Pulmonary Hypertension

High blood pressure that affects the arteries that supply the lung is called Pulmonary Hypertension.  This is a serious condition that progressively worsens and can lead to right heart failure and death.  

Causes

Normally the heart has a right and left side. The right side is usually a low pressure area and the blood is pumped from the right heart to the pulmonary blood vessels.  This blood is taken to the alveoli by the small pulmonary blood vessels.  Oxygen and carbon dioxide exchange takes place in the alveoli.  Purified blood is returned to the left side of the heart to supply different parts of the body.  In Pulmonary Hypertension, pressure in the pulmonary blood vessels is increased. These blood vessels can narrow and cause insufficient gas exchange.

There are two types of Pulmonary Hypertension:

1) Primary or idiopathic pulmonary hypertension.   This is a condition where no cause can be found for pulmonary hypertension.  It is genetic and more females are affected than males.

2)  Secondary pulmonary hypertension- has many causes.

a) COPD (Chronic obstructive pulmonary disease), emphysema

b) Pulmonary emboli or clot in the lung

c) Sleep apnea- where carbon dioxide level is elevated

d) Congenital heart diseases

e) Cirrhosis

f) Pulmonary disease- like fibrosis

g) Left sided heart failure

h) High altitudes

i) stimulants- such as cocaine

j) HIV

Symptoms 

Chest pain, usually in the front of the chest, fatigue, fainting or weakness, dizziness, exercise intolerance, and shortness of breath

There can be four classifications:

1)      Diagnosed with  no symptoms

2)      No symptoms at rest- but fatigue and shortness of breath on activity

3)      Comfortable at rest but has symptoms with exercise

4)      Symptoms at rest

Diagnosis

• History,

• Physical examination can show abnormal heart sounds, such as a split second heart sounds, neck vein enlargement, leg swelling, enlarged liver and spleen, and shortness of breath in advanced cases. Breath sounds may be normal.

• Chest x-ray may show right ventricular enlargement. 

• Cat scan of the chest,

• EKG,

• Echocardiography

• Nuclear scan of the lung

• Cardiac catheterization- right heart and pulmonary artery pressure can be directly measured by this

• Pulmonary arteriogram

• Pulmonary function tests

• Genetic testing

Treatment

There is no known cure.  The goal of treatment is to control symptoms.  If cause of high blood pressure is known- treat the cause.

 Treatment needs to be done in highly specialized centers. 

 Drugs used:

1)   Vasodilators-

a.      Epoprostenol- it is a short acting drug, given as continuous IV injection. Side effects include diarrhea, leg cramps and pain at injection site.

b.     Iloprost- also a vasodilator which can be inhaled via vaporizer. Side effects include chest pain, headache and shortness of breathe

2)      Endothelin receptor antagonist-  Endothelin is a substance which causes blood vessels to constrict.  Endothelin receptor antagonist blocks this action

a.      Bonsentan

3)      Sildenafil- causes pulmonary blood vessels to dilate

4)      Calcium channel blockers- these relax the muscles of the blood vessels, leading to blood vessel dilatation

a.      Diltiazem, nefidipine, and amlodipine

5)      Ambrisentan- stops narrowing of blood vessels. Side effects include serious liver damage

Anticoagulants are used in these patients to prevent clot formation.  Diuretics decrease the work of the heart by eliminating excess fluid.  Supplemental oxygen is used when necessary.  

Lifestyle changes that help these patients include plenty of rest, moderate exercise, avoid smoking, avoid pregnancy, and maintain healthy weight and diet.

Complications

Right heart failure, blood clots, arrthymias, bleedings which may lead to hemoptysis.

Prognosis

Prognosis is very poor and can progress to heart failure and death.