Table of Contents
Definition of Pulmonary Hypertension
Elevated BLOOD PRESSURE in the PULMONARY ARTERIES and the arteries within the LUNGS. Pulmonary HYPERTENSION develops when the arteries in the lungs become stiff and narrowed, increasing the resistance BLOOD encounters in trying to flow through them. The condition typically starts in the smallest of arteries, the arterioles, and progressively involves larger arteries until pressure within the pulmonary arteries from the HEART also rises.
Elevated pressure within the pulmonary arteries increases the force the right ventricle must exert to pump blood from the heart to the lungs. Though early in the course of the condition the right ventricle can compensate by enlarging, eventually the increased workload can lead to right HEART FAILURE.
Doctors classify pulmonary hypertension, also called pulmonary arterial hypertension (PAH), as either secondary or primary. Secondary pulmonary hypertension develops as a complication of other health conditions, notably connective tissue disorders and chronic health conditions such as CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) and PULMONARY EMBOLISM. Because it follows other health conditions that become more likely with advancing age, secondary pulmonary hypertension tends to occur more frequently in people over age 60.
Causes of Pulmonary Hypertension
|CONDITIONS THAT CAN CAUSE PULMONARY HYPERTENSION|
|chronic hemolytic ANEMIA||CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)|
|COCAINE use||HEART FAILURE|
|OBSTRUCTIVE SLEEP APNEA||PULMONARY EMBOLISM|
|PULMONARY FIBROSIS||RHEUMATIC HEART DISEASE|
|scleroderma||SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)|
|VALVULAR HEART DISEASE|
Primary pulmonary hypertension (PPH) exists independently of other health conditions and is far less common than secondary pulmonary hypertension. Most often doctors do not know what causes PPH, though they believe in many people the condition is congenital (present at birth). Though systemic hypertension-what people think of as high blood pressure-may damage blood vessels throughout the body as well as damage the heart, pulmonary hypertension and systemic hypertension are different conditions. PPH can affect people of any age though is more common among people under age 50.
Symptoms and Diagnostic Path
The earliest symptom of pulmonary hypertension is shortness of breath (DYSPNEA), typically with exertion. As the condition progresses, symptoms may include fatigue, SYNCOPE (fainting), chest pressure or PAIN, peripheral edema (swelling of the lower legs, feet, wrists, and hands), ASCITES(fluid retention in the abdominal cavity), and PULMONARY EDEMA (fluid accumulation in the alveoli, or air sacs, in the lungs). Symptoms of advanced disease often include shortness of breath at rest, CYANOSIS (bluish hue to the SKIN and lips), and ARRHYTHMIA (abnormal HEART RATE).
The diagnostic path begins with ELECTROCARDIOGRAM (ECG), which reveals right ventricular hypertrophy (enlargement), and ECHOCARDIOGRAM, which shows the heart’s changed structure and function. The right ventricle typically enlarges and its walls thicken as the pulmonary hypertension begins to cause symptoms. Other diagnostic procedures may include MAGNETIC RESONANCE IMAGING (MRI) for additional visualization of the heart, PULMONARY FUNCTION TESTS to assess LUNG CAPACITY and the ability of the lungs to exchange oxygen and carbon dioxide, and CARDIAC CATHETERIZATIONto measure the pressure within the pulmonary arteries.
Treatment Options and Outlook
Doctors may prescribe medications such as vasodilators and calcium channel blockers to help relax the arteries in the lungs and lower resistance to the flow of blood, anticoagulant medications to lower the risk for blood clots, and diuretics (“water pills”) to reduce edema. Research suggests that many people who have pulmonary hypertension have elevated levels of endothelin, an amino acid compound (peptide) naturally present in the walls of the arteries that causes them to constrict. Whether this elevation is a consequence or cause of pulmonary hypertension remains unclear, though its recognition has resulted in the development of medications called endothelin receptor antagonists. These medications relieve the symptoms of pulmonary hypertension by relaxing the walls of the arteries in the lungs. Oxygen therapy can improve the amount of oxygen that enters the blood circulation.
Treatment targets the underlying cause, to the extent possible, when pulmonary hypertension is secondary, as well as aims to lower pulmonary blood pressure. However, any damage that occurs to the heart is generally irreversible. PPH is progressive and as yet there is no curative treatment. Early diagnosis and medications can slow PPH’s progression and improve QUALITY OF LIFE.
Lifestyle modifications, such as WEIGHT LOSS AND WEIGHT MANAGEMENT, SMOKING CESSATION, and regular physical activity within the capacity the person’s cardiovascular function allows, help keep the cardiovascular system functioning as efficiently as possible. LUNG TRANSPLANTATION may be a treatment option for younger people when PPH is the only significant health condition. People who also have severe heart failure may benefit from a combined heart-lung transplantation. These are complex operations, however, and donor organs are extremely limited.
Risk Factors and Preventive Measures
The risk factors for secondary pulmonary hypertension are the conditions that may cause it. Early diagnosis and appropriate treatment for these conditions helps prevent pulmonary hypertension from developing. Because doctors do not know what causes PPH, they cannot identify clear risk factors.