Dr John M

cardiac electrophysiologist, cyclist, learner

Shocking AF — What’s the rush?

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This post is in introduction to my most recent column over at Trials and Fibrillations on Medscape | Cardiology.

If I had just one thing to say to patients and doctors about the disease atrial fibrillation it would be this:

Be as scared of AF treatment as you are of the disease.

Yes, it is true: AF can make people feel bad. (It sure did that to me.) It induces fear in both patients and caregivers. And, AF also increases the risk for stroke and heart failure in the future. The emphasis being on the future–as in weeks, months, and years, not usually tomorrow.

One striking aspect of the mainstream—non-electrophysiology—way of treating AF is the urgency. It seems everyone is in a rush. This is not good, especially when the topic of shocking the static fibrillating atria back to regular rhythm is concerned. Here I am talking about cardioversion, which is a severe euphemism for high-voltage shocks. (Wait. can euphemisms actually be severe?) But make no mistake; shocking the heart is no small thing, especially when patients are not taking an anticoagulant drug.

As an AF doctor, I spend endless hours undoing fear—and the dangerous stuff that comes from fear. One is surely the rush to get people out of AF quickly. These are busy people who are feeling terrible, after all. They need to get back to their inflamed lives.

There exists this legend that if AF has been ongoing for less than 48 hours, it is safe to shock (cardiovert) the patient without using an anticoagulant drug.

A new study from a Finnish research group, published today in the Journal of the American Medical Association, sheds important light on this frequently encountered scenario–a decidedly cautionary light.

Many years ago, I was involved in the care of middle-aged professional man who died after such an unprotected cardioversion. This case, and the new data, moved me to write about the matter of shocking people without the protection of anticoagulant drugs.

Here is the link and title of the post: Cardioversion for New-Onset AF: Time to Hit the Pause Button?

JMM

The new blood thinners and personal accountability

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I recently came across a very important blog post on the use of the novel new blood-thinner, dabigatran (Pradaxa).

Fellow Kentucky cardiologist, and frequent TheHeart.org contributor, Dr. Melissa Walton-Shirley wrote this very detailed case presentation involving a cantankerous non-compliant rural patient with AF (atrial fibrillation) that sustained a stroke while “taking” dabigatran.

Dr. Walton-Shirley details the very commonly done procedure of cardioversion (shock) for AF. As she clearly points out, the most important safety feature of shocking AF back to regular rhythm entails adequate blood thinning before and after the procedure. Thin blood prevents the possibility of clots dislodging after restoring normal contraction to the top chambers of the heart (atria).

Herein lies the rub with dabigatran, and the two soon-to-be-approved non-warfarin blood-thinning agents, apixaban and rivaroxaban. In the past, with warfarin, the doctor was responsible for confirming a patient’s compliance. This task was easy on the doctor: patients come in for weekly INRs before and after the shock. If an inadequate INR was found, the procedure was postponed. Responsibility was squarely on the doctor.

But the irony of the new blood-thinning drugs is that their most attractive feature, convenience of not needing frequent blood tests, shifts the burden of responsibility to the patient. Because these new blood-thinners do not reliably affect any measurable blood tests, the doctor cannot know whether the patient has had an adequate period of blood thinning before (or after) shocking the AF back to rhythm. Only the patient can know. In a RE-LY sub-study, cardioversion with dabigatran was found to be safe, but these were study patients, not cantankerous patients that “a secretary had to deploy the National Guard to locate.”

In Dr. Walton-Shirley’s case, she took the patient at his word: that he was taking dabigatran before the shock. But after he suffered a stroke less than 24 hours later, both circumstantial and real evidence suggests that he was non-compliant with his regimen of dabigatran. Fortunately, the patient recovered well from his stroke, albeit with a rocky course.

Dr. Walton-Shirley goes on to dissect the case. She writes about three lessons that could be learned in this case. It’s an important discussion.

Role of TEE (trans-esophageal echo) before the case:

She mentions the possibility of searching for a clot inside the heart by doing a TEE before the shock. The problem here is that doing a TEE means sedating a patient and sticking a very large rigid black tube into the esophagus. This far from non-invasive procedure is not needed in patients who have adequate blood thinning before the shock. In her case, the patient ended up with a severe complication from a TEE at an outside institution. She rightly concludes that TEEs are not the answer to confirming patient compliance.

Role of measuring the PTT (a common measure of blood-thinning) pre-shock:

Though it is true that patients that have taken dabigatran the day before the procedure have elevated PTTs, it does not in anyway confirm that the patient was taking the drug for the prior 3 weeks. Nor does it imply the patient will take the drug after the shock, which is of equal significance.

The general concept of using dabigatran in patients non-compliant with warfarin:

After this case, Dr. Walton-Shirley writes, “I will never utilize dabigatran in a patient with a history of poor or marginal compliance, because even if their PTT is adequate at the time of cardioversion, there is no guarantee they will be taking it regularly in the future or that they’ve been compliant with it consistently.”
Few could disagree with that statement.

I commend Dr. Walton-Shirley for writing such an important case report.

My comments on the case are as follows:

The new paradigm that these novel blood-thinning drugs have created represents a seismic shift for doctors and patients. For doctors, we have to decide, no, call it judge, perhaps even trust, that our patients will comply with taking an expensive drug that makes them feel no differently.

Doctors vary in the degree that they mother patients. Some will send the National Guard to locate a patient to get them into the office for their care, while others are of the ilk that think a patient needs to accept at least enough responsibility to get to the doctor’s office for routine care. They take the view, if a person can afford 12$ per day for cigarettes, they can afford a ride to clinic. This notion of mothering will have a lot to do with how a doctor uses these new drugs. Do they want the responsibility (of confirming INRs), or is it okay for the patient to be responsible (for taking the drug as directed)?

Ultimately, preventing strokes with potent drugs that patients must take as directed, and doctors cannot confirm that they have done so, highlight three important criteria for good outcomes with any medical treatment:

  • The critical role of patient responsibility for their own health. Non-warfarin blood thinners place the onus on the patient. The conveniences of these drugs come with a hefty price: personal accountability.
  • The ever-important communication skills of the doctor in explaining the concepts of these novel drugs.
  • The requirement that doctors exercise sound judgment in deciding whether a patients can garner benefits from this very new paradigm of therapy.

It’s an exciting time to be an AF doctor.

Thanks to Dr. Walton-Shirley for sharing such an important case.

JMM

I confess: mindless medical forms and I do not get along…

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It’s official.

It now takes longer to do all the necessary forms, than to do a simple cardiac procedure, like a cardio-version. Seeing the patient, administering a sedative, and delivering a synchronized shock that converts AF to regular rhythm takes just a few minutes.

However, in 2010 (in all hospitals), the number of forms has grown like a Kentuckian’s belly.  There is the History and Physical which has to be updated, even if I saw the patient that morning in my office.  There are two consent forms.  Not sure why there are two, I stopped asking a long time ago.  The medicine reconciliation sheet which includes all medicines, even ginko biloba, and the like, has to be checked and signed.  

The king of all forms though, is the sedation form.  This scary form has evolved, and now devolved, at the whim of what the hospital surveyors say it should be. The right words change all the time.  Sedation seems to be on our watch list presently. Even the timing of the pre-procedure assessment has come under close surveillance. An arbitrary window of time exists between when I should have assessed the patient, and when sedation is delivered.  I am not sure the exact number of minutes, but I am pretty sure the patients neck isn’t getting any fatter in any number of minutes. Thankfully, there is usually a stickie note telling me what time to write in.  

Please do not think my disclosure of silliness is a marker of carelessness.  I, and my experienced EP lab staff do think of sedation issues.  We simply do not have problems with sedation.  As close to never as imaginable. We are really good at it, and the comfort of our patients during and after the procedure is a source of pride. The administrator-laden forms would suggest I am a medical student, but after administering sedation for years, I know my limitations.  The anesthesiologists reside right around the corner.  For the “biggie-chair” people we get help.

The new sedation form asks: “Plan for sedation.”

I really do not know the present-day–but sure to change soon–politically correct words to answer this simple question. Neither do my experienced EP nurses.  Just for grins, I surveyed them today.  “It’s conscious sedation,” one said.  The other, “no, it’s moderate sedation.”

Ok, it’s settled.  I know what to write on the form.

Plan for sedation:  “The same as I have done for the past fifteen years.”  Or, “just the right amount.”

We will see how this goes.

Environmentally speaking, green is not the color of medical documentation in this new era of protocols and forms.

“Time out.”

JMM