Tuesday, November 27, 2007
Imagine that you’re Dick Cheney.
OK, imagine that you’re a person like Dick Cheney, a person who has had significant heart problems in the past and who wakes up on Monday morning with a heart that feels like it’s flopping in his chest. You feel for your pulse and for an instant, it’s racing faster than you can count. Then it’s slower but has an irregular beat like a drum machine with no rhythm. You go through your mental checklist: no chest pain, no sweating, no shortness of breath, nothing like your heart attack a few years back. You haven’t forgotten that feeling. You wait a few minutes but your heartbeat still feels funky and the decision is made. You’re off to the hospital.
Atrial fibrillation is a common heart rhythm, where the electrical system of the upper chambers of the heart fails to beat in an organized manner and instead jiggle likes a bowl of jello.
Normally, the heart acts like a two stage electrical pump. There is a single electrical impulse that is generated from specialized cells in the atrium or upper chamber of the heart. This electrical impulse causes the atrium which collects blood from the body to contract and push blood into the lower heart chamber called the ventricle. That initial electrical signal makes its way to the ventricle and causes it to beat and pump blood back to the body.
In A Fib, the upper chamber of the heart becomes irritated and numerous electrical signals are generated but the atrium gets confused and just jiggles and fails to beat. The ventricle gets bombarded by all these signals and picks and tries to respond to as many as it can. This makes the contractions and the heart beat irregular and sometimes very fast. An irregular heart beat is no big deal and A Fib is not life threatening, but the when the atrium just sits there and jiggles, there is a potential for blood clots to form along its walls, break off and block blood vessels in the body. Bad things then happen like stroke or loss of blood supply to bowel or legs. It takes time for these clots to form, give or take a couple of days.
So you wander into your local ER and the docs and nurses hook you up to monitors and ask you too many questions for you liking and they spend lots of time asking when the heat palpitations started. The goal is to get your heart back into a regular lub-dub rhythm. If the onset of the atrial fibrillation is within 24-48 hours, that opportunity may exist. After 48 hours though, the shock may shower the body with clot; bad form to have the heart look good but cause the brain to stroke.
You’re solid in knowing that the irregular heart beat started just a couple hours ago, so you’re good to go. You presume that you’re heading to some high tech place in the hospital, but the ER crew has you wired for sound with IVs, monitor wires and a machine that looks suspiciously like the “everybody clear, we’re going to shock now” thing you’ve seen on television. The doc tells you that you won’t remember anything and some anesthetic drugs are pumped into your IV. As you fall asleep, you hear…everybody clear.
(It’s less fun using electricity to cardiovert or defibrillate people with the new machines. Electrical gel pads are put on the chest and they’re activated by a button on the machine. No more holding paddles and leaning over a patient while delivering the shock.)
Your heart converts to normal rhythm but you’re fast asleep and will probably wake up in ten minutes or so. The nurse smiles and you wonder when they are planning to do the procedure. Once again they tell you that you’re done, you have to wake up a bit and then it’s time to go home. Unless, that is, you’re Dick Cheney. Then it’s back to work.
Sometimes people show up in my ER and want things done that they saw on television, heard about on the radio or read on some internet site like this one. I have to remind myself and sometimes my patients that they should take in some of this information with a grain of salt.
Atrial fibrillation is a stable rhythm and not life threatening. Sometimes a regular heart rhythm cannot be restored and the decision is made to use coumadin (warfarin) to anti-coagulate or thin the blood to prevent blood clot formation. Benefits and risks of electrical cardioversion have to be determined for each patient. Not every patient is a candidate for…everybody clear.