Other AreasFen-Phen
Health RisksPPH Info
What is Primary Pulmonary Hypertension?
Primary Pulmonary Hypertension or PPH is a pulmonary disease that involves significantly elevated pressures in the pulmonary arteries when no cardio-pulmonary, or other, disease or dysfunction has been identified or diagnosed as the cause of the elevated pressures. [If such a disease or dysfunction is identified as the cause, then the pulmonary hypertension is not classified as primary but rather as secondary.]
An increase in the pressures within the pulmonary arteries places an increased workload on the right side of the heart. That is, the right ventricle and the right atrium are forced to work harder to overcome the increased blood-flow resistance created by the abnormally high pressure in the pulmonary arteries. As a result, the right side of the heart becomes enlarged - oftentimes, as the disease progresses, leading to congestive heart failure.
What are the Symptoms of PPH?
The initial and most common symptom of PPH is shortness of breath that often progresses to dyspnea (breathing with marked difficulty) and occasional hyperventilation. Additional symptoms include:
- fatigue;
- light-headedness;
- dizziness;
- fainting;
- chest pain;
- general physical weakness;
- edema (fluid retention) of the extremities.
What are some of the Clinical Effects of PPH?
Increased pressure in the pulmonary arteries results from a progressive narrowing of the pulmonary arterioles - the smaller branches of the main pulmonary arteries. One direct effect of these abnormally elevated pressures is blood leakage from the pulmonary vessels. A blood-producing cough is oftentimes an indicator of leakage from the pulmonary vessels.
The increased pressures in the pulmonary arteries and arterioles can trigger a cyclical chain of adverse events beginning with a decrease in the blood's oxygen content. The body then responds to this low oxygen content by increasing its production of red blood cells. This is known as polycythemia. By doing so, the body attempts to compensate for the blood's low oxygen content by increasing the number of oxygen carriers, i.e. the red blood cells. As the red blood cell count increases, the blood thickens, making the heart (already under increased stress from the elevated pressures) work that much harder to pump the thicker blood throughout the body. This further increases arterial pressures and can lead to congestive heart failure.
How is PPH Diagnosed?
To diagnose Primary Pulmonary Hypertension, the attending physician will conduct a series of tests designed to rule out all known and identifiable afflictions that can cause pulmonary hypertension. If such an affliction is diagnosed, the pulmonary hypertension is characterized (and diagnosed) not a primary, but rather as secondary to the affliction. If such a known and identifiable affliction is absent, the pulmonary hypertension is then diagnosed as primary.
Consequently, a diagnosis of PPH is made based on a finding of:
- pulmonary arterial pressures >25mmHg at rest or >30mmHg with exercise; and
- the absence of significant:
- parenchymal lung disease;
- chronic thromboembolic disease;
- left-sided valvular or myocardial disease;
- congenital heart disease;
- systemic connective tissue disease (such as lupus);
- sleep apnea. **
[**Based on criteria established by the National Institutes of Health]
What common Diagnostic Tests are used to Confirm Suspected PPH?
The most common test performed in an effort to confirm a diagnosis of suspected PPH are:
- Pulmonary Function Tests (to measure and evaluate lung function);
- Connective Tissue Serology (to rule out systemic connective tissue disease);
- Echocardiogram (to measure and evaluate cardiac function);
- Cardiac Catheterization (to measure and evaluate cardiac function);
- Perfusion Lung Scans (to rule out thromboembolic disease);
- Pulmonary Angiography (to rule out the presence of clots and other blockages in the lungs).
