Pulmonary Hypertension

Pulmonary hypertension is a type of high blood pressure. It affects the arteries in the lungs and right side of the heart. In this type, the arteries in the lungs become narrowed. As a result, your heart has to work hard to pump blood through the arteries of lungs. It affects the pulmonary circulation that conducts blood from the right side of the heart through the lungs. In lungs, the pulmonary arterial pressure is 20/8mmHg and the mean pulmonary arterial pressure is 12-15mmHg. The mean pulmonary arterial pressure causes variations during rest or exercise. It may increase up to 25mmHg during rest or 30mmHg during exercise. Another term used in pulmonary hypertension is pulmonary vascular resistance. It is the measure of obstacle in the pulmonary blood vessels. Heart failure is most common as a result of pulmonary hypertension. It is more common in females. It can develop in any age but the chance increases with increasing age.

Symptoms

The signs and symptoms of pulmonary hypertension includes,

• Chest pain
• Palpitations
• Dyspnea (shortness of breath)
• Exercise intolerance
• Hoarseness of voice
• Fatigue
• Cough
• Dizziness
• Syncope ( loss of consciousness due to decrease in blood pressure)
• Cyanosis (bluish discoloration of lips and nails)
• Loss of appetite
• Pain in the upper abdomen
• Hemoptysis

Causes

Pulmonary hypertension is caused by high blood pressure in the lungs arteries. This pressure is increased due to any congenital heart disease, coronary heart disease, hypertension, cirrhosis and blood clots. Genetics also play a role in the development of pulmonary hypertension.

Treatment

There is no treatment available for pulmonary hypertension. The general medicines used are,

Calcium channel blockers

They are well tolerated especially for elderly patients and those with ischemic heart disease or diabetes. They protect the heart tissue by inhibiting the entry of calcium into cardiac and smooth muscles. All calcium channels blockers are arteriolar vasodilators. They cause a decrease in smooth muscle tone and peripheral vascular resistance. There are two main types of calcium channel blockers, dihydropyridines and non dihydropyridines. Dihydropyridines include amlodipine, felodipine and nifedipine. Non dihydropyridine calcium channel blockers include diltiazem and verapamil. Due to negative inotropic effects, verapamil should be avoided in pulmonary hypertension.

Prostacyclins

It improves the rate of survival, quality of life and exercise tolerance. It is a vasodilator with anti-proliferative effects. Prostacyclins should be given because the production of prostaglandins or prostacyclins is inadequate in pulmonary hypertension. Drugs included epoprostenol, iloprost and treprostinil.

Diuretics

They are cheap and effective for the management of high blood pressure. They are more effective in older patients and resistant hypertension. There are two main types of diuretics, loop and thiazide. Drugs included are bendroflumethiazide, spironolactone and furosemide.

Anti-coagulants

Heparin causes inactivation of blood clotting factors. It also inhibits conversion of fibrinogen into fibrin & prothrombin to thrombin. In anticoagulants, warfarin and pentasaachrides are also used for the treatment of pulmonary hypertension. Pentasaachrides are more potent anti-thrombotic agent.

Digoxin

It is used in the treatment of congestive heart failure and arrhythmias. It strengthens the contraction of your heart muscles. It is very effective in lowering your heart rate.

Oxygen therapy

This therapy plays a vital role in the treatment of pulmonary hypertension. Oxygen acts as a vasodilator. It helps in the relaxation of arteries in the lungs and reduces pressure in these arteries. 

Endothelin receptor antagonists

Endothelin receptor antagonists are used in the treatment of pulmonary hypertension. They have the ability to reverse the damage of the heart and lungs. They can also slow down the progression of disease. Drugs used are bosentan, ambrisentan and macitentan.

Soluble guanylate cyclase stimulators

They are a type of targeted therapy. They slow down the progression of pulmonary hypertension. Drug used is riociguat.