands of patients are annually at risk of residual pulmonary hypertension from this disorder. The actual number is not easily determined because most cases of pulmonary embolism go undiagnosed.
What are we learning about pulmonary hypertension?
Pathophysiology, causes: genetic, environment, microbes
The last 20 years have witnessed an explosion of clinical and research advances in pulmonary arterial hypertension (PAH) that have resulted from better understanding of the mechanisms of the disease. A genetic cause of PAH was found by two groups in 2000, and it has led to research and increased understanding of the condition. Mutations in an oddly named receptor, bone morphogenetic protein receptor type 2 (BMPR2), are the cause of heritable PAH in over 85% of afflicted families.
BMPR2 mutations are found in about 10 to 20% of people with PAH who have no other family members with the disease. It is now known that multiple biological pathways lead to PAH, and, therefore, different drug treatments may ultimately benefit specific types of patients. In addition, PAH has been associated with connective tissue diseases (especially scleroderma), liver disease (portapulmonary hypertension), human immunodeficiency virus (HIV) infection, congenital heart disease, and stimulant drug ingestion. However, the most common type of PAH is idiopathic - with no known cause!
Little is known about the effect of the environment or microbes on pulmonary hypertension, although molecular mediators of inflammation interact with many molecules that affect changes in pulmonary blood vessels. Stimulants such as amphetamines, the erstwhile diet pill fenfluramine/phentermine (Fenphen), methamphetamine, and cocaine can cause or exacerbate pulmonary hypertension.
How is it prevented, treated, and managed?
Prevention, treatment, staying healthy, prognosis.
There is no way to prevent pulmonary hypertension, although drugs and toxins that cause or worsen the disease should be avoided. Because it is best detected and measured by echocardiography or right heart catheterisation tests that most patients do not undergo, pulmonary hypertension is generally not diagnosed until the disease is advanced and the right heart begins to fail. By then, the disease is usually incurable.
In some patients with pulmonary arterial hypertension (PAH), vasodilator drugs, such as calcium channel blockers, reduce pulmonary hypertension and improve quality of life. Unfortunately, only a minority of patients - less than 10% - benefit from this therapy. Also, PAH usually involves the accumulation of fibrous tissue in the pulmonary arteries, a problem not amenable to vasodilatation.
Understanding the physiology of the blood vessels in the lungs has led to the development and testing of several new classes of drugs. These drugs have vasodilator potential but also other beneficial characteristics, including platelet inhibition, anti-smooth muscle proliferation, and improved cardiac function. The overall survival of patients with idiopathic PAH has doubled with these drugs, and quality of life has markedly improved.
In addition to calcium channel blockers, three other classes of vasoactive drugs are used to treat pulmonary hypertension: endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and prostaglandins (of which prostacyclins is the most important). Endothelin receptor antagonists block the endothelin effects of vasoconstriction and smooth muscle growth.
Phosphodiesterase-5 inhibitors address the relative lack of nitric oxide in patients with PAH. Nitric oxide is a potent relaxant of the blood vessels. There are minimal side effects with this class and, similar to the endothelin receptor antagonists, these drugs are moderately effective in treating pulmonary hypertension.
The first fully effective treatment for PAH was the prostacyclin derivative Epoprostenol, which was approved in 1995. It has been shown to improve survival in this disease, but it has many side effects, like flushing, jaw pain, and nausea to name a few.
Although each of these classes of drugs is a major advance in the therapy of PAH, a proportion of patients will continue to worsen despite treatment with the best drugs. These patients may be candidates for lung transplantation or, very rarely, for a procedure called atrial septostomy, which creates a connection from the right side of the heart to the left side to allow blood to bypass the lungs.
Staying healthy with most forms of pulmonary hypertension can often be challenging. Patients must work with their healthcare team. Drug regimens often require frequent dosing and have many side effects. In addition, patients with heart failure are usually asked to follow a low salt diet and to limit the amount of liquids they drink daily.
Because patients with pulmonary hypertension cannot tolerate the stress of pregnancy, women of childbearing age are generally told not to get pregnant and encouraged to be sterilized. Patients whose pulmonary artery pressure significantly improves with a vasodilator have a much better prognosis.
Are we making a difference?
Research past, present, and future
The accurate diagnosis and effective management of pulmonary hypertension is a medical triumph made possible by the development of right heart catheterisation in the 1940's. In 1951, the entity "primary pulmonary hypertension" was accurately described. A major advance was the development of Doppler echocardiography, which allowed non-invasive images of the right ventricle and estimation of pulmonary artery pressure.
The discovery that calcium channel blockers improved quality of life but also doubled survival stimulated research into the development of other agents. The genetic revolution, funded by the National Institutes of Health and other agencies, led to the discovery of the genes responsible for heritable pulmonary hypertension and is leading to the identification of other genes that may permit or modify disease. These discoveries have resulted in more awareness of the intricate and complicated interactions of various cells and their metabolic pathways. The biological revolution in intracellular signalling and cell-to-cell communication has led to insights into the mechanisms of disease.
New drugs are being developed and tested for beneficial effects. Because of the hope engendered by these advances, patient and family-centred associations, such as the USA based Pulmonary Hypertension Association, have become forces for education, research, and service to people affected by pulmonary hypertension and professionals dedicated to defeating the disease.
What we need to cure or eliminate pulmonary hypertension?
Better tests are needed to make an early diagnosis. The tests should be convenient for screening and could identify persons at risk or give a measure of how severe the disease is. They could be in the form of genetic markers, which could identify risk, or of blood hormones or mediators, such as brain natriuretic peptide, that might rise with worsening disease. What is currently available, however does not adequately assess either risk of severity.
Further research will be needed to produce safer and more effective drugs that one day may be used in presymtpomatic patients at high risk for pulmonary hypertension, such as those with scleroderma or those who have family members with pulmonary hypertension. Although there is much more to be done, the future has never been brighter.
For article references and websites of interest see www.thoracic.org or go to phna.info/education/ph-puzzle for the complete article.
Pulmonary Hypertension by mechanism of disease
Due to left heart disease (Increased back pressure in the pulmonary vessels)
Decreases affecting the whole lung (lung diseases obliterate blood vessels)
Hypoxia Related (decreased oxygen constricts pulmonary blood vessels)
Pulmonary arterial hypertension (changes in the structure and function of the pulmonary arteries)
Primarily obstructing diseases of the pulmonary vessels
Classification Table for PH
Pulmonary arterial hypertension (PAH) represents Group 1 within the Pulmonary Hypertension World Health Organisation (WHO) clinical classification system (Dana Point 2008) and is one of five such groups. The groups are divided based on aetiology. The table below shows the classifications of pulmonary hypertension:
Group 1. Pulmonary arterial hypertension (PAH)
Group 1'. Pulmonary veno-occlusive disease (PVOD) and/or pulmonary capillary haemangiomatosis (PCH)
Group 2. Pulmonary hypertension due to left heart diseases
Group 3. Pulmonary hypertension due to lung diseases and/or hypoxemia
Group 4. Chronic thromboembolic pulmonary hypertension (CTEPH)
Group 5. PH with unclear multi factorial mechanisms
Haematological disorders: myeloproliferative disorders, splenectomy
One of the more common forms of PAH is idiopathic PAH (IPAH), which corresponds to sporadic disease in which there is neither a family history of PAH nor an identified risk factor.1 Heritable PAH (HPAH) accounts for at least 6% of cases of PAH2 and mutations in the bone morphogenetic protein receptor 2 (BMPR2) have been identified in the majority of cases.3
PAH is also a rare side effect of certain anorexigenic agents, such as fenfluramine.1,4 However, the incidence of drug-induced PAH related to fenfluramine is decreasing as these agents are no longer available.
PAH can also be associated with a number of other conditions (associated PAH, APAH), which together account for most other cases. These conditions include:1
Connective tissue diseases
Congenital heart disease
Chronic haemolytic anaemia (e.g. sickle cell disease)
PAH associated with connective tissue disease
PAH associated with HIV infection
PAH associated with portal hypertension
PAH associated with congenital heart disease
PAH associated with schistosomiasis
PAH associated with sickle cell disease(click to minimise)
Defining Pulmonary Hypertension
Causes, Symptoms & Diagnosis
Pulmonary hypertension (PH) is a severe lung condition that causes shortness of breath, chest pain, fatigue, and dizziness among other symptoms. It’s a disease that can affect anyone, at any age, although women are more prone to developing the condition.
Since pulmonary hypertension is a rare disease and its symptoms are very similar to other respiratory and lung diseases, patients are often misdiagnosed many times and doctors can take several years to get an accurate diagnosis of PH. Asthma, sleep apnea or COPD are some of the diseases that are usually diagnosed instead of pulmonary hypertension.
In this video from 2012 by UT Health Northeast, we find the renowned University of Texas Health Science Center pulmonologist Dr. Julie Philley briefly explaining pulmonary hypertension, defining PH, pointing to causes, symptoms, how to diagnose, and general differences between pulmonary hypertension and “regular” high blood pressure. She also acknowledges the existence of prior defects or illnesses that lead up to pulmonary hypertension and how properly treating those defects earlier may make PH “disappear”. But how is pulmonary hypertension diagnosed? Learn more about it here. Find out who is more at risk of developing pulmonary hypertension in this article.
Pulmonary Hypertension Definition:
The rare and severe lung disease called pulmonary hypertension (PH) affects the pulmonary arteries, causing high blood pressure. The pulmonary arteries transport the blood from the right heart ventricle to the lungs, but when affected by the disease, they become narrowed and thickened.
The hearts of patients with pulmonary hypertension need to work harder to properly pump the blood, which makes them enlarged, weakened and more susceptible to complications like right heart failure. It can also be related to some other diseases. Learn more about some of these diseases:
1. Lupus-Associated Pulmonary Hypertension: Lupus-associated pulmonary hypertension can be due to a number of issues. PH symptoms may involve left heart dysfunction, right heart dysfunction, inflammation of the small blood vessels in the lung, pulmonary embolism (blood clots) or irritation of the area around the air sacs. Each of these symptoms requires different treatments making lupus-associated PH more complex than PH on its own. (Read more about it here)
2. Pulmonary Hypertension and Sleep Apnea: Sleep apnea is a well-known contributor to the development of cardiovascular disease and pulmonary hypertension. This correlation happens because the disease increases the risk of hypertension, pulmonary vascular disease, ischemic heart disease, stroke, congestive heart failure and arrhythmias. (Read more about it here)
3. Scleroderma-Associated: PAH is a late complication of scleroderma (SSc) in 8-10% of cases. People with cutaneous scleroderma are at a greater risk of developing PAH than those with diffused cutaneous scleroderma. It so happens that the endothelial cells in the inner lining of the blood vessels are injured and the connective tissue is laid down inside the walls of these blood vessels. The time taken for the development of PAH in SSc patients varies between 5 to 10 years after the first onset of SSc symptoms. (Read more about it here)
4. COPD With Pulmonary Hypertension: Pulmonary hypertension is often a result of suffering from COPD and it is associated with increased risks of exacerbation and decreased survival. PH as a consequence of COPD can be mild-to-moderate and the combination of the two disorders can lead to a discouraging prognosis for patients, being the symptoms particularly worsened during exercise, sleep and exacerbation. (Read more about it here).
5. Pulmonary Hypertension And Lupus: Pulmonary hypertension and lupus are two very different conditions and pulmonary hypertension does not cause lupus. However, lupus may be able to cause pulmonary hypertension in a small range of patients, although the coexistence of the two diseases is very rare. Pulmonary hypertension and lupus is more common among female patients who are younger than traditional patients who suffer from PH. (Read more about it here)
6. Pulmonary Hypertension and Liver Transplant: Candidates for liver transplant or patients recently submitted for liver transplant are particularly at risk of suffering pulmonary hypertension for different reasons. Advanced liver disease or cirrhosis causes fibrosis and changes the actual architecture of the liver. Progression of the disease varies according to each patient, affecting other organs and tissues as well. (Read more about it here).
7. Pulmonary Hypertension and Hypoxia: Hypoxia is a condition that occurs when body tissues do not receive enough oxygen to properly function and it’s one of the diseases which can cause pulmonary hypertension. Due to the lack of oxygen, it is a life-threatening condition, which can result in damage not only to the heart and lungs, but also to the brain, liver and other organs. (Read more about it here)
8. Pulmonary Hypertension and Sarcoidosis: Sarcoidosis is an inflammatory disease and its signs include asymptomatic symptoms, systemic complaints, fever, dyspnea on exertion, cough, chest pain, hemoptysis, and Löfgren syndrome. The combination of the two diseases can occur in any patient, but it is more common among patients in an advanced stage. Restrictive lung physiology, hypoxemia, advanced Scadding chest X-ray stage, and low carbon monoxide diffusion capacity are important risk factors that impact the development of pulmonary hypertension in patients with sarcoidosis. (Read more about it here)
9. Pulmonary Hypertension and Cirrhosis: The development of pulmonary hypertension by patients with cirrhosis is usually related to portal hypertension, which is typical in patients with cirrhosis and can result in PH. Volume overload from sodium retention can be one of the causes for high pulmonary artery pressures. In addition, patients with cirrhosis can also develop pulmonary hypertension due to other reasons. (Read more about it here)
10. Pulmonary Hypertension and Fibrosis: Interstitial lung diseases, a group that includes pulmonary fibrosis, is one of the most common causes of pulmonary hypertension due to the damage it causes to the vessels and lungs. Pulmonary fibrosis is a condition that causes scarring in the lung tissue, making it more difficult for the organ to properly work. Similarly to pulmonary hypertension, there are numerous reasons that can cause it, and when not found, it is also termed idiopathic. (Read more about it here)
11. Pulmonary Hypertension and Ulcerative Colitis: Inflammatory bowel disease, and ulcerative colitis in particular, causes irritation in the digestive tract, which leads to diarrhea, often with blood or pus, abdominal pain and cramping, rectal pain or bleeding, difficulties in normally defecating, weight loss, fatigue and fever. In addition, the disease can also result in a variety of respiratory complications. (Read more about it here)
Are you phaware? Here are some facts about pulmonary hypertension that may surprise you...from phaware.global