Neuroscientists Beware! Here Come the Cardiologists!

DrRich | May 29th, 2010 - 10:24 am

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Throughout the millennia, the characteristic that has distinguished robust barbarians from extinct ones is that, when forces beyond their control begin encroaching on their turf, they simply pick up and encroach on the turf of less aggressive people (generally, of people who are more advanced, both intellectually and culturally, than they are).

And so, when the Feds begin making noises about limiting some of cardiology’s favorite revenue-generating activities, the cardiologists – among the most robust of the medical barbarians – are quick to overrun the turf of other, less bloodthirsty and more civilized, medical specialists.

DrRich in the past has attempted to warn his medical colleagues about the predatory nature of cardiologists. He has told how the cardiologists have driven the formerly proud and powerful cardiothoracic surgeons into a sad state of underemployment, how they have usurped the formerly sovereign territory of diabetes specialists, and how they are currently laying siege to sleep medicine and bariatrics.

And now, continuing his public service to the less robust medical specialists (whose great achievements, like all cardiologists, DrRich admires), he must reluctantly extend his words of warning to his friends, the neuroscientists.

Cardiologists began encroaching on the field of neurology many years ago, but only surreptitiously, when they took to blaming imbalances of the autonomic nervous system (i.e., dysautonomia) on mitral valve prolapse. In more recent years, somewhat more blatantly, they have attempted to take ownership of migraine headaches. And now, just last week, in a full frontal assault, cardiologists laid claim to Alzheimer’s Disease.

Neuroscientists, nobody is safe! Hide your women and children!

The pattern of behavior employed by the invaders is easy enough to spot. First, cardiologists call attention to an alleged association between some cardiac condition (a condition they will manufacture if necessary), and a non-cardiac medical problem. Then, immediately, they will assert that (or at least begin behaving as if) the association proves a cause-and-effect relationship. Finally, since they have “proven” that the non-cardiac medical problem is caused by a cardiac condition, patients who have (or might develop) that non-cardiac medical problem need to be referred to cardiologists, who, lo and behold, have invented a well-paying procedure to treat it, or at least, to study it further.

The best known example is mitral valve prolapse (MVP), a congenital condition in which the mitral valve partially flops open when it should be closed, thus allowing blood to flow backwards (i.e., to regurgitate) across the mitral valve as the heart contracts. (For anyone interested, here’s a brief description of the heart’s chambers and valves.) Now, significant MVP can be a serious medical problem, and it often requires mitral valve surgery. Fortunately, however, significant MVP is a relatively uncommon condition.

The problem is that echocardiography (a non-invasive test using sound waves to create an image of the beating heart) has become so advanced that some degree of trivial MVP, it seems, can be found in almost anybody. According to some studies, as many as 25 – 35% of healthy individuals – people without any cardiac problems or any symptoms whatsoever – can be said to have some degree of MVP. In fact, whether you have MVP or not depends largely on what criteria the echocardiographer uses to make the call, and how badly the doctor wants you to have the diagnosis.

Over the years it has become customary to diagnose MVP in young, apparently normal people who have the temerity to complain about the highly disruptive symptoms of dysautonomia (such as fatigue, weakness, strange pains, dizziness, constipation, diarrhea, cramps or passing out), without supplying the kinds of objective physical or laboratory findings which, doctors insist, patients are always obligated to provide. Such thoughtless patients are now routinely sent for echocardiography, so that MVP can be diagnosed (since it can be diagnosed just about whenever it is looked for). The patient is then given the diagnosis of “mitral prolapse syndrome,” even though: a) the MVP is usually so trivial as to be nonexistent; b) the studies which claim to show an association between MVP and these sorts of symptoms are generally based on a gross over-diagnosis of MVP; and c) there is no credible theory based on actual physiology to explain how MVP – even real MVP, much less the trivial kind – might cause such symptoms.

But no matter. “Rule out MVP” has become one of the most common reasons for young, healthy people to be referred for echocardiography, and has become a staple source of income for cardiologists.

The story is similar for the association between patent foramen ovale (PFO) and migraine headaches. In the developing fetus, the foramen ovale is a hole that is present in the atrial septum (the thin structure that separates the right atrium from the left atrium). At birth, a flap of tissue imposes itself over the foramen ovale, causing it to close. In some people, however – people with PFO – the tissue flap is still capable of flopping open. In people with PFO, the foramen ovale can open transiently if the pressure in the right atrium becomes transiently greater than the pressure in the left atrium, such as with coughing, or straining during a bowel movement.

In rare instances, strokes in healthy young patients have been attributed to PFO. The supporting theory is that a stroke can occur when a blood clot happens to be coursing through the right atrium at the precise moment a person with PFO is coughing (for instance), allowing the clot to move into the left atrium, and on to the brain. And because this theory is at least plausible, in a young person who has an unexplained stroke and is then found to have a PFO, it makes at least some sense to close the PFO.

But the presence or absence of a PFO is a little like the presence or absence of MVP. Its diagnosis depends on how hard the echocardiographer looks for it, and on how much the doctor would appreciate the diagnosis. With modern echocardiographic equipment, at least some sign of PFO can be found in as many as 25% of normal individuals.

Being able to make this nifty diagnosis is of little use to cardiologists if the only clinical problem it may cause is a one-in-a-million chance of stroke. One cannot make a living, or even make a car payment, doing echocardiograms in young patients with cryptic strokes. They’re just too darned rare. So it didn’t take long for cardiologists to draw a more useful association – this time, between PFOs and migraine headaches.

While all the things that have to happen in order for a PFO to cause a stroke are very unlikely, it is at least possible that they could all occur simultaneously in a patient. This is not the case with migraine. No plausible theory has been advanced to explain how PFO might cause migraines. The only reason PFO is being invoked as a cause for migraine is that when patients with migraine have been carefully studied for the presence of PFO, an increased incidence of PFO was found. But (as we have seen) when PFO is carefully sought in any population of patients, it is more likely to be found. The only likely reason PFO has not been associated with cancer, red hair, type A personality, or difficulty in memorizing the multiplication tables is that cardiologists have not thought of looking for it (yet) in these conditions.

For cardiologists, the poorly-supported allegation that PFO causes migraine is particularly compelling, since not only can they get paid to look for PFOs in migraine sufferers, but also there is an invasive (and lucrative) procedure they can do to close PFOs, to “treat” the migraines. Studies to date have not been successful in showing that closing PFOs improves migraine headaches, but that hasn’t kept cardiologists from screening migraine patients for PFO, then offering them PFO closure as a therapeutic option.  This, again, is because an association implies cause and effect, at least when that implication can be helpful to someone.

Migraine sufferers are particularly vulnerable to this and many other unproven therapies, since they are often disabled by their condition, and in many cases medical science (or medical ignorance) offers them insufficient help. Consequently, anecdotal stories abound regarding unorthodox therapies that cure migraines. DrRich, himself a migraine sufferer for many decades, has heard all the stories. (He even has one of his own. If DrRich maintains a schedule of running at least 20 – 25 miles a week, he does not get migraines. If he quits running for a few weeks the headaches come roaring back. He has mentioned this decades-long and reproducible pattern to several neurologists and other specialists over the years. They conclude that DrRich – and this should not be a surprise to many of his readers – is nuts. But if cardiologists had a billable procedure that could make you exercise, you can bet they’d fold DrRich’s experience into their formal clinical guidelines.) In any case, merely performing PFO closures on a few migraine suffers was almost guaranteed to produce a patient here or there who would report a positive response. And despite the continued negativity of actual clinical trials so far, that’s what happened.

So, at least by anecdote if not by controlled trial, closing PFOs can cure migraines.

But now it gets even worse for the neuroscientists. Any neurologists who ignored the cardiologist’s usurpation of dysautonomia, and who may have felt only a little more concern when cardiologists began to lay claim to migraine headaches, had best sit up and take notice. Because now, cardiologists have a way of treating (at least preventing, if not actually curing) Alzheimer’s Disease.

This time it is DrRich’s own particular sub-branch of the cardiology tribe which is the culprit – the electrophysiologists.  In a way, it is a little disappointing for DrRich to see his EP brethren going in for the same, turf-grabbing sophistry used by lesser cardiologists. EPs are known for being more intellectually sophisticated than your typical heart doctor (who, after all, is a glorified plumber). Indeed (as he thinks he may have mentioned in the past), DrRich has a neurosurgeon friend who, when he wants to convey the idea that what he is doing isn’t quite as difficult as it appears, but at the same time what he is doing is, in fact, neurosurgery, will say, “It’s not exactly electrophysiology!” But of course, he may not say this anymore once he finds out what we EPs are up to.

Last week, at the Heart Rhythm Society Scientific Sessions, researchers presented a study suggesting that ablation procedures for atrial fibrillation are associated with a lower risk of Alzheimer’s disease. (Here’s some information on atrial fibrillation and its treatment for anyone who is interested.) The study was presented as an abstract only, so we know relatively little about the specifics.

But, really. Atrial fibrillation and Alzheimer’s are both disorders associated with aging, so it is not surprising that they are associated with each other – in the same way that atrial fibrillation is associated with gray hair, cataracts, and bunions. Ablation for atrial fibrillation is a relatively lengthy and difficult procedure, whose results are relatively middling, and which carries a substantial risk of some really nasty complications. So these ablation procedures are generally reserved for carefully selected, reasonably ideal candidates – usually, the relatively young, relatively healthy atrial fibrillation patients, who are less likely to get Alzheimer’s disease over the next few years whether they have ablations or not.

So there is a lot to be cautious about in interpreting a preliminary study like this one. For a well-presented, comprehensive treatment of why the results of this study should be largely ignored for now, see Dr. John M’s blog. (It sounds like John M is as embarrassed by his fellow EPs in this instance as is DrRich).

But such objections as DrRich and John M may express are just quibbles. The headlines are already blaring: “Ablation Procedures For Atrial Fibrillation Prevents Alzheimer’s.” Whatever the details and limitations of this study, cardiologists can now treat Alzheimer’s. Mission accomplished.

Having duly (and humanely) called this problem to the attention of his neuroscience friends, DrRich would like to finish by emphasizing a larger point.

You can’t fight the Feds. When the sovereign authority, at the point of a gun, decides to reach down into the world of the medical specialists, and dictate which medical services are no longer going to be feasible (all for the noblest of purposes, of course – to maximize quality and efficiency and the collective good), the affected medical specialists have a limited range of possible responses. And fighting the Feds is NOT among these available responses.  Better to fight the change of seasons.

So the affected specialists can contract their horizons, take what’s left, and try to make the best of it. Or, they can do what the Visigoths did when the people of the steppes displaced them. Strike out against other, weaker specialists, and take what’s theirs. If you can’t grow the pie anymore, then take the other guy’s piece.

DrRich is not passing any judgment on his cardiology brethren here. He is just describing what’s happening, as a public service. You neuro-types, he believes, have a right to be told what’s happening. You can do with the information as you see fit.

In the meantime, DrRich remains supremely confident that his cardiology colleagues can find a nearly unlimited supply of plunder in this brave new world. They are very robust barbarians.

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