Chronic PE (Primary Pulmonary Hypertension)

00:02 What's the clinical presentation of somebody with primary pulmonary hypertension? Well, the clinical presentation is dependent on the cause, so for example, somebody with primary pulmonary hypertension will tend to be a younger woman, whereas multiple PEs could be any age and sex and they could have history of previous PEs and known risk factors or may not, or there could be a family history of hypercoagulability. The clinical effects though are similar, which is progressive dyspnoea over weeks or months. So the patient will say “I'm breathless on exertion, I can't walk as far as I used to walk and that ability to walk is getting worse over time”. And that's a very similar presentation to patients with COPD, interstitial lung disease, and cardiac failure. Then maybe, if somebody is having multiple PEs, occasional episode of pleuritic chest pain or haemoptysis that might suggest it's a PE but actually in most patients, it's just breathlessness, which is the main symptom.

01:00 When you examine somebody with pulmonary hypertension or chronic PEs, they could be cyanosed, but there aren't many signs that you can pick up when you listen to the lungs, in fact, usually there's nothing. They may have signs of pulmonary hypertension and they may have signs of decompensated right heart failure with a raised JVP, ankle oedema, etc. but only when the disease is really quite marked. So as I said, if you got clinical signs of pulmonary hypertension there's a raised JVP, a loud pulmonary component of the second heart sound, a right ventricular heave, a right ventricular third and fourth heart sound.

01:38 But these are actually very difficult clinical signs to be sure about, and a raised JVP could occur for other reasons as well. Very severe pulmonary hypertension will lead to tricuspid regurgitation, as dilatation in the right ventricle will make the valve area larger, and basically pull the valve leaves apart, and that will occur with pansystolic murmur at the left sternal edge, V waves in the JVP, which are a very obvious one and occasionally pulsatile hepatomegaly. As I mentioned before, if you have bad right-sided heart failure the patient has peripheral oedema, could have ascites, could have pleural effusions.

02:17 The problem about all those clinical signs is that they are very nonspecific and difficult, so you need to think about pulmonary hypertension or chronic PEs as a cause in patients presenting with what could be right-sided heart failure by itself.

02:34 Confirming the presence of pulmonary hypertension, again is not straightforward, the chest X ray could show oligaemic lung fields, that means the blood vessels are less distinct than normal but that’s a very subtle sign. Occasionally you get an X ray like we have here as an example where the pulmonary arteries are very large indeed, and that's much more obvious that the patient will have pulmonary hypertension. But unfortunately, that's not that common. A CT scan may show enlarged pulmonary arteries and it’s a more sensitive way of identifying those, but again it’s not a particularly good way of identifying the presence of pulmonary hypertension.

03:10 VQ scan may be abnormal if they have multiple PEs due to the mismatched perfusion ventilation defects we discussed before, but importantly patients with pulmonary hypertension will have right heart problems and therefore the tests that you really need to use to identify pulmonary hypertension are looking at the right heart. So an ECG shows right heart strain, T wave inversions V1-V3 right axis deviation. An echocardiogram will show right ventricular hypertrophy and dilatation, and if there's a little bit tricuspid regurgitation, they can measure the pulmonary artery pressure and actually give you a record of what the pressure is and therefore confirm the presence of pulmonary hypertension or not.

03:58 Lung function tests as we discussed earlier, the volumes in spirometry do not change in patients with pulmonary hypertension by itself, but the retransfer factor is reduced due to the decreased blood flow to the lung. So a transfer factor along with the echocardiogram are the very useful tests for identifying patients with pulmonary hypertension.

04:20 And pulmonary invasive angiography is reserved for those cases with clear-cut pulmonary hypertension or younger patients where it's not clear what's going on, and you really need to identify the disease. It's also used as a way of identifying causes of pulmonary hypertension and their response to treatment, but it's a very specialized test, that's used by specialized centers in general. If you identify somebody who has pulmonary hypertension, you're then next to identify, why they have pulmonary hypertension. Now the common causes are chronic PEs, lung disease, and cardiac disease, so the test that you need to identify those are CT pulmonary angiogram or a VQ scan for the PEs, an echocardiogram, which as well as identifying the presence of right ventricular hypertrophy, and pulmonary hypertension can also look for left-sided disease that might be the cause of that pulmonary hypertension. And lung function tests, which again the transfer factor will reflect the pulmonary hypertension, but if that patient has significant lung disease, COPD, interstitial lung disease or even chest wall restriction, then the lung volumes in spirometry will be abnormal. I mentioned already that invasive pulmonary angiography can give very distinctive appearances which will suggest chronic-embolic disease or primary pulmonary hypertension and that's used by specialized centers to make the diagnosis of the cause. And there are various blood tests that could be used to identify patients with autoimmune diseases, HIV and sickle-cell disease, schistosomiasis etc.

05:56 We actually frequently use sleep studies as well because obstructive sleep apnea, obesity hyperventilation, nocturnal hypoxia due to chronic lung disease are frequently common causes of pulmonary for hypertension.