Archive for the ‘arrhythmia’ Category

Traditions

September 29, 2010

One of my earliest memories is getting up very early in the morning and loading into the car for the long drive to see the doctors at Johns Hopkins. My parents were younger back then; with a little luck we could make the trip in one day. Just about sunrise we’d encounter a Stuckey’s Restaurant close to the North Carolina – Virgina state line. That was where we always stopped for breakfast, and the light blue roof became one of our landmarks. I looked forward to the restaurant, and the folks did too. Then one day…

…. one day, we came around the corner to find our favorite restaurant was now a pile of ashes! The only thing left, somehow, was the roof. It was pretty much intact, as if someone or something had gently removed it and set it aside before the restaurant burned, then returned it to its proper place.

Well, that’s not good. So we found breakfast somewhere else, and didn’t think anything about it until we got to Hopkins. There, we found out that my Cardiologist – arguably the best Cardiologist in the world – had left. Dr. Richard Rowe was now Head of Cardiology at a hospital in Canada.

No Stuckey’s, no doctor… these two events must be connected in some way, correct? And by the way, I am not superstitious!

I wear a pair of lucky socks whenever I have a doctor’s appointment. One day they’ll wear out, and I’ll rescue them from the trashcan. If I have to cut a small section out of the toe and stick it in my pocket, I will.

Why? At one appointment my doc looked at the EKG and his eyebrows shot up. That is never a good sign.

“You’ve developed an Atrial Fibrillation since your last appointment,” he said. Not good – A-Fib can lead to fainting or a stroke. And I was already taking Amiodarone to combat A-Fib, so apparently the Fibrillation had broken through.

“Double your Amiodarone and have an EKG test in two weeks. Have them fax us a copy. You may eventually have to have an ablation to try to knock that A-Fib down.”

Ablation – a catheter maneuvered inside of the heart with a probe on the end, designed to burn away the areas causing the out of sync heartbeats. Wonderful.

So two weeks passed, and I had the EKG done and faxed. Naturally, the EKG tech won’t even tell you the time of day, no matter how much you beg. But I got my answer that evening, when they called and told me I needed to come to the hospital for an appointment with the Electrophysiologist.

So the next week I was back, being examined by the specialist – wearing a new pair of socks. Didn’t bring that pair intentionally, just needed an extra pair and tossed them into my carry bag.

The doc hooked me up to a 12 lead EKG (the first one I had ever seen), listened with his stethoscope, and asked me several questions.

“So, how do you feel?”

“Worried about what you are going to find, but other than that, pretty good.”

“Tell me how you feel when you are having an episode.”

“Actually Doc, I can’t tell you. I don’t feel them.”

“Not at all?”

“No sir.”

He put the stethoscope back on my chest. “You are in A-Fib right now. Do you feel any different? Anything at all?”

“No sir,” I said.

He listened some more, and run another EKG. “I’m going to discuss this with your Cardiologist,” he said as he excused himself from the room.

In a few minutes he was back. “Since you don’t even feel it, and it doesn’t seem to be bothering you, I’m going to discontinue the Amiodarone. Get an EKG faxed to my office in two weeks. And if you feel light headed or more tired than usual, call me ASAP. But if it doesn’t bother you, I’m not going to medicate you for it.”

And with that we were out the door. The two-week EKG was acceptable and I felt fine, so all he told me to do was to discontinue the medication and come back for a routine checkup in one year. And ever since then, I walk into a doctor’s office wearing my lucky socks.

But I’m not superstitious…. what makes you think that? 🙂

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It isn’t working

April 11, 2010

Durn it!

Dronedarone, the Atrial Fibrillation drug that has been highlighted here before, isn’t living up to the hype. It was already known that it is not as effective as Amiodarone, but it doesn’t have the side effects that drug has. The hope was that if you developed A-Fib at an early age, or have a milder form of A-Fib, you could be switched from Amiodarone to Dronedarone. Amiodarone is an effective suppressor of A-Fib but the side effects can be terrible.

In fact, the last time I wrote about Amiodarone, I was accused of using “scare tactics” to get my point across. I wouldn’t do that – Heart Defects are  scary things; As any parent/CHDer knows. I’m not going to add to the hysteria. Behind every link on this blog is more information about a subject; click and read for yourself. HERE is the link I used the last time, it’s written by a Cardiologist. Obviously, he knows more about this drug than I do, and he isn’t a fan of Amiodarone, either.

Further testing has shown that Dronedarone is only half as effective in humans and doubles the rate of death! Dronedarone is recommended only as a second or third choice for people who can’t tolerate Amiodarone. Britain’s National Institute for Health and Clinical Excellence (NICE) gave the drug its approval after originally turning it down, based on its limited effectiveness and its price.

So while Dronedarone doesn’t look like it can be the answer everyone was looking for, perhaps it does have a place in the “medical toolbox”. For right now, the first drug of choice is still Amiodarone, and Cardiac Ablation is still an option.

And other researchers will continue to search for better answers.

There’s a SQUID in Wisconsin!

April 7, 2010

You may remember an article that appeared on the Funky Heart! blog in February that highlighted the SQUID, which stands for Superconducting QUantum Interference Device. A SQUID is a super sensitive magnetometer that is able to detect magnetic fields and determine their strength. SQUIDs could have medical applications, but are rarely used because they are much too strong. For a squid to be effective it has to be shielded from all the sources of metal around it; and how much metal is in your average hospital? The SQUID highlighted earlier had better shielding and an easier control system.

There are very few SQUID units in hospitals today, and the ones that exist are being used for adult brain scan. But there is one unit dedicated to the study of fetal hearts, located at the University of Wisconsin-Madison.

Dr. Janette Strasburger supervises the patients during the procedure, which is painless and non invasive. The result is an hour long continuous recording of the baby’s heart rhythm and “the closest thing there is to a cardiac intensive care unit for fetuses,” Dr. Strasburger says.

Needless to say, the unit is much too big to be portable and patients have to travel to Wisconsin. That could be changing, as a portable unit is currently under construction.

A Replacement for Warfarin?

March 22, 2010

A lot of people dislike Warfarin. Also known by its brand name Coumadin, it is the most prescribed anticoagulant (Blood thinner) in North America. If you can get past the fact that you are taking something that is also used as rat poison, the constant monitoring and dosage adjustments are a pain in the butt. Every six weeks you must have a blood test, and it reacts with nearly everything. Other medications and even your choice of foods can make the drug more or less effective. This requires you to adjust your medication and have another blood test. It’s enough to make you yell!

But there are two new anticoagulants being developed that could replace Warfarin. The first is Dabigatran, which is marketed in Europe as Pradaxa. Dabigatran was approved for use in Europe and Canada in 2008 and is currently being considered here in the United States by the Food and Drug Administration.

Dabigatran has all the appearances of a wonder drug. It has done well in scientific studies: the RE-LY clinical trail shows that it performs better than Warfarin at some dosage levels; the RECOVER study proves that there is no need for the constant monitoring and no food/drug interactions.

If you’re waiting on the other shoe to drop, here it comes: Dabigatran is expensive. Great Britain’s National Health Service pays £4.20 per day for Dabigatran, and about £1 per day for Warfarin.

Ugh. Now that’s a problem.There are several theories that the cost difference can be recouped not only through the savings in monitoring costs, but the costs associated with stroke recovery. The simpler a medical therapy is to use, the more likely someone is to follow the instructions and benefit from it. Warfarin is difficult to maintain, while Dabigatran wouldn’t be. Just take your pill and go about your business.

The other new drug is Betrixaban, which is still being developed. It’s a joint venture between Merck and Co. and Portola, and like Dabigatran requires no monitoring and has almost no interactions. But it is still in Phase 2 testing, a long way from public use. Also, Portola is developing an “off switch”; another drug that can be administered in case of a heavy bleed and deactivate Betrixaban.

The potential market for any company that can develop a Warfarin replacement that has less interaction and less monitoring needs is wide open. Hopefully market forces will not only benefit the companies developing new drugs, but those of us who rely on them.

The Devil’s Drug

February 27, 2010

Woe to the CHDer who develops an arrhythmia. (irregular heart beat) The problem is, it seems we all develop one sooner or later, and the choices we have to combat it are limited. Certainly pacemakers and ICDs are available, but those are expensive. So is an ablation; so often, we start with a drug regimen.

One of the best Antiarrhythmia drugs is Amiodarone, because it can control the irregular beats fairly well and there is less of a chance of a proarrhythmia. A proarrhythmia is a new or more frequently occurring arrhythmia that is triggered by the use of antiarrhythmia drugs. It’s diabolical – using the drugs that can calm down an irregular heartbeat can actually cause more irregular beats!

Oh, boy.

Amiodarone is pretty good about not causing proarrhythmia, but that is probably it’s one positive factor. Dr. Rich is convinced that Satan himself invented it – it’s that nasty!

For the drug to become effective, it has to saturate the body. So at first you are given a “loading dose” – a high dosage of the medication to get the patient to the proper level of the drug in their blood quickly.

Most of the time a drug is eliminated through the bloodstream, taken to the kidneys where it is filtered out, and the eliminated through the body’s natural waste disposal system. Not Amiodarone, no sir. The only way you get rid of it is by getting rid of cells. That’s a naturally occurring process, but it is slow and you can’t speed it up. Sometimes it takes a year for the Amio to completely clear your system.

And while it is in your system, it sets up shop in every organ of your body.

Possible liver damage? Yep!

Possible lung damage? Got you covered!

Thyroid damage? Amio is on top of that, too! In fact, you know that rough spot on the bottom of your left foot… well, you probably can’t blame Amiodarone for that one.

But every year you are on the drug, you’ll be visiting your eye doctor for an examination. Not the usual eye exam, mind you, but he’ll be looking for deposits in your eyes caused by the drug.

And you’ll have a lung function test every year, also. You’ll sit in a small walled in area that looks like a phone booth with a plastic tube in front of you. You’ll be asked blow as hard as possible into the tube, blow, blow, come’on empty your lungs! Then you’ll inhale as much as possible; you’ll hold your breath then blow it out – several different lung exercises. You’ll want to bring a friend with you – there’s no reason that you can’t drive home yourself, but you’ll be exhausted from the exercises. And they’ll repeat this test every year to make sure that your lungs aren’t being damaged by the Amiodarone.

If you haven’t guessed, this stuff isn’t very usuer friendly. There are newer drugs available that do not cause proarrhythmia (Yay!) and do not have the side effects of Amio (Yay again!) but isn’t as effective. (Aw, man!)

So if this drug is recommended to you by your doctor, you probably do need it. But have a long, honest discussion with your physician about the benefits and side effects of Amiodarone.

New findings indicate source of A-Fib

December 29, 2009

Atrial Fibrillation, or A-fib, is one of the problems many CHDers will face. In a normal heart, an electrical signal is generated by the Sinoatrial node (also known as the SA node and is located near the top of the Right Atrium) and flows outward, causing the Atria to contract. When the electrical impulse reaches the Atrioventricular node, (AV node) it triggers its own electrical impulse which causes the Ventricles to contract, creating the “lub-dub” heartbeat we are all familiar with.

But when extra electrical impulses are moving through the heart’s electrical system, the Atria won’t contract, but rather fibrillate, or quiver. And if the electrical pulse isn’t strong enough the AV node won’t activate the Ventricles. A-fib is usually asymptomatic and painless, (though you can feel your heart beating out of rhythm) but there is a very real chance that the blood pooling in the not-quite-beating upper chambers can clot and cause a stroke.They can also lead to Congestive Heart Failure. (CHF)

One of the usual techniques used to stop A-fib is ablation. Before an ablation, the heart is examined closely and “mapped” to determine where the extra electrical impulses are coming from. Then a catheter is inserted through a vein in the leg or the neck and is guided to the heart. The sources of the extra electrical impulses are then “zapped” (or frozen) to knock them out, and the heart beat should be restored to normal. It doesn’t always work.

But researchers have recently determined that the cells that produce the heart’s electrical charge – and can cause Atrial Fibrillation – also express the protein DCT. DCT only originates from a couple of sources in the body, and only one inside the heart – the electrical current cells. So if scientists can learn a way to identify DCT cells in the heart, they’ll have a way to determine where electrical pulses can orgininate – and deaden the ones causing A-fib.

But this technology is a long way from being reality, if it works at all. Right now, studies are being conducted on mouse hearts. Mouse hearts are similar to human hearts, close enough to be used in research. But when it comes to transferring the results from a mouse to a man, there is a lot of difference!