Pulmonary hypertension (PH) is a very complex disease difficult to diagnose and treat. Despite many advances in the last 20 years, and 9 medications being available to treat, average life expectancy is only 7 years according to Pulmonaryhypertension.com website. PH is defined as an increase of blood pressure in the pulmonary vessels leading to shortness of breath, fainting, leg swelling or dizziness. Patient manifest markedly decreased exercise tolerance over many months. If not treated, it can lead to heart failure.
PH may be rare in the general population but is much more common in cardiology practice. According to PAH-info.com, the estimated prevalence is 15-50 cases per million. Prevalence in certain risk group is much higher. Sometimes a routine echocardiogram can reveal PH requiring full workup to find out the cause.
Initial pathology involves stiffening of blood vessels connected to and within lungs. This makes it harder for the heart to pump blood through the lung, much as it is harder to make water flow through a kinked water hose. Over time increased workload causes right heart enlargement and failure. Less blood is pumped to the left side causing left ventricular failure.
PH presents in a very subtle manner; its diagnosis requires a higher index of suspicion. Most commonly patient has shortness of breath on exertion which progressively gets worse overtime. Sometimes this might be the only symptom present. Other symptoms include chest pain, syncope, lethargy and leg swelling.
Etiology of PH can be far and wide. It can be from being unknown to congenital heart defect, collagen vascular disease like scleroderma or lupus, left heart disease due to lung problems like chronic obstructive pulmonary disease and sleep apnea. PH can also be due to left ventricular failure, Valvular heart disease, pulmonary thrombus or embolus. Sometimes physical examination can yield important information about possible etiology of the disorder. For example, clubbing or cyanotic fingernails mean congenital heart disease or interstitial lung disease.
Transthoracic Echocardiogram (TE) with Doppler is most common test used to diagnose PH. It is used to estimate the right ventricular systolic pressure (RVSP). Electrocardiogram can show right or left atrial or ventricular enlargement. Sleep study can diagnose obstructive sleep apnea and chronic hypoxia.
The management of PH should aim to handle vasodilatation of the pulmonary arteries, treat right ventricular failure, improve functional capacity and quality of life and improve survival. The patient may require oxygen, water pill, digoxin and blood thinner. Only three therapies associated with mortality benefits are blood thinner, calcium channel blocker and Epoprostenol. Only Epoprostenol has been shown to improve survival in a prospective, randomised trial.
Sometimes patient requires combination of medications in order to treat severe cases. Six minute walk tests, echocardiogram and right heart catheterisation are used in follow up of patients. They are not allowed to lift more than 25 pounds. Low level cardiovascular aerobic exercise is encouraged to prevent deconditioning. Bilateral lung or heart-lung transplantation is the last option. Cause of death is usually progressive right heart failure or sudden death.
PH is a serious illness that becomes progressively worse and is sometimes fatal. Although PH is not curable, treatment is available that can help lessen the symptom and improve quality of life.