Pulmonary hypertension (PH) is a serious, progressive disease in which there is elevated blood pressure in the pulmonary arteries. The blood flow from the heart to the lungs is disrupted due to constriction in blood vessels. This causes extra load on heart pumping blood to the lungs, eventually leading to weakness of heart muscles. The supply of oxygenated blood to the tissues and other organs is diminished leading to various symptoms. Normal pressures in pulmonary arteries are 15-30 mm Hg systolic pressure and 4-12 mm Hg diastolic pressure. If the pressure is greater than 30/12 mm Hg, then it is known as pulmonary hypertension.
Causes of Pulmonary Hypertension
The different causes of pulmonary hypertension include idiopathic causes, genetic disorder, rheumatoid arthritis, lupus, scleroderma, CREST syndrome, liver diseases, atrial and ventricular septal defects, sickle cell disease, HIV infection, schistosomiasis, It is also be caused by certain drugs such as diet pills (fenfluramine and dexfenfluramine) and recreational drugs. Other causes include chronic obstructive pulmonary disease (COPD), emphysema, pulmonary fibrosis (interstitial lung diseases) and sleep apnea. In addition, it can also be caused by pulmonary emboli, mitral valve disease, chronic systemic elevated blood pressure, polycythemia vera, thrombocythemia, thyroid diseases, glycogen storage disease, sarcoidosis, vasculitis, kidney diseases and other conditions including tumors.
Pulmonary hypertension is more prevalent in females than in males in age group of 30 to 40.
Symptoms of Pulmonary Hypertension
The symptoms of secondary pulmonary hypertension arise due to increased pressure in the pulmonary arteries, leading to constriction of blood vessels. This in turn creates excess stress to heart muscles ultimately leading to weakness of heart muscles with time. The common symptoms of secondary pulmonary hypertension are fatigue, difficulty breathing and dizziness. Other symptoms include rapid breathing, exertional shortness of breath (dyspnea), chest pain, anxiety, lower extremity swelling, tachycardia, distention of jugular vein, ascites (fluid collection in the abdomen), and clubbing of fingers. In addition, severe pulmonary hypertension may also lead to heart failure.
What is the Prognosis of Pulmonary Hypertension?
Unfortunately, even with advancement in medical field there is no permanent treatment for PH. Medications, lifestyle changes, and proper management can only slow the progression of disease. The prognosis of the disease is very poor, if it is left untreated the patient dies within 3 years of diagnosis. If the patient is in low risk group then the patient can live for over 10 years. The death of PH patient occurs due to right ventricular failure in most cases. The survival rate of the patient with pulmonary hypertension depends on the etiology. Data recovered from a large group of patients in early 2000s reveal, overall, one year survival rate as 85%, three year survival rate as 68%, five year survival rate as 57% and seven year survival rate as 49%.
The data also revealed that the prognosis is poor for patients whose etiology includes genetic disorder, connective tissue disorder or related to liver disease as compared to congenital heart disease. Poor prognosis is seen in patients with pericardial effusion as compared to patients who do not have pericardial effusion. The prognosis is poor in patients whose exercise capacity and distance covered in a six-minute walk is less as compared to patients who have greater six-minute walk distance. The prognosis is also worse for patients who have very high right atrial pressure and pulmonary vascular resistance as compared to patients who have low values of them. Patients with impaired kidney function and elevated levels of BNP (Brain Natriuretic Peptide) have a very poor prognosis too as compared to patients who have normal kidney function or who have low BNP. The mortality rate is also high in pregnant women.
However, the survival rates of patients with pulmonary hypertension has drastically improved with the advent of medications and improved quality of life. It was not until 1994, the first medication (Flolan) was introduced for the management of pulmonary hypertension and in the past two decades, there have been several medications available in the market. Hopefully, with more research and studies the survival rate and prognosis of patients with PH will continue to improve.
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