At a later stage the corresponding murmur was no longer present and arch aorto- graphy showed complete obstruction of the left carotid with a tight stenosis of the right internal carotid where a murmur persisted. A variable murmur may therefore indicate a variable degree of obstruction, yet still have been significant when heard; and a murmur may be significant of stenosis yet the stenosis producing it may not be the one which matters.
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