Tag Archives: Circulation

What Goes Around Comes Around

When I was a cardiology fellow back in the 1980s, I learned about a variety of early tools for evaluating heart health that had been displaced by the modern standards of electrocardiography (ECG, or EKG for the Deutschephiles) and echocardiography. One such technique – ballistocardiography – stuck with me, and may be making a comeback.

Ballistocardiography is based on the observation that the mechanical action of the heart leads to subtle but reproducible movement of the whole body. It is the old “every action has an equal and opposite reaction” maxim in, well, action. We literally shudder a little bit each time the heart ejects blood. Back in the day, researchers compared patterns of that shudder to detect and quantify disorders of cardiac output. As someone who had studied biomedical engineering in college, I thought it was pretty cool that you could non-invasively estimate cardiac output by measuring how much somebody bounced up and down with each heartbeat, even though it had been eclipsed by more accurate and easier to use technology.

By the way, you can easily measure the effect yourself, if you have an analog bathroom scale. Just stand on it as still as you can, and you will notice the needle deflects slightly with each heart beat – as the blood goes “up” out of your heart, your body goes “down” and your weight appears to increase momentarily. More elaborate ways to measure and quantify the effect are, of course, available on YouTube.

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Prevention Paradox

Every clinician knows that “framing” – how we present information to patients – has a big impact on decisions they make about their care. Even something as simple and apparently transparent as talking about “survival” versus “mortality” is important, with “a 90% chance of living” sounding a lot better than “a 10% chance of dying” even if both phrases convey the same estimate of risk.

Things get even more dicey when doctors start talking to patients about more subtle concepts like risk-reduction or number needed to treat. The clinical impact of a big relative risk reduction operating on a low absolute risk can be hard for doctors to explain and patients to understand.

The impact of that complexity was the subject of a recent editorial in Circulation. In it, Diprose and Verster speculate that doing a better job of explaining these things to patients, which certainly seems like a good idea, may paradoxically lead to worse population health outcomes. Here’s how it could happen.

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Rethinking a No-Brainer

What does someone having a heart attack look like? I think the New York Times captured what many of us probably have in mind, when they published this picture as part of a recent series on advances in cardiovascular care:

Nash_Blog_ImageMark Makela for The New York Times. Retrieved from http://www.nytimes.com/2015/06/21/health/saving-heart-attack-victims-stat.html

Here is the iconic middle-aged guy, in extremis, pointing to his chest, with a team of health care professionals at the bedside. There are also signs of initial management – he has ECG electrodes on his chest, an IV in his left arm, what looks like monitor/defibrillator pads on his right chest and below his left arm and, of course, an oxygen mask.

What is wrong with this picture?
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