The Lancet revists cardiac arrhythmia. . . . It's an epic story!

Oct 26, 2012 17:11 EDT

We have all enjoyed really good days. You know what I mean, days that when you look back at your life, you are glad they went the way they did. This is how I feel about the day I chose electrophysiology. Not once have I ever thought it a bad decision to forgo squishing blockages for curing arrhythmia. What a great ride it has been—and fortunately, continues to be.

As I sat down to write my thoughts about a recently published review of arrhythmia, this was the paragraph that echoed off the keyboard. (Granted; it's a little gooey. What can I say? I'm an electrophysiologist.)

More to the point . . .

The last time the Lancet published a review of arrhythmia was 1993—three years BG (before Google.) In the world of electrophysiology, 19 years approaches that of an eon. In 1993, I was a first-year cardiology fellow at Indiana. We carried a cellphone as big as a backpack; ICDs were implanted in the OR with leads, and patches were stitched onto the heart and attached to a monster in the belly, and even the idea of AF ablation was yet to be conceived. Heck, WPW took all day to ablate.

So, yes, it seems a great time to update one of the human body's most amazing accomplishments: the heart rhythm. Do you ever hear your heartbeat in your ear? Or put a stethoscope to your own heart? If you close your eyes and mindfully listen, the heart will impress--and soothe. I like to remind my most pessimistic patients that their heart may not be flawless but it beats 100,000 times per day.

On the eve of the American Heart Association meeting next month in Los Angeles, the European version of the New England Journal— the Lancet—has put together a series of three textbooklike articles (plus one historical comment) on cardiac arrhythmia.

I read them in reverse order, starting with wordsmith extraordinaire Prof John Camm from the UK. His piece walks a reader through the past two decades of arrhythmia history. He celebrates our triumphs, (pacemakers, CRTs, and catheter ablation), bemoans our failures (dismal risk stratification for sudden death and all antiarrhythmic medicines), and then points out the many upcoming challenges. Dr Camm deserves a strong "RT" for mentioning dronedarone in the same paragraph as the infamous trial of encainide in post-MI patients (CAST).

The distinguished EP group from Brigham and Women's Hospital confirms their well-deserved reputation for excellent teaching with this overview of ventricular tachyarrhythmia and sudden death. It's superbly written and filled with useful up-to-date information. A reader will definitely want to Evernote or Dropbox this one for reference.

Dr Jonathan Kalman 's group from Australia adds this equally well-done review of atrial arrhythmia. Perhaps the niftiest thing about their review is the illustrations. In explaining heart rhythm disorders, a picture tells the story far better than words. (It's why I have whiteboards in my exam rooms.) Their pics are beautiful—and, oh, do electrophysiologists love nice images. Nebulous concepts like macroreentry tachycardia rotating around ablation lines or atriotomy scars come to life in their images.

I left the best article for last.

The crazy thing about the progress we have made in treating heart-rhythm disorders is that we have done so without an in-depth understanding of biology. The proof of an arrhythmia mechanism is often that it goes away after burning.

Patients often ask why the pulmonary veins are important in AF. Or why can't we predict which patient is at risk for sudden death. Or this zinger: my neighbor has similarly bothersome palpitations and has had ablation and an ICD . . . how do you know my palpitations are benign?

Drs Dan Roden (Vanderbilt University, Nashville, TN) and Andrew Grace (University of Cambridge, UK) discuss the role of systems biology in arrhythmia. Namely, a systems approach to arrhythmia describes how phenotypes mesh with genetics and experimental models. For instance: consider the mysterious notion of why pulmonary veins are important in AF. Here's a sentence from the paper:

[On chromosome 4] PITX2 isoform c (PITX2c) is a homeobox transcription actor involved in assignment of laterality and in the development of the pulmonary myocardium that is implicated in the differentiation of the muscular sleeves around pulmonary veins.

My translation is that genetic factors, likely modified by environment, affect the ability of electrically active pulmonary vein musculature to initiate and then sustain AF in the substrate—the left atrium.

The biology and genetics of arrhythmia are more than just a trivial pursuit. More thorough understanding of biology will not only make us sound smarter; it will guide us to better targets in the EP lab; maybe lead to a useful antiarrhythmic drug (for the first time in a decade), and surely, this knowledge will transform us into better teachers. In the mysterious world of arrhythmia, one of the best therapeutic tools is good information. Ask any AF patient how they feel after leaving the office of an enlightened afibologist. They almost always feel better—because now they understand stuff.

I'll close with this idea: Perhaps the biggest weakness in electrophysiology has been the lack of vigor with which we have educated our peers. Caregivers on the front lines of medicine must know what we can (and cannot) do for arrhythmia. In this era of information, we must not have ICDs being implanted for curable VT or in patients too ill to benefit. We must not have AF patients suffering through multiple hospitalizations and trials of drug therapy when ablation is available. We must not have patients at great risk for stroke not educated about their choices of anticoagulants.

Without doubt, genomics, cell biology, and engineering will lead the way to better treatments. Although the future looks bright, the present moment is pretty good too. Hopefully you agree with me that it is critical for heart-rhythm experts to tell the amazing stories of all that we can offer our patients.

That's why I loved seeing these articles published on such a prominent stage.

JMM