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Video transcript

atrial fibrillation is a heart arrhythmia more commonly known as a fib it's one of the super ventricular tachycardias in a normal heart electrical wavelets are conducted from the SA node the AV node in an organized fashion and since you have organized conduction going from the SA node to the AV node you're going to get concentric or unified contraction of the atrial tissue however an afib the wavelets are in disarray so notice how they're all erratic and going everywhere because you lose this organized signal you're not going to have the unified contraction of the atria instead with these erratic wave lists you're going to have atrial spasming so it actually kind of looks like there's a bag of worms in the atria and they're all moving around if you can imagine that also the wavelets are doing their own thing so they're gonna be signaling the AV node erratically and this is going to lead to an irregular rhythm because of the irregular stimulation classically the afib EKG is said to be irregularly irregular what does that mean well notice how the distance between the are are intervals is different with each beat in a normal heart you can see evenly-spaced are our intervals both a fib you have different distances between the R and the R intervals also an afib there are no distinct P waves on EKG instead you have these coarse squiggly lines running through but there are noticing P waves that's because remember the atria is spasming so you're not going to get that nice unified concentric contraction of the atria so you have these coarse wiggly lines instead representing the atrial spasm what are the risk factors for atrial fibrillation well anyone who has diseased atrial tissue has an increased risk for afib and how does atrial tissue become diseased well with old age so the skin in your body tends to get old with age so does your atrial tissue also anything that causes the tissue of the atria become in lamed can cause atrial fibrillation so imagine if you just had a recent heart procedure that causes inflammation that will increase your risk for atrial fibrillation and anything that causes atrial enlargement so this includes years of high blood pressure and also certain types of valve disease like mitral stenosis certain types of lung disease and previously having afib can enlarge your atria other things that increase your risk include certain hormonal abnormalities specifically your thyroid hormone and years of alcohol abuse it's also worth mentioning that people who have afib are an increased risk for having strokes so these people are typically put on some sort of blood thinner medication now why are these people at a higher risk for stroke when the atria is spasming Bloods going to pool in the atrium when the atrial tissue is spasming blood then pools and the atria and it doesn't move and what happens to blood that doesn't move it clots now imagine so I'm drawing a big clot right here and imagine if this clot escaped the atrium went to the ventricle and then out to the rest of the circulation it can go to other organs including the brain and if a clot goes to a blood vessel that supplies the brain well that can lead to stroke therefore people who've had afib are usually put on blood thinners which will help prevent clot formation and thereby reduce the risk of certain kinds of strokes