An unexpectedly large number of patients who survive a blood clot in the lungs develop a potentially dangerous high blood pressure in the pulmonary artery researchers report. Finding show that pulmonary hypertension occurs far more frequently than expected.
Pulmonary embolism, a blockage of an artery in the lungs, strikes an estimated 600,000 Americans every year and causes approximately 60,000 deaths. It is, in fact, one of the leading causes of sudden death in this country.
Pulmonary hypertension, on the other hand, is a condition that can strain the heart, which must work harder to push blood through the lungs, but one that is often ignored because it causes few or no symptoms in many patients.
It has been thought that only a few of those who survive a pulmonary embolism go on to develop pulmonary hypertension -- one in 1,000 at most. But the incidence amount of those patients studied (223) was much higher says a report in an issue of the New England Journal of Medicine.
At six months, 1 percent of patients had pulmonary hypertension. That increased to 3.1 percent after one year and 3.8 percent after two years. Hypertension generally developse slowly after a pulmonary embolism. There is "a honeymoon period" of a few months, and then the incidence begins to increase.
The condition can be caused by lung disease, by failure of the left side of the heart or by a congenital heart disorder such as a faulty valve. In a small number of cases, usually involving young women, there is no apparent cause.
These often are difficult to diagnose and have treatments that are quite different. For example, if the cause is a bad heart valve, surgery is done to replace the valve. If the cause is lung disease, treatment is aimed at correcting the lung condition.
When the cause is a plmonary embolism, an effective treatment is endarterectomy, surgery to removed the clots that are blocking the artery. The technique was developed at the University of California, San Diego, and is now widely used.
Often, the only warning sign of pulmonary hypertension is shortness of breath. And how often is that ignored