Heart Matters

The human heart is a tough and reliable machine

For obvious reasons, dependable power plants are pretty important in aviation. Modern commercial turbine motors are now approaching an unbelievable in-flight shut down rate of one per million flight hours. Yet for all our engineering prowess, even our very best designs still aren’t as robust as our very own power plant.

The human heart will start beating at about 22 days after conception. In the vast majority of cases, it will continue to do so without interruption or overt maintenance for a whole lifetime. If you live to the age of 80, your heart would have contracted and relaxed about three billion times. It will adjust its delivery rate automatically to your needs, circulating oxygen and nutrients to and carbon dioxide and wastes away from your thirty trillion cells. Give or take a few. Barring any manufacturing defects, all you need to do to maintain the operation, is to treat it with respect.

Like all machines, components can give trouble.

Of course, your mileage may vary. Like all machines, there will be wear and tear as time goes on. The different subcomponents of our amazing engines may all be affected by age, genetics, infection, neglect or abuse. For one, the compression may let go, due to faulty valves. We call these valvulopathies, but it is much the same as your Lycoming needing a valve job. The spark may also be disrupted (we have a twin spark system by the way!) The circulation system itself can block up. This results in anything from a condition called angina to myocardial infarction, depending on severity. Or the muscle itself can stretch out and fail. This is called cardiomyopathy and is really bad news.

In the general practice setting, we do have some means of measuring the health of the heart. Through proper clinical examination, many of the signs of heart problems can be detected. We also have at our disposal the venerable electrocardiogram (ECG.) Although the study and collective wisdom of what the actual squiggles mean is rather dynamic, the technology itself is older than powered flight, stemming from advances in the late 19^th century. It revolutionised our understanding of cardiology, but as can be imagined, it has its limitations.

Have your heart checked regularly for malfunctioning components.

For starters, it cannot actually tell me if you are going to have a heart attack. The disappointment in the room when I tell this to my pilots is almost always palpable. If we ‘up the revs’ a bit and perform an exercise or stress ECG, it may give a better indication, but that is also still no guarantee. For the record, in the emergency room setting it is extremely valuable.  It may confirm that you are indeed having a heart attack! The reason for this is that it simply measures the electrical activity of the heart. Abnormal muscle has an abnormal ECG.  So why do it during a flight medical you may well ask? The ECG does give us a host of valuable telemetry. It may show irregular beats, abnormal enlargements and abnormal electrolyte levels and so on. Performing it certainly isn’t without merit in the routine setting.

If there is doubt, there are a host of other tests that a cardiologist can order that will indeed show if there is a blockage that needs attention. Most of us will not undergo such a test unless we develop symptoms. The cost and accessibility of these tests unfortunately places them beyond the average annual flight medical.

Stick to tried and tested standard operating procedures.

So, what does our owner’s manual recommend in order to maintain normal operations? For a start, respect the red line. The rate at which the pump turns decreases with age. Your maximum heart rate is easily calculated by a rule of thumb – 220 minus your age. Exceed that rate at your own peril.

That said, regular service intervals are important. By this I mean the ‘Italian tune up.’ Regular exercise combats obesity, which amongst other things, is a major risk factor for heart disease.

Having a normal and not excessive cholesterol level (specifically the unavoidable but bad low density cholesterol) assists in keeping the arteries open. This will be an entire discussion for another day though. Furthermore don’t smoke. Don’t stress and don’t exercise when you are feeling ill.

Prevention is better than cure. Data varies, but approximately 25% of first cardiac events are fatal. It is therefore best to avoid one if possible!

You don’t want to fail a flight  medical!

Should a pilot undergo a procedure such as a coronary artery stent or bypass, a six month waiting period will be required before application for the necessary recertification may be made to the CAA. Thereafter, with the exception of agricultural pilots, all Class 1 medicals are restricted to multi-crew operations. Pilots holding Class 2 medicals and lower may operate without restriction, but unfortunately, the expense and effort of maintaining the medical’s validity does go up.

This is a fairly brief overview on what is a massive topic. Keep your hearts healthy and they should work up until the very last moment. I promise!