In last week’s video, I outlined how the heart and lungs ‘interact’ from an anatomy perspective. Today I’ll follow this up with some common examples I see each week in my practice, where a lung issue has caused a heart problem. Like a lot of conditions in my clinic, the thing they have in common is patients pitch up with the same symptoms despite different causes; in this case breathlessness. The trick then (and job satisfaction for me) is working out what the underlying problem is.
Last week a saw a man in his late 60s, referred to me by a respiratory consultant colleague. The patient had suffered clots on his lungs (called pulmonary emboli) out of the blue last autumn. Sometimes these clots have an underlying trigger – for example recent surgery, cancer or immobility, but sometimes there is no obvious cause (as in this case). If the clots are big, the pressure/resistance against which the right-hand side of the heart has to pump suddenly increases. The right ventricle is thinner-walled than the left, and runs as lower pressure, so it doesn’t like having to work harder. As a result, it enlarges (dilates), and this in turn can lead to a leaky valve, which in turn often leads to leg swelling. It was actually the leg swelling that prompted the referral to my heart failure clinic, yet it all stemmed from the original blood clots in the lung arteries. Thankfully often the right-heart goes back to normal size as the lung clots dissolve, but sometimes patients are left with permanently high blood pressure in the lungs, which we call pulmonary hypertension, and is a tough condition to treat effectively.
The last example was of a problem with the lung arteries, but much commoner, are diseases of the lungs themselves. There is a list of these as long as my arm, but includes things like COPD / asthma, bronchiectasis, and lung fibrosis. Many of these are chronic conditions, so whilst not so acute a presentation as a blood clot, the overall effect can be the same. Over many years, the right heart is exposed to increasingly high pressure. It doesn’t like this, and gradually gets larger, less efficient and ultimately fails. Part of the problem with treating this is that the problem has been so many years in the making, the changes are often irreversible. The medical term is ‘cor pulmonale’ (derived from the latin cor – heart and pulmo – lungs). Sadly I see this commonly in my heart failure clinic.
Allow me a little digression: occasionally I will see a patient with high lung pressures who I end up prescribing viagra for. Yes you read that right. I’ve had a few funny conversations about that with patients I can assure you! This all stems from the fact that viagra was originally developed as a heart drug. The aim was for a drug that lowered blood pressure, and in fact subsequently it has been found to specifically lower the pressure in the blood vessels in the lungs, making it useful in the treatment of some cases of pulmonary hypertension as I describe above. It’s effects to improve erections were found purely by chance. An astute nurse working on the original trial noticed that when she came to check on the male patients blood pressure, they were often lying on their stomachs. When she enquired why, she discovered many of them had embarrassingly got erections. This observation ultimately led to a multi-billion dollar drug for its makers Pfizer!