Atrial Flutter: Difference between revisions
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| adenosine = temporary reduced AV conduction (eg 4:1) | | adenosine = temporary reduced AV conduction (eg 4:1) | ||
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During atrial flutter the atria depolarize in an organized circular movement. This is caused by [[Arrhythmias#Re-entry|re-entry]]. The atria contract typically at around 300 bpm, which results in a fast sequence of p-waves in a sawtooth pattern on the ECG. For most AV-nodes this is way | During atrial flutter the atria depolarize in an organized circular movement. This is caused by [[Arrhythmias#Re-entry|re-entry]]. The atria contract typically at around 300 bpm, which results in a fast sequence of p-waves in a sawtooth pattern on the ECG. For most AV-nodes this is way too fast to be able to conduct the signal to the ventricles, so typically there is a 2:1, 3:1 or 4:1 block, resulting in a ventricular frequency of 150, 100 or 75 bpm respectively. Often the grade of block changes every couple of beats, resulting in e.g. 2:1, or 3:1 blocks and a somewhat irregular ventricular heart rate. The saw-tooth is especially prominent in lead II, this lead normally shows constant electrical activity: it is never horizontal. Causes and risk of atrial flutter are comparable to atrial fibrillation. | ||
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==Examples== | ==Examples== | ||